greenplumn ginfast 源码
greenplumn ginfast 代码
文件路径：/src/backend/access/gin/ginfast.c
/*-------------------------------------------------------------------------
*
* ginfast.c
* Fast insert routines for the Postgres inverted index access method.
* Pending entries are stored in linear list of pages. Later on
* (typically during VACUUM), ginInsertCleanup() will be invoked to
* transfer pending entries into the regular index structure. This
* wins because bulk insertion is much more efficient than retail.
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/access/gin/ginfast.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/gin_private.h"
#include "access/ginxlog.h"
#include "access/xloginsert.h"
#include "access/xlog.h"
#include "commands/vacuum.h"
#include "catalog/pg_am.h"
#include "miscadmin.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/acl.h"
#include "postmaster/autovacuum.h"
#include "storage/indexfsm.h"
#include "storage/lmgr.h"
#include "storage/predicate.h"
#include "utils/builtins.h"
/* GUC parameter */
int gin_pending_list_limit = 0;
#define GIN_PAGE_FREESIZE \
( BLCKSZ - MAXALIGN(SizeOfPageHeaderData) - MAXALIGN(sizeof(GinPageOpaqueData)) )
typedef struct KeyArray
{
Datum *keys; /* expansible array */
GinNullCategory *categories; /* another expansible array */
int32 nvalues; /* current number of valid entries */
int32 maxvalues; /* allocated size of arrays */
} KeyArray;
/*
* Build a pending-list page from the given array of tuples, and write it out.
*
* Returns amount of free space left on the page.
*/
static int32
writeListPage(Relation index, Buffer buffer,
IndexTuple *tuples, int32 ntuples, BlockNumber rightlink)
{
Page page = BufferGetPage(buffer);
int32 i,
freesize,
size = 0;
OffsetNumber l,
off;
PGAlignedBlock workspace;
char *ptr;
START_CRIT_SECTION();
GinInitBuffer(buffer, GIN_LIST);
off = FirstOffsetNumber;
ptr = workspace.data;
for (i = 0; i < ntuples; i++)
{
int this_size = IndexTupleSize(tuples[i]);
memcpy(ptr, tuples[i], this_size);
ptr += this_size;
size += this_size;
l = PageAddItem(page, (Item) tuples[i], this_size, off, false, false);
if (l == InvalidOffsetNumber)
elog(ERROR, "failed to add item to index page in \"%s\"",
RelationGetRelationName(index));
off++;
}
Assert(size <= BLCKSZ); /* else we overran workspace */
GinPageGetOpaque(page)->rightlink = rightlink;
/*
* tail page may contain only whole row(s) or final part of row placed on
* previous pages (a "row" here meaning all the index tuples generated for
* one heap tuple)
*/
if (rightlink == InvalidBlockNumber)
{
GinPageSetFullRow(page);
GinPageGetOpaque(page)->maxoff = 1;
}
else
{
GinPageGetOpaque(page)->maxoff = 0;
}
MarkBufferDirty(buffer);
if (RelationNeedsWAL(index))
{
ginxlogInsertListPage data;
XLogRecPtr recptr;
data.rightlink = rightlink;
data.ntuples = ntuples;
XLogBeginInsert();
XLogRegisterData((char *) &data, sizeof(ginxlogInsertListPage));
XLogRegisterBuffer(0, buffer, REGBUF_WILL_INIT);
XLogRegisterBufData(0, workspace.data, size);
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_INSERT_LISTPAGE);
PageSetLSN(page, recptr);
}
/* get free space before releasing buffer */
freesize = PageGetExactFreeSpace(page);
UnlockReleaseBuffer(buffer);
END_CRIT_SECTION();
return freesize;
}
static void
makeSublist(Relation index, IndexTuple *tuples, int32 ntuples,
