/*
* _hash_initbitmap()
*
* Initialize a new bitmap page. The metapage has a write-lock upon
* entering the function, and must be written by caller after return.
*
* 'blkno' is the block number of the new bitmap page.
*
* All bits in the new bitmap page are set to "1", indicating "in use".
*/
void
_hash_initbitmap(Relation rel, HashMetaPage metap, BlockNumber blkno)
{
Buffer buf;
Page pg;
HashPageOpaque op;
uint32 *freep;
/*
* It is okay to write-lock the new bitmap page while holding metapage
* write lock, because no one else could be contending for the new page.
* Also, the metapage lock makes it safe to extend the index using P_NEW,
* which we want to do to ensure the smgr's idea of the relation size
* stays in step with ours.
*
* There is some loss of concurrency in possibly doing I/O for the new
* page while holding the metapage lock, but this path is taken so seldom
* that it's not worth worrying about.
*/
buf = _hash_getbuf(rel, P_NEW, HASH_WRITE);
if (BufferGetBlockNumber(buf) != blkno)
elog(ERROR, "unexpected hash relation size: %u, should be %u",
BufferGetBlockNumber(buf), blkno);
pg = BufferGetPage(buf);
/* initialize the page */
_hash_pageinit(pg, BufferGetPageSize(buf));
op = (HashPageOpaque) PageGetSpecialPointer(pg);
op->hasho_prevblkno = InvalidBlockNumber;
op->hasho_nextblkno = InvalidBlockNumber;
op->hasho_bucket = -1;
op->hasho_flag = LH_BITMAP_PAGE;
op->hasho_filler = HASHO_FILL;
/* set all of the bits to 1 */
freep = HashPageGetBitmap(pg);
MemSet(freep, 0xFF, BMPGSZ_BYTE(metap));
/* write out the new bitmap page (releasing write lock and pin) */
_hash_wrtbuf(rel, buf);
/* 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] = blkno;
metap->hashm_nmaps++;
}
/*
* _hash_initbitmap()
*
* Initialize a new bitmap page. The metapage has a write-lock upon
* entering the function, and must be written by caller after return.
*
* 'blkno' is the block number of the new bitmap page.
*
* All bits in the new bitmap page are set to "1", indicating "in use".
*/
void
_hash_initbitmap(Relation rel, HashMetaPage metap, BlockNumber blkno,
ForkNumber forkNum)
{
Buffer buf;
Page pg;
HashPageOpaque op;
uint32 *freep;
/*
* It is okay to write-lock the new bitmap page while holding metapage
* write lock, because no one else could be contending for the new page.
* Also, the metapage lock makes it safe to extend the index using
* _hash_getnewbuf.
*
* There is some loss of concurrency in possibly doing I/O for the new
* page while holding the metapage lock, but this path is taken so seldom
* that it's not worth worrying about.
*/
buf = _hash_getnewbuf(rel, blkno, forkNum);
pg = BufferGetPage(buf);
/* initialize the page's special space */
op = (HashPageOpaque) PageGetSpecialPointer(pg);
op->hasho_prevblkno = InvalidBlockNumber;
op->hasho_nextblkno = InvalidBlockNumber;
op->hasho_bucket = -1;
op->hasho_flag = LH_BITMAP_PAGE;
op->hasho_page_id = HASHO_PAGE_ID;
/* set all of the bits to 1 */
freep = HashPageGetBitmap(pg);
MemSet(freep, 0xFF, BMPGSZ_BYTE(metap));
/* write out the new bitmap page (releasing write lock and pin) */
_hash_wrtbuf(rel, buf);
/* 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] = blkno;
metap->hashm_nmaps++;
}