diff options
Diffstat (limited to 'lib/libc/db/btree/bt_get.c')
-rw-r--r-- | lib/libc/db/btree/bt_get.c | 141 |
1 files changed, 4 insertions, 137 deletions
diff --git a/lib/libc/db/btree/bt_get.c b/lib/libc/db/btree/bt_get.c index 28b2d60..74824c7 100644 --- a/lib/libc/db/btree/bt_get.c +++ b/lib/libc/db/btree/bt_get.c @@ -1,5 +1,5 @@ /*- - * Copyright (c) 1990, 1993 + * Copyright (c) 1990, 1993, 1994 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by @@ -35,7 +35,7 @@ */ #if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "@(#)bt_get.c 8.2 (Berkeley) 9/7/93"; +static char sccsid[] = "@(#)bt_get.c 8.6 (Berkeley) 7/20/94"; #endif /* LIBC_SCCS and not lint */ #include <sys/types.h> @@ -91,148 +91,15 @@ __bt_get(dbp, key, data, flags) return (RET_SPECIAL); } - /* - * A special case is if we found the record but it's flagged for - * deletion. In this case, we want to find another record with the - * same key, if it exists. Rather than look around the tree we call - * __bt_first and have it redo the search, as __bt_first will not - * return keys marked for deletion. Slow, but should never happen. - */ - if (ISSET(t, B_DELCRSR) && e->page->pgno == t->bt_bcursor.pgno && - e->index == t->bt_bcursor.index) { - mpool_put(t->bt_mp, e->page, 0); - if ((e = __bt_first(t, key, &exact)) == NULL) - return (RET_ERROR); - if (!exact) - return (RET_SPECIAL); - } + status = __bt_ret(t, e, NULL, NULL, data, &t->bt_rdata, 0); - status = __bt_ret(t, e, NULL, data); /* * If the user is doing concurrent access, we copied the * key/data, toss the page. */ - if (ISSET(t, B_DB_LOCK)) + if (F_ISSET(t, B_DB_LOCK)) mpool_put(t->bt_mp, e->page, 0); else t->bt_pinned = e->page; return (status); } - -/* - * __BT_FIRST -- Find the first entry. - * - * Parameters: - * t: the tree - * key: the key - * - * Returns: - * The first entry in the tree greater than or equal to key. - */ -EPG * -__bt_first(t, key, exactp) - BTREE *t; - const DBT *key; - int *exactp; -{ - register PAGE *h; - register EPG *e; - EPG save; - pgno_t cpgno, pg; - indx_t cindex; - int found; - - /* - * Find any matching record; __bt_search pins the page. Only exact - * matches are tricky, otherwise just return the location of the key - * if it were to be inserted into the tree. - */ - if ((e = __bt_search(t, key, exactp)) == NULL) - return (NULL); - if (!*exactp) - return (e); - - if (ISSET(t, B_DELCRSR)) { - cpgno = t->bt_bcursor.pgno; - cindex = t->bt_bcursor.index; - } else { - cpgno = P_INVALID; - cindex = 0; /* GCC thinks it's uninitialized. */ - } - - /* - * Walk backwards, skipping empty pages, as long as the entry matches - * and there are keys left in the tree. Save a copy of each match in - * case we go too far. A special case is that we don't return a match - * on records that the cursor references that have already been flagged - * for deletion. - */ - save = *e; - h = e->page; - found = 0; - do { - if (cpgno != h->pgno || cindex != e->index) { - if (save.page->pgno != e->page->pgno) { - mpool_put(t->bt_mp, save.page, 0); - save = *e; - } else - save.index = e->index; - found = 1; - } - /* - * Make a special effort not to unpin the page the last (or - * original) match was on, but also make sure it's unpinned - * if an error occurs. - */ - while (e->index == 0) { - if (h->prevpg == P_INVALID) - goto done1; - if (h->pgno != save.page->pgno) - mpool_put(t->bt_mp, h, 0); - if ((h = mpool_get(t->bt_mp, h->prevpg, 0)) == NULL) { - if (h->pgno == save.page->pgno) - mpool_put(t->bt_mp, save.page, 0); - return (NULL); - } - e->page = h; - e->index = NEXTINDEX(h); - } - --e->index; - } while (__bt_cmp(t, key, e) == 0); - - /* - * Reach here with the last page that was looked at pinned, which may - * or may not be the same as the last (or original) match page. If - * it's not useful, release it. - */ -done1: if (h->pgno != save.page->pgno) - mpool_put(t->bt_mp, h, 0); - - /* - * If still haven't found a record, the only possibility left is the - * next one. Move forward one slot, skipping empty pages and check. - */ - if (!found) { - h = save.page; - if (++save.index == NEXTINDEX(h)) { - do { - pg = h->nextpg; - mpool_put(t->bt_mp, h, 0); - if (pg == P_INVALID) { - *exactp = 0; - return (e); - } - if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL) - return (NULL); - } while ((save.index = NEXTINDEX(h)) == 0); - save.page = h; - } - if (__bt_cmp(t, key, &save) != 0) { - *exactp = 0; - return (e); - } - } - *e = save; - *exactp = 1; - return (e); -} |