GinMetaPageData *res)
{
Buffer curBuffer = InvalidBuffer;
Buffer prevBuffer = InvalidBuffer;
int i,
size = 0,
tupsize;
int startTuple = 0;
Assert(ntuples > 0);
/*
* Split tuples into pages
*/
for (i = 0; i < ntuples; i++)
{
if (curBuffer == InvalidBuffer)
{
curBuffer = GinNewBuffer(index);
if (prevBuffer != InvalidBuffer)
{
res->nPendingPages++;
writeListPage(index, prevBuffer,
tuples + startTuple,
i - startTuple,
BufferGetBlockNumber(curBuffer));
}
else
{
res->head = BufferGetBlockNumber(curBuffer);
}
prevBuffer = curBuffer;
startTuple = i;
size = 0;
}
tupsize = MAXALIGN(IndexTupleSize(tuples[i])) + sizeof(ItemIdData);
if (size + tupsize > GinListPageSize)
{
/* won't fit, force a new page and reprocess */
i--;
curBuffer = InvalidBuffer;
}
else
{
size += tupsize;
}
}
/*
* Write last page
*/
res->tail = BufferGetBlockNumber(curBuffer);
res->tailFreeSize = writeListPage(index, curBuffer,
tuples + startTuple,
ntuples - startTuple,
InvalidBlockNumber);
res->nPendingPages++;
/* that was only one heap tuple */
res->nPendingHeapTuples = 1;
}
/*
* Write the index tuples contained in *collector into the index's
* pending list.
*
* Function guarantees that all these tuples will be inserted consecutively,
* preserving order
*/
void
ginHeapTupleFastInsert(GinState *ginstate, GinTupleCollector *collector)
{
Relation index = ginstate->index;
Buffer metabuffer;
Page metapage;
GinMetaPageData *metadata = NULL;
Buffer buffer = InvalidBuffer;
Page page = NULL;
ginxlogUpdateMeta data;
bool separateList = false;
bool needCleanup = false;
int cleanupSize;
bool needWal;
if (collector->ntuples == 0)
return;
needWal = RelationNeedsWAL(index);
data.node = index->rd_node;
data.ntuples = 0;
data.newRightlink = data.prevTail = InvalidBlockNumber;
metabuffer = ReadBuffer(index, GIN_METAPAGE_BLKNO);
metapage = BufferGetPage(metabuffer);
/*
* An insertion to the pending list could logically belong anywhere in the
* tree, so it conflicts with all serializable scans. All scans acquire a
* predicate lock on the metabuffer to represent that.
*/
CheckForSerializableConflictIn(index, NULL, metabuffer);
if (collector->sumsize + collector->ntuples * sizeof(ItemIdData) > GinListPageSize)
{
/*
* Total size is greater than one page => make sublist
*/
separateList = true;
}
else
{
LockBuffer(metabuffer, GIN_EXCLUSIVE);
metadata = GinPageGetMeta(metapage);
if (metadata->head == InvalidBlockNumber ||
collector->sumsize + collector->ntuples * sizeof(ItemIdData) > metadata->tailFreeSize)
{
/*
* Pending list is empty or total size is greater than freespace
* on tail page => make sublist
*
* We unlock metabuffer to keep high concurrency
*/
separateList = true;
LockBuffer(metabuffer, GIN_UNLOCK);
}
}
if (separateList)
{
/*
* We should make sublist separately and append it to the tail
*/
GinMetaPageData sublist;
memset(&sublist, 0, sizeof(GinMetaPageData));
makeSublist(index, collector->tuples, collector->ntuples, &sublist);
if (needWal)
XLogBeginInsert();
/*
* metapage was unlocked, see above
*/
LockBuffer(metabuffer, GIN_EXCLUSIVE);
metadata = GinPageGetMeta(metapage);
if (metadata->head == InvalidBlockNumber)
{
/*
* Main list is empty, so just insert sublist as main list
*/
START_CRIT_SECTION();
metadata->head = sublist.head;
metadata->tail = sublist.tail;
metadata->tailFreeSize = sublist.tailFreeSize;
