aboutsummaryrefslogtreecommitdiffstats
path: root/main/db1-ast/btree/bt_search.c
diff options
context:
space:
mode:
Diffstat (limited to 'main/db1-ast/btree/bt_search.c')
-rw-r--r--main/db1-ast/btree/bt_search.c213
1 files changed, 0 insertions, 213 deletions
diff --git a/main/db1-ast/btree/bt_search.c b/main/db1-ast/btree/bt_search.c
deleted file mode 100644
index 623f43949..000000000
--- a/main/db1-ast/btree/bt_search.c
+++ /dev/null
@@ -1,213 +0,0 @@
-/*-
- * 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
- * Mike Olson.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)bt_search.c 8.8 (Berkeley) 7/31/94";
-#endif /* LIBC_SCCS and not lint */
-
-#include <sys/types.h>
-
-#include <stdio.h>
-
-#include "../include/db.h"
-#include "btree.h"
-
-static int __bt_snext __P((BTREE *, PAGE *, const DBT *, int *));
-static int __bt_sprev __P((BTREE *, PAGE *, const DBT *, int *));
-
-/*
- * __bt_search --
- * Search a btree for a key.
- *
- * Parameters:
- * t: tree to search
- * key: key to find
- * exactp: pointer to exact match flag
- *
- * Returns:
- * The EPG for matching record, if any, or the EPG for the location
- * of the key, if it were inserted into the tree, is entered into
- * the bt_cur field of the tree. A pointer to the field is returned.
- */
-EPG *
-__bt_search(t, key, exactp)
- BTREE *t;
- const DBT *key;
- int *exactp;
-{
- PAGE *h;
- indx_t base, index, lim;
- pgno_t pg;
- int cmp;
-
- BT_CLR(t);
- for (pg = P_ROOT;;) {
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (NULL);
-
- /* Do a binary search on the current page. */
- t->bt_cur.page = h;
- for (base = 0, lim = NEXTINDEX(h); lim; lim >>= 1) {
- t->bt_cur.index = index = base + (lim >> 1);
- if ((cmp = __bt_cmp(t, key, &t->bt_cur)) == 0) {
- if (h->flags & P_BLEAF) {
- *exactp = 1;
- return (&t->bt_cur);
- }
- goto next;
- }
- if (cmp > 0) {
- base = index + 1;
- --lim;
- }
- }
-
- /*
- * If it's a leaf page, we're almost done. If no duplicates
- * are allowed, or we have an exact match, we're done. Else,
- * it's possible that there were matching keys on this page,
- * which later deleted, and we're on a page with no matches
- * while there are matches on other pages. If at the start or
- * end of a page, check the adjacent page.
- */
- if (h->flags & P_BLEAF) {
- if (!F_ISSET(t, B_NODUPS)) {
- if (base == 0 &&
- h->prevpg != P_INVALID &&
- __bt_sprev(t, h, key, exactp))
- return (&t->bt_cur);
- if (base == NEXTINDEX(h) &&
- h->nextpg != P_INVALID &&
- __bt_snext(t, h, key, exactp))
- return (&t->bt_cur);
- }
- *exactp = 0;
- t->bt_cur.index = base;
- return (&t->bt_cur);
- }
-
- /*
- * No match found. Base is the smallest index greater than
- * key and may be zero or a last + 1 index. If it's non-zero,
- * decrement by one, and record the internal page which should
- * be a parent page for the key. If a split later occurs, the
- * inserted page will be to the right of the saved page.
- */
- index = base ? base - 1 : base;
-
-next: BT_PUSH(t, h->pgno, index);
- pg = GETBINTERNAL(h, index)->pgno;
- mpool_put(t->bt_mp, h, 0);
- }
-}
-
-/*
- * __bt_snext --
- * Check for an exact match after the key.
- *
- * Parameters:
- * t: tree
- * h: current page
- * key: key
- * exactp: pointer to exact match flag
- *
- * Returns:
- * If an exact match found.
- */
-static int
-__bt_snext(t, h, key, exactp)
- BTREE *t;
- PAGE *h;
- const DBT *key;
- int *exactp;
-{
- EPG e;
-
- /*
- * Get the next page. The key is either an exact
- * match, or not as good as the one we already have.
- */
- if ((e.page = mpool_get(t->bt_mp, h->nextpg, 0)) == NULL)
- return (0);
- e.index = 0;
- if (__bt_cmp(t, key, &e) == 0) {
- mpool_put(t->bt_mp, h, 0);
- t->bt_cur = e;
- *exactp = 1;
- return (1);
- }
- mpool_put(t->bt_mp, e.page, 0);
- return (0);
-}
-
-/*
- * __bt_sprev --
- * Check for an exact match before the key.
- *
- * Parameters:
- * t: tree
- * h: current page
- * key: key
- * exactp: pointer to exact match flag
- *
- * Returns:
- * If an exact match found.
- */
-static int
-__bt_sprev(t, h, key, exactp)
- BTREE *t;
- PAGE *h;
- const DBT *key;
- int *exactp;
-{
- EPG e;
-
- /*
- * Get the previous page. The key is either an exact
- * match, or not as good as the one we already have.
- */
- if ((e.page = mpool_get(t->bt_mp, h->prevpg, 0)) == NULL)
- return (0);
- e.index = NEXTINDEX(e.page) - 1;
- if (__bt_cmp(t, key, &e) == 0) {
- mpool_put(t->bt_mp, h, 0);
- t->bt_cur = e;
- *exactp = 1;
- return (1);
- }
- mpool_put(t->bt_mp, e.page, 0);
- return (0);
-}