/*
* replay addition of overflow page for hash index
*/
static void
hash_xlog_add_ovfl_page(XLogReaderState *record)
{
XLogRecPtr lsn = record->EndRecPtr;
xl_hash_add_ovfl_page *xlrec = (xl_hash_add_ovfl_page *) XLogRecGetData(record);
Buffer leftbuf;
Buffer ovflbuf;
Buffer metabuf;
BlockNumber leftblk;
BlockNumber rightblk;
BlockNumber newmapblk = InvalidBlockNumber;
Page ovflpage;
HashPageOpaque ovflopaque;
uint32 *num_bucket;
char *data;
Size datalen PG_USED_FOR_ASSERTS_ONLY;
bool new_bmpage = false;
XLogRecGetBlockTag(record, 0, NULL, NULL, &rightblk);
XLogRecGetBlockTag(record, 1, NULL, NULL, &leftblk);
ovflbuf = XLogInitBufferForRedo(record, 0);
Assert(BufferIsValid(ovflbuf));
data = XLogRecGetBlockData(record, 0, &datalen);
num_bucket = (uint32 *) data;
Assert(datalen == sizeof(uint32));
_hash_initbuf(ovflbuf, InvalidBlockNumber, *num_bucket, LH_OVERFLOW_PAGE,
true);
/* update backlink */
ovflpage = BufferGetPage(ovflbuf);
ovflopaque = (HashPageOpaque) PageGetSpecialPointer(ovflpage);
ovflopaque->hasho_prevblkno = leftblk;
PageSetLSN(ovflpage, lsn);
MarkBufferDirty(ovflbuf);
if (XLogReadBufferForRedo(record, 1, &leftbuf) == BLK_NEEDS_REDO)
{
Page leftpage;
HashPageOpaque leftopaque;
leftpage = BufferGetPage(leftbuf);
leftopaque = (HashPageOpaque) PageGetSpecialPointer(leftpage);
leftopaque->hasho_nextblkno = rightblk;
PageSetLSN(leftpage, lsn);
MarkBufferDirty(leftbuf);
}
if (BufferIsValid(leftbuf))
UnlockReleaseBuffer(leftbuf);
UnlockReleaseBuffer(ovflbuf);
/*
* Note: in normal operation, we'd update the bitmap and meta page while
* still holding lock on the overflow pages. But during replay it's not
* necessary to hold those locks, since no other index updates can be
* happening concurrently.
*/
if (XLogRecHasBlockRef(record, 2))
{
Buffer mapbuffer;
if (XLogReadBufferForRedo(record, 2, &mapbuffer) == BLK_NEEDS_REDO)
{
Page mappage = (Page) BufferGetPage(mapbuffer);
uint32 *freep = NULL;
char *data;
uint32 *bitmap_page_bit;
freep = HashPageGetBitmap(mappage);
data = XLogRecGetBlockData(record, 2, &datalen);
bitmap_page_bit = (uint32 *) data;
SETBIT(freep, *bitmap_page_bit);
PageSetLSN(mappage, lsn);
MarkBufferDirty(mapbuffer);
}
if (BufferIsValid(mapbuffer))
UnlockReleaseBuffer(mapbuffer);
}
if (XLogRecHasBlockRef(record, 3))
{
Buffer newmapbuf;
newmapbuf = XLogInitBufferForRedo(record, 3);
_hash_initbitmapbuffer(newmapbuf, xlrec->bmsize, true);
new_bmpage = true;
newmapblk = BufferGetBlockNumber(newmapbuf);
MarkBufferDirty(newmapbuf);
PageSetLSN(BufferGetPage(newmapbuf), lsn);
UnlockReleaseBuffer(newmapbuf);
}
if (XLogReadBufferForRedo(record, 4, &metabuf) == BLK_NEEDS_REDO)
{
HashMetaPage metap;
Page page;
uint32 *firstfree_ovflpage;
data = XLogRecGetBlockData(record, 4, &datalen);
firstfree_ovflpage = (uint32 *) data;
page = BufferGetPage(metabuf);
metap = HashPageGetMeta(page);
metap->hashm_firstfree = *firstfree_ovflpage;
if (!xlrec->bmpage_found)
{
metap->hashm_spares[metap->hashm_ovflpoint]++;
if (new_bmpage)
{
Assert(BlockNumberIsValid(newmapblk));
metap->hashm_mapp[metap->hashm_nmaps] = newmapblk;
metap->hashm_nmaps++;
metap->hashm_spares[metap->hashm_ovflpoint]++;
}
}
PageSetLSN(page, lsn);
MarkBufferDirty(metabuf);
}
if (BufferIsValid(metabuf))
UnlockReleaseBuffer(metabuf);
}
/*
* replay allocation of page for split operation
*/
static void
hash_xlog_split_allocate_page(XLogReaderState *record)
{
XLogRecPtr lsn = record->EndRecPtr;
xl_hash_split_allocate_page *xlrec = (xl_hash_split_allocate_page *) XLogRecGetData(record);
Buffer oldbuf;
Buffer newbuf;
Buffer metabuf;
Size datalen PG_USED_FOR_ASSERTS_ONLY;
char *data;
XLogRedoAction action;
/*
* To be consistent with normal operation, here we take cleanup locks on
* both the old and new buckets even though there can't be any concurrent
* inserts.
