database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-07 19:06:32 +03:00
Code Activity

Revamp the WAL record format.

Browse Source 
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.

There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.

This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.

For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.

The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.

Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
This commit is contained in:
Heikki Linnakangas
2014-11-20 17:56:26 +02:00
parent 8dc626defe
commit 2c03216d83
93 changed files with 3945 additions and 4366 deletions
Download Patch File Download Diff File Expand all files Collapse all files

111
src/backend/access/brin/brin_xlog.c
View File

@@ -20,17 +20,15 @@
* xlog replay routines
*/
static void
brin_xlog_createidx(XLogRecPtr lsn, XLogRecord *record)
brin_xlog_createidx(XLogReaderState *record)
{
XLogRecPtr lsn = record->EndRecPtr;
xl_brin_createidx *xlrec = (xl_brin_createidx *) XLogRecGetData(record);
Buffer buf;
Page page;
/* Backup blocks are not used in create_index records */
Assert(!(record->xl_info & XLR_BKP_BLOCK_MASK));
/* create the index' metapage */
buf = XLogReadBuffer(xlrec->node, BRIN_METAPAGE_BLKNO, true);
buf = XLogInitBufferForRedo(record, 0);
Assert(BufferIsValid(buf));
page = (Page) BufferGetPage(buf);
brin_metapage_init(page, xlrec->pagesPerRange, xlrec->version);
@@ -44,51 +42,47 @@ brin_xlog_createidx(XLogRecPtr lsn, XLogRecord *record)
* revmap.
*/
static void
brin_xlog_insert_update(XLogRecPtr lsn, XLogRecord *record,
xl_brin_insert *xlrec, BrinTuple *tuple)
brin_xlog_insert_update(XLogReaderState *record,
xl_brin_insert *xlrec)
{
BlockNumber blkno;
XLogRecPtr lsn = record->EndRecPtr;
Buffer buffer;
Page page;
XLogRedoAction action;
blkno = ItemPointerGetBlockNumber(&xlrec->tid);
/*
* If we inserted the first and only tuple on the page, re-initialize the
* page from scratch.
*/
if (record->xl_info & XLOG_BRIN_INIT_PAGE)
if (XLogRecGetInfo(record) & XLOG_BRIN_INIT_PAGE)
{
/*
* No full-page image here. Don't try to read it, because there
* might be one for the revmap buffer, below.
*/
buffer = XLogReadBuffer(xlrec->node, blkno, true);
buffer = XLogInitBufferForRedo(record, 0);
page = BufferGetPage(buffer);
brin_page_init(page, BRIN_PAGETYPE_REGULAR);
action = BLK_NEEDS_REDO;
}
else
{
action = XLogReadBufferForRedo(lsn, record, 0,
xlrec->node, blkno, &buffer);
action = XLogReadBufferForRedo(record, 0, &buffer);
}
/* insert the index item into the page */
if (action == BLK_NEEDS_REDO)
{
OffsetNumber offnum;
BrinTuple *tuple;
Size tuplen;
tuple = (BrinTuple *) XLogRecGetBlockData(record, 0, &tuplen);
Assert(tuple->bt_blkno == xlrec->heapBlk);
page = (Page) BufferGetPage(buffer);
offnum = ItemPointerGetOffsetNumber(&(xlrec->tid));
offnum = xlrec->offnum;
if (PageGetMaxOffsetNumber(page) + 1 < offnum)
elog(PANIC, "brin_xlog_insert_update: invalid max offset number");
offnum = PageAddItem(page, (Item) tuple, xlrec->tuplen, offnum, true,
false);
offnum = PageAddItem(page, (Item) tuple, tuplen, offnum, true, false);
if (offnum == InvalidOffsetNumber)
elog(PANIC, "brin_xlog_insert_update: failed to add tuple");
@@ -99,16 +93,17 @@ brin_xlog_insert_update(XLogRecPtr lsn, XLogRecord *record,
UnlockReleaseBuffer(buffer);
/* update the revmap */
action = XLogReadBufferForRedo(lsn, record,
record->xl_info & XLOG_BRIN_INIT_PAGE ? 0 : 1,
xlrec->node,
xlrec->revmapBlk, &buffer);
action = XLogReadBufferForRedo(record, 1, &buffer);
if (action == BLK_NEEDS_REDO)
{
ItemPointerData tid;
BlockNumber blkno = BufferGetBlockNumber(buffer);
ItemPointerSet(&tid, blkno, xlrec->offnum);
page = (Page) BufferGetPage(buffer);
brinSetHeapBlockItemptr(buffer, xlrec->pagesPerRange, xlrec->heapBlk,
xlrec->tid);
tid);
PageSetLSN(page, lsn);
MarkBufferDirty(buffer);
}
@@ -122,34 +117,26 @@ brin_xlog_insert_update(XLogRecPtr lsn, XLogRecord *record,
* replay a BRIN index insertion
*/
static void
brin_xlog_insert(XLogRecPtr lsn, XLogRecord *record)
brin_xlog_insert(XLogReaderState *record)
{
xl_brin_insert *xlrec = (xl_brin_insert *) XLogRecGetData(record);
BrinTuple *newtup;
newtup = (BrinTuple *) ((char *) xlrec + SizeOfBrinInsert);
brin_xlog_insert_update(lsn, record, xlrec, newtup);
brin_xlog_insert_update(record, xlrec);
