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--- Libc/Libc-262.3.2/db/btree/bt_seq.c
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@@ -1,401 +0,0 @@
-/*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-/*
- * Copyright (c) 1990, 1993
- * 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.
- */
-
-
-#include <sys/types.h>
-
-#include <errno.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include <db.h>
-#include "btree.h"
-
-static int bt_seqadv __P((BTREE *, EPG *, int));
-static int bt_seqset __P((BTREE *, EPG *, DBT *, int));
-
-/*
- * Sequential scan support.
- *
- * The tree can be scanned sequentially, starting from either end of the tree
- * or from any specific key. A scan request before any scanning is done is
- * initialized as starting from the least node.
- *
- * Each tree has an EPGNO which has the current position of the cursor. The
- * cursor has to survive deletions/insertions in the tree without losing its
- * position. This is done by noting deletions without doing them, and then
- * doing them when the cursor moves (or the tree is closed).
- */
-
-/*
- * __BT_SEQ -- Btree sequential scan interface.
- *
- * Parameters:
- * dbp: pointer to access method
- * key: key for positioning and return value
- * data: data return value
- * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
- *
- * Returns:
- * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
- */
-int
-__bt_seq(dbp, key, data, flags)
- const DB *dbp;
- DBT *key, *data;
- u_int flags;
-{
- BTREE *t;
- EPG e;
- int status;
-
- t = dbp->internal;
-
- /* Toss any page pinned across calls. */
- if (t->bt_pinned != NULL) {
- mpool_put(t->bt_mp, t->bt_pinned, 0);
- t->bt_pinned = NULL;
- }
-
- /*
- * If scan unitialized as yet, or starting at a specific record, set
- * the scan to a specific key. Both bt_seqset and bt_seqadv pin the
- * page the cursor references if they're successful.
- */
- switch(flags) {
- case R_NEXT:
- case R_PREV:
- if (ISSET(t, B_SEQINIT)) {
- status = bt_seqadv(t, &e, flags);
- break;
- }
- /* FALLTHROUGH */
- case R_CURSOR:
- case R_FIRST:
- case R_LAST:
- status = bt_seqset(t, &e, key, flags);
- break;
- default:
- errno = EINVAL;
- return (RET_ERROR);
- }
-
- if (status == RET_SUCCESS) {
- status = __bt_ret(t, &e, key, data);
-
- /* Update the actual cursor. */
- t->bt_bcursor.pgno = e.page->pgno;
- t->bt_bcursor.index = e.index;
-
- /*
- * If the user is doing concurrent access, we copied the
- * key/data, toss the page.
- */
- if (ISSET(t, B_DB_LOCK))
- mpool_put(t->bt_mp, e.page, 0);
- else
- t->bt_pinned = e.page;
- SET(t, B_SEQINIT);
- }
- return (status);
-}
-
-/*
- * BT_SEQSET -- Set the sequential scan to a specific key.
- *
- * Parameters:
- * t: tree
- * ep: storage for returned key
- * key: key for initial scan position
- * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV
- *
- * Side effects:
- * Pins the page the cursor references.
- *
- * Returns:
- * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
- */
-static int
-bt_seqset(t, ep, key, flags)
- BTREE *t;
- EPG *ep;
- DBT *key;
- int flags;
-{
- EPG *e;
- PAGE *h;
- pgno_t pg;
- int exact;
-
- /*
- * Delete any already deleted record that we've been saving because
- * the cursor pointed to it. Since going to a specific key, should
- * delete any logically deleted records so they aren't found.
- */
- if (ISSET(t, B_DELCRSR) && __bt_crsrdel(t, &t->bt_bcursor))
- return (RET_ERROR);
-
- /*
- * Find the first, last or specific key in the tree and point the cursor
- * at it. The cursor may not be moved until a new key has been found.
- */
- switch(flags) {
- case R_CURSOR: /* Keyed scan. */
- /*
- * Find the first instance of the key or the smallest key which
- * is greater than or equal to the specified key. If run out
- * of keys, return RET_SPECIAL.
- */
- if (key->data == NULL || key->size == 0) {
- errno = EINVAL;
- return (RET_ERROR);
- }
- e = __bt_first(t, key, &exact); /* Returns pinned page. */
- if (e == NULL)
- return (RET_ERROR);
- /*
- * If at the end of a page, skip any empty pages and find the
- * next entry.