*/
/* replay the record for old bucket */
action = XLogReadBufferForRedoExtended(record, 0, RBM_NORMAL, true, &oldbuf);
/*
* Note that we still update the page even if it was restored from a full
* page image, because the special space is not included in the image.
*/
if (action == BLK_NEEDS_REDO || action == BLK_RESTORED)
{
Page oldpage;
HashPageOpaque oldopaque;
oldpage = BufferGetPage(oldbuf);
oldopaque = (HashPageOpaque) PageGetSpecialPointer(oldpage);
oldopaque->hasho_flag = xlrec->old_bucket_flag;
oldopaque->hasho_prevblkno = xlrec->new_bucket;
PageSetLSN(oldpage, lsn);
MarkBufferDirty(oldbuf);
}
/* replay the record for new bucket */
newbuf = XLogInitBufferForRedo(record, 1);
_hash_initbuf(newbuf, xlrec->new_bucket, xlrec->new_bucket,
xlrec->new_bucket_flag, true);
if (!IsBufferCleanupOK(newbuf))
elog(PANIC, "hash_xlog_split_allocate_page: failed to acquire cleanup lock");
MarkBufferDirty(newbuf);
PageSetLSN(BufferGetPage(newbuf), lsn);
/*
* We can release the lock on old bucket early as well but doing here to
* consistent with normal operation.
*/
if (BufferIsValid(oldbuf))
UnlockReleaseBuffer(oldbuf);
if (BufferIsValid(newbuf))
UnlockReleaseBuffer(newbuf);
/*
* Note: in normal operation, we'd update the meta page while still
* holding lock on the old and new bucket pages. But during replay it's
* not necessary to hold those locks, since no other bucket splits can be
* happening concurrently.
*/
/* replay the record for metapage changes */
if (XLogReadBufferForRedo(record, 2, &metabuf) == BLK_NEEDS_REDO)
{
Page page;
HashMetaPage metap;
page = BufferGetPage(metabuf);
metap = HashPageGetMeta(page);
metap->hashm_maxbucket = xlrec->new_bucket;
data = XLogRecGetBlockData(record, 2, &datalen);
if (xlrec->flags & XLH_SPLIT_META_UPDATE_MASKS)
{
uint32 lowmask;
uint32 *highmask;
/* extract low and high masks. */
memcpy(&lowmask, data, sizeof(uint32));
highmask = (uint32 *) ((char *) data + sizeof(uint32));
/* update metapage */
metap->hashm_lowmask = lowmask;
metap->hashm_highmask = *highmask;
data += sizeof(uint32) * 2;
}
if (xlrec->flags & XLH_SPLIT_META_UPDATE_SPLITPOINT)
{
uint32 ovflpoint;
uint32 *ovflpages;
/* extract information of overflow pages. */
memcpy(&ovflpoint, data, sizeof(uint32));
ovflpages = (uint32 *) ((char *) data + sizeof(uint32));
/* update metapage */
metap->hashm_spares[ovflpoint] = *ovflpages;
metap->hashm_ovflpoint = ovflpoint;
}
MarkBufferDirty(metabuf);
PageSetLSN(BufferGetPage(metabuf), lsn);
}
if (BufferIsValid(metabuf))
UnlockReleaseBuffer(metabuf);
}
/*
* _hash_init() -- Initialize the metadata page of a hash index,
* the initial buckets, and the initial bitmap page.
*
* The initial number of buckets is dependent on num_tuples, an estimate
* of the number of tuples to be loaded into the index initially. The
* chosen number of buckets is returned.
*
* We are fairly cavalier about locking here, since we know that no one else
* could be accessing this index. In particular the rule about not holding
* multiple buffer locks is ignored.
*/
uint32
_hash_init(Relation rel, double num_tuples, ForkNumber forkNum)
{
Buffer metabuf;
Buffer buf;
Buffer bitmapbuf;
Page pg;
HashMetaPage metap;
RegProcedure procid;
int32 data_width;
int32 item_width;
int32 ffactor;
uint32 num_buckets;
uint32 i;
bool use_wal;
/* safety check */
if (RelationGetNumberOfBlocksInFork(rel, forkNum) != 0)
elog(ERROR, "cannot initialize non-empty hash index \"%s\"",
RelationGetRelationName(rel));
/*
* WAL log creation of pages if the relation is persistent, or this is the
* init fork. Init forks for unlogged relations always need to be WAL
* logged.
*/
use_wal = RelationNeedsWAL(rel) || forkNum == INIT_FORKNUM;
/*
* Determine the target fill factor (in tuples per bucket) for this index.
