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help / color / mirror / Atom feedFrom: Kyotaro Horiguchi <[email protected]>
Subject: [PATCH v18 2/5] Move page-reader out of XLogReadRecord().
Date: Thu, 30 Sep 2021 12:04:37 +0900
This is the second step of removing callbacks from the WAL decoder.
XLogReadRecord() return XLREAD_NEED_DATA to indicate that the caller
should supply new data, and the decoder works as a state machine.
Author: Kyotaro HORIGUCHI <[email protected]>
Author: Heikki Linnakangas <[email protected]>
Reviewed-by: Antonin Houska <[email protected]>
Reviewed-by: Alvaro Herrera <[email protected]>
Reviewed-by: Takashi Menjo <[email protected]>
Reviewed-by: Thomas Munro <[email protected]>
Discussion: https://postgr.es/m/20190418.210257.43726183.horiguchi.kyotaro%40lab.ntt.co.jp
---
src/backend/access/transam/twophase.c | 16 +-
src/backend/access/transam/xlog.c | 60 +-
src/backend/access/transam/xlogreader.c | 760 ++++++++++--------
src/backend/access/transam/xlogutils.c | 17 +-
src/backend/replication/logical/logical.c | 29 +-
.../replication/logical/logicalfuncs.c | 16 +-
src/backend/replication/slotfuncs.c | 21 +-
src/backend/replication/walsender.c | 35 +-
src/bin/pg_rewind/parsexlog.c | 93 ++-
src/bin/pg_waldump/pg_waldump.c | 39 +-
src/include/access/xlogreader.h | 124 ++-
src/include/access/xlogutils.h | 4 +-
src/include/pg_config_manual.h | 2 +-
src/include/replication/logical.h | 11 +-
14 files changed, 703 insertions(+), 524 deletions(-)
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 2156de187c..9b42a935a7 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1330,11 +1330,8 @@ XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
char *errormsg;
TimeLineID save_currtli = ThisTimeLineID;
- xlogreader = XLogReaderAllocate(wal_segment_size, NULL,
- XL_ROUTINE(.page_read = &read_local_xlog_page,
- .segment_open = &wal_segment_open,
- .segment_close = &wal_segment_close),
- NULL);
+ xlogreader = XLogReaderAllocate(wal_segment_size, NULL, wal_segment_close);
+
if (!xlogreader)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
@@ -1342,7 +1339,14 @@ XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
errdetail("Failed while allocating a WAL reading processor.")));
XLogBeginRead(xlogreader, lsn);
- record = XLogReadRecord(xlogreader, &errormsg);
+ while (XLogReadRecord(xlogreader, &record, &errormsg) == XLREAD_NEED_DATA)
+ {
+ if (!read_local_xlog_page(xlogreader))
+ {
+ XLogTerminateRead(xlogreader);
+ break;
+ }
+ }
/*
* Restore immediately the timeline where it was previously, as
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 1557ceb8c1..316ba256f6 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -836,13 +836,6 @@ static XLogSource currentSource = XLOG_FROM_ANY;
static bool lastSourceFailed = false;
static bool pendingWalRcvRestart = false;
-typedef struct XLogPageReadPrivate
-{
- int emode;
- bool fetching_ckpt; /* are we fetching a checkpoint record? */
- bool randAccess;
-} XLogPageReadPrivate;
-
/*
* These variables track when we last obtained some WAL data to process,
* and where we got it from. (XLogReceiptSource is initially the same as
@@ -918,8 +911,8 @@ static bool InstallXLogFileSegment(XLogSegNo *segno, char *tmppath,
static int XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli,
XLogSource source, bool notfoundOk);
static int XLogFileReadAnyTLI(XLogSegNo segno, int emode, XLogSource source);
-static bool XLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
- int reqLen, XLogRecPtr targetRecPtr, char *readBuf);
+static bool XLogPageRead(XLogReaderState *xlogreader,
+ bool fetching_ckpt, int emode, bool randAccess);
static bool WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess,
bool fetching_ckpt, XLogRecPtr tliRecPtr);
static void XLogShutdownWalRcv(void);
@@ -1233,8 +1226,7 @@ XLogInsertRecord(XLogRecData *rdata,
appendBinaryStringInfo(&recordBuf, rdata->data, rdata->len);
if (!debug_reader)
- debug_reader = XLogReaderAllocate(wal_segment_size, NULL,
- XL_ROUTINE(), NULL);
+ debug_reader = XLogReaderAllocate(wal_segment_size, NULL, NULL);
if (!debug_reader)
{
@@ -4395,15 +4387,10 @@ CleanupBackupHistory(void)
* record is available.
*/
static XLogRecord *
-ReadRecord(XLogReaderState *xlogreader, int emode,
- bool fetching_ckpt)
+ReadRecord(XLogReaderState *xlogreader, int emode, bool fetching_ckpt)
{
XLogRecord *record;
- XLogPageReadPrivate *private = (XLogPageReadPrivate *) xlogreader->private_data;
-
- private->fetching_ckpt = fetching_ckpt;
- private->emode = emode;
- private->randAccess = (xlogreader->ReadRecPtr == InvalidXLogRecPtr);
+ bool randAccess = (xlogreader->ReadRecPtr == InvalidXLogRecPtr);
/* This is the first attempt to read this page. */
lastSourceFailed = false;
@@ -4411,8 +4398,18 @@ ReadRecord(XLogReaderState *xlogreader, int emode,
for (;;)
{
char *errormsg;
+ XLogReadRecordResult result;
+
+ while ((result = XLogReadRecord(xlogreader, &record, &errormsg))
+ == XLREAD_NEED_DATA)
+ {
+ if (!XLogPageRead(xlogreader, fetching_ckpt, emode, randAccess))
+ {
+ XLogTerminateRead(xlogreader);
+ break;
+ }
+ }
- record = XLogReadRecord(xlogreader, &errormsg);
ReadRecPtr = xlogreader->ReadRecPtr;
EndRecPtr = xlogreader->EndRecPtr;
if (record == NULL)
@@ -6547,7 +6544,6 @@ StartupXLOG(void)
bool backupFromStandby = false;
DBState dbstate_at_startup;
XLogReaderState *xlogreader;
- XLogPageReadPrivate private;
bool promoted = false;
struct stat st;
@@ -6706,13 +6702,9 @@ StartupXLOG(void)
OwnLatch(&XLogCtl->recoveryWakeupLatch);
/* Set up XLOG reader facility */
- MemSet(&private, 0, sizeof(XLogPageReadPrivate));
xlogreader =
- XLogReaderAllocate(wal_segment_size, NULL,
- XL_ROUTINE(.page_read = &XLogPageRead,
- .segment_open = NULL,
- .segment_close = wal_segment_close),
- &private);
+ XLogReaderAllocate(wal_segment_size, NULL, wal_segment_close);
+
if (!xlogreader)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
@@ -12300,12 +12292,13 @@ CancelBackup(void)
* sleep and retry.
*/
static bool
-XLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr, int reqLen,
- XLogRecPtr targetRecPtr, char *readBuf)
+XLogPageRead(XLogReaderState *xlogreader,
+ bool fetching_ckpt, int emode, bool randAccess)
{
- XLogPageReadPrivate *private =
- (XLogPageReadPrivate *) xlogreader->private_data;
- int emode = private->emode;
+ char *readBuf = xlogreader->readBuf;
+ XLogRecPtr targetPagePtr = xlogreader->readPagePtr;
+ int reqLen = xlogreader->readLen;
+ XLogRecPtr targetRecPtr = xlogreader->ReadRecPtr;
uint32 targetPageOff;
XLogSegNo targetSegNo PG_USED_FOR_ASSERTS_ONLY;
int r;
@@ -12348,8 +12341,8 @@ retry:
flushedUpto < targetPagePtr + reqLen))
{
if (!WaitForWALToBecomeAvailable(targetPagePtr + reqLen,
- private->randAccess,
- private->fetching_ckpt,
+ randAccess,
+ fetching_ckpt,
targetRecPtr))
{
if (readFile >= 0)
@@ -12469,6 +12462,7 @@ retry:
goto next_record_is_invalid;
}
+ Assert(xlogreader->readPagePtr == targetPagePtr);
xlogreader->readLen = readLen;
return true;
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index 1d9976ecf4..4501a09245 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -43,7 +43,7 @@ static bool XLogNeedData(XLogReaderState *state, XLogRecPtr pageptr,
int reqLen, bool header_inclusive);
static void XLogReaderInvalReadState(XLogReaderState *state);
static bool ValidXLogRecordHeader(XLogReaderState *state, XLogRecPtr RecPtr,
- XLogRecPtr PrevRecPtr, XLogRecord *record, bool randAccess);
+ XLogRecPtr PrevRecPtr, XLogRecord *record);
static bool ValidXLogRecord(XLogReaderState *state, XLogRecord *record,
XLogRecPtr recptr);
static void ResetDecoder(XLogReaderState *state);
@@ -76,7 +76,7 @@ report_invalid_record(XLogReaderState *state, const char *fmt,...)
