diff options
Diffstat (limited to 'db2/btree/bt_search.c')
| -rw-r--r-- | db2/btree/bt_search.c | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/db2/btree/bt_search.c b/db2/btree/bt_search.c index c39c9af322..09ce46d90a 100644 --- a/db2/btree/bt_search.c +++ b/db2/btree/bt_search.c @@ -1,7 +1,7 @@ /*- * See the file LICENSE for redistribution information. * - * Copyright (c) 1996, 1997 + * Copyright (c) 1996, 1997, 1998 * Sleepycat Software. All rights reserved. */ /* @@ -47,15 +47,13 @@ #include "config.h" #ifndef lint -static const char sccsid[] = "@(#)bt_search.c 10.9 (Sleepycat) 11/18/97"; +static const char sccsid[] = "@(#)bt_search.c 10.15 (Sleepycat) 5/6/98"; #endif /* not lint */ #ifndef NO_SYSTEM_INCLUDES #include <sys/types.h> #include <errno.h> -#include <stdio.h> -#include <stdlib.h> #include <string.h> #endif @@ -68,13 +66,13 @@ static const char sccsid[] = "@(#)bt_search.c 10.9 (Sleepycat) 11/18/97"; * Search a btree for a key. * * PUBLIC: int __bam_search __P((DB *, - * PUBLIC: const DBT *, u_int, int, db_recno_t *, int *)); + * PUBLIC: const DBT *, u_int32_t, int, db_recno_t *, int *)); */ int __bam_search(dbp, key, flags, stop, recnop, exactp) DB *dbp; const DBT *key; - u_int flags; + u_int32_t flags; int stop, *exactp; db_recno_t *recnop; { @@ -109,8 +107,7 @@ __bam_search(dbp, key, flags, stop, recnop, exactp) * Retrieve the root page. */ pg = PGNO_ROOT; - stack = F_ISSET(dbp, DB_BT_RECNUM) && - (flags == S_INSERT || flags == S_DELETE); + stack = F_ISSET(dbp, DB_BT_RECNUM) && LF_ISSET(S_STACK); if ((ret = __bam_lget(dbp, 0, pg, stack ? DB_LOCK_WRITE : DB_LOCK_READ, &lock)) != 0) return (ret); @@ -179,6 +176,14 @@ __bam_search(dbp, key, flags, stop, recnop, exactp) if (LF_ISSET(S_EXACT)) goto notfound; + /* + * !!! + * Possibly returning a deleted record -- DB_SET_RANGE, + * DB_KEYFIRST and DB_KEYLAST don't require an exact + * match, and we don't want to walk multiple pages here + * to find an undeleted record. This is handled in the + * __bam_c_search() routine. + */ BT_STK_ENTER(t, h, base, lock, ret); return (ret); } @@ -249,7 +254,10 @@ match: *exactp = 1; /* * If we got here, we know that we have a btree leaf page. * - * If there are duplicates, go to the first/last one. + * If there are duplicates, go to the first/last one. This is + * safe because we know that we're not going to leave the page, + * all duplicate sets that are not on overflow pages exist on a + * single leaf page. */ if (LF_ISSET(S_DUPLAST)) while (indx < (db_indx_t)(NUM_ENT(h) - P_INDX) && @@ -261,8 +269,8 @@ match: *exactp = 1; indx -= P_INDX; /* - * Now check if we are allowed to return deleted item; if not - * find/last the first non-deleted item. + * Now check if we are allowed to return deleted items; if not + * find the next (or previous) non-deleted item. */ if (LF_ISSET(S_DELNO)) { if (LF_ISSET(S_DUPLAST)) |