diff options
Diffstat (limited to 'src/backend/storage/buffer/localbuf.c')
| -rw-r--r-- | src/backend/storage/buffer/localbuf.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/src/backend/storage/buffer/localbuf.c b/src/backend/storage/buffer/localbuf.c index 4dd5619f39f..5431419cfe6 100644 --- a/src/backend/storage/buffer/localbuf.c +++ b/src/backend/storage/buffer/localbuf.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/buffer/localbuf.c,v 1.85 2009/01/01 17:23:47 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/storage/buffer/localbuf.c,v 1.86 2009/01/12 05:10:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -53,6 +53,43 @@ static Block GetLocalBufferStorage(void); /* + * LocalPrefetchBuffer - + * initiate asynchronous read of a block of a relation + * + * Do PrefetchBuffer's work for temporary relations. + * No-op if prefetching isn't compiled in. + */ +void +LocalPrefetchBuffer(SMgrRelation smgr, ForkNumber forkNum, + BlockNumber blockNum) +{ +#ifdef USE_PREFETCH + BufferTag newTag; /* identity of requested block */ + LocalBufferLookupEnt *hresult; + + INIT_BUFFERTAG(newTag, smgr->smgr_rnode, forkNum, blockNum); + + /* Initialize local buffers if first request in this session */ + if (LocalBufHash == NULL) + InitLocalBuffers(); + + /* See if the desired buffer already exists */ + hresult = (LocalBufferLookupEnt *) + hash_search(LocalBufHash, (void *) &newTag, HASH_FIND, NULL); + + if (hresult) + { + /* Yes, so nothing to do */ + return; + } + + /* Not in buffers, so initiate prefetch */ + smgrprefetch(smgr, forkNum, blockNum); +#endif /* USE_PREFETCH */ +} + + +/* * LocalBufferAlloc - * Find or create a local buffer for the given page of the given relation. * |