[src/trunk]: src/lib/libc/db/hash Delay moving to the next key until the next...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e5d6608069f2
branches:  trunk
changeset: 339021:e5d6608069f2
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Jun 22 18:50:06 2015 +0000

description:
Delay moving to the next key until the next iteration. This avoids returning
invalid data to the user if the user deletes the current key, but it also
fails to iterate over some keys as will be shown by a unit test. From FreeBSD.

diffstat:

 lib/libc/db/hash/hash.c |  25 +++++++++++++++----------
 1 files changed, 15 insertions(+), 10 deletions(-)

diffs (61 lines):

diff -r 283b149c2d0b -r e5d6608069f2 lib/libc/db/hash/hash.c
--- a/lib/libc/db/hash/hash.c   Mon Jun 22 17:43:23 2015 +0000
+++ b/lib/libc/db/hash/hash.c   Mon Jun 22 18:50:06 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: hash.c,v 1.33 2013/12/01 00:22:48 christos Exp $       */
+/*     $NetBSD: hash.c,v 1.34 2015/06/22 18:50:06 christos Exp $       */
 
 /*-
  * Copyright (c) 1990, 1993, 1994
@@ -37,7 +37,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: hash.c,v 1.33 2013/12/01 00:22:48 christos Exp $");
+__RCSID("$NetBSD: hash.c,v 1.34 2015/06/22 18:50:06 christos Exp $");
 
 #include "namespace.h"
 #include <sys/param.h>
@@ -720,6 +720,7 @@
                hashp->cpage = NULL;
        }
 
+next_bucket:
        for (bp = NULL; !bp || !bp[0]; ) {
                if (!(bufp = hashp->cpage)) {
                        for (bucket = hashp->cbucket;
@@ -738,8 +739,19 @@
                                hashp->cbucket = -1;
                                return (ABNORMAL);
                        }
-               } else
+               } else {
                        bp = (uint16_t *)(void *)hashp->cpage->page;
+                       if (flag == R_NEXT || flag == 0) {
+                               hashp->cndx += 2;
+                               if (hashp->cndx > bp[0]) {
+                                       hashp->cpage = NULL;
+                                       hashp->cbucket++;
+                                       hashp->cndx = 1;
+                                       goto next_bucket;
+                               }
+                       }
+               }
+
 
                _DIAGASSERT(bp != NULL);
                _DIAGASSERT(bufp != NULL);
@@ -768,13 +780,6 @@
                key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
                data->data = (uint8_t *)hashp->cpage->page + bp[ndx + 1];
                data->size = bp[ndx] - bp[ndx + 1];
-               ndx += 2;
-               if (ndx > bp[0]) {
-                       hashp->cpage = NULL;
-                       hashp->cbucket++;
-                       hashp->cndx = 1;
-               } else
-                       hashp->cndx = ndx;
        }
        return (SUCCESS);
 }