}
/*
* replay a BRIN index update
*/
static void
brin_xlog_update(XLogRecPtr lsn, XLogRecord *record)
brin_xlog_update(XLogReaderState *record)
{
XLogRecPtr lsn = record->EndRecPtr;
xl_brin_update *xlrec = (xl_brin_update *) XLogRecGetData(record);
BlockNumber blkno;
Buffer buffer;
BrinTuple *newtup;
XLogRedoAction action;
newtup = (BrinTuple *) ((char *) xlrec + SizeOfBrinUpdate);
/* First remove the old tuple */
blkno = ItemPointerGetBlockNumber(&(xlrec->oldtid));
action = XLogReadBufferForRedo(lsn, record, 2, xlrec->insert.node,
blkno, &buffer);
action = XLogReadBufferForRedo(record, 2, &buffer);
if (action == BLK_NEEDS_REDO)
{
Page page;
@@ -157,7 +144,7 @@ brin_xlog_update(XLogRecPtr lsn, XLogRecord *record)
page = (Page) BufferGetPage(buffer);
offnum = ItemPointerGetOffsetNumber(&(xlrec->oldtid));
offnum = xlrec->oldOffnum;
if (PageGetMaxOffsetNumber(page) + 1 < offnum)
elog(PANIC, "brin_xlog_update: invalid max offset number");
@@ -168,7 +155,7 @@ brin_xlog_update(XLogRecPtr lsn, XLogRecord *record)
}
/* Then insert the new tuple and update revmap, like in an insertion. */
brin_xlog_insert_update(lsn, record, &xlrec->insert, newtup);
brin_xlog_insert_update(record, &xlrec->insert);
if (BufferIsValid(buffer))
UnlockReleaseBuffer(buffer);
@@ -178,30 +165,27 @@ brin_xlog_update(XLogRecPtr lsn, XLogRecord *record)
* Update a tuple on a single page.
*/
static void
brin_xlog_samepage_update(XLogRecPtr lsn, XLogRecord *record)
brin_xlog_samepage_update(XLogReaderState *record)
{
XLogRecPtr lsn = record->EndRecPtr;
xl_brin_samepage_update *xlrec;
BlockNumber blkno;
Buffer buffer;
XLogRedoAction action;
xlrec = (xl_brin_samepage_update *) XLogRecGetData(record);
blkno = ItemPointerGetBlockNumber(&(xlrec->tid));
action = XLogReadBufferForRedo(lsn, record, 0, xlrec->node, blkno,
&buffer);
action = XLogReadBufferForRedo(record, 0, &buffer);
if (action == BLK_NEEDS_REDO)
{
int tuplen;
Size tuplen;
BrinTuple *mmtuple;
Page page;
OffsetNumber offnum;
tuplen = record->xl_len - SizeOfBrinSamepageUpdate;
mmtuple = (BrinTuple *) ((char *) xlrec + SizeOfBrinSamepageUpdate);
mmtuple = (BrinTuple *) XLogRecGetBlockData(record, 0, &tuplen);
page = (Page) BufferGetPage(buffer);
offnum = ItemPointerGetOffsetNumber(&(xlrec->tid));
offnum = xlrec->offnum;
if (PageGetMaxOffsetNumber(page) + 1 < offnum)
elog(PANIC, "brin_xlog_samepage_update: invalid max offset number");
@@ -223,18 +207,23 @@ brin_xlog_samepage_update(XLogRecPtr lsn, XLogRecord *record)
* Replay a revmap page extension
*/
static void
brin_xlog_revmap_extend(XLogRecPtr lsn, XLogRecord *record)
brin_xlog_revmap_extend(XLogReaderState *record)
{
XLogRecPtr lsn = record->EndRecPtr;
xl_brin_revmap_extend *xlrec;
Buffer metabuf;
Buffer buf;
Page page;
BlockNumber targetBlk;
XLogRedoAction action;
xlrec = (xl_brin_revmap_extend *) XLogRecGetData(record);
XLogRecGetBlockTag(record, 1, NULL, NULL, &targetBlk);
Assert(xlrec->targetBlk == targetBlk);
/* Update the metapage */
action = XLogReadBufferForRedo(lsn, record, 0, xlrec->node,
BRIN_METAPAGE_BLKNO, &metabuf);
action = XLogReadBufferForRedo(record, 0, &metabuf);
if (action == BLK_NEEDS_REDO)
{
Page metapg;
@@ -255,7 +244,7 @@ brin_xlog_revmap_extend(XLogRecPtr lsn, XLogRecord *record)
* image here.
*/
buf = XLogReadBuffer(xlrec->node, xlrec->targetBlk, true);
buf = XLogInitBufferForRedo(record, 1);
page = (Page) BufferGetPage(buf);
brin_page_init(page, BRIN_PAGETYPE_REVMAP);
@@ -268,26 +257,26 @@ brin_xlog_revmap_extend(XLogRecPtr lsn, XLogRecord *record)
}
void
brin_redo(XLogRecPtr lsn, XLogRecord *record)
brin_redo(XLogReaderState *record)
{
uint8 info = record->xl_info & ~XLR_INFO_MASK;
uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
switch (info & XLOG_BRIN_OPMASK)
{
case XLOG_BRIN_CREATE_INDEX:
brin_xlog_createidx(lsn, record);
brin_xlog_createidx(record);
break;
case XLOG_BRIN_INSERT:
brin_xlog_insert(lsn, record);
brin_xlog_insert(record);
break;
case XLOG_BRIN_UPDATE:
brin_xlog_update(lsn, record);
brin_xlog_update(record);
break;
case XLOG_BRIN_SAMEPAGE_UPDATE:
brin_xlog_samepage_update(lsn, record);
brin_xlog_samepage_update(record);
break;
case XLOG_BRIN_REVMAP_EXTEND:
brin_xlog_revmap_extend(lsn, record);
brin_xlog_revmap_extend(record);
break;
default:
elog(PANIC, "brin_redo: unknown op code %u", info);