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[PATCH 2/2] Simplify XLogReader's open_segment API
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* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* [PATCH 2/2] Simplify XLogReader's open_segment API
@ 2020-05-08 21:03 Alvaro Herrera <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: Alvaro Herrera @ 2020-05-08 21:03 UTC (permalink / raw)

Instead of returning the file descriptor, install it directly in
XLogReaderState->seg.ws_file.
---
 src/backend/access/transam/xlogreader.c |  4 ++--
 src/backend/access/transam/xlogutils.c  | 32 ++++++++++++-------------
 src/backend/replication/walsender.c     | 12 ++++------
 src/bin/pg_waldump/pg_waldump.c         |  9 ++++---
 src/include/access/xlogreader.h         | 12 +++++-----
 src/include/access/xlogutils.h          |  2 +-
 6 files changed, 33 insertions(+), 38 deletions(-)

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index f42dee2640..a533241370 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1092,8 +1092,8 @@ WALRead(XLogReaderState *state,
 				state->routine.segment_close(state);
 
 			XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
-			state->seg.ws_file = state->routine.segment_open(state, nextSegNo,
-															 &state->segcxt, &tli);
+			state->routine.segment_open(state, nextSegNo, &state->segcxt, &tli);
+			Assert(state->seg.ws_file >= 0);	/* shouldn't happen */
 
 			/* Update the current segment info. */
 			state->seg.ws_tli = tli;
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index fc0bb7d059..1cc2c624a4 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -784,7 +784,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
 }
 
 /* XLogReaderRoutine->segment_open callback for local pg_wal files */
-int
+void
 wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 				 WALSegmentContext *segcxt, TimeLineID *tli_p)
 {
@@ -793,22 +793,20 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
 	int			fd;
 
 	XLogFilePath(path, tli, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
-
-	if (errno == ENOENT)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						path)));
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-
-	return -1;					/* keep compiler quiet */
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file < 0)
+	{
+		if (errno == ENOENT)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("requested WAL segment %s has already been removed",
+							path)));
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not open file \"%s\": %m",
+							path)));
+	}
 }
 
 /* stock XLogReaderRoutine->segment_close callback */
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ed8c08cb6a..b9f029d44f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -248,7 +248,7 @@ static void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
 static TimeOffset LagTrackerRead(int head, XLogRecPtr lsn, TimestampTz now);
 static bool TransactionIdInRecentPast(TransactionId xid, uint32 epoch);
 
-static int	WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
+static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
 							  WALSegmentContext *segcxt, TimeLineID *tli_p);
 static void UpdateSpillStats(LogicalDecodingContext *ctx);
 
@@ -2445,13 +2445,12 @@ WalSndKill(int code, Datum arg)
 }
 
 /* XLogReaderRoutine->segment_open callback */
-static int
+static void
 WalSndSegmentOpen(XLogReaderState *state,
 				  XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				  TimeLineID *tli_p)
 {
 	char		path[MAXPGPATH];
-	int			fd;
 
 	/*-------
 	 * When reading from a historic timeline, and there is a timeline switch
@@ -2488,9 +2487,9 @@ WalSndSegmentOpen(XLogReaderState *state,
 	}
 
 	XLogFilePath(path, *tli_p, nextSegNo, segcxt->ws_segsize);
-	fd = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (fd >= 0)
-		return fd;
+	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
+	if (state->seg.ws_file >= 0)
+		return;
 
 	/*
 	 * If the file is not found, assume it's because the standby asked for a
@@ -2513,7 +2512,6 @@ WalSndSegmentOpen(XLogReaderState *state,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
 						path)));
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 46734914b7..1a5c5a157c 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -280,7 +280,7 @@ identify_target_directory(char *directory, char *fname)
 }
 
 /* pg_waldump's XLogReaderRoutine->segment_open callback */
-static int
+static void
 WALDumpOpenSegment(XLogReaderState *state,
 				   XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 				   TimeLineID *tli_p)
@@ -300,9 +300,9 @@ WALDumpOpenSegment(XLogReaderState *state,
 	 */
 	for (tries = 0; tries < 10; tries++)
 	{
-		fd = open_file_in_directory(segcxt->ws_dir, fname);
-		if (fd >= 0)
-			return fd;
+		state->seg.ws_file = open_file_in_directory(segcxt->ws_dir, fname);
+		if (state->seg.ws_file >= 0)
+			return;
 		if (errno == ENOENT)
 		{
 			int			save_errno = errno;
@@ -318,7 +318,6 @@ WALDumpOpenSegment(XLogReaderState *state,
 	}
 
 	fatal_error("could not find file \"%s\": %m", fname);
-	return -1;					/* keep compiler quiet */
 }
 
