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author | delphij <delphij@FreeBSD.org> | 2009-03-28 06:38:31 +0000 |
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committer | delphij <delphij@FreeBSD.org> | 2009-03-28 06:38:31 +0000 |
commit | 8d5f207dd117429b795e3fe026c15e8cf8721520 (patch) | |
tree | 24e190980bd4567b85a3c32895463bdf393d0e53 | |
parent | be23f69f403b512b59926d78baae02cd2fb18778 (diff) | |
download | FreeBSD-src-8d5f207dd117429b795e3fe026c15e8cf8721520.zip FreeBSD-src-8d5f207dd117429b795e3fe026c15e8cf8721520.tar.gz |
- Avoid overwriting the cursor page when the cursor page becomes the
LRU page.
- Fix for sequential retrieval failure when using large key/data pairs.
Obtained from: OpenBSD
-rw-r--r-- | lib/libc/db/hash/hash_buf.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/lib/libc/db/hash/hash_buf.c b/lib/libc/db/hash/hash_buf.c index 8741ea5..6d26b16 100644 --- a/lib/libc/db/hash/hash_buf.c +++ b/lib/libc/db/hash/hash_buf.c @@ -164,11 +164,31 @@ newbuf(HTAB *hashp, u_int32_t addr, BUFHEAD *prev_bp) oaddr = 0; bp = LRU; + + /* It is bad to overwrite the page under the cursor. */ + if (bp == hashp->cpage) { + BUF_REMOVE(bp); + MRU_INSERT(bp); + bp = LRU; + } + + /* If prev_bp is part of bp overflow, create a new buffer. */ + if (hashp->nbufs == 0 && prev_bp && bp->ovfl) { + BUFHEAD *ovfl; + + for (ovfl = bp->ovfl; ovfl ; ovfl = ovfl->ovfl) { + if (ovfl == prev_bp) { + hashp->nbufs++; + break; + } + } + } + /* * If LRU buffer is pinned, the buffer pool is too small. We need to * allocate more buffers. */ - if (hashp->nbufs || (bp->flags & BUF_PIN)) { + if (hashp->nbufs || (bp->flags & BUF_PIN) || bp == hashp->cpage) { /* Allocate a new one */ if ((bp = (BUFHEAD *)calloc(1, sizeof(BUFHEAD))) == NULL) return (NULL); |