Adding upstream version 1.6.3.upstream/1.6.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 320 insertions, 0 deletions

diff --git a/dbm/sdbm/sdbm_pair.c b/dbm/sdbm/sdbm_pair.c
new file mode 100644
index 0000000..50d7965
--- /dev/null
+++ b/dbm/sdbm/sdbm_pair.c
@@ -0,0 +1,320 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * sdbm - ndbm work-alike hashed database library
+ * based on Per-Aake Larson's Dynamic Hashing algorithms. BIT 18 (1978).
+ * author: oz@nexus.yorku.ca
+ * status: ex-public domain.
+ *
+ * page-level routines
+ */
+
+#include "apr_sdbm.h"
+
+#include "sdbm_tune.h"
+#include "sdbm_pair.h"
+#include "sdbm_private.h"
+
+#include <string.h>	/* for memset() */
+
+
+#define exhash(item)	sdbm_hash((item).dptr, (item).dsize)
+
+/* 
+ * forward 
+ */
+static int seepair(char *, int, char *, int);
+
+/*
+ * page format:
+ *	+------------------------------+
+ * ino	| n | keyoff | datoff | keyoff |
+ * 	+------------+--------+--------+
+ *	| datoff | - - - ---->	       |
+ *	+--------+---------------------+
+ *	|	 F R E E A R E A       |
+ *	+--------------+---------------+
+ *	|  <---- - - - | data          |
+ *	+--------+-----+----+----------+
+ *	|  key   | data     | key      |
+ *	+--------+----------+----------+
+ *
+ * calculating the offsets for free area:  if the number
+ * of entries (ino[0]) is zero, the offset to the END of
+ * the free area is the block size. Otherwise, it is the
+ * nth (ino[ino[0]]) entry's offset.
+ */
+
+int
+fitpair(pag, need)
+char *pag;
+int need;
+{
+	register int n;
+	register int off;
+	register int avail;
+	register short *ino = (short *) pag;
+
+	off = ((n = ino[0]) > 0) ? ino[n] : PBLKSIZ;
+	avail = off - (n + 1) * sizeof(short);
+	need += 2 * sizeof(short);
+
+	debug(("avail %d need %d\n", avail, need));
+
+	return need <= avail;
+}
+
+void
+putpair(pag, key, val)
+char *pag;
+apr_sdbm_datum_t key;
+apr_sdbm_datum_t val;
+{
+	register int n;
+	register int off;
+	register short *ino = (short *) pag;
+
+	off = ((n = ino[0]) > 0) ? ino[n] : PBLKSIZ;
+/*
+ * enter the key first
+ */
+	off -= key.dsize;
+	(void) memcpy(pag + off, key.dptr, key.dsize);
+	ino[n + 1] = off;
+/*
+ * now the data
+ */
+	off -= val.dsize;
+	(void) memcpy(pag + off, val.dptr, val.dsize);
+	ino[n + 2] = off;
+/*
+ * adjust item count
+ */
+	ino[0] += 2;
+}
+
+apr_sdbm_datum_t
+getpair(pag, key)
+char *pag;
+apr_sdbm_datum_t key;
+{
+	register int i;
+	register int n;
+	apr_sdbm_datum_t val;
+	register short *ino = (short *) pag;
+
+	if ((n = ino[0]) == 0)
+		return sdbm_nullitem;
+
+	if ((i = seepair(pag, n, key.dptr, key.dsize)) == 0)
+		return sdbm_nullitem;
+
+	val.dptr = pag + ino[i + 1];
+	val.dsize = ino[i] - ino[i + 1];
+	return val;
+}
+
+int
+duppair(pag, key)
+char *pag;
+apr_sdbm_datum_t key;
+{
+	register short *ino = (short *) pag;
+	return ino[0] > 0 && seepair(pag, ino[0], key.dptr, key.dsize) > 0;
+}
+
+apr_sdbm_datum_t
+getnkey(pag, num)
+char *pag;
+int num;
+{
+	apr_sdbm_datum_t key;
+	register int off;
+	register short *ino = (short *) pag;
+
+	num = num * 2 - 1;
+	if (ino[0] == 0 || num > ino[0])
+		return sdbm_nullitem;
+
+	off = (num > 1) ? ino[num - 1] : PBLKSIZ;
+
+	key.dptr = pag + ino[num];
+	key.dsize = off - ino[num];
+
+	return key;
+}
+
+int
+delpair(pag, key)
+char *pag;
+apr_sdbm_datum_t key;
+{
+	register int n;
+	register int i;
+	register short *ino = (short *) pag;
+
+	if ((n = ino[0]) == 0)
+		return 0;
+
+	if ((i = seepair(pag, n, key.dptr, key.dsize)) == 0)
+		return 0;
+/*
+ * found the key. if it is the last entry
+ * [i.e. i == n - 1] we just adjust the entry count.