metadata->nPendingPages = sublist.nPendingPages;
metadata->nPendingHeapTuples = sublist.nPendingHeapTuples;
}
else
{
/*
* Merge lists
*/
data.prevTail = metadata->tail;
data.newRightlink = sublist.head;
buffer = ReadBuffer(index, metadata->tail);
LockBuffer(buffer, GIN_EXCLUSIVE);
page = BufferGetPage(buffer);
Assert(GinPageGetOpaque(page)->rightlink == InvalidBlockNumber);
START_CRIT_SECTION();
GinPageGetOpaque(page)->rightlink = sublist.head;
MarkBufferDirty(buffer);
metadata->tail = sublist.tail;
metadata->tailFreeSize = sublist.tailFreeSize;
metadata->nPendingPages += sublist.nPendingPages;
metadata->nPendingHeapTuples += sublist.nPendingHeapTuples;
if (needWal)
XLogRegisterBuffer(1, buffer, REGBUF_STANDARD);
}
}
else
{
/*
* Insert into tail page. Metapage is already locked
*/
OffsetNumber l,
off;
int i,
tupsize;
char *ptr;
char *collectordata;
buffer = ReadBuffer(index, metadata->tail);
LockBuffer(buffer, GIN_EXCLUSIVE);
page = BufferGetPage(buffer);
off = (PageIsEmpty(page)) ? FirstOffsetNumber :
OffsetNumberNext(PageGetMaxOffsetNumber(page));
collectordata = ptr = (char *) palloc(collector->sumsize);
data.ntuples = collector->ntuples;
if (needWal)
XLogBeginInsert();
START_CRIT_SECTION();
/*
* Increase counter of heap tuples
*/
Assert(GinPageGetOpaque(page)->maxoff <= metadata->nPendingHeapTuples);
GinPageGetOpaque(page)->maxoff++;
metadata->nPendingHeapTuples++;
for (i = 0; i < collector->ntuples; i++)
{
tupsize = IndexTupleSize(collector->tuples[i]);
l = PageAddItem(page, (Item) collector->tuples[i], tupsize, off, false, false);
if (l == InvalidOffsetNumber)
elog(ERROR, "failed to add item to index page in \"%s\"",
RelationGetRelationName(index));
memcpy(ptr, collector->tuples[i], tupsize);
ptr += tupsize;
off++;
}
Assert((ptr - collectordata) <= collector->sumsize);
if (needWal)
{
XLogRegisterBuffer(1, buffer, REGBUF_STANDARD);
XLogRegisterBufData(1, collectordata, collector->sumsize);
}
metadata->tailFreeSize = PageGetExactFreeSpace(page);
MarkBufferDirty(buffer);
}
/*
* Set pd_lower just past the end of the metadata. This is essential,
* because without doing so, metadata will be lost if xlog.c compresses
* the page. (We must do this here because pre-v11 versions of PG did not
* set the metapage's pd_lower correctly, so a pg_upgraded index might
* contain the wrong value.)
*/
((PageHeader) metapage)->pd_lower =
((char *) metadata + sizeof(GinMetaPageData)) - (char *) metapage;
/*
* Write metabuffer, make xlog entry
*/
MarkBufferDirty(metabuffer);
if (needWal)
{
XLogRecPtr recptr;
memcpy(&data.metadata, metadata, sizeof(GinMetaPageData));
XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT | REGBUF_STANDARD);
XLogRegisterData((char *) &data, sizeof(ginxlogUpdateMeta));
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_UPDATE_META_PAGE);
PageSetLSN(metapage, recptr);
if (buffer != InvalidBuffer)
{
PageSetLSN(page, recptr);
}
}
if (buffer != InvalidBuffer)
UnlockReleaseBuffer(buffer);
/*
* Force pending list cleanup when it becomes too long. And,
* ginInsertCleanup could take significant amount of time, so we prefer to
* call it when it can do all the work in a single collection cycle. In
* non-vacuum mode, it shouldn't require maintenance_work_mem, so fire it
* while pending list is still small enough to fit into
* gin_pending_list_limit.