 /*
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e77f478d68..b73df02218 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -63,10 +63,10 @@ typedef int (*XLogPageReadCB) (XLogReaderState *xlogreader,
 							   int reqLen,
 							   XLogRecPtr targetRecPtr,
 							   char *readBuf);
-typedef int (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
-								 XLogSegNo nextSegNo,
-								 WALSegmentContext *segcxt,
-								 TimeLineID *tli_p);
+typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
+								  XLogSegNo nextSegNo,
+								  WALSegmentContext *segcxt,
+								  TimeLineID *tli_p);
 typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
 
 typedef struct XLogReaderRoutine
@@ -94,8 +94,8 @@ typedef struct XLogReaderRoutine
 	XLogPageReadCB page_read;
 
 	/*
-	 * Callback to open the specified WAL segment for reading.  The file
-	 * descriptor of the opened segment shall be returned.  In case of
+	 * Callback to open the specified WAL segment for reading.  ->seg.ws_file
+	 * shall be set to the file descriptor of the opened segment.  In case of
 	 * failure, an error shall be raised by the callback and it shall not
 	 * return.
 	 *
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 68ce815476..b7bdc5db34 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -50,7 +50,7 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
-extern int	wal_segment_open(XLogReaderState *state,
+extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 WALSegmentContext *segcxt,
 							 TimeLineID *tli_p);
-- 
2.20.1


--/04w6evG8XlLl3ft--





^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* Re: Parallel Aggregates for string_agg and array_agg
@ 2023-01-19 07:44 David Rowley <[email protected]>
  2023-01-23 00:49 ` Re: Parallel Aggregates for string_agg and array_agg David Rowley <[email protected]>
  0 siblings, 1 reply; 22+ messages in thread

From: David Rowley @ 2023-01-19 07:44 UTC (permalink / raw)
  To: Tom Lane <[email protected]>; +Cc: pgsql-hackers; Robert Haas <[email protected]>; Stephen Frost <[email protected]>; Andres Freund <[email protected]>; Tomas Vondra <[email protected]>

On Wed, 3 Aug 2022 at 12:18, Tom Lane <[email protected]> wrote:
> Hmm.  My estimate of the percentages of users who will be pleased or
> not hasn't really changed since [2].  Also, realizing that you can't
> apply these aggregates to extremely large input sets, I wonder just how
> much it buys to be able to parallelize them.  So I still put this patch
> in the category of "just because we can doesn't mean we should".

It's a shame you categorised it without testing the actual
performance. That's disappointingly unscientific.

Here's a quick benchmark to let you see what we might expect and how
it compares to the existing aggregate functions which can already be
parallelised:

create table ab (a int, b int);
insert into ab select x,y from
generate_series(1,1000)x,generate_Series(1,1000)y;

In the attached agg_comparison_milliseconds.png, you can see the time
it took to execute "select a,sum(b) from ab group by a;" and "select
a,string_agg(b::text,',') from ab group by a;". Both queries seem to
increase in performance roughly the same amount when adding additional
parallel workers.

The attached agg_comparison_scalability.png shows the time it took to
execute the query with 0 workers divided by the time for N workers,
thus showing how many times the query was sped up with N workers. The
scalability of the string_agg() appears slightly better than the sum()
in this test due to the string_agg() query being slightly slower with
0 workers than the sum() version of the query. The sum query got 7.63x
faster with 32 workers whereas the string_agg query beat that slightly
with 7.67x faster than when the query was executed with parallelism
disabled.

I'd expect that scalability, especially the sum() version of the
query, to improve further with more rows.

Tested on an amd3990x machine with 64 cores / 128 threads.

> Now as against that, if the underlying relation scan is parallelized
> then you already have unpredictable input ordering and thus unpredictable
> aggregate results.  So anyone who cares about that has already had
> to either disable parallelism or insert an ORDER BY somewhere, and
> either of those fixes will still work if the aggregates support
> parallelism.

I'm glad you're no longer worried about users skipping the ORDER BY to
increase performance and relying on luck for the input ordering.

I think, in addition to this now allowing parallel aggregation for
string_agg() and array_agg(), it's also important not to forget that
there are more reasons to have combine/serialize/deserialize functions
for all aggregates.  Currently, a partition-wise aggregate can be
performed partially on the partition then if further grouping is
required at the top-level then we'll need the combine function to
perform the final grouping. No parallelism is required.  Also, with
all the advancements that have been made in postgres_fdw of late, then
I imagine it surely can't be long until someone wants to invent some
syntax for requesting partially aggregated results at the SQL level.
It sure would be a shame if that worked for every aggregate but
string_agg and array_agg needed the foreign server to spit those
tuples out individually so that the aggregation could be performed
(painstakingly) on the local server.

> Hence, I'm not going to fight hard if you really want
> to do it.  But I remain unconvinced that the cost/benefit tradeoff
> is attractive.

