diff options
| author | Todd C. Miller <millert@cvs.openbsd.org> | 2002-02-01 18:15:25 +0000 |
|---|---|---|
| committer | Todd C. Miller <millert@cvs.openbsd.org> | 2002-02-01 18:15:25 +0000 |
| commit | 3801d99fa0fa8b9c9b7afc7ac549ce1b8b59ec46 (patch) | |
| tree | 86de553d66787e4046ffab8eabecb29a66f879b3 /lib | |
| parent | 93b4e6704377c5ff1166010856501183fa43a4f8 (diff) | |
If (keysize+datasize)%(bsize=14)==0, insertion of a `big key' would cause an
invariant (actually, an ugly hack) to fail, and all Hell would break loose.
When deleting a big key, the offset of an empty page should be bsize, not
bsize-1; otherwise an insertion into the empty page will cause the new key to
be elongated by 1 byte.
Make the packing more dense in a couple of cases.
From mycroft@netbsd.org
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libc/db/hash/hash_bigkey.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/lib/libc/db/hash/hash_bigkey.c b/lib/libc/db/hash/hash_bigkey.c index 4e5e236879c..6859d0dec55 100644 --- a/lib/libc/db/hash/hash_bigkey.c +++ b/lib/libc/db/hash/hash_bigkey.c @@ -1,4 +1,4 @@ -/* $OpenBSD: hash_bigkey.c,v 1.7 2000/10/03 18:16:48 mickey Exp $ */ +/* $OpenBSD: hash_bigkey.c,v 1.8 2002/02/01 18:15:24 millert Exp $ */ /*- * Copyright (c) 1990, 1993, 1994 @@ -40,7 +40,7 @@ #if 0 static char sccsid[] = "@(#)hash_bigkey.c 8.3 (Berkeley) 5/31/94"; #else -static char rcsid[] = "$OpenBSD: hash_bigkey.c,v 1.7 2000/10/03 18:16:48 mickey Exp $"; +static char rcsid[] = "$OpenBSD: hash_bigkey.c,v 1.8 2002/02/01 18:15:24 millert Exp $"; #endif #endif /* LIBC_SCCS and not lint */ @@ -128,18 +128,30 @@ __big_insert(hashp, bufp, key, val) return (-1); n = p[0]; if (!key_size) { - if (FREESPACE(p)) { - move_bytes = MIN(FREESPACE(p), val_size); + space = FREESPACE(p); + if (space) { + move_bytes = MIN(space, val_size); + /* + * If the data would fit exactly in the + * remaining space, we must overflow it to the + * next page; otherwise the invariant that the + * data must end on a page with FREESPACE + * non-zero would fail. + */ + if (space == val_size && val_size == val->size) + goto toolarge; off = OFFSET(p) - move_bytes; - p[n] = off; memmove(cp + off, val_data, move_bytes); val_data += move_bytes; val_size -= move_bytes; + p[n] = off; p[n - 2] = FULL_KEY_DATA; FREESPACE(p) = FREESPACE(p) - move_bytes; OFFSET(p) = off; - } else + } else { + toolarge: p[n - 2] = FULL_KEY; + } } p = (u_int16_t *)bufp->page; cp = bufp->page; @@ -251,7 +263,7 @@ __big_delete(hashp, bufp) n -= 2; bp[0] = n; FREESPACE(bp) = hashp->BSIZE - PAGE_META(n); - OFFSET(bp) = hashp->BSIZE - 1; + OFFSET(bp) = hashp->BSIZE; bufp->flags |= BUF_MOD; if (rbufp) |