*/
XLogReaderState *
XLogReaderAllocate(int wal_segment_size, const char *waldir,
- XLogReaderRoutine *routine, void *private_data)
+ WALSegmentCleanupCB cleanup_cb)
{
XLogReaderState *state;
@@ -87,7 +87,7 @@ XLogReaderAllocate(int wal_segment_size, const char *waldir,
return NULL;
/* initialize caller-provided support functions */
- state->routine = *routine;
+ state->cleanup_cb = cleanup_cb;
state->max_block_id = -1;
@@ -110,8 +110,6 @@ XLogReaderAllocate(int wal_segment_size, const char *waldir,
WALOpenSegmentInit(&state->seg, &state->segcxt, wal_segment_size,
waldir);
- /* system_identifier initialized to zeroes above */
- state->private_data = private_data;
/* ReadRecPtr, EndRecPtr and readLen initialized to zeroes above */
state->errormsg_buf = palloc_extended(MAX_ERRORMSG_LEN + 1,
MCXT_ALLOC_NO_OOM);
@@ -143,8 +141,8 @@ XLogReaderFree(XLogReaderState *state)
{
int block_id;
- if (state->seg.ws_file != -1)
- state->routine.segment_close(state);
+ if (state->seg.ws_file >= 0)
+ state->cleanup_cb(state);
for (block_id = 0; block_id <= XLR_MAX_BLOCK_ID; block_id++)
{
@@ -249,6 +247,7 @@ XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr)
/* Begin at the passed-in record pointer. */
state->EndRecPtr = RecPtr;
state->ReadRecPtr = InvalidXLogRecPtr;
+ state->readRecordState = XLREAD_NEXT_RECORD;
}
/*
@@ -257,12 +256,12 @@ XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr)
* XLogBeginRead() or XLogFindNextRecord() must be called before the first call
* to XLogReadRecord().
*
- * If the page_read callback fails to read the requested data, NULL is
- * returned. The callback is expected to have reported the error; errormsg
- * is set to NULL.
+ * This function may return XLREAD_NEED_DATA several times before returning a
+ * result record. The caller shall read in some new data then call this
+ * function again with the same parameters.
*
- * If the reading fails for some other reason, NULL is also returned, and
- * *errormsg is set to a string with details of the failure.
+ * When a record is successfully read, returns XLREAD_SUCCESS with result
+ * record being stored in *record. Otherwise *record is NULL.
*
* Returns XLREAD_NEED_DATA if more data is needed to finish reading the
* current record. In that case, state->readPagePtr and state->readLen inform
@@ -307,329 +306,458 @@ XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr)
* state. This behavior allows to continue reading a reacord switching among
* different souces, while streaming replication.
*/
-XLogRecord *
-XLogReadRecord(XLogReaderState *state, char **errormsg)
+XLogReadRecordResult
+XLogReadRecord(XLogReaderState *state, XLogRecord **record, char **errormsg)
{
- XLogRecPtr RecPtr;
- XLogRecord *record;
- XLogRecPtr targetPagePtr;
- bool randAccess;
- uint32 len,
- total_len;
- uint32 targetRecOff;
- uint32 pageHeaderSize;
- bool assembled;
- bool gotheader;
+ XLogRecord *prec;
- /*
- * randAccess indicates whether to verify the previous-record pointer of
- * the record we're reading. We only do this if we're reading
- * sequentially, which is what we initially assume.
- */
- randAccess = false;
+ *record = NULL;
/* reset error state */
*errormsg = NULL;
state->errormsg_buf[0] = '\0';
- ResetDecoder(state);
state->abortedRecPtr = InvalidXLogRecPtr;
state->missingContrecPtr = InvalidXLogRecPtr;
- RecPtr = state->EndRecPtr;
-
- if (state->ReadRecPtr != InvalidXLogRecPtr)
- {
- /* read the record after the one we just read */
-
- /*
- * EndRecPtr is pointing to end+1 of the previous WAL record. If
- * we're at a page boundary, no more records can fit on the current
- * page. We must skip over the page header, but we can't do that until
- * we've read in the page, since the header size is variable.
- */
- }
- else
- {
- /*
- * Caller supplied a position to start at.
- *
- * In this case, EndRecPtr should already be pointing to a valid
- * record starting position.
- */
- Assert(XRecOffIsValid(RecPtr));
- randAccess = true;
- }
-
restart:
- state->currRecPtr = RecPtr;
- assembled = false;
-
- targetPagePtr = RecPtr - (RecPtr % XLOG_BLCKSZ);
- targetRecOff = RecPtr % XLOG_BLCKSZ;
-
- /*
- * Read the page containing the record into state->readBuf. Request enough
- * byte to cover the whole record header, or at least the part of it that
- * fits on the same page.
- */
- while (XLogNeedData(state, targetPagePtr,
- Min(targetRecOff + SizeOfXLogRecord, XLOG_BLCKSZ),
- targetRecOff != 0))
+ switch (state->readRecordState)
{
- if (!state->routine.page_read(state, state->readPagePtr, state->readLen,
- RecPtr, state->readBuf))
- break;
- }
-
- if (!state->page_verified)
- goto err;
-
- /*
- * We have at least the page header, so we can examine it now.
- */
- pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) state->readBuf);
- if (targetRecOff == 0)
- {
- /*
- * At page start, so skip over page header.
- */
- RecPtr += pageHeaderSize;
- targetRecOff = pageHeaderSize;
- }
- else if (targetRecOff < pageHeaderSize)
- {
- report_invalid_record(state, "invalid record offset at %X/%X",
- LSN_FORMAT_ARGS(RecPtr));
- goto err;
- }
+ case XLREAD_NEXT_RECORD:
+ ResetDecoder(state);
- if ((((XLogPageHeader) state->readBuf)->xlp_info & XLP_FIRST_IS_CONTRECORD) &&
- targetRecOff == pageHeaderSize)
- {
- report_invalid_record(state, "contrecord is requested by %X/%X",
- LSN_FORMAT_ARGS(RecPtr));
- goto err;
- }
-
- /* XLogNeedData has verified the page header */
- Assert(pageHeaderSize <= state->readLen);
-
- /*
- * Read the record length.
- *
- * NB: Even though we use an XLogRecord pointer here, the whole record
- * header might not fit on this page. xl_tot_len is the first field of the
- * struct, so it must be on this page (the records are MAXALIGNed), but we
- * cannot access any other fields until we've verified that we got the
- * whole header.
- */
- record = (XLogRecord *) (state->readBuf + RecPtr % XLOG_BLCKSZ);
- total_len = record->xl_tot_len;
-
- /*
- * If the whole record header is on this page, validate it immediately.
- * Otherwise do just a basic sanity check on xl_tot_len, and validate the
- * rest of the header after reading it from the next page. The xl_tot_len
- * check is necessary here to ensure that we enter the "Need to reassemble
- * record" code path below; otherwise we might fail to apply
- * ValidXLogRecordHeader at all.
- */
- if (targetRecOff <= XLOG_BLCKSZ - SizeOfXLogRecord)
- {
- if (!ValidXLogRecordHeader(state, RecPtr, state->ReadRecPtr, record,
- randAccess))
- goto err;
- gotheader = true;
- }
- else
- {
- /* XXX: more validation should be done here */
- if (total_len < SizeOfXLogRecord)
- {
- report_invalid_record(state,
- "invalid record length at %X/%X: wanted %u, got %u",
- LSN_FORMAT_ARGS(RecPtr),
- (uint32) SizeOfXLogRecord, total_len);
- goto err;
- }
- gotheader = false;
- }
-
- len = XLOG_BLCKSZ - RecPtr % XLOG_BLCKSZ;
- if (total_len > len)
- {
- /* Need to reassemble record */
- char *contdata;
- XLogPageHeader pageHeader;
- char *buffer;
- uint32 gotlen;
-
- assembled = true;
-
- /*
- * Enlarge readRecordBuf as needed.
- */
- if (total_len > state->readRecordBufSize &&
- !allocate_recordbuf(state, total_len))
- {
- /* We treat this as a "bogus data" condition */
- report_invalid_record(state, "record length %u at %X/%X too long",
- total_len, LSN_FORMAT_ARGS(RecPtr));
- goto err;
- }
-
- /* Copy the first fragment of the record from the first page. */
- memcpy(state->readRecordBuf,
- state->readBuf + RecPtr % XLOG_BLCKSZ, len);
- buffer = state->readRecordBuf + len;
- gotlen = len;
-
- do
- {
- int rest_len = total_len - gotlen;
-
- /* Calculate pointer to beginning of next page */
- targetPagePtr += XLOG_BLCKSZ;
-
- /* Wait for the next page to become available */
- while (XLogNeedData(state, targetPagePtr,
- Min(rest_len, XLOG_BLCKSZ),
- false))
+ if (state->ReadRecPtr != InvalidXLogRecPtr)
+ {
+ /* read the record after the one we just read */
+
+ /*
+ * EndRecPtr is pointing to end+1 of the previous WAL record.
+ * If we're at a page boundary, no more records can fit on the
+ * current page. We must skip over the page header, but we
+ * can't do that until we've read in the page, since the
+ * header size is variable.