*
* ginInsertCleanup() should not be called inside our CRIT_SECTION.
*/
cleanupSize = GinGetPendingListCleanupSize(index);
if (metadata->nPendingPages * GIN_PAGE_FREESIZE > cleanupSize * 1024L)
needCleanup = true;
UnlockReleaseBuffer(metabuffer);
END_CRIT_SECTION();
/*
* Since it could contend with concurrent cleanup process we cleanup
* pending list not forcibly.
*/
if (needCleanup)
ginInsertCleanup(ginstate, false, true, false, NULL);
}
/*
* Create temporary index tuples for a single indexable item (one index column
* for the heap tuple specified by ht_ctid), and append them to the array
* in *collector. They will subsequently be written out using
* ginHeapTupleFastInsert. Note that to guarantee consistent state, all
* temp tuples for a given heap tuple must be written in one call to
* ginHeapTupleFastInsert.
*/
void
ginHeapTupleFastCollect(GinState *ginstate,
GinTupleCollector *collector,
OffsetNumber attnum, Datum value, bool isNull,
ItemPointer ht_ctid)
{
Datum *entries;
GinNullCategory *categories;
int32 i,
nentries;
/*
* Extract the key values that need to be inserted in the index
*/
entries = ginExtractEntries(ginstate, attnum, value, isNull,
&nentries, &categories);
/*
* Protect against integer overflow in allocation calculations
*/
if (nentries < 0 ||
collector->ntuples + nentries > MaxAllocSize / sizeof(IndexTuple))
elog(ERROR, "too many entries for GIN index");
/*
* Allocate/reallocate memory for storing collected tuples
*/
if (collector->tuples == NULL)
{
/*
* Determine the number of elements to allocate in the tuples array
* initially. Make it a power of 2 to avoid wasting memory when
* resizing (since palloc likes powers of 2).
*/
collector->lentuples = 16;
while (collector->lentuples < nentries)
collector->lentuples *= 2;
collector->tuples = (IndexTuple *) palloc(sizeof(IndexTuple) * collector->lentuples);
}
else if (collector->lentuples < collector->ntuples + nentries)
{
/*
* Advance lentuples to the next suitable power of 2. This won't
* overflow, though we could get to a value that exceeds
* MaxAllocSize/sizeof(IndexTuple), causing an error in repalloc.
*/
do
{
collector->lentuples *= 2;
} while (collector->lentuples < collector->ntuples + nentries);
collector->tuples = (IndexTuple *) repalloc(collector->tuples,
sizeof(IndexTuple) * collector->lentuples);
}
/*
* Build an index tuple for each key value, and add to array. In pending
* tuples we just stick the heap TID into t_tid.
*/
for (i = 0; i < nentries; i++)
{
IndexTuple itup;
itup = GinFormTuple(ginstate, attnum, entries[i], categories[i],
NULL, 0, 0, true);
itup->t_tid = *ht_ctid;
collector->tuples[collector->ntuples++] = itup;
collector->sumsize += IndexTupleSize(itup);
}
}
/*
* Deletes pending list pages up to (not including) newHead page.
* If newHead == InvalidBlockNumber then function drops the whole list.
*
* metapage is pinned and exclusive-locked throughout this function.
