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help / color / mirror / Atom feedFrom: Alvaro Herrera <[email protected]>
Subject: [PATCH 2/2] Simplify XLogReader's open_segment API
Date: Fri, 8 May 2020 17:03:09 -0400
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--
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