+ */
+ state->PrevRecPtr = state->ReadRecPtr;
+ state->ReadRecPtr = state->EndRecPtr;
+ }
+ else
{
- if (!state->routine.page_read(state, state->readPagePtr,
- state->readLen,
- state->ReadRecPtr,
- state->readBuf))
+ /*
+ * Caller supplied a position to start at.
+ *
+ * In this case, EndRecPtr should already be pointing to a
+ * valid record starting position.
+ */
+ Assert(XRecOffIsValid(state->EndRecPtr));
+ state->ReadRecPtr = state->EndRecPtr;
+
+ /*
+ * We cannot verify the previous-record pointer when we're
+ * seeking to a particular record. Reset PrevRecPtr so that we
+ * won't try doing that.
+ */
+ state->PrevRecPtr = InvalidXLogRecPtr;
+ state->EndRecPtr = InvalidXLogRecPtr; /* to be tidy */
+ }
+
+ state->record_verified = false;
+ state->readRecordState = XLREAD_TOT_LEN;
+ /* fall through */
+
+ case XLREAD_TOT_LEN:
+ {
+ uint32 total_len;
+ uint32 pageHeaderSize;
+ XLogRecPtr targetPagePtr;
+ uint32 targetRecOff;
+ XLogPageHeader pageHeader;
+
+ targetPagePtr =
+ state->ReadRecPtr - (state->ReadRecPtr % XLOG_BLCKSZ);
+ targetRecOff = state->ReadRecPtr % XLOG_BLCKSZ;
+
+ /*
+ * Check if we have enough data. For the first record in the
+ * page, the requesting length doesn't contain page header.
+ */
+ if (XLogNeedData(state, targetPagePtr,
+ Min(targetRecOff + SizeOfXLogRecord, XLOG_BLCKSZ),
+ targetRecOff != 0))
+ return XLREAD_NEED_DATA;
+
+ /* error out if caller supplied bogus page */
+ if (!state->page_verified)
+ goto err;
+
+ /* examine page header now. */
+ pageHeaderSize =
+ XLogPageHeaderSize((XLogPageHeader) state->readBuf);
+ if (targetRecOff == 0)
+ {
+ /* At page start, so skip over page header. */
+ state->ReadRecPtr += pageHeaderSize;
+ targetRecOff = pageHeaderSize;
+ }
+ else if (targetRecOff < pageHeaderSize)
+ {
+ report_invalid_record(state, "invalid record offset at %X/%X",
+ LSN_FORMAT_ARGS(state->ReadRecPtr));
+ goto err;
+ }
+
+ pageHeader = (XLogPageHeader) state->readBuf;
+ if ((pageHeader->xlp_info & XLP_FIRST_IS_CONTRECORD) &&
+ targetRecOff == pageHeaderSize)
+ {
+ report_invalid_record(state, "contrecord is requested by %X/%X",
+ (uint32) (state->ReadRecPtr >> 32),
+ (uint32) state->ReadRecPtr);
+ goto err;
+ }
+
+ /* XLogNeedData has verified the page header */
+ Assert(pageHeaderSize <= state->readLen);
+
+ /*
+ * Read the record length.
+ *
+ * NB: Even though we use an XLogRecord pointer here, the
+ * whole record header might not fit on this page. xl_tot_len
+ * is the first field of the struct, so it must be on this
+ * page (the records are MAXALIGNed), but we cannot access any
+ * other fields until we've verified that we got the whole
+ * header.
+ */
+ prec = (XLogRecord *) (state->readBuf +
+ state->ReadRecPtr % XLOG_BLCKSZ);
+ total_len = prec->xl_tot_len;
+
+ /*
+ * If the whole record header is on this page, validate it
+ * immediately. Otherwise do just a basic sanity check on
+ * xl_tot_len, and validate the rest of the header after
+ * reading it from the next page. The xl_tot_len check is
+ * necessary here to ensure that we enter the
+ * XLREAD_CONTINUATION state below; otherwise we might fail to
+ * apply ValidXLogRecordHeader at all.
+ */
+ if (targetRecOff <= XLOG_BLCKSZ - SizeOfXLogRecord)
+ {
+ if (!ValidXLogRecordHeader(state, state->ReadRecPtr,
+ state->PrevRecPtr, prec))
+ goto err;
+
+ state->record_verified = true;
+ }
+ else
+ {
+ /* XXX: more validation should be done here */
+ if (total_len < SizeOfXLogRecord)
+ {
+ report_invalid_record(state,
+ "invalid record length at %X/%X: wanted %u, got %u",
+ LSN_FORMAT_ARGS(state->ReadRecPtr),
+ (uint32) SizeOfXLogRecord, total_len);
+ goto err;
+ }
+ }
+
+ /*
+ * Wait for the rest of the record, or the part of the record
+ * that fit on the first page if crossed a page boundary, to
+ * become available.
+ */
+ state->recordGotLen = 0;
+ state->recordRemainLen = total_len;
+ state->readRecordState = XLREAD_FIRST_FRAGMENT;
+ }
+ /* fall through */
+
+ case XLREAD_FIRST_FRAGMENT:
+ {
+ uint32 total_len = state->recordRemainLen;
+ uint32 request_len;
+ uint32 record_len;
+ XLogRecPtr targetPagePtr;
+ uint32 targetRecOff;
+
+ /*
+ * Wait for the rest of the record on the first page to become
+ * available
+ */
+ targetPagePtr =
+ state->ReadRecPtr - (state->ReadRecPtr % XLOG_BLCKSZ);
+ targetRecOff = state->ReadRecPtr % XLOG_BLCKSZ;
+
+ request_len = Min(targetRecOff + total_len, XLOG_BLCKSZ);
+ record_len = request_len - targetRecOff;
+
+ /* ReadRecPtr contains page header */
+ Assert(targetRecOff != 0);
+ if (XLogNeedData(state, targetPagePtr, request_len, true))
+ return XLREAD_NEED_DATA;
+
+ /* error out if caller supplied bogus page */
+ if (!state->page_verified)
+ goto err;
+
+ prec = (XLogRecord *) (state->readBuf + targetRecOff);
+
+ /* validate record header if not yet */
+ if (!state->record_verified && record_len >= SizeOfXLogRecord)
+ {
+ if (!ValidXLogRecordHeader(state, state->ReadRecPtr,
+ state->PrevRecPtr, prec))
+ goto err;
+
+ state->record_verified = true;
+ }
+
+
+ if (total_len == record_len)
+ {
+ /* Record does not cross a page boundary */
+ Assert(state->record_verified);
+
+ if (!ValidXLogRecord(state, prec, state->ReadRecPtr))
+ goto err;
+
+ state->record_verified = true; /* to be tidy */
+
+ /* We already checked the header earlier */
+ state->EndRecPtr = state->ReadRecPtr + MAXALIGN(record_len);
+
+ *record = prec;
+ state->readRecordState = XLREAD_NEXT_RECORD;
break;
- }
+ }
- if (!state->page_verified)
- goto err;
+ /*
+ * The record continues on the next page. Need to reassemble
+ * record
+ */
+ Assert(total_len > record_len);
- Assert(SizeOfXLogShortPHD <= state->readLen);
+ /* Enlarge readRecordBuf as needed. */
+ if (total_len > state->readRecordBufSize &&
+ !allocate_recordbuf(state, total_len))
+ {
+ /* We treat this as a "bogus data" condition */
+ report_invalid_record(state,
+ "record length %u at %X/%X too long",
+ total_len,
+ LSN_FORMAT_ARGS(state->ReadRecPtr));
+ goto err;
+ }
- pageHeader = (XLogPageHeader) state->readBuf;
+ /* Copy the first fragment of the record from the first page. */
+ memcpy(state->readRecordBuf, state->readBuf + targetRecOff,
+ record_len);
+ state->recordGotLen += record_len;
+ state->recordRemainLen -= record_len;
- /*
- * If we were expecting a continuation record and got an
- * "overwrite contrecord" flag, that means the continuation record
- * was overwritten with a different record. Restart the read by
- * assuming the address to read is the location where we found
- * this flag; but keep track of the LSN of the record we were
- * reading, for later verification.
- */
- if (pageHeader->xlp_info & XLP_FIRST_IS_OVERWRITE_CONTRECORD)
- {
- state->overwrittenRecPtr = state->currRecPtr;
- ResetDecoder(state);
- RecPtr = targetPagePtr;
- goto restart;
- }
+ /* Calculate pointer to beginning of next page */
+ state->recordContRecPtr = state->ReadRecPtr + record_len;
+ Assert(state->recordContRecPtr % XLOG_BLCKSZ == 0);
- /* Check that the continuation on next page looks valid */
- if (!(pageHeader->xlp_info & XLP_FIRST_IS_CONTRECORD))
- {
- report_invalid_record(state,
- "there is no contrecord flag at %X/%X",
- LSN_FORMAT_ARGS(RecPtr));
- goto err;
+ state->readRecordState = XLREAD_CONTINUATION;
}
+ /* fall through */
- /*
- * Cross-check that xlp_rem_len agrees with how much of the record
- * we expect there to be left.
