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help / color / mirror / Atom feedFrom: Kyotaro Horiguchi <[email protected]>
Subject: [PATCH v9 3/4] Remove globals readSegNo, readOff, readLen
Date: Tue, 10 Sep 2019 17:28:48 +0900
These global variables is functionally duplicated with them in
XLogReaderState. Remove the globals.
---
src/backend/access/transam/xlog.c | 77 ++++++++++++++-----------------
src/include/access/xlogreader.h | 1 +
2 files changed, 36 insertions(+), 42 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index ce3dcbb399..e8a4c7916b 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -783,14 +783,10 @@ static XLogSegNo openLogSegNo = 0;
* These variables are used similarly to the ones above, but for reading
* the XLOG. Note, however, that readOff generally represents the offset
* of the page just read, not the seek position of the FD itself, which
- * will be just past that page. readLen indicates how much of the current
- * page has been read into readBuf, and readSource indicates where we got
- * the currently open file from.
+ * will be just past that page. readSource indicates where we got the
+ * currently open file from.
*/
static int readFile = -1;
-static XLogSegNo readSegNo = 0;
-static uint32 readOff = 0;
-static uint32 readLen = 0;
static XLogSource readSource = 0; /* XLOG_FROM_* code */
/*
@@ -877,10 +873,12 @@ static bool InstallXLogFileSegment(XLogSegNo *segno, char *tmppath,
static int XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli,
int source, bool notfoundOk);
static int XLogFileReadAnyTLI(XLogSegNo segno, int emode, int source);
-static bool XLogPageRead(XLogReaderState *xlogreader,
+static bool XLogPageRead(XLogReaderState *state,
bool fetching_ckpt, int emode, bool randAccess);
static bool WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess,
- bool fetching_ckpt, XLogRecPtr tliRecPtr);
+ bool fetching_ckpt,
+ XLogRecPtr tliRecPtr,
+ XLogSegNo readSegNo);
static int emode_for_corrupt_record(int emode, XLogRecPtr RecPtr);
static void XLogFileClose(void);
static void PreallocXlogFiles(XLogRecPtr endptr);
@@ -7512,7 +7510,8 @@ StartupXLOG(void)
XLogRecPtr pageBeginPtr;
pageBeginPtr = EndOfLog - (EndOfLog % XLOG_BLCKSZ);
- Assert(readOff == XLogSegmentOffset(pageBeginPtr, wal_segment_size));
+ Assert(XLogSegmentOffset(xlogreader->readPagePtr, wal_segment_size) ==
+ XLogSegmentOffset(pageBeginPtr, wal_segment_size));
firstIdx = XLogRecPtrToBufIdx(EndOfLog);
@@ -11532,13 +11531,14 @@ CancelBackup(void)
* sleep and retry.
*/
static bool
-XLogPageRead(XLogReaderState *xlogreader,
+XLogPageRead(XLogReaderState *state,
bool fetching_ckpt, int emode, bool randAccess)
{
- char *readBuf = xlogreader->readBuf;
- XLogRecPtr targetPagePtr = xlogreader->readPagePtr;
- int reqLen = xlogreader->readLen;
- XLogRecPtr targetRecPtr = xlogreader->ReadRecPtr;
+ char *readBuf = state->readBuf;
+ XLogRecPtr targetPagePtr = state->readPagePtr;
+ int reqLen = state->readLen;
+ int readLen = 0;
+ XLogRecPtr targetRecPtr = state->ReadRecPtr;
uint32 targetPageOff;
XLogSegNo targetSegNo PG_USED_FOR_ASSERTS_ONLY;
int r;
@@ -11551,7 +11551,7 @@ XLogPageRead(XLogReaderState *xlogreader,
* is not in the currently open one.