*/
static void
shiftList(Relation index, Buffer metabuffer, BlockNumber newHead,
bool fill_fsm, IndexBulkDeleteResult *stats)
{
Page metapage;
GinMetaPageData *metadata;
BlockNumber blknoToDelete;
metapage = BufferGetPage(metabuffer);
metadata = GinPageGetMeta(metapage);
blknoToDelete = metadata->head;
do
{
Page page;
int i;
int64 nDeletedHeapTuples = 0;
ginxlogDeleteListPages data;
Buffer buffers[GIN_NDELETE_AT_ONCE];
BlockNumber freespace[GIN_NDELETE_AT_ONCE];
data.ndeleted = 0;
while (data.ndeleted < GIN_NDELETE_AT_ONCE && blknoToDelete != newHead)
{
freespace[data.ndeleted] = blknoToDelete;
buffers[data.ndeleted] = ReadBuffer(index, blknoToDelete);
LockBuffer(buffers[data.ndeleted], GIN_EXCLUSIVE);
page = BufferGetPage(buffers[data.ndeleted]);
data.ndeleted++;
Assert(!GinPageIsDeleted(page));
nDeletedHeapTuples += GinPageGetOpaque(page)->maxoff;
blknoToDelete = GinPageGetOpaque(page)->rightlink;
}
if (stats)
stats->pages_deleted += data.ndeleted;
/*
* This operation touches an unusually large number of pages, so
* prepare the XLogInsert machinery for that before entering the
* critical section.
*/
if (RelationNeedsWAL(index))
XLogEnsureRecordSpace(data.ndeleted, 0);
START_CRIT_SECTION();
metadata->head = blknoToDelete;
Assert(metadata->nPendingPages >= data.ndeleted);
metadata->nPendingPages -= data.ndeleted;
Assert(metadata->nPendingHeapTuples >= nDeletedHeapTuples);
metadata->nPendingHeapTuples -= nDeletedHeapTuples;
if (blknoToDelete == InvalidBlockNumber)
{
metadata->tail = InvalidBlockNumber;
metadata->tailFreeSize = 0;
metadata->nPendingPages = 0;
metadata->nPendingHeapTuples = 0;
}
/*
* Set pd_lower just past the end of the metadata. This is essential,
* because without doing so, metadata will be lost if xlog.c
* compresses the page. (We must do this here because pre-v11
* versions of PG did not set the metapage's pd_lower correctly, so a
* pg_upgraded index might contain the wrong value.)
*/
((PageHeader) metapage)->pd_lower =
((char *) metadata + sizeof(GinMetaPageData)) - (char *) metapage;
MarkBufferDirty(metabuffer);
for (i = 0; i < data.ndeleted; i++)
{
page = BufferGetPage(buffers[i]);
GinPageGetOpaque(page)->flags = GIN_DELETED;
MarkBufferDirty(buffers[i]);
}
if (RelationNeedsWAL(index))
{
XLogRecPtr recptr;
XLogBeginInsert();
XLogRegisterBuffer(0, metabuffer,
REGBUF_WILL_INIT | REGBUF_STANDARD);
for (i = 0; i < data.ndeleted; i++)
XLogRegisterBuffer(i + 1, buffers[i], REGBUF_WILL_INIT);
memcpy(&data.metadata, metadata, sizeof(GinMetaPageData));
XLogRegisterData((char *) &data,
sizeof(ginxlogDeleteListPages));
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_DELETE_LISTPAGE);
PageSetLSN(metapage, recptr);
for (i = 0; i < data.ndeleted; i++)
{
page = BufferGetPage(buffers[i]);
PageSetLSN(page, recptr);
}
}
for (i = 0; i < data.ndeleted; i++)
UnlockReleaseBuffer(buffers[i]);
END_CRIT_SECTION();
for (i = 0; fill_fsm && i < data.ndeleted; i++)
RecordFreeIndexPage(index, freespace[i]);
} while (blknoToDelete != newHead);
}
/* Initialize empty KeyArray */
static void
initKeyArray(KeyArray *keys, int32 maxvalues)
{
keys->keys = (Datum *) palloc(sizeof(Datum) * maxvalues);
keys->categories = (GinNullCategory *)
palloc(sizeof(GinNullCategory) * maxvalues);
keys->nvalues = 0;
keys->maxvalues = maxvalues;
}
/* Add datum to KeyArray, resizing if needed */
static void
addDatum(KeyArray *keys, Datum datum, GinNullCategory category)
{
if (keys->nvalues >= keys->maxvalues)
{
keys->maxvalues *= 2;
keys->keys = (Datum *)
repalloc(keys->keys, sizeof(Datum) * keys->maxvalues);
keys->categories = (GinNullCategory *)
repalloc(keys->categories, sizeof(GinNullCategory) * keys->maxvalues);
}
keys->keys[keys->nvalues] = datum;
keys->categories[keys->nvalues] = category;
keys->nvalues++;
}
/*
* Collect data from a pending-list page in preparation for insertion into
* the main index.