- */
- if (pageHeader->xlp_rem_len == 0 ||
- total_len != (pageHeader->xlp_rem_len + gotlen))
+ case XLREAD_CONTINUATION:
{
- report_invalid_record(state,
- "invalid contrecord length %u (expected %lld) at %X/%X",
- pageHeader->xlp_rem_len,
- ((long long) total_len) - gotlen,
- LSN_FORMAT_ARGS(RecPtr));
- goto err;
- }
+ XLogPageHeader pageHeader;
+ uint32 pageHeaderSize;
+ XLogRecPtr targetPagePtr;
- /* Append the continuation from this page to the buffer */
- pageHeaderSize = XLogPageHeaderSize(pageHeader);
+ /*
+ * we enter this state only if we haven't read the whole
+ * record.
+ */
+ Assert(state->recordRemainLen > 0);
- Assert(pageHeaderSize <= state->readLen);
+ while (state->recordRemainLen > 0)
+ {
+ char *contdata;
+ uint32 request_len;
+ uint32 record_len;
- contdata = (char *) state->readBuf + pageHeaderSize;
- len = XLOG_BLCKSZ - pageHeaderSize;
- if (pageHeader->xlp_rem_len < len)
- len = pageHeader->xlp_rem_len;
+ /* Wait for the next page to become available */
+ targetPagePtr = state->recordContRecPtr;
- Assert(pageHeaderSize + len <= state->readLen);
- memcpy(buffer, (char *) contdata, len);
- buffer += len;
- gotlen += len;
+ /* this request contains page header */
+ Assert(targetPagePtr != 0);
+ if (XLogNeedData(state, targetPagePtr,
+ Min(state->recordRemainLen, XLOG_BLCKSZ),
+ false))
+ return XLREAD_NEED_DATA;
- /* If we just reassembled the record header, validate it. */
- if (!gotheader)
- {
- record = (XLogRecord *) state->readRecordBuf;
- if (!ValidXLogRecordHeader(state, RecPtr, state->ReadRecPtr,
- record, randAccess))
+ if (!state->page_verified)
+ goto err;
+
+ Assert(SizeOfXLogShortPHD <= state->readLen);
+
+ /* Check that the continuation on next page looks valid */
+ pageHeader = (XLogPageHeader) state->readBuf;
+
+ /*
+ * If we were expecting a continuation record and got an
+ * "overwrite contrecord" flag, that means the continuation
+ * record was overwritten with a different record. Restart
+ * the read by assuming the address to read is the location
+ * where we found this flag; but keep track of the LSN of
+ * the record we were reading, for later verification.
+ */
+ if (pageHeader->xlp_info &
+ XLP_FIRST_IS_OVERWRITE_CONTRECORD)
+ {
+ state->overwrittenRecPtr = state->ReadRecPtr;
+ state->EndRecPtr = targetPagePtr;
+ state->readRecordState = XLREAD_NEXT_RECORD;
+
+ /*
+ * ReadRecPtr is the PrevRecPtr of the next
+ * record. Keep the LSN at the retry.
+ */
+ state->ReadRecPtr = state->PrevRecPtr;
+
+ goto restart;
+ }
+
+ if (!(pageHeader->xlp_info & XLP_FIRST_IS_CONTRECORD))
+ {
+ report_invalid_record(
+ state,
+ "there is no contrecord flag at %X/%X reading %X/%X",
+ (uint32) (state->recordContRecPtr >> 32),
+ (uint32) state->recordContRecPtr,
+ (uint32) (state->ReadRecPtr >> 32),
+ (uint32) state->ReadRecPtr);
+ goto err;
+ }
+
+ /*
+ * Cross-check that xlp_rem_len agrees with how much of
+ * the record we expect there to be left.
+ */
+ if (pageHeader->xlp_rem_len == 0 ||
+ pageHeader->xlp_rem_len != state->recordRemainLen)
+ {
+ report_invalid_record(
+ state,
+ "invalid contrecord length %u at %X/%X reading %X/%X, expected %u",
+ pageHeader->xlp_rem_len,
+ (uint32) (state->recordContRecPtr >> 32),
+ (uint32) state->recordContRecPtr,
+ (uint32) (state->ReadRecPtr >> 32),
+ (uint32) state->ReadRecPtr,
+ state->recordRemainLen);
+ goto err;
+ }
+
+ /* Append the continuation from this page to the buffer */
+ pageHeaderSize = XLogPageHeaderSize(pageHeader);
+
+ /*
+ * XLogNeedData should have ensured that the whole page
+ * header was read
+ */
+ Assert(state->readLen >= pageHeaderSize);
+
+ contdata = (char *) state->readBuf + pageHeaderSize;
+ record_len = XLOG_BLCKSZ - pageHeaderSize;
+ if (pageHeader->xlp_rem_len < record_len)
+ record_len = pageHeader->xlp_rem_len;
+
+ request_len = record_len + pageHeaderSize;
+
+ /*
+ * XLogNeedData should have ensured all needed data was
+ * read
+ */
+ Assert(state->readLen >= request_len);
+
+ memcpy(state->readRecordBuf + state->recordGotLen,
+ (char *) contdata, record_len);
+ state->recordGotLen += record_len;
+ state->recordRemainLen -= record_len;
+
+ /* If we just reassembled the record header, validate it. */
+ if (!state->record_verified)
+ {
+ Assert(state->recordGotLen >= SizeOfXLogRecord);
+ if (!ValidXLogRecordHeader(state, state->ReadRecPtr,
+ state->PrevRecPtr,
+ (XLogRecord *) state->readRecordBuf))
+ goto err;
+
+ state->record_verified = true;
+ }
+
+ /*
+ * Calculate pointer to beginning of next page, and
+ * continue
+ */
+ state->recordContRecPtr += XLOG_BLCKSZ;
+ }
+
+ /* targetPagePtr is pointing the last-read page here */
+ prec = (XLogRecord *) state->readRecordBuf;
+ if (!ValidXLogRecord(state, prec, state->ReadRecPtr))
goto err;
- gotheader = true;
- }
- } while (gotlen < total_len);
-
- Assert(gotheader);
-
- record = (XLogRecord *) state->readRecordBuf;
- if (!ValidXLogRecord(state, record, RecPtr))
- goto err;
-
- pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) state->readBuf);
- state->ReadRecPtr = RecPtr;
- state->EndRecPtr = targetPagePtr + pageHeaderSize
- + MAXALIGN(pageHeader->xlp_rem_len);
- }
- else
- {
- /* Wait for the record data to become available */
- while (XLogNeedData(state, targetPagePtr,
- Min(targetRecOff + total_len, XLOG_BLCKSZ), true))
- {
- if (!state->routine.page_read(state, state->readPagePtr,
- state->readLen,
- state->ReadRecPtr, state->readBuf))
+
+ pageHeaderSize =
+ XLogPageHeaderSize((XLogPageHeader) state->readBuf);
+ state->EndRecPtr = targetPagePtr + pageHeaderSize
+ + MAXALIGN(pageHeader->xlp_rem_len);
+
+ *record = prec;
+ state->readRecordState = XLREAD_NEXT_RECORD;
break;
- }
-
- if (!state->page_verified)
- goto err;
-
- /* Record does not cross a page boundary */
- if (!ValidXLogRecord(state, record, RecPtr))
- goto err;
-
- state->EndRecPtr = RecPtr + MAXALIGN(total_len);
-
- state->ReadRecPtr = RecPtr;
+ }
}
/*
* Special processing if it's an XLOG SWITCH record
*/
- if (record->xl_rmid == RM_XLOG_ID &&
- (record->xl_info & ~XLR_INFO_MASK) == XLOG_SWITCH)
+ if ((*record)->xl_rmid == RM_XLOG_ID &&
+ ((*record)->xl_info & ~XLR_INFO_MASK) == XLOG_SWITCH)
{
/* Pretend it extends to end of segment */
state->EndRecPtr += state->segcxt.ws_segsize - 1;
state->EndRecPtr -= XLogSegmentOffset(state->EndRecPtr, state->segcxt.ws_segsize);
}
- if (DecodeXLogRecord(state, record, errormsg))
- return record;
- else
- return NULL;
+ Assert(!*record || state->readLen >= 0);
+ if (DecodeXLogRecord(state, *record, errormsg))
+ return XLREAD_SUCCESS;
+
+ *record = NULL;
+ return XLREAD_FAIL;
err:
- if (assembled)
+ Assert(state->readRecordState != XLREAD_NEXT_RECORD);
+ XLogTerminateRead(state);
+
+ if (state->errormsg_buf[0] != '\0')
+ *errormsg = state->errormsg_buf;
+
+ *record = NULL;
+
+ return XLREAD_FAIL;
+}
+
+/*
+ * Terminate read WAL.
+ *
+ * When the caller failed to read the data requested from XLogReadRecord, it is
+ * supposed to call this function to set the correct reader state to reflect
+ * the failure.
+ */
+void
+XLogTerminateRead(XLogReaderState *state)
+{
+ if (state->readRecordState == XLREAD_CONTINUATION)
{
/*
* We get here when a record that spans multiple pages needs to be
@@ -640,20 +768,15 @@ err:
* in turn signal downstream WAL consumers that the broken WAL record
* is to be ignored.
