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-rw-r--r--db/btree/bt_put.c320
1 files changed, 320 insertions, 0 deletions
diff --git a/db/btree/bt_put.c b/db/btree/bt_put.c
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+/*-
+ * 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_put.c	8.8 (Berkeley) 7/26/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "btree.h"
+
+static EPG *bt_fast __P((BTREE *, const DBT *, const DBT *, int *));
+
+/*
+ * __BT_PUT -- Add a btree item to the tree.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key
+ *	data:	data
+ *	flag:	R_NOOVERWRITE
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the
+ *	tree and R_NOOVERWRITE specified.
+ */
+int
+__bt_put(dbp, key, data, flags)
+	const DB *dbp;
+	DBT *key;
+	const DBT *data;
+	u_int flags;
+{
+	BTREE *t;
+	DBT tkey, tdata;
+	EPG *e;
+	PAGE *h;
+	indx_t index, nxtindex;
+	pgno_t pg;
+	u_int32_t nbytes;
+	int dflags, exact, status;
+	char *dest, db[NOVFLSIZE], kb[NOVFLSIZE];
+
+	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;
+	}
+
+	/* Check for change to a read-only tree. */
+	if (F_ISSET(t, B_RDONLY)) {
+		errno = EPERM;
+		return (RET_ERROR);
+	}
+
+	switch (flags) {
+	case 0:
+	case R_NOOVERWRITE:
+		break;
+	case R_CURSOR:
+		/*
+		 * If flags is R_CURSOR, put the cursor.  Must already
+		 * have started a scan and not have already deleted it.
+		 */
+		if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
+		    !F_ISSET(&t->bt_cursor,
+		        CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE))
+			break;
+		/* FALLTHROUGH */
+	default:
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	/*
+	 * If the key/data pair won't fit on a page, store it on overflow
+	 * pages.  Only put the key on the overflow page if the pair are
+	 * still too big after moving the data to an overflow page.
+	 *
+	 * XXX
+	 * If the insert fails later on, the overflow pages aren't recovered.
+	 */
+	dflags = 0;
+	if (key->size + data->size > t->bt_ovflsize) {
+		if (key->size > t->bt_ovflsize) {
+storekey:		if (__ovfl_put(t, key, &pg) == RET_ERROR)
+				return (RET_ERROR);
+			tkey.data = kb;
+			tkey.size = NOVFLSIZE;
+			memmove(kb, &pg, sizeof(pgno_t));
+			memmove(kb + sizeof(pgno_t),
+			    &key->size, sizeof(u_int32_t));
+			dflags |= P_BIGKEY;
+			key = &tkey;
+		}
+		if (key->size + data->size > t->bt_ovflsize) {
+			if (__ovfl_put(t, data, &pg) == RET_ERROR)
+				return (RET_ERROR);
+			tdata.data = db;
+			tdata.size = NOVFLSIZE;
+			memmove(db, &pg, sizeof(pgno_t));
+			memmove(db + sizeof(pgno_t),
+			    &data->size, sizeof(u_int32_t));
+			dflags |= P_BIGDATA;
+			data = &tdata;
+		}
+		if (key->size + data->size > t->bt_ovflsize)
+			goto storekey;
+	}
+
+	/* Replace the cursor. */
+	if (flags == R_CURSOR) {
+		if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL)
+			return (RET_ERROR);
+		index = t->bt_cursor.pg.index;
+		goto delete;
+	}
+
+	/*
+	 * Find the key to delete, or, the location at which to insert.
+	 * Bt_fast and __bt_search both pin the returned page.
+	 */
+	if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL)
+		if ((e = __bt_search(t, key, &exact)) == NULL)
+			return (RET_ERROR);
+	h = e->page;
+	index = e->index;
+
+	/*
+	 * Add the key/data pair to the tree.  If an identical key is already
+	 * in the tree, and R_NOOVERWRITE is set, an error is returned.  If
+	 * R_NOOVERWRITE is not set, the key is either added (if duplicates are
+	 * permitted) or an error is returned.
+	 */
+	switch (flags) {
+	case R_NOOVERWRITE:
+		if (!exact)
+			break;
+		mpool_put(t->bt_mp, h, 0);
+		return (RET_SPECIAL);
+	default:
+		if (!exact || !F_ISSET(t, B_NODUPS))
+			break;
+		/*
+		 * !!!
