database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-13 07:41:39 +03:00
Code Activity

Install infrastructure for shared-memory free space map. Doesn't actually

Browse Source 
do anything yet, but it has the necessary connections to initialization
and so forth.  Make some gestures towards allowing number of blocks in
a relation to be BlockNumber, ie, unsigned int, rather than signed int.
(I doubt I got all the places that are sloppy about it, yet.)  On the
way, replace the hardwired NLOCKS_PER_XACT fudge factor with a GUC
variable.
This commit is contained in:
Tom Lane
2001-06-27 23:31:40 +00:00
parent b559382134
commit e0c9301c87
26 changed files with 572 additions and 316 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
src/backend/access/heap/heapam.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.119 2001/06/22 19:16:20 wieck Exp $
* $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.120 2001/06/27 23:31:38 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -121,8 +121,8 @@ heapgettup(Relation relation,
{
ItemId lpp;
Page dp;
int page;
int pages;
BlockNumber page;
BlockNumber pages;
int lines;
OffsetNumber lineoff;
int linesleft;
@ -172,7 +172,7 @@ heapgettup(Relation relation,
/*
* return null immediately if relation is empty
*/
if (!(pages = relation->rd_nblocks))
if ((pages = relation->rd_nblocks) == 0)
{
if (BufferIsValid(*buffer))
ReleaseBuffer(*buffer);
@ -233,15 +233,8 @@ heapgettup(Relation relation,
{
page = ItemPointerGetBlockNumber(tid); /* current page */
}
if (page < 0)
{
if (BufferIsValid(*buffer))
ReleaseBuffer(*buffer);
*buffer = InvalidBuffer;
tuple->t_datamcxt = NULL;
tuple->t_data = NULL;
return;
}
Assert(page < pages);
*buffer = ReleaseAndReadBuffer(*buffer,
relation,
@ -283,15 +276,7 @@ heapgettup(Relation relation,
OffsetNumberNext(ItemPointerGetOffsetNumber(tid));
}
if (page >= pages)
{
if (BufferIsValid(*buffer))
ReleaseBuffer(*buffer);
*buffer = InvalidBuffer;
tuple->t_datamcxt = NULL;
tuple->t_data = NULL;
return;
}
Assert(page < pages);
*buffer = ReleaseAndReadBuffer(*buffer,
relation,
@ -369,12 +354,11 @@ heapgettup(Relation relation,
* and it's time to move to the next.
*/
LockBuffer(*buffer, BUFFER_LOCK_UNLOCK);
page = (dir < 0) ? (page - 1) : (page + 1);
/*
* return NULL if we've exhausted all the pages
*/
if (page < 0 || page >= pages)
if ((dir < 0) ? (page == 0) : (page+1 >= pages))
{
if (BufferIsValid(*buffer))
ReleaseBuffer(*buffer);
@ -384,6 +368,10 @@ heapgettup(Relation relation,
return;
}
page = (dir < 0) ? (page - 1) : (page + 1);
Assert(page < pages);
*buffer = ReleaseAndReadBuffer(*buffer,
relation,
page,