*/
- state->abortedRecPtr = RecPtr;
- state->missingContrecPtr = targetPagePtr;
+ state->abortedRecPtr = state->ReadRecPtr;
+ state->missingContrecPtr = state->recordContRecPtr;
}
/*
- * Invalidate the read state. We might read from a different source after
+ * Invalidate the read page. We might read from a different source after
* failure.
*/
XLogReaderInvalReadState(state);
-
- if (state->errormsg_buf[0] != '\0')
- *errormsg = state->errormsg_buf;
-
- return NULL;
}
/*
@@ -805,11 +928,12 @@ XLogReaderInvalReadState(XLogReaderState *state)
*
* This is just a convenience subroutine to avoid duplicated code in
* XLogReadRecord. It's not intended for use from anywhere else.
+ *
+ * If PrevRecPtr is valid, the xl_prev is is cross-checked with it.
*/
static bool
ValidXLogRecordHeader(XLogReaderState *state, XLogRecPtr RecPtr,
- XLogRecPtr PrevRecPtr, XLogRecord *record,
- bool randAccess)
+ XLogRecPtr PrevRecPtr, XLogRecord *record)
{
if (record->xl_tot_len < SizeOfXLogRecord)
{
@@ -826,7 +950,7 @@ ValidXLogRecordHeader(XLogReaderState *state, XLogRecPtr RecPtr,
record->xl_rmid, LSN_FORMAT_ARGS(RecPtr));
return false;
}
- if (randAccess)
+ if (PrevRecPtr == InvalidXLogRecPtr)
{
/*
* We can't exactly verify the prev-link, but surely it should be less
@@ -1056,11 +1180,14 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
* XLogReadRecord() will read the next valid record.
*/
XLogRecPtr
-XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr)
+XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr,
+ XLogFindNextRecordCB read_page, void *private)
{
XLogRecPtr tmpRecPtr;
XLogRecPtr found = InvalidXLogRecPtr;
XLogPageHeader header;
+ XLogRecord *record;
+ XLogReadRecordResult result;
char *errormsg;
Assert(!XLogRecPtrIsInvalid(RecPtr));
@@ -1093,9 +1220,7 @@ XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr)
while (XLogNeedData(state, targetPagePtr, targetRecOff,
targetRecOff != 0))
{
- if (!state->routine.page_read(state, state->readPagePtr,
- state->readLen,
- state->ReadRecPtr, state->readBuf))
+ if (!read_page(state, private))
break;
}
@@ -1147,8 +1272,16 @@ XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr)
* or we just jumped over the remaining data of a continuation.
*/
XLogBeginRead(state, tmpRecPtr);
- while (XLogReadRecord(state, &errormsg) != NULL)
+ while ((result = XLogReadRecord(state, &record, &errormsg)) !=
+ XLREAD_FAIL)
{
+ if (result == XLREAD_NEED_DATA)
+ {
+ if (!read_page(state, private))
+ goto err;
+ continue;
+ }
+
/* past the record we've found, break out */
if (RecPtr <= state->ReadRecPtr)
{
@@ -1168,9 +1301,9 @@ err:
#endif /* FRONTEND */
/*
- * Helper function to ease writing of XLogRoutine->page_read callbacks.
- * If this function is used, caller must supply a segment_open callback in
- * 'state', as that is used here.
+ * Helper function to ease writing of page_read callback.
+ * If this function is used, caller must supply a segment_open callback and
+ * segment_close callback as that is used here.
*
* Read 'count' bytes into 'buf', starting at location 'startptr', from WAL
* fetched from timeline 'tli'.
@@ -1183,6 +1316,7 @@ err:
*/
bool
WALRead(XLogReaderState *state,
+ WALSegmentOpenCB segopenfn, WALSegmentCloseCB segclosefn,
char *buf, XLogRecPtr startptr, Size count, TimeLineID tli,
WALReadError *errinfo)
{
@@ -1214,10 +1348,10 @@ WALRead(XLogReaderState *state,
XLogSegNo nextSegNo;
if (state->seg.ws_file >= 0)
- state->routine.segment_close(state);
+ segclosefn(state);
XLByteToSeg(recptr, nextSegNo, state->segcxt.ws_segsize);
- state->routine.segment_open(state, nextSegNo, &tli);
+ segopenfn(state, nextSegNo, &tli);
/* This shouldn't happen -- indicates a bug in segment_open */
Assert(state->seg.ws_file >= 0);
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index 421040f391..fc09a72b8b 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -706,8 +706,7 @@ XLogTruncateRelation(RelFileNode rnode, ForkNumber forkNum,
void
XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wantLength)
{
- const XLogRecPtr lastReadPage = state->seg.ws_segno *
- state->segcxt.ws_segsize + state->readLen;
+ const XLogRecPtr lastReadPage = state->readPagePtr;
Assert(wantPage != InvalidXLogRecPtr && wantPage % XLOG_BLCKSZ == 0);
Assert(wantLength <= XLOG_BLCKSZ);
@@ -722,7 +721,7 @@ XLogReadDetermineTimeline(XLogReaderState *state, XLogRecPtr wantPage, uint32 wa
* current TLI has since become historical.
*/
if (lastReadPage == wantPage &&
- state->readLen != 0 &&
+ state->page_verified &&
lastReadPage + state->readLen >= wantPage + Min(wantLength, XLOG_BLCKSZ - 1))
return;
@@ -808,6 +807,7 @@ wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo,
char path[MAXPGPATH];
XLogFilePath(path, tli, nextSegNo, state->segcxt.ws_segsize);
+ elog(LOG, "HOGE: %lu, %d => %s", nextSegNo, tli, path);
state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
if (state->seg.ws_file >= 0)
return;
@@ -845,9 +845,11 @@ wal_segment_close(XLogReaderState *state)
* loop for now.
*/
bool
-read_local_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr,
- int reqLen, XLogRecPtr targetRecPtr, char *cur_page)
+read_local_xlog_page(XLogReaderState *state)
{
+ XLogRecPtr targetPagePtr = state->readPagePtr;
+ int reqLen = state->readLen;
+ char *cur_page = state->readBuf;
XLogRecPtr read_upto,
loc;
TimeLineID tli;
@@ -960,11 +962,12 @@ read_local_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr,
* as 'count', read the whole page anyway. It's guaranteed to be
* zero-padded up to the page boundary if it's incomplete.
*/
- if (!WALRead(state, cur_page, targetPagePtr, XLOG_BLCKSZ, tli,
- &errinfo))
+ if (!WALRead(state, wal_segment_open, wal_segment_close,
+ cur_page, targetPagePtr, XLOG_BLCKSZ, tli, &errinfo))
WALReadRaiseError(&errinfo);
/* number of valid bytes in the buffer */
+ state->readPagePtr = targetPagePtr;
state->readLen = count;
return true;
}
diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c
index aae0ae5b8a..2a88aa063a 100644
--- a/src/backend/replication/logical/logical.c
+++ b/src/backend/replication/logical/logical.c
@@ -148,7 +148,8 @@ StartupDecodingContext(List *output_plugin_options,
TransactionId xmin_horizon,
bool need_full_snapshot,
bool fast_forward,
- XLogReaderRoutine *xl_routine,
+ LogicalDecodingXLogPageReadCB page_read,
+ WALSegmentCleanupCB cleanup_cb,
LogicalOutputPluginWriterPrepareWrite prepare_write,
LogicalOutputPluginWriterWrite do_write,
LogicalOutputPluginWriterUpdateProgress update_progress)
@@ -198,11 +199,12 @@ StartupDecodingContext(List *output_plugin_options,
ctx->slot = slot;
- ctx->reader = XLogReaderAllocate(wal_segment_size, NULL, xl_routine, ctx);
+ ctx->reader = XLogReaderAllocate(wal_segment_size, NULL, cleanup_cb);
if (!ctx->reader)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
+ ctx->page_read = page_read;
ctx->reorder = ReorderBufferAllocate();
ctx->snapshot_builder =
@@ -319,7 +321,8 @@ CreateInitDecodingContext(const char *plugin,
List *output_plugin_options,
bool need_full_snapshot,
XLogRecPtr restart_lsn,
- XLogReaderRoutine *xl_routine,
+ LogicalDecodingXLogPageReadCB page_read,
+ WALSegmentCleanupCB cleanup_cb,
LogicalOutputPluginWriterPrepareWrite prepare_write,
LogicalOutputPluginWriterWrite do_write,
LogicalOutputPluginWriterUpdateProgress update_progress)
@@ -422,7 +425,7 @@ CreateInitDecodingContext(const char *plugin,
ctx = StartupDecodingContext(NIL, restart_lsn, xmin_horizon,
need_full_snapshot, false,
- xl_routine, prepare_write, do_write,
+ page_read, cleanup_cb, prepare_write, do_write,
update_progress);
/* call output plugin initialization callback */
@@ -478,7 +481,8 @@ LogicalDecodingContext *
CreateDecodingContext(XLogRecPtr start_lsn,
List *output_plugin_options,
bool fast_forward,
- XLogReaderRoutine *xl_routine,
+ LogicalDecodingXLogPageReadCB page_read,
+ WALSegmentCleanupCB cleanup_cb,
LogicalOutputPluginWriterPrepareWrite prepare_write,