*
* Go through all tuples >= startoff on page and collect values in accum
*
* Note that ka is just workspace --- it does not carry any state across
* calls.
*/
static void
processPendingPage(BuildAccumulator *accum, KeyArray *ka,
Page page, OffsetNumber startoff)
{
ItemPointerData heapptr;
OffsetNumber i,
maxoff;
OffsetNumber attrnum;
/* reset *ka to empty */
ka->nvalues = 0;
maxoff = PageGetMaxOffsetNumber(page);
Assert(maxoff >= FirstOffsetNumber);
ItemPointerSetInvalid(&heapptr);
attrnum = 0;
for (i = startoff; i <= maxoff; i = OffsetNumberNext(i))
{
IndexTuple itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, i));
OffsetNumber curattnum;
Datum curkey;
GinNullCategory curcategory;
/* Check for change of heap TID or attnum */
curattnum = gintuple_get_attrnum(accum->ginstate, itup);
if (!ItemPointerIsValid(&heapptr))
{
heapptr = itup->t_tid;
attrnum = curattnum;
}
else if (!(ItemPointerEquals(&heapptr, &itup->t_tid) &&
curattnum == attrnum))
{
/*
* ginInsertBAEntries can insert several datums per call, but only
* for one heap tuple and one column. So call it at a boundary,
* and reset ka.
*/
ginInsertBAEntries(accum, &heapptr, attrnum,
ka->keys, ka->categories, ka->nvalues);
ka->nvalues = 0;
heapptr = itup->t_tid;
attrnum = curattnum;
}
/* Add key to KeyArray */
curkey = gintuple_get_key(accum->ginstate, itup, &curcategory);
addDatum(ka, curkey, curcategory);
}
/* Dump out all remaining keys */
ginInsertBAEntries(accum, &heapptr, attrnum,
ka->keys, ka->categories, ka->nvalues);
}
/*
* Move tuples from pending pages into regular GIN structure.
*
* On first glance it looks completely not crash-safe. But if we crash
* after posting entries to the main index and before removing them from the
* pending list, it's okay because when we redo the posting later on, nothing
* bad will happen.
*
* fill_fsm indicates that ginInsertCleanup should add deleted pages
* to FSM otherwise caller is responsible to put deleted pages into
* FSM.
*
* If stats isn't null, we count deleted pending pages into the counts.
*/
void
ginInsertCleanup(GinState *ginstate, bool full_clean,
bool fill_fsm, bool forceCleanup,
IndexBulkDeleteResult *stats)
{
Relation index = ginstate->index;
Buffer metabuffer,
buffer;
Page metapage,
page;
GinMetaPageData *metadata;
MemoryContext opCtx,
oldCtx;
BuildAccumulator accum;
KeyArray datums;
BlockNumber blkno,
blknoFinish;
bool cleanupFinish = false;
bool fsm_vac = false;
Size workMemory;
/*
* We would like to prevent concurrent cleanup process. For that we will
* lock metapage in exclusive mode using LockPage() call. Nobody other
* will use that lock for metapage, so we keep possibility of concurrent
* insertion into pending list
*/
if (forceCleanup)
{
/*
* We are called from [auto]vacuum/analyze or gin_clean_pending_list()
* and we would like to wait concurrent cleanup to finish.