+ * hard case: move all data down onto the deleted pair,
+ * shift offsets onto deleted offsets, and adjust them.
+ * [note: 0 < i < n]
+ */
+	if (i < n - 1) {
+		register int m;
+		register char *dst = pag + (i == 1 ? PBLKSIZ : ino[i - 1]);
+		register char *src = pag + ino[i + 1];
+		register short zoo = (short) (dst - src);
+
+		debug(("free-up %d ", zoo));
+/*
+ * shift data/keys down
+ */
+		m = ino[i + 1] - ino[n];
+
+#undef DUFF	/* just use memmove. it should be plenty fast. */
+#ifdef DUFF
+#define MOVB 	*--dst = *--src
+
+		if (m > 0) {
+			register int loop = (m + 8 - 1) >> 3;
+
+			switch (m & (8 - 1)) {
+			case 0:	do {
+				MOVB;	case 7:	MOVB;
+			case 6:	MOVB;	case 5:	MOVB;
+			case 4:	MOVB;	case 3:	MOVB;
+			case 2:	MOVB;	case 1:	MOVB;
+				} while (--loop);
+			}
+		}
+#else
+		dst -= m;
+		src -= m;
+		memmove(dst, src, m);
+#endif
+
+/*
+ * adjust offset index up
+ */
+		while (i < n - 1) {
+			ino[i] = ino[i + 2] + zoo;
+			i++;
+		}
+	}
+	ino[0] -= 2;
+	return 1;
+}
+
+/*
+ * search for the key in the page.
+ * return offset index in the range 0 < i < n.
+ * return 0 if not found.
+ */
+static int
+seepair(pag, n, key, siz)
+char *pag;
+register int n;
+register char *key;
+register int siz;
+{
+	register int i;
+	register int off = PBLKSIZ;
+	register short *ino = (short *) pag;
+
+	for (i = 1; i < n; i += 2) {
+		if (siz == off - ino[i] &&
+		    memcmp(key, pag + ino[i], siz) == 0)
+			return i;
+		off = ino[i + 1];
+	}
+	return 0;
+}
+
+void
+splpage(pag, new, sbit)
+char *pag;
+char *new;
+long sbit;
+{
+	apr_sdbm_datum_t key;
+	apr_sdbm_datum_t val;
+
+	register int n;
+	register int off = PBLKSIZ;
+	char cur[PBLKSIZ];
+	register short *ino = (short *) cur;
+
+	(void) memcpy(cur, pag, PBLKSIZ);
+	(void) memset(pag, 0, PBLKSIZ);
+	(void) memset(new, 0, PBLKSIZ);
+
+	n = ino[0];
+	for (ino++; n > 0; ino += 2) {
+		key.dptr = cur + ino[0]; 
+		key.dsize = off - ino[0];
+		val.dptr = cur + ino[1];
+		val.dsize = ino[0] - ino[1];
+/*
+ * select the page pointer (by looking at sbit) and insert
+ */
+		(void) putpair((exhash(key) & sbit) ? new : pag, key, val);
+
+		off = ino[1];
+		n -= 2;
+	}
+
+	debug(("%d split %d/%d\n", ((short *) cur)[0] / 2, 
+	       ((short *) new)[0] / 2,
+	       ((short *) pag)[0] / 2));
+}
+
+/*
+ * check page sanity: 
+ * number of entries should be something
+ * reasonable, and all offsets in the index should be in order.
+ * this could be made more rigorous.
+ */
+int
+chkpage(pag)
+char *pag;
+{
+	register int n;
+	register int off;
+	register short *ino = (short *) pag;
+
+	if ((n = ino[0]) < 0 || n > PBLKSIZ / sizeof(short))
+		return 0;
+
+	if (n > 0) {
+		off = PBLKSIZ;
+		for (ino++; n > 0; ino += 2) {
+			if (ino[0] < 0 || ino[0] > off ||
+			    ino[1] < 0 || ino[1] > off ||
+			    ino[1] > ino[0])
+				return 0;
+			off = ino[1];
+			n -= 2;
+		}
+	}
+	return 1;
+}