* The idea is to make the fill factor correspond to pages about as full
* as the user-settable fillfactor parameter says. We can compute it
* exactly since the index datatype (i.e. uint32 hash key) is fixed-width.
*/
data_width = sizeof(uint32);
item_width = MAXALIGN(sizeof(IndexTupleData)) + MAXALIGN(data_width) +
sizeof(ItemIdData); /* include the line pointer */
ffactor = RelationGetTargetPageUsage(rel, HASH_DEFAULT_FILLFACTOR) / item_width;
/* keep to a sane range */
if (ffactor < 10)
ffactor = 10;
procid = index_getprocid(rel, 1, HASHSTANDARD_PROC);
/*
* We initialize the metapage, the first N bucket pages, and the first
* bitmap page in sequence, using _hash_getnewbuf to cause smgrextend()
* calls to occur. This ensures that the smgr level has the right idea of
* the physical index length.
*
* Critical section not required, because on error the creation of the
* whole relation will be rolled back.
*/
metabuf = _hash_getnewbuf(rel, HASH_METAPAGE, forkNum);
_hash_init_metabuffer(metabuf, num_tuples, procid, ffactor, false);
MarkBufferDirty(metabuf);
pg = BufferGetPage(metabuf);
metap = HashPageGetMeta(pg);
/* XLOG stuff */
if (use_wal)
{
xl_hash_init_meta_page xlrec;
XLogRecPtr recptr;
xlrec.num_tuples = num_tuples;
xlrec.procid = metap->hashm_procid;
xlrec.ffactor = metap->hashm_ffactor;
XLogBeginInsert();
XLogRegisterData((char *) &xlrec, SizeOfHashInitMetaPage);
XLogRegisterBuffer(0, metabuf, REGBUF_WILL_INIT);
recptr = XLogInsert(RM_HASH_ID, XLOG_HASH_INIT_META_PAGE);
PageSetLSN(BufferGetPage(metabuf), recptr);
}
num_buckets = metap->hashm_maxbucket + 1;
/*
* Release buffer lock on the metapage while we initialize buckets.
* Otherwise, we'll be in interrupt holdoff and the CHECK_FOR_INTERRUPTS
* won't accomplish anything. It's a bad idea to hold buffer locks for
* long intervals in any case, since that can block the bgwriter.
*/
LockBuffer(metabuf, BUFFER_LOCK_UNLOCK);
/*
* Initialize and WAL Log the first N buckets
*/
for (i = 0; i < num_buckets; i++)
{
BlockNumber blkno;
/* Allow interrupts, in case N is huge */
CHECK_FOR_INTERRUPTS();
blkno = BUCKET_TO_BLKNO(metap, i);
buf = _hash_getnewbuf(rel, blkno, forkNum);
_hash_initbuf(buf, metap->hashm_maxbucket, i, LH_BUCKET_PAGE, false);
MarkBufferDirty(buf);
if (use_wal)
log_newpage(&rel->rd_node,
forkNum,
blkno,
BufferGetPage(buf),
true);
_hash_relbuf(rel, buf);
}
/* Now reacquire buffer lock on metapage */
LockBuffer(metabuf, BUFFER_LOCK_EXCLUSIVE);
/*
* Initialize bitmap page
*/
bitmapbuf = _hash_getnewbuf(rel, num_buckets + 1, forkNum);
_hash_initbitmapbuffer(bitmapbuf, metap->hashm_bmsize, false);
MarkBufferDirty(bitmapbuf);
/* add the new bitmap page to the metapage's list of bitmaps */
/* metapage already has a write lock */
if (metap->hashm_nmaps >= HASH_MAX_BITMAPS)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("out of overflow pages in hash index \"%s\"",
RelationGetRelationName(rel))));
metap->hashm_mapp[metap->hashm_nmaps] = num_buckets + 1;
metap->hashm_nmaps++;
MarkBufferDirty(metabuf);
/* XLOG stuff */
if (use_wal)
{
xl_hash_init_bitmap_page xlrec;
XLogRecPtr recptr;
xlrec.bmsize = metap->hashm_bmsize;
XLogBeginInsert();
XLogRegisterData((char *) &xlrec, SizeOfHashInitBitmapPage);
XLogRegisterBuffer(0, bitmapbuf, REGBUF_WILL_INIT);
/*
* This is safe only because nobody else can be modifying the index at
* this stage; it's only visible to the transaction that is creating
* it.
*/
XLogRegisterBuffer(1, metabuf, REGBUF_STANDARD);
recptr = XLogInsert(RM_HASH_ID, XLOG_HASH_INIT_BITMAP_PAGE);
PageSetLSN(BufferGetPage(bitmapbuf), recptr);
PageSetLSN(BufferGetPage(metabuf), recptr);
}
/* all done */
_hash_relbuf(rel, bitmapbuf);
_hash_relbuf(rel, metabuf);
return num_buckets;
}