LogicalOutputPluginWriterWrite do_write,
LogicalOutputPluginWriterUpdateProgress update_progress)
@@ -534,8 +538,8 @@ CreateDecodingContext(XLogRecPtr start_lsn,
ctx = StartupDecodingContext(output_plugin_options,
start_lsn, InvalidTransactionId, false,
- fast_forward, xl_routine, prepare_write,
- do_write, update_progress);
+ fast_forward, page_read, cleanup_cb,
+ prepare_write, do_write, update_progress);
/* call output plugin initialization callback */
old_context = MemoryContextSwitchTo(ctx->context);
@@ -603,7 +607,16 @@ DecodingContextFindStartpoint(LogicalDecodingContext *ctx)
char *err = NULL;
/* the read_page callback waits for new WAL */
- record = XLogReadRecord(ctx->reader, &err);
+ while (XLogReadRecord(ctx->reader, &record, &err) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!ctx->page_read(ctx->reader))
+ {
+ XLogTerminateRead(ctx->reader);
+ break;
+ }
+ }
+
if (err)
elog(ERROR, "%s", err);
if (!record)
diff --git a/src/backend/replication/logical/logicalfuncs.c b/src/backend/replication/logical/logicalfuncs.c
index e59939aad1..f68d08fdee 100644
--- a/src/backend/replication/logical/logicalfuncs.c
+++ b/src/backend/replication/logical/logicalfuncs.c
@@ -224,9 +224,8 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
ctx = CreateDecodingContext(InvalidXLogRecPtr,
options,
false,
- XL_ROUTINE(.page_read = read_local_xlog_page,
- .segment_open = wal_segment_open,
- .segment_close = wal_segment_close),
+ read_local_xlog_page,
+ wal_segment_close,
LogicalOutputPrepareWrite,
LogicalOutputWrite, NULL);
@@ -275,7 +274,16 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
XLogRecord *record;
char *errm = NULL;
- record = XLogReadRecord(ctx->reader, &errm);
+ while (XLogReadRecord(ctx->reader, &record, &errm) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!ctx->page_read(ctx->reader))
+ {
+ XLogTerminateRead(ctx->reader);
+ break;
+ }
+ }
+
if (errm)
elog(ERROR, "%s", errm);
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index 17df99c2ac..57426aa9d7 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -144,9 +144,8 @@ create_logical_replication_slot(char *name, char *plugin,
ctx = CreateInitDecodingContext(plugin, NIL,
false, /* just catalogs is OK */
restart_lsn,
- XL_ROUTINE(.page_read = read_local_xlog_page,
- .segment_open = wal_segment_open,
- .segment_close = wal_segment_close),
+ read_local_xlog_page,
+ wal_segment_close,
NULL, NULL, NULL);
/*
@@ -503,9 +502,8 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
ctx = CreateDecodingContext(InvalidXLogRecPtr,
NIL,
true, /* fast_forward */
- XL_ROUTINE(.page_read = read_local_xlog_page,
- .segment_open = wal_segment_open,
- .segment_close = wal_segment_close),
+ read_local_xlog_page,
+ wal_segment_close,
NULL, NULL, NULL);
/*
@@ -527,7 +525,16 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
* Read records. No changes are generated in fast_forward mode,
* but snapbuilder/slot statuses are updated properly.
*/
- record = XLogReadRecord(ctx->reader, &errm);
+ while (XLogReadRecord(ctx->reader, &record, &errm) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!ctx->page_read(ctx->reader))
+ {
+ XLogTerminateRead(ctx->reader);
+ break;
+ }
+ }
+
if (errm)
elog(ERROR, "%s", errm);
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ddba340653..78d805ab80 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -575,10 +575,7 @@ StartReplication(StartReplicationCmd *cmd)
/* create xlogreader for physical replication */
xlogreader =
- XLogReaderAllocate(wal_segment_size, NULL,
- XL_ROUTINE(.segment_open = WalSndSegmentOpen,
- .segment_close = wal_segment_close),
- NULL);
+ XLogReaderAllocate(wal_segment_size, NULL, wal_segment_close);
if (!xlogreader)
ereport(ERROR,
@@ -803,9 +800,11 @@ StartReplication(StartReplicationCmd *cmd)
* set every time WAL is flushed.
*/
static bool
-logical_read_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
- XLogRecPtr targetRecPtr, char *cur_page)
+logical_read_xlog_page(XLogReaderState *state)
{
+ XLogRecPtr targetPagePtr = state->readPagePtr;
+ int reqLen = state->readLen;
+ char *cur_page = state->readBuf;
XLogRecPtr flushptr;
int count;
WALReadError errinfo;
@@ -833,7 +832,7 @@ logical_read_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr, int req
count = flushptr - targetPagePtr; /* part of the page available */
/* now actually read the data, we know it's there */
- if (!WALRead(state,
+ if (!WALRead(state, WalSndSegmentOpen, wal_segment_close,
cur_page,
targetPagePtr,
XLOG_BLCKSZ,
@@ -1023,9 +1022,8 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
ctx = CreateInitDecodingContext(cmd->plugin, NIL, need_full_snapshot,
InvalidXLogRecPtr,
- XL_ROUTINE(.page_read = logical_read_xlog_page,
- .segment_open = WalSndSegmentOpen,
- .segment_close = wal_segment_close),
+ logical_read_xlog_page,
+ wal_segment_close,
WalSndPrepareWrite, WalSndWriteData,
WalSndUpdateProgress);
@@ -1183,9 +1181,8 @@ StartLogicalReplication(StartReplicationCmd *cmd)
*/
logical_decoding_ctx =
CreateDecodingContext(cmd->startpoint, cmd->options, false,
- XL_ROUTINE(.page_read = logical_read_xlog_page,
- .segment_open = WalSndSegmentOpen,
- .segment_close = wal_segment_close),
+ logical_read_xlog_page,
+ wal_segment_close,
WalSndPrepareWrite, WalSndWriteData,
WalSndUpdateProgress);
xlogreader = logical_decoding_ctx->reader;
@@ -2778,7 +2775,7 @@ XLogSendPhysical(void)
enlargeStringInfo(&output_message, nbytes);
retry:
- if (!WALRead(xlogreader,
+ if (!WALRead(xlogreader, WalSndSegmentOpen, wal_segment_close,
&output_message.data[output_message.len],
startptr,
nbytes,
@@ -2876,7 +2873,15 @@ XLogSendLogical(void)
*/
WalSndCaughtUp = false;
- record = XLogReadRecord(logical_decoding_ctx->reader, &errm);
+ while (XLogReadRecord(logical_decoding_ctx->reader, &record, &errm) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!logical_decoding_ctx->page_read(logical_decoding_ctx->reader))
+ {
+ XLogTerminateRead(logical_decoding_ctx->reader);
+ break;
+ }
+ }
/* xlog record was invalid */
if (errm != NULL)
diff --git a/src/bin/pg_rewind/parsexlog.c b/src/bin/pg_rewind/parsexlog.c
index cf119848b0..da723e5340 100644
--- a/src/bin/pg_rewind/parsexlog.c
+++ b/src/bin/pg_rewind/parsexlog.c
@@ -41,15 +41,9 @@ static int xlogreadfd = -1;
static XLogSegNo xlogreadsegno = -1;
static char xlogfpath[MAXPGPATH];
-typedef struct XLogPageReadPrivate
-{
- const char *restoreCommand;
- int tliIndex;
-} XLogPageReadPrivate;
-
-static bool SimpleXLogPageRead(XLogReaderState *xlogreader,
- XLogRecPtr targetPagePtr,
- int reqLen, XLogRecPtr targetRecPtr, char *readBuf);
+static bool SimpleXLogPageRead(XLogReaderState *xlogreader,
+ const char *datadir, int *tliIndex,
+ const char *restoreCommand);
/*
* Read WAL from the datadir/pg_wal, starting from 'startpoint' on timeline
@@ -66,20 +60,25 @@ extractPageMap(const char *datadir, XLogRecPtr startpoint, int tliIndex,
XLogRecord *record;
XLogReaderState *xlogreader;
char *errormsg;
- XLogPageReadPrivate private;
- private.tliIndex = tliIndex;
- private.restoreCommand = restoreCommand;
- xlogreader = XLogReaderAllocate(WalSegSz, datadir,
- XL_ROUTINE(.page_read = &SimpleXLogPageRead),
- &private);
+ xlogreader = XLogReaderAllocate(WalSegSz, datadir, NULL);
+
if (xlogreader == NULL)
pg_fatal("out of memory");
XLogBeginRead(xlogreader, startpoint);
do
{
- record = XLogReadRecord(xlogreader, &errormsg);
+ while (XLogReadRecord(xlogreader, &record, &errormsg) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!SimpleXLogPageRead(xlogreader, datadir,
+ &tliIndex, restoreCommand))
+ {
+ XLogTerminateRead(xlogreader);
+ break;
+ }
+ }
if (record == NULL)
{
@@ -123,19 +122,22 @@ readOneRecord(const char *datadir, XLogRecPtr ptr, int tliIndex,
XLogRecord *record;
XLogReaderState *xlogreader;
char *errormsg;
- XLogPageReadPrivate private;
XLogRecPtr endptr;
- private.tliIndex = tliIndex;