Thanks. Pending one last look, I'm planning to move ahead with it
unless there are any further objections or concerns.

David

#!/bin/bash

for q in "select a,sum(b) from ab group by a;" "select a,string_agg(b::text,',') from ab group by a;"
do
	for i in {0..32}
	do
			echo Testing with $i parallel workers: $q
			psql -c "alter table ab set (parallel_workers = $i);" postgres
			echo "select a,sum(b) from ab group by a;" > bench.sql
			pgbench -f bench.sql -n -T 3 postgres | grep latency
	done
done




Attachments:

  [text/plain] string_agg_scale_test.sh.txt (378B, ../../CAApHDvpNuGFkjmQ4b3VWxo9MSYxsR6yGykemLRRNU8heYhiNTA@mail.gmail.com/2-string_agg_scale_test.sh.txt)
  download | inline:
#!/bin/bash

for q in "select a,sum(b) from ab group by a;" "select a,string_agg(b::text,',') from ab group by a;"
do
	for i in {0..32}
	do
			echo Testing with $i parallel workers: $q
			psql -c "alter table ab set (parallel_workers = $i);" postgres
			echo "select a,sum(b) from ab group by a;" > bench.sql
			pgbench -f bench.sql -n -T 3 postgres | grep latency
	done
done



  [image/png] agg_comparison_milliseconds.png (84.0K, ../../CAApHDvpNuGFkjmQ4b3VWxo9MSYxsR6yGykemLRRNU8heYhiNTA@mail.gmail.com/3-agg_comparison_milliseconds.png)
  download | view image

  [image/png] agg_comparison_scalability.png (113.3K, ../../CAApHDvpNuGFkjmQ4b3VWxo9MSYxsR6yGykemLRRNU8heYhiNTA@mail.gmail.com/4-agg_comparison_scalability.png)
  download | view image

^ permalink  raw  reply  [nested|flat] 22+ messages in thread

* Re: Parallel Aggregates for string_agg and array_agg
  2023-01-19 07:44 Re: Parallel Aggregates for string_agg and array_agg David Rowley <[email protected]>
@ 2023-01-23 00:49 ` David Rowley <[email protected]>
  0 siblings, 0 replies; 22+ messages in thread

From: David Rowley @ 2023-01-23 00:49 UTC (permalink / raw)
  To: Tom Lane <[email protected]>; +Cc: pgsql-hackers; Robert Haas <[email protected]>; Stephen Frost <[email protected]>; Andres Freund <[email protected]>; Tomas Vondra <[email protected]>

On Thu, 19 Jan 2023 at 20:44, David Rowley <[email protected]> wrote:
> The attached agg_comparison_scalability.png shows the time it took to
> execute the query with 0 workers divided by the time for N workers,
> thus showing how many times the query was sped up with N workers. The
> scalability of the string_agg() appears slightly better than the sum()
> in this test due to the string_agg() query being slightly slower with
> 0 workers than the sum() version of the query. The sum query got 7.63x
> faster with 32 workers whereas the string_agg query beat that slightly
> with 7.67x faster than when the query was executed with parallelism
> disabled.

I was just looking at this again today and I noticed I messed up the
script and used the sum(b) query twice instead of the
string_agg(b::text, ',') query. oops.

I've attached the correct graphs this time.  The scalability of
string_agg() is not quite as good as I reported before, but it's still
good.  sum(b) with 32 workers with a new benchmark run I found to be
7.15x faster than with 0 parallel workers and string_agg(b::text, ',')
I found to be 6.49x faster with 32 workers than with 0 parallel
workers. This test showed that the string_agg query scaled better with
up to 6 workers before the scalability dropped below that of the
sum(b) query.

David


Attachments:

  [image/png] agg_comparison_milliseconds_v2.png (71.3K, ../../CAApHDvq7ChY83NaCw9e8rP1jUd_hgVj=jespHFY56gA4TynnfA@mail.gmail.com/2-agg_comparison_milliseconds_v2.png)
  download | view image

  [image/png] agg_comparison_scalability_v2.png (77.8K, ../../CAApHDvq7ChY83NaCw9e8rP1jUd_hgVj=jespHFY56gA4TynnfA@mail.gmail.com/3-agg_comparison_scalability_v2.png)
  download | view image

^ permalink  raw  reply  [nested|flat] 22+ messages in thread

end of thread, other threads:[~2023-01-23 00:49 UTC | newest]

Thread overview: 22+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2020-05-08 21:03 [PATCH 2/2] Simplify XLogReader's open_segment API Alvaro Herrera <[email protected]>
2023-01-19 07:44 Re: Parallel Aggregates for string_agg and array_agg David Rowley <[email protected]>
2023-01-23 00:49 ` Re: Parallel Aggregates for string_agg and array_agg David Rowley <[email protected]>

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