*/
LockPage(index, GIN_METAPAGE_BLKNO, ExclusiveLock);
workMemory =
(IsAutoVacuumWorkerProcess() && autovacuum_work_mem != -1) ?
autovacuum_work_mem : maintenance_work_mem;
}
else
{
/*
* We are called from regular insert and if we see concurrent cleanup
* just exit in hope that concurrent process will clean up pending
* list.
*/
if (!ConditionalLockPage(index, GIN_METAPAGE_BLKNO, ExclusiveLock))
return;
workMemory = work_mem;
}
metabuffer = ReadBuffer(index, GIN_METAPAGE_BLKNO);
LockBuffer(metabuffer, GIN_SHARE);
metapage = BufferGetPage(metabuffer);
metadata = GinPageGetMeta(metapage);
if (metadata->head == InvalidBlockNumber)
{
/* Nothing to do */
UnlockReleaseBuffer(metabuffer);
UnlockPage(index, GIN_METAPAGE_BLKNO, ExclusiveLock);
return;
}
/*
* Remember a tail page to prevent infinite cleanup if other backends add
* new tuples faster than we can cleanup.
*/
blknoFinish = metadata->tail;
/*
* Read and lock head of pending list
*/
blkno = metadata->head;
buffer = ReadBuffer(index, blkno);
LockBuffer(buffer, GIN_SHARE);
page = BufferGetPage(buffer);
LockBuffer(metabuffer, GIN_UNLOCK);
/*
* Initialize. All temporary space will be in opCtx
*/
opCtx = AllocSetContextCreate(CurrentMemoryContext,
"GIN insert cleanup temporary context",
ALLOCSET_DEFAULT_SIZES);
oldCtx = MemoryContextSwitchTo(opCtx);
initKeyArray(&datums, 128);
ginInitBA(&accum);
accum.ginstate = ginstate;
/*
* At the top of this loop, we have pin and lock on the current page of
* the pending list. However, we'll release that before exiting the loop.
* Note we also have pin but not lock on the metapage.
*/
for (;;)
{
Assert(!GinPageIsDeleted(page));
/*
* Are we walk through the page which as we remember was a tail when
* we start our cleanup? But if caller asks us to clean up whole
* pending list then ignore old tail, we will work until list becomes
* empty.
*/
if (blkno == blknoFinish && full_clean == false)
cleanupFinish = true;
/*
* read page's datums into accum
*/
processPendingPage(&accum, &datums, page, FirstOffsetNumber);
vacuum_delay_point();
/*
* Is it time to flush memory to disk? Flush if we are at the end of
* the pending list, or if we have a full row and memory is getting
* full.
*/
if (GinPageGetOpaque(page)->rightlink == InvalidBlockNumber ||
(GinPageHasFullRow(page) &&
(accum.allocatedMemory >= workMemory * 1024L)))
{
ItemPointerData *list;
uint32 nlist;
Datum key;
GinNullCategory category;
OffsetNumber maxoff,
attnum;
/*
* Unlock current page to increase performance. Changes of page
* will be checked later by comparing maxoff after completion of
* memory flush.
*/
maxoff = PageGetMaxOffsetNumber(page);
LockBuffer(buffer, GIN_UNLOCK);
/*
* Moving collected data into regular structure can take
* significant amount of time - so, run it without locking pending
* list.
*/
ginBeginBAScan(&accum);
while ((list = ginGetBAEntry(&accum,
&attnum, &key, &category, &nlist)) != NULL)
{
ginEntryInsert(ginstate, attnum, key, category,
list, nlist, NULL);
vacuum_delay_point();
}
/*
* Lock the whole list to remove pages
*/
LockBuffer(metabuffer, GIN_EXCLUSIVE);
LockBuffer(buffer, GIN_SHARE);
Assert(!GinPageIsDeleted(page));
/*
* While we left the page unlocked, more stuff might have gotten
* added to it. If so, process those entries immediately. There
* shouldn't be very many, so we don't worry about the fact that
* we're doing this with exclusive lock. Insertion algorithm
* guarantees that inserted row(s) will not continue on next page.