- private.restoreCommand = restoreCommand;
- xlogreader = XLogReaderAllocate(WalSegSz, datadir,
- XL_ROUTINE(.page_read = &SimpleXLogPageRead),
- &private);
+ xlogreader = XLogReaderAllocate(WalSegSz, datadir, NULL);
if (xlogreader == NULL)
pg_fatal("out of memory");
XLogBeginRead(xlogreader, ptr);
- record = XLogReadRecord(xlogreader, &errormsg);
+ while (XLogReadRecord(xlogreader, &record, &errormsg) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!SimpleXLogPageRead(xlogreader, datadir, &tliIndex, restoreCommand))
+ {
+ XLogTerminateRead(xlogreader);
+ break;
+ }
+ }
if (record == NULL)
{
if (errormsg)
@@ -170,7 +172,6 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, int tliIndex,
XLogRecPtr searchptr;
XLogReaderState *xlogreader;
char *errormsg;
- XLogPageReadPrivate private;
/*
* The given fork pointer points to the end of the last common record,
@@ -186,11 +187,7 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, int tliIndex,
forkptr += SizeOfXLogShortPHD;
}
- private.tliIndex = tliIndex;
- private.restoreCommand = restoreCommand;
- xlogreader = XLogReaderAllocate(WalSegSz, datadir,
- XL_ROUTINE(.page_read = &SimpleXLogPageRead),
- &private);
+ xlogreader = XLogReaderAllocate(WalSegSz, datadir, NULL);
if (xlogreader == NULL)
pg_fatal("out of memory");
@@ -200,7 +197,16 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, int tliIndex,
uint8 info;
XLogBeginRead(xlogreader, searchptr);
- record = XLogReadRecord(xlogreader, &errormsg);
+ while (XLogReadRecord(xlogreader, &record, &errormsg) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!SimpleXLogPageRead(xlogreader, datadir,
+ &tliIndex, restoreCommand))
+ {
+ XLogTerminateRead(xlogreader);
+ break;
+ }
+ }
if (record == NULL)
{
@@ -247,10 +253,11 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, int tliIndex,
/* XLogReader callback function, to read a WAL page */
static bool
-SimpleXLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
- int reqLen, XLogRecPtr targetRecPtr, char *readBuf)
+SimpleXLogPageRead(XLogReaderState *xlogreader, const char *datadir,
+ int *tliIndex, const char *restoreCommand)
{
- XLogPageReadPrivate *private = (XLogPageReadPrivate *) xlogreader->private_data;
+ XLogRecPtr targetPagePtr = xlogreader->readPagePtr;
+ char *readBuf = xlogreader->readBuf;
uint32 targetPageOff;
XLogRecPtr targetSegEnd;
XLogSegNo targetSegNo;
@@ -283,14 +290,14 @@ SimpleXLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
* be done both forward and backward, consider also switching timeline
* accordingly.
*/
- while (private->tliIndex < targetNentries - 1 &&
- targetHistory[private->tliIndex].end < targetSegEnd)
- private->tliIndex++;
- while (private->tliIndex > 0 &&
- targetHistory[private->tliIndex].begin >= targetSegEnd)
- private->tliIndex--;
+ while (*tliIndex < targetNentries - 1 &&
+ targetHistory[*tliIndex].end < targetSegEnd)
+ (*tliIndex)++;
+ while (*tliIndex > 0 &&
+ targetHistory[*tliIndex].begin >= targetSegEnd)
+ (*tliIndex)--;
- XLogFileName(xlogfname, targetHistory[private->tliIndex].tli,
+ XLogFileName(xlogfname, targetHistory[*tliIndex].tli,
xlogreadsegno, WalSegSz);
snprintf(xlogfpath, MAXPGPATH, "%s/" XLOGDIR "/%s",
@@ -303,7 +310,7 @@ SimpleXLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
/*
* If we have no restore_command to execute, then exit.
*/
- if (private->restoreCommand == NULL)
+ if (restoreCommand == NULL)
{
pg_log_error("could not open file \"%s\": %m", xlogfpath);
xlogreader->readLen = -1;
@@ -317,7 +324,7 @@ SimpleXLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
xlogreadfd = RestoreArchivedFile(xlogreader->segcxt.ws_dir,
xlogfname,
WalSegSz,
- private->restoreCommand);
+ restoreCommand);
if (xlogreadfd < 0)
{
@@ -359,7 +366,7 @@ SimpleXLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
Assert(targetSegNo == xlogreadsegno);
- xlogreader->seg.ws_tli = targetHistory[private->tliIndex].tli;
+ xlogreader->seg.ws_tli = targetHistory[*tliIndex].tli;
xlogreader->readLen = XLOG_BLCKSZ;
return true;
}
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 833a64210b..80182621f8 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -331,12 +331,17 @@ WALDumpCloseSegment(XLogReaderState *state)
state->seg.ws_file = -1;
}
-/* pg_waldump's XLogReaderRoutine->page_read callback */
+/*
+ * pg_waldump's WAL page rader, also used as page_read callback for
+ * XLogFindNextRecord
+ */
static bool
-WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
- XLogRecPtr targetPtr, char *readBuff)
+WALDumpReadPage(XLogReaderState *state, void *priv)
{
- XLogDumpPrivate *private = state->private_data;
+ XLogRecPtr targetPagePtr = state->readPagePtr;
+ int reqLen = state->readLen;
+ char *readBuff = state->readBuf;
+ XLogDumpPrivate *private = (XLogDumpPrivate *) priv;
int count = XLOG_BLCKSZ;
WALReadError errinfo;
@@ -354,8 +359,8 @@ WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
}
}
- if (!WALRead(state, readBuff, targetPagePtr, count, private->timeline,
- &errinfo))
+ if (!WALRead(state, WALDumpOpenSegment, WALDumpCloseSegment,
+ readBuff, targetPagePtr, count, private->timeline, &errinfo))
{
WALOpenSegment *seg = &errinfo.wre_seg;
char fname[MAXPGPATH];
@@ -375,6 +380,7 @@ WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
errinfo.wre_req);
}
+ Assert(count >= state->readLen);
state->readLen = count;
return true;
}
@@ -1057,16 +1063,14 @@ main(int argc, char **argv)
/* we have everything we need, start reading */
xlogreader_state =
- XLogReaderAllocate(WalSegSz, waldir,
- XL_ROUTINE(.page_read = WALDumpReadPage,
- .segment_open = WALDumpOpenSegment,
- .segment_close = WALDumpCloseSegment),
- &private);
+ XLogReaderAllocate(WalSegSz, waldir, WALDumpCloseSegment);
+
if (!xlogreader_state)
fatal_error("out of memory");
/* first find a valid recptr to start from */
- first_record = XLogFindNextRecord(xlogreader_state, private.startptr);
+ first_record = XLogFindNextRecord(xlogreader_state, private.startptr,
+ &WALDumpReadPage, (void*) &private);
if (first_record == InvalidXLogRecPtr)
fatal_error("could not find a valid record after %X/%X",
@@ -1089,7 +1093,16 @@ main(int argc, char **argv)
for (;;)
{
/* try to read the next record */
- record = XLogReadRecord(xlogreader_state, &errormsg);
+ while (XLogReadRecord(xlogreader_state, &record, &errormsg) ==
+ XLREAD_NEED_DATA)
+ {
+ if (!WALDumpReadPage(xlogreader_state, (void *) &private))
+ {
+ XLogTerminateRead(xlogreader_state);
+ break;
+ }
+ }
+
if (!record)
{
if (!config.follow || private.endptr_reached)
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index f3cf4f2f49..ff1aca719b 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -57,64 +57,15 @@ typedef struct WALSegmentContext
typedef struct XLogReaderState XLogReaderState;
-/* Function type definition for the read_page callback */
-typedef bool (*XLogPageReadCB) (XLogReaderState *xlogreader,
- XLogRecPtr targetPagePtr,
- int reqLen,
- XLogRecPtr targetRecPtr,
- char *readBuf);
+/* Function type definition for the segment cleanup callback */
+typedef void (*WALSegmentCleanupCB) (XLogReaderState *xlogreader);
+
+/* Function type definition for the open/close callbacks for WALRead() */
typedef void (*WALSegmentOpenCB) (XLogReaderState *xlogreader,
XLogSegNo nextSegNo,
TimeLineID *tli_p);
typedef void (*WALSegmentCloseCB) (XLogReaderState *xlogreader);
-typedef struct XLogReaderRoutine
-{
- /*
- * Data input callback
- *
- * This callback shall read at least reqLen valid bytes of the xlog page
- * starting at targetPagePtr, and store them in readBuf. The callback
- * shall return the number of bytes read (never more than XLOG_BLCKSZ), or
- * -1 on failure. The callback shall sleep, if necessary, to wait for the
- * requested bytes to become available. The callback will not be invoked
- * again for the same page unless more than the returned number of bytes
- * are needed.