+		 * Note, the delete may empty the page, so we need to put a
+		 * new entry into the page immediately.
+		 */
+delete:		if (__bt_dleaf(t, key, h, index) == RET_ERROR) {
+			mpool_put(t->bt_mp, h, 0);
+			return (RET_ERROR);
+		}
+		break;
+	}
+
+	/*
+	 * If not enough room, or the user has put a ceiling on the number of
+	 * keys permitted in the page, split the page.  The split code will
+	 * insert the key and data and unpin the current page.  If inserting
+	 * into the offset array, shift the pointers up.
+	 */
+	nbytes = NBLEAFDBT(key->size, data->size);
+	if (h->upper - h->lower < nbytes + sizeof(indx_t)) {
+		if ((status = __bt_split(t, h, key,
+		    data, dflags, nbytes, index)) != RET_SUCCESS)
+			return (status);
+		goto success;
+	}
+
+	if (index < (nxtindex = NEXTINDEX(h)))
+		memmove(h->linp + index + 1, h->linp + index,
+		    (nxtindex - index) * sizeof(indx_t));
+	h->lower += sizeof(indx_t);
+
+	h->linp[index] = h->upper -= nbytes;
+	dest = (char *)h + h->upper;
+	WR_BLEAF(dest, key, data, dflags);
+
+	/* If the cursor is on this page, adjust it as necessary. */
+	if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
+	    !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) &&
+	    t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= index)
+		++t->bt_cursor.pg.index;
+
+	if (t->bt_order == NOT)
+		if (h->nextpg == P_INVALID) {
+			if (index == NEXTINDEX(h) - 1) {
+				t->bt_order = FORWARD;
+				t->bt_last.index = index;
+				t->bt_last.pgno = h->pgno;
+			}
+		} else if (h->prevpg == P_INVALID) {
+			if (index == 0) {
+				t->bt_order = BACK;
+				t->bt_last.index = 0;
+				t->bt_last.pgno = h->pgno;
+			}
+		}
+
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+
+success:
+	if (flags == R_SETCURSOR)
+		__bt_setcur(t, e->page->pgno, e->index);
+
+	F_SET(t, B_MODIFIED);
+	return (RET_SUCCESS);
+}
+
+#ifdef STATISTICS
+u_long bt_cache_hit, bt_cache_miss;
+#endif
+
+/*
+ * BT_FAST -- Do a quick check for sorted data.
+ *
+ * Parameters:
+ *	t:	tree
+ *	key:	key to insert
+ *
+ * Returns:
+ * 	EPG for new record or NULL if not found.
+ */
+static EPG *
+bt_fast(t, key, data, exactp)
+	BTREE *t;
+	const DBT *key, *data;
+	int *exactp;
+{
+	PAGE *h;
+	u_int32_t nbytes;
+	int cmp;
+
+	if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) {
+		t->bt_order = NOT;
+		return (NULL);
+	}
+	t->bt_cur.page = h;
+	t->bt_cur.index = t->bt_last.index;
+
+	/*
+	 * If won't fit in this page or have too many keys in this page,
+	 * have to search to get split stack.
+	 */
+	nbytes = NBLEAFDBT(key->size, data->size);
+	if (h->upper - h->lower < nbytes + sizeof(indx_t))
+		goto miss;
+
+	if (t->bt_order == FORWARD) {
+		if (t->bt_cur.page->nextpg != P_INVALID)
+			goto miss;
+		if (t->bt_cur.index != NEXTINDEX(h) - 1)
+			goto miss;
+		if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0)
+			goto miss;
+		t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index;
+	} else {
+		if (t->bt_cur.page->prevpg != P_INVALID)
+			goto miss;
+		if (t->bt_cur.index != 0)
+			goto miss;
+		if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0)
+			goto miss;
+		t->bt_last.index = 0;
+	}
+	*exactp = cmp == 0;
+#ifdef STATISTICS
+	++bt_cache_hit;
+#endif
+	return (&t->bt_cur);
+
+miss:
+#ifdef STATISTICS
+	++bt_cache_miss;
+#endif
+	t->bt_order = NOT;
+	mpool_put(t->bt_mp, h, 0);
+	return (NULL);
+}
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-25 03:51:48 +0000