* NOTE: intentionally no vacuum_delay_point in this loop.
*/
if (PageGetMaxOffsetNumber(page) != maxoff)
{
ginInitBA(&accum);
processPendingPage(&accum, &datums, page, maxoff + 1);
ginBeginBAScan(&accum);
while ((list = ginGetBAEntry(&accum,
&attnum, &key, &category, &nlist)) != NULL)
ginEntryInsert(ginstate, attnum, key, category,
list, nlist, NULL);
}
/*
* Remember next page - it will become the new list head
*/
blkno = GinPageGetOpaque(page)->rightlink;
UnlockReleaseBuffer(buffer); /* shiftList will do exclusive
* locking */
/*
* remove read pages from pending list, at this point all content
* of read pages is in regular structure
*/
shiftList(index, metabuffer, blkno, fill_fsm, stats);
/* At this point, some pending pages have been freed up */
fsm_vac = true;
Assert(blkno == metadata->head);
LockBuffer(metabuffer, GIN_UNLOCK);
/*
* if we removed the whole pending list or we cleanup tail (which
* we remembered on start our cleanup process) then just exit
*/
if (blkno == InvalidBlockNumber || cleanupFinish)
break;
/*
* release memory used so far and reinit state
*/
MemoryContextReset(opCtx);
initKeyArray(&datums, datums.maxvalues);
ginInitBA(&accum);
}
else
{
blkno = GinPageGetOpaque(page)->rightlink;
UnlockReleaseBuffer(buffer);
}
/*
* Read next page in pending list
*/
vacuum_delay_point();
buffer = ReadBuffer(index, blkno);
LockBuffer(buffer, GIN_SHARE);
page = BufferGetPage(buffer);
}
UnlockPage(index, GIN_METAPAGE_BLKNO, ExclusiveLock);
ReleaseBuffer(metabuffer);
/*
* As pending list pages can have a high churn rate, it is desirable to
* recycle them immediately to the FreeSpace Map when ordinary backends
* clean the list.
*/
if (fsm_vac && fill_fsm)
IndexFreeSpaceMapVacuum(index);
/* Clean up temporary space */
MemoryContextSwitchTo(oldCtx);
MemoryContextDelete(opCtx);
}
/*
* SQL-callable function to clean the insert pending list
*/
Datum
gin_clean_pending_list(PG_FUNCTION_ARGS)
{
Oid indexoid = PG_GETARG_OID(0);
Relation indexRel = index_open(indexoid, RowExclusiveLock);
IndexBulkDeleteResult stats;
GinState ginstate;
if (RecoveryInProgress())
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("recovery is in progress"),
errhint("GIN pending list cannot be cleaned up during recovery.")));
/* Must be a GIN index */
if (indexRel->rd_rel->relkind != RELKIND_INDEX ||
indexRel->rd_rel->relam != GIN_AM_OID)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a GIN index",
RelationGetRelationName(indexRel))));
/*
* Reject attempts to read non-local temporary relations; we would be
* likely to get wrong data since we have no visibility into the owning
* session's local buffers.
*/
if (RELATION_IS_OTHER_TEMP(indexRel))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot access temporary indexes of other sessions")));
/* User must own the index (comparable to privileges needed for VACUUM) */
if (!pg_class_ownercheck(indexoid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
RelationGetRelationName(indexRel));
memset(&stats, 0, sizeof(stats));
initGinState(&ginstate, indexRel);
ginInsertCleanup(&ginstate, true, true, true, &stats);
index_close(indexRel, RowExclusiveLock);
PG_RETURN_INT64((int64) stats.pages_deleted);
}
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