- *
- * targetRecPtr is the position of the WAL record we're reading. Usually
- * it is equal to targetPagePtr + reqLen, but sometimes xlogreader needs
- * to read and verify the page or segment header, before it reads the
- * actual WAL record it's interested in. In that case, targetRecPtr can
- * be used to determine which timeline to read the page from.
- *
- * The callback shall set ->seg.ws_tli to the TLI of the file the page was
- * read from.
- */
- XLogPageReadCB page_read;
-
- /*
- * 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.
- *
- * "nextSegNo" is the number of the segment to be opened.
- *
- * "tli_p" is an input/output argument. WALRead() uses it to pass the
- * timeline in which the new segment should be found, but the callback can
- * use it to return the TLI that it actually opened.
- */
- WALSegmentOpenCB segment_open;
-
- /*
- * WAL segment close callback. ->seg.ws_file shall be set to a negative
- * number.
- */
- WALSegmentCloseCB segment_close;
-} XLogReaderRoutine;
-
-#define XL_ROUTINE(...) &(XLogReaderRoutine){__VA_ARGS__}
-
typedef struct
{
/* Is this block ref in use? */
@@ -144,12 +95,36 @@ typedef struct
uint16 data_bufsz;
} DecodedBkpBlock;
+/* Return code from XLogReadRecord */
+typedef enum XLogReadRecordResult
+{
+ XLREAD_SUCCESS, /* record is successfully read */
+ XLREAD_NEED_DATA, /* need more data. see XLogReadRecord. */
+ XLREAD_FAIL /* failed during reading a record */
+} XLogReadRecordResult;
+
+/*
+ * internal state of XLogReadRecord
+ *
+ * XLogReadState runs a state machine while reading a record. Theses states
+ * are not seen outside the function. Each state may repeat several times
+ * exiting requesting caller for new data. See the comment of XLogReadRecrod
+ * for details.
+ */
+typedef enum XLogReadRecordState
+{
+ XLREAD_NEXT_RECORD,
+ XLREAD_TOT_LEN,
+ XLREAD_FIRST_FRAGMENT,
+ XLREAD_CONTINUATION
+} XLogReadRecordState;
+
struct XLogReaderState
{
/*
* Operational callbacks
*/
- XLogReaderRoutine routine;
+ WALSegmentCleanupCB cleanup_cb;
/* ----------------------------------------
* Public parameters
@@ -162,18 +137,14 @@ struct XLogReaderState
*/
uint64 system_identifier;
- /*
- * Opaque data for callbacks to use. Not used by XLogReader.
- */
- void *private_data;
-
/*
* Start and end point of last record read. EndRecPtr is also used as the
* position to read next. Calling XLogBeginRead() sets EndRecPtr to the
* starting position and ReadRecPtr to invalid.
*/
- XLogRecPtr ReadRecPtr; /* start of last record read */
+ XLogRecPtr ReadRecPtr; /* start of last record read or being read */
XLogRecPtr EndRecPtr; /* end+1 of last record read */
+ XLogRecPtr PrevRecPtr; /* start of previous record read */
/*
* Set at the end of recovery: the start point of a partial record at the
@@ -196,7 +167,9 @@ struct XLogReaderState
* read by reader, which must be larger than
* the request, or -1 on error */
char *readBuf; /* buffer to store data */
- bool page_verified; /* is the page on the buffer verified? */
+ bool page_verified; /* is the page header on the buffer verified? */
+ bool record_verified; /* is the current record header verified? */
+
/* ----------------------------------------
* Decoded representation of current record
@@ -237,8 +210,6 @@ struct XLogReaderState
XLogRecPtr latestPagePtr;
TimeLineID latestPageTLI;
- /* beginning of the WAL record being read. */
- XLogRecPtr currRecPtr;
/* timeline to read it from, 0 if a lookup is required */
TimeLineID currTLI;
@@ -265,6 +236,15 @@ struct XLogReaderState
char *readRecordBuf;
uint32 readRecordBufSize;
+ /*
+ * XLogReadRecord() state
+ */
+ XLogReadRecordState readRecordState; /* state machine state */
+ int recordGotLen; /* amount of current record that has already
+ * been read */
+ int recordRemainLen; /* length of current record that remains */
+ XLogRecPtr recordContRecPtr; /* where the current record continues */
+
/* Buffer to hold error message */
char *errormsg_buf;
};
@@ -272,9 +252,7 @@ struct XLogReaderState
/* Get a new XLogReader */
extern XLogReaderState *XLogReaderAllocate(int wal_segment_size,
const char *waldir,
- XLogReaderRoutine *routine,
- void *private_data);
-extern XLogReaderRoutine *LocalXLogReaderRoutine(void);
+ WALSegmentCleanupCB cleanup_cb);
/* Free an XLogReader */
extern void XLogReaderFree(XLogReaderState *state);
@@ -282,12 +260,19 @@ extern void XLogReaderFree(XLogReaderState *state);
/* Position the XLogReader to given record */
extern void XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr);
#ifdef FRONTEND
-extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr);
+/* Function type definition for the read_page callback */
+typedef bool (*XLogFindNextRecordCB) (XLogReaderState *xlogreader,
+ void *private);
+extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr,
+ XLogFindNextRecordCB read_page, void *private);
#endif /* FRONTEND */
/* Read the next XLog record. Returns NULL on end-of-WAL or failure */
-extern struct XLogRecord *XLogReadRecord(XLogReaderState *state,
- char **errormsg);
+extern XLogReadRecordResult XLogReadRecord(XLogReaderState *state,
+ XLogRecord **record,
+ char **errormsg);
+/* Finalize function when the caller of XLogReadRecord failed */
+extern void XLogTerminateRead(XLogReaderState *state);
/* Validate a page */
extern bool XLogReaderValidatePageHeader(XLogReaderState *state,
@@ -307,6 +292,7 @@ typedef struct WALReadError
} WALReadError;
extern bool WALRead(XLogReaderState *state,
+ WALSegmentOpenCB segopenfn, WALSegmentCloseCB sgclosefn,
char *buf, XLogRecPtr startptr, Size count,
TimeLineID tli, WALReadError *errinfo);
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index 8669f7eeb3..e403d253d6 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -89,9 +89,7 @@ extern Buffer XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
extern Relation CreateFakeRelcacheEntry(RelFileNode rnode);
extern void FreeFakeRelcacheEntry(Relation fakerel);
-extern bool read_local_xlog_page(XLogReaderState *state,
- XLogRecPtr targetPagePtr, int reqLen,
- XLogRecPtr targetRecPtr, char *cur_page);
+extern bool read_local_xlog_page(XLogReaderState *state);
extern void wal_segment_open(XLogReaderState *state,
XLogSegNo nextSegNo,
TimeLineID *tli_p);
diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index 614035e215..fecffdb3f6 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -390,7 +390,7 @@
* Enable debugging print statements for WAL-related operations; see
* also the wal_debug GUC var.
*/
-/* #define WAL_DEBUG */
+#define WAL_DEBUG
/*
* Enable tracing of resource consumption during sort operations;
diff --git a/src/include/replication/logical.h b/src/include/replication/logical.h
index e0f513b773..3346188b48 100644
--- a/src/include/replication/logical.h
+++ b/src/include/replication/logical.h
@@ -29,6 +29,10 @@ typedef void (*LogicalOutputPluginWriterUpdateProgress) (struct LogicalDecodingC
TransactionId xid
);
+typedef struct LogicalDecodingContext LogicalDecodingContext;
+
+typedef bool (*LogicalDecodingXLogPageReadCB)(XLogReaderState *ctx);
+
typedef struct LogicalDecodingContext
{
/* memory context this is all allocated in */
@@ -39,6 +43,7 @@ typedef struct LogicalDecodingContext
/* infrastructure pieces for decoding */
XLogReaderState *reader;
+ LogicalDecodingXLogPageReadCB page_read;
struct ReorderBuffer *reorder;
struct SnapBuild *snapshot_builder;
@@ -115,14 +120,16 @@ extern LogicalDecodingContext *CreateInitDecodingContext(const char *plugin,
List *output_plugin_options,
bool need_full_snapshot,
XLogRecPtr restart_lsn,
- XLogReaderRoutine *xl_routine,
+ LogicalDecodingXLogPageReadCB page_read,
+ WALSegmentCleanupCB cleanup_cb,
LogicalOutputPluginWriterPrepareWrite prepare_write,
LogicalOutputPluginWriterWrite do_write,
LogicalOutputPluginWriterUpdateProgress update_progress);
extern LogicalDecodingContext *CreateDecodingContext(XLogRecPtr start_lsn,
List *output_plugin_options,
bool fast_forward,
- XLogReaderRoutine *xl_routine,
+ LogicalDecodingXLogPageReadCB page_read,
+ WALSegmentCleanupCB cleanup_cb,
LogicalOutputPluginWriterPrepareWrite prepare_write,
LogicalOutputPluginWriterWrite do_write,
LogicalOutputPluginWriterUpdateProgress update_progress);
--
2.27.0
----Next_Part(Thu_Oct__7_17_28_20_2021_531)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v18-0003-Remove-globals-readOff-readLen-and-readSegNo.patch"
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Subject: Re: [PATCH v18 2/5] Move page-reader out of XLogReadRecord().
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