*/
if (readFile >= 0 &&
- !XLByteInSeg(targetPagePtr, readSegNo, wal_segment_size))
+ !XLByteInSeg(targetPagePtr, state->readSegNo, wal_segment_size))
{
/*
* Request a restartpoint if we've replayed too much xlog since the
@@ -11559,10 +11559,10 @@ XLogPageRead(XLogReaderState *xlogreader,
*/
if (bgwriterLaunched)
{
- if (XLogCheckpointNeeded(readSegNo))
+ if (XLogCheckpointNeeded(state->readSegNo))
{
(void) GetRedoRecPtr();
- if (XLogCheckpointNeeded(readSegNo))
+ if (XLogCheckpointNeeded(state->readSegNo))
RequestCheckpoint(CHECKPOINT_CAUSE_XLOG);
}
}
@@ -11572,7 +11572,7 @@ XLogPageRead(XLogReaderState *xlogreader,
readSource = 0;
}
- XLByteToSeg(targetPagePtr, readSegNo, wal_segment_size);
+ XLByteToSeg(targetPagePtr, state->readSegNo, wal_segment_size);
retry:
/* See if we need to retrieve more data */
@@ -11581,17 +11581,14 @@ retry:
receivedUpto < targetPagePtr + reqLen))
{
if (!WaitForWALToBecomeAvailable(targetPagePtr + reqLen,
- randAccess,
- fetching_ckpt,
- targetRecPtr))
+ randAccess, fetching_ckpt,
+ targetRecPtr, state->readSegNo))
{
if (readFile >= 0)
close(readFile);
readFile = -1;
- readLen = 0;
readSource = 0;
-
- xlogreader->readLen = -1;
+ state->readLen = -1;
return false;
}
}
@@ -11619,40 +11616,36 @@ retry:
else
readLen = XLOG_BLCKSZ;
- /* Read the requested page */
- readOff = targetPageOff;
-
pgstat_report_wait_start(WAIT_EVENT_WAL_READ);
- r = pg_pread(readFile, readBuf, XLOG_BLCKSZ, (off_t) readOff);
+ r = pg_pread(readFile, readBuf, XLOG_BLCKSZ, (off_t) targetPageOff);
if (r != XLOG_BLCKSZ)
{
char fname[MAXFNAMELEN];
int save_errno = errno;
pgstat_report_wait_end();
- XLogFileName(fname, curFileTLI, readSegNo, wal_segment_size);
+ XLogFileName(fname, curFileTLI, state->readSegNo, wal_segment_size);
if (r < 0)
{
errno = save_errno;
ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
(errcode_for_file_access(),
errmsg("could not read from log segment %s, offset %u: %m",
- fname, readOff)));
+ fname, targetPageOff)));
}
else
ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
(errcode(ERRCODE_DATA_CORRUPTED),
errmsg("could not read from log segment %s, offset %u: read %d of %zu",
- fname, readOff, r, (Size) XLOG_BLCKSZ)));
+ fname, targetPageOff, r, (Size) XLOG_BLCKSZ)));
goto next_record_is_invalid;
}
pgstat_report_wait_end();
- Assert(targetSegNo == readSegNo);
- Assert(targetPageOff == readOff);
+ Assert(targetSegNo == state->readSegNo);
Assert(reqLen <= readLen);
- xlogreader->seg.ws_tli = curFileTLI;
+ state->seg.ws_tli = curFileTLI;
/*
* Check the page header immediately, so that we can retry immediately if
@@ -11680,15 +11673,15 @@ retry:
* Validating the page header is cheap enough that doing it twice
* shouldn't be a big deal from a performance point of view.
*/
- if (!XLogReaderValidatePageHeader(xlogreader, targetPagePtr, readBuf))
+ if (!XLogReaderValidatePageHeader(state, targetPagePtr, readBuf))
{
- /* reset any error XLogReaderValidatePageHeader() might have set */
- xlogreader->errormsg_buf[0] = '\0';
+ /* reset any error StateValidatePageHeader() might have set */
+ state->errormsg_buf[0] = '\0';
goto next_record_is_invalid;
}
- Assert(xlogreader->readPagePtr == targetPagePtr);
- xlogreader->readLen = readLen;
+ Assert(state->readPagePtr == targetPagePtr);
+ state->readLen = readLen;
return true;
next_record_is_invalid:
@@ -11697,14 +11690,13 @@ next_record_is_invalid:
if (readFile >= 0)
close(readFile);
readFile = -1;
- readLen = 0;
readSource = 0;
/* In standby-mode, keep trying */
if (StandbyMode)
goto retry;
- xlogreader->readLen = -1;
+ state->readLen = -1;
return false;
}
@@ -11736,7 +11728,8 @@ next_record_is_invalid:
*/
static bool
WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess,
- bool fetching_ckpt, XLogRecPtr tliRecPtr)
+ bool fetching_ckpt, XLogRecPtr tliRecPtr,
+ XLogSegNo readSegNo)
{
static TimestampTz last_fail_time = 0;
TimestampTz now;
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index 8e39b5c1f6..dc84d39f60 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -133,6 +133,7 @@ struct XLogReaderState
* read by reader, which must be larger than
* the request, or -1 on error */
TimeLineID readPageTLI; /* TLI for data currently in readBuf */
+ XLogSegNo readSegNo; /* Segment # for data currently in readBuf */
char *readBuf; /* buffer to store data */
bool page_verified; /* is the page header on the buffer verified? */
bool record_verified;/* is the current record header verified? */
--
2.23.0
----Next_Part(Thu_Oct_24_14_51_01_2019_720)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v9-0004-Change-policy-of-XLog-read-buffer-allocation.patch"
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