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authortwilson <twilson@f38db490-d61c-443f-a65b-d21fe96a405b>2011-07-06 20:58:12 +0000
committertwilson <twilson@f38db490-d61c-443f-a65b-d21fe96a405b>2011-07-06 20:58:12 +0000
commit9b10a0c265265d787eba75de81be2bc5a286734b (patch)
treeb4a3f36ffe91a5226485088c3bb2c5c6ac698fa1 /utils/db1-ast/hash/hash_func.c
parentbacd87fb8e73ef3eed30c2f49a5a7a38842f3b51 (diff)
Replace Berkeley DB with SQLite 3
There were some bugs in the very ancient version of Berkeley DB that Asterisk used. Instead of spending the time tracking down the bugs in the Berkeley code we move to the much better documented SQLite 3. Conversion of the old astdb happens at runtime by running the included astdb2sqlite3 utility. The ast_db API with SQLite 3 backend should behave identically to the old Berkeley backend, but in the future we could offer a much more robust interface. We do not include the SQLite 3 library in the source tree, but instead rely upon the distribution-provided libraries. SQLite is so ubiquitous that this should not place undue burden on administrators. git-svn-id: http://svn.digium.com/svn/asterisk/trunk@326589 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'utils/db1-ast/hash/hash_func.c')
-rw-r--r--utils/db1-ast/hash/hash_func.c225
1 files changed, 225 insertions, 0 deletions
diff --git a/utils/db1-ast/hash/hash_func.c b/utils/db1-ast/hash/hash_func.c
new file mode 100644
index 000000000..4d7907b57
--- /dev/null
+++ b/utils/db1-ast/hash/hash_func.c
@@ -0,0 +1,225 @@
+/*-
+ * Copyright (c) 1990, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * 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[] = "@(#)hash_func.c 8.2 (Berkeley) 2/21/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include "../include/db.h"
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+/* only one of these can be defined */
+/* #define HASH1_EJB 1 */
+/* #define HASH2_PHONG 1 */
+/* #define HASH3_SDBM 1 */
+#define HASH4_TOREK 1
+
+static u_int32_t hashfunc __P((const void *, size_t));
+
+/* Global default hash function */
+u_int32_t (*__default_hash) __P((const void *, size_t)) = hashfunc;
+
+/*
+ * HASH FUNCTIONS
+ *
+ * Assume that we've already split the bucket to which this key hashes,
+ * calculate that bucket, and check that in fact we did already split it.
+ *
+ * This came from ejb's hsearch.
+ */
+
+#ifdef HASH1_EJB
+
+#define PRIME1 37
+#define PRIME2 1048583
+
+static u_int32_t
+hashfunc(keyarg, len)
+ const void *keyarg;
+ register size_t len;
+{
+ register const u_char *key;
+ register u_int32_t h;
+
+ /* Convert string to integer */
+ for (key = keyarg, h = 0; len--;)
+ h = h * PRIME1 ^ (*key++ - ' ');
+ h %= PRIME2;
+ return (h);
+}
+
+#endif
+
+#ifdef HASH2_PHONG
+/*
+ * Phong's linear congruential hash
+ */
+#define dcharhash(h, c) ((h) = 0x63c63cd9*(h) + 0x9c39c33d + (c))
+
+static u_int32_t
+hashfunc(keyarg, len)
+ const void *keyarg;
+ size_t len;
+{
+ register const u_char *e, *key;
+ register u_int32_t h;
+ register u_char c;
+
+ key = keyarg;
+ e = key + len;
+ for (h = 0; key != e;) {
+ c = *key++;
+ if (!c && key > e)
+ break;
+ dcharhash(h, c);
+ }
+ return (h);
+}
+#endif
+
+#ifdef HASH3_SDBM
+/*
+ * This is INCREDIBLY ugly, but fast. We break the string up into 8 byte
+ * units. On the first time through the loop we get the "leftover bytes"
+ * (strlen % 8). On every other iteration, we perform 8 HASHC's so we handle
+ * all 8 bytes. Essentially, this saves us 7 cmp & branch instructions. If
+ * this routine is heavily used enough, it's worth the ugly coding.
+ *
+ * OZ's original sdbm hash
+ */
+static u_int32_t
+hashfunc(keyarg, len)
+ const void *keyarg;
+ register size_t len;
+{
+ register const u_char *key;
+ register size_t loop;
+ register u_int32_t h;
+
+#define HASHC h = *key++ + 65599 * h
+
+ h = 0;
+ key = keyarg;
+ if (len > 0) {
+ loop = (len + 8 - 1) >> 3;
+
+ switch (len & (8 - 1)) {
+ case 0:
+ do {
+ HASHC;
+ /* FALLTHROUGH */
+ case 7:
+ HASHC;
+ /* FALLTHROUGH */
+ case 6:
+ HASHC;
+ /* FALLTHROUGH */
+ case 5:
+ HASHC;
+ /* FALLTHROUGH */
+ case 4:
+ HASHC;
+ /* FALLTHROUGH */
+ case 3:
+ HASHC;
+ /* FALLTHROUGH */
+ case 2:
+ HASHC;
+ /* FALLTHROUGH */
+ case 1:
+ HASHC;
+ } while (--loop);
+ }
+ }
+ return (h);
+}
+#endif
+
+#ifdef HASH4_TOREK
+/* Hash function from Chris Torek. */
+static u_int32_t
+hashfunc(keyarg, len)
+ const void *keyarg;
+ register size_t len;
+{
+ register const u_char *key;
+ register size_t loop;
+ register u_int32_t h;
+
+#define HASH4a h = (h << 5) - h + *key++;
+#define HASH4b h = (h << 5) + h + *key++;
+#define HASH4 HASH4b
+
+ h = 0;
+ key = keyarg;
+ if (len > 0) {
+ loop = (len + 8 - 1) >> 3;
+
+ switch (len & (8 - 1)) {
+ case 0:
+ do {
+ HASH4;
+ /* FALLTHROUGH */
+ case 7:
+ HASH4;
+ /* FALLTHROUGH */
+ case 6:
+ HASH4;
+ /* FALLTHROUGH */
+ case 5:
+ HASH4;
+ /* FALLTHROUGH */
+ case 4:
+ HASH4;
+ /* FALLTHROUGH */
+ case 3:
+ HASH4;
+ /* FALLTHROUGH */
+ case 2:
+ HASH4;
+ /* FALLTHROUGH */
+ case 1:
+ HASH4;
+ } while (--loop);
+ }
+ }
+ return (h);
+}
+#endif