BSD 4_4 release

[unix-history] / usr / src / lib / libc / db / btree / bt_search.c

diff --git a/usr/src/lib/libc/db/btree/bt_search.c b/usr/src/lib/libc/db/btree/bt_search.c
index 97d5fd9..06aba11 100644 (file)
--- a/usr/src/lib/libc/db/btree/bt_search.c
+++ b/usr/src/lib/libc/db/btree/bt_search.c
@@ -1,20 +1,48 @@
 /*-
 /*-

- * Copyright (c) 1990 The Regents of the University of California.
- * All rights reserved.
+ * 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.
  *
  *
  * This code is derived from software contributed to Berkeley by
  * Mike Olson.
  *

- * %sccs.include.redist.c%
+ * 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)
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)

-static char sccsid[] = "@(#)bt_search.c        5.4 (Berkeley) %G%";
+static char sccsid[] = "@(#)bt_search.c        8.1 (Berkeley) 6/4/93";

 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/types.h>
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/types.h>

-#include <db.h>
+

 #include <stdio.h>
 #include <stdio.h>

+
+#include <db.h>

 #include "btree.h"
 
 /*
 #include "btree.h"
 
 /*


@@ -39,12 +67,13 @@ __bt_search(t, key, exactp)
        const DBT *key;
        int *exactp;
 {
        const DBT *key;
        int *exactp;
 {

-       register index_t index;
+       register indx_t index;

        register int base, cmp, lim;
        register PAGE *h;
        pgno_t pg;
        static EPG e;
 
        register int base, cmp, lim;
        register PAGE *h;
        pgno_t pg;
        static EPG e;
 

+       BT_CLR(t);

        for (pg = P_ROOT;;) {
                if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
                        return (NULL);
        for (pg = P_ROOT;;) {
                if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
                        return (NULL);


@@ -66,21 +95,22 @@ __bt_search(t, key, exactp)
                        }
                }
 
                        }
                }
 

-               /*
-                * No match found.  Base is the smallest index greater than
-                * key but may be an illegal index.  Use base if it's a leaf
-                * page, decrement it by one if it's an internal page.  This
-                * is safe because internal pages can't be empty.
-                */
-               index = h->flags & P_BLEAF ? base : base - 1;
-

                /* If it's a leaf page, we're done. */
                if (h->flags & P_BLEAF) {
                /* If it's a leaf page, we're done. */
                if (h->flags & P_BLEAF) {

-                       e.index = index;
+                       e.index = base;

                        *exactp = 0;
                        return (&e);
                }
 
                        *exactp = 0;
                        return (&e);
                }
 

+               /*
+                * 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:          if (__bt_push(t, h->pgno, index) == RET_ERROR)
                        return (NULL);
                pg = GETBINTERNAL(h, index)->pgno;
 next:          if (__bt_push(t, h->pgno, index) == RET_ERROR)
                        return (NULL);
                pg = GETBINTERNAL(h, index)->pgno;