- */
- if (e->index == NEXTINDEX(e->page)) {
- h = e->page;
- do {
- pg = h->nextpg;
- mpool_put(t->bt_mp, h, 0);
- if (pg == P_INVALID)
- return (RET_SPECIAL);
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (RET_ERROR);
- } while (NEXTINDEX(h) == 0);
- e->index = 0;
- e->page = h;
- }
- *ep = *e;
- break;
- case R_FIRST: /* First record. */
- case R_NEXT:
- /* Walk down the left-hand side of the tree. */
- for (pg = P_ROOT;;) {
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (RET_ERROR);
- if (h->flags & (P_BLEAF | P_RLEAF))
- break;
- pg = GETBINTERNAL(h, 0)->pgno;
- mpool_put(t->bt_mp, h, 0);
- }
-
- /* Skip any empty pages. */
- while (NEXTINDEX(h) == 0 && h->nextpg != P_INVALID) {
- pg = h->nextpg;
- mpool_put(t->bt_mp, h, 0);
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (RET_ERROR);
- }
-
- if (NEXTINDEX(h) == 0) {
- mpool_put(t->bt_mp, h, 0);
- return (RET_SPECIAL);
- }
-
- ep->page = h;
- ep->index = 0;
- break;
- case R_LAST: /* Last record. */
- case R_PREV:
- /* Walk down the right-hand side of the tree. */
- for (pg = P_ROOT;;) {
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (RET_ERROR);
- if (h->flags & (P_BLEAF | P_RLEAF))
- break;
- pg = GETBINTERNAL(h, NEXTINDEX(h) - 1)->pgno;
- mpool_put(t->bt_mp, h, 0);
- }
-
- /* Skip any empty pages. */
- while (NEXTINDEX(h) == 0 && h->prevpg != P_INVALID) {
- pg = h->prevpg;
- mpool_put(t->bt_mp, h, 0);
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (RET_ERROR);
- }
-
- if (NEXTINDEX(h) == 0) {
- mpool_put(t->bt_mp, h, 0);
- return (RET_SPECIAL);
- }
-
- ep->page = h;
- ep->index = NEXTINDEX(h) - 1;
- break;
- }
- return (RET_SUCCESS);
-}
-
-/*
- * BT_SEQADVANCE -- Advance the sequential scan.
- *
- * Parameters:
- * t: tree
- * flags: R_NEXT, R_PREV
- *
- * Side effects:
- * Pins the page the new key/data record is on.
- *
- * Returns:
- * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
- */
-static int
-bt_seqadv(t, e, flags)
- BTREE *t;
- EPG *e;
- int flags;
-{
- EPGNO *c, delc;
- PAGE *h;
- indx_t index;
- pgno_t pg;
-
- /* Save the current cursor if going to delete it. */
- c = &t->bt_bcursor;
- if (ISSET(t, B_DELCRSR))
- delc = *c;
-
- if ((h = mpool_get(t->bt_mp, c->pgno, 0)) == NULL)
- return (RET_ERROR);
-
- /*
- * Find the next/previous record in the tree and point the cursor at it.
- * The cursor may not be moved until a new key has been found.
- */
- index = c->index;
- switch(flags) {
- case R_NEXT: /* Next record. */
- if (++index == NEXTINDEX(h)) {
- do {
- pg = h->nextpg;
- mpool_put(t->bt_mp, h, 0);
- if (pg == P_INVALID)
- return (RET_SPECIAL);
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (RET_ERROR);
- } while (NEXTINDEX(h) == 0);
- index = 0;
- }
- break;
- case R_PREV: /* Previous record. */
- if (index-- == 0) {
- do {
- pg = h->prevpg;
- mpool_put(t->bt_mp, h, 0);
- if (pg == P_INVALID)
- return (RET_SPECIAL);
- if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
- return (RET_ERROR);
- } while (NEXTINDEX(h) == 0);
- index = NEXTINDEX(h) - 1;
- }
- break;
- }
-
- e->page = h;
- e->index = index;
-
- /*
- * Delete any already deleted record that we've been saving because the
- * cursor pointed to it. This could cause the new index to be shifted
- * down by one if the record we're deleting is on the same page and has
- * a larger index.
- */
- if (ISSET(t, B_DELCRSR)) {
- CLR(t, B_DELCRSR); /* Don't try twice. */
- if (c->pgno == delc.pgno && c->index > delc.index)
- --c->index;
- if (__bt_crsrdel(t, &delc))
- return (RET_ERROR);
- }
- return (RET_SUCCESS);
-}
-
-/*
- * __BT_CRSRDEL -- Delete the record referenced by the cursor.
- *
- * Parameters:
- * t: tree
- *
- * Returns:
- * RET_ERROR, RET_SUCCESS
- */
-int
-__bt_crsrdel(t, c)
- BTREE *t;
- EPGNO *c;
-{
- PAGE *h;
- int status;
-
- CLR(t, B_DELCRSR); /* Don't try twice. */
- if ((h = mpool_get(t->bt_mp, c->pgno, 0)) == NULL)
- return (RET_ERROR);
- status = __bt_dleaf(t, h, c->index);
- mpool_put(t->bt_mp, h, MPOOL_DIRTY);
- return (status);
-}