Initial revision

CVS patchset: 5630
CVS date: 2002/08/14 16:31:49

2 files changed, 185 insertions, 0 deletions

diff --git a/db/common/db_idspace.c b/db/common/db_idspace.c
new file mode 100644
index 000000000..7defde82b
--- /dev/null
+++ b/db/common/db_idspace.c
@@ -0,0 +1,93 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 2001-2002
+ *	Sleepycat Software.  All rights reserved.
+ */
+
+#include "db_config.h"
+
+#ifndef lint
+static const char revid[] = "Id: db_idspace.c,v 1.5 2002/02/01 18:15:29 bostic Exp ";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <stdlib.h>
+#endif
+
+#include "db_int.h"
+
+static int __db_idcmp __P((const void *, const void *));
+
+static int
+__db_idcmp(a, b)
+	const void *a;
+	const void *b;
+{
+	u_int32_t i, j;
+
+	i = *(u_int32_t *)a;
+	j = *(u_int32_t *)b;
+
+	if (i < j)
+		return (-1);
+	else if (i > j)
+		return (1);
+	else
+		return (0);
+}
+
+/*
+ * __db_idspace --
+ *
+ * On input, minp and maxp contain the minimum and maximum valid values for
+ * the name space and on return, they contain the minimum and maximum ids
+ * available (by finding the biggest gap).
+ *
+ * PUBLIC: void __db_idspace __P((u_int32_t *, int, u_int32_t *, u_int32_t *));
+ */
+void
+__db_idspace(inuse, n, minp, maxp)
+	u_int32_t *inuse;
+	int n;
+	u_int32_t *minp, *maxp;
+{
+	int i, low;
+	u_int32_t gap, t;
+
+	/* A single locker ID is a special case. */
+	if (n == 1) {
+		/*
+		 * If the single item in use is the last one in the range,
+		 * then we've got to perform wrap which means that we set
+		 * the min to the minimum ID, which is what we came in with,
+		 * so we don't do anything.
+		 */
+		if (inuse[0] != *maxp)
+			*minp = inuse[0];
+		*maxp = inuse[0] - 1;
+		return;
+	}
+
+	gap = 0;
+	low = 0;
+	qsort(inuse, n, sizeof(u_int32_t), __db_idcmp);
+	for (i = 0; i < n - 1; i++)
+		if ((t = (inuse[i + 1] - inuse[i])) > gap) {
+			gap = t;
+			low = i;
+		}
+
+	/* Check for largest gap at the end of the space. */
+	if ((*maxp - inuse[n - 1]) + (inuse[0] - *minp) > gap) {
+		/* Do same check as we do in the n == 1 case. */
+		if (inuse[n - 1] != *maxp)
+			*minp = inuse[n - 1];
+		*maxp = inuse[0];
+	} else {
+		*minp = inuse[low];
+		*maxp = inuse[low + 1];
+	}
+}
diff --git a/db/common/util_cache.c b/db/common/util_cache.c
new file mode 100644
index 000000000..c8af63062
--- /dev/null
+++ b/db/common/util_cache.c
@@ -0,0 +1,92 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 2000-2002
+ *	Sleepycat Software.  All rights reserved.
+ */
+
+#include "db_config.h"
+
+#ifndef lint
+static const char revid[] = "Id: util_cache.c,v 1.3 2002/04/04 18:50:10 bostic Exp ";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <stdlib.h>
+
+#include <string.h>
+#include <unistd.h>
+#endif
+
+#include "db_int.h"
+
+/*
+ * __db_util_cache --
+ *	Compute if we have enough cache.
+ *
+ * PUBLIC: int __db_util_cache __P((DB_ENV *, DB *, u_int32_t *, int *));
+ */
+int
+__db_util_cache(dbenv, dbp, cachep, resizep)
+	DB_ENV *dbenv;
+	DB *dbp;
+	u_int32_t *cachep;
+	int *resizep;
+{
+	DBTYPE type;
+	DB_BTREE_STAT *bsp;
+	DB_HASH_STAT *hsp;
+	DB_QUEUE_STAT *qsp;
+	u_int32_t pgsize;
+	int ret;
+	void *sp;
+
+	/*
+	 * The current cache size is in cachep.  If it's insufficient, set the
+	 * the memory referenced by resizep to 1 and set cachep to the minimum
+	 * size needed.
+	 */
+	if ((ret = dbp->get_type(dbp, &type)) != 0) {
+		dbenv->err(dbenv, ret, "DB->get_type");
+		return (ret);
+	}
+
+	if ((ret = dbp->stat(dbp, &sp, DB_FAST_STAT)) != 0) {
+		dbenv->err(dbenv, ret, "DB->stat");
+		return (ret);
+	}
+
+	switch (type) {
+	case DB_QUEUE:
+		qsp = (DB_QUEUE_STAT *)sp;
+		pgsize = qsp->qs_pagesize;
+		break;
+	case DB_HASH:
+		hsp = (DB_HASH_STAT *)sp;
+		pgsize = hsp->hash_pagesize;
+		break;
+	case DB_BTREE:
+	case DB_RECNO:
+		bsp = (DB_BTREE_STAT *)sp;
+		pgsize = bsp->bt_pagesize;
+		break;
+	default:
+		dbenv->err(dbenv, ret, "unknown database type: %d", type);
+		return (EINVAL);
+	}
+	free(sp);
+
+	/*
+	 * Make sure our current cache is big enough.  We want at least
+	 * DB_MINPAGECACHE pages in the cache.
+	 */
+	if ((*cachep / pgsize) < DB_MINPAGECACHE) {
+		*resizep = 1;
+		*cachep = pgsize * DB_MINPAGECACHE;
+	} else
+		*resizep = 0;
+
+	return (0);
+}