--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nss/lib/dbm/include/mpool.h	Tue Aug 05 18:32:02 2014 +0200
@@ -0,0 +1,97 @@
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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. ***REMOVED*** - see 
+ *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
+ * 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.
+ *
+ *	@(#)mpool.h	8.2 (Berkeley) 7/14/94
+ */
+
+#include <sys/queue.h>
+
+/*
+ * The memory pool scheme is a simple one.  Each in-memory page is referenced
+ * by a bucket which is threaded in up to two of three ways.  All active pages
+ * are threaded on a hash chain (hashed by page number) and an lru chain.
+ * Inactive pages are threaded on a free chain.  Each reference to a memory
+ * pool is handed an opaque MPOOL cookie which stores all of this information.
+ */
+#define	HASHSIZE	128
+#define	HASHKEY(pgno)	((pgno - 1) % HASHSIZE)
+
+/* The BKT structures are the elements of the queues. */
+typedef struct _bkt {
+	CIRCLEQ_ENTRY(_bkt) hq;		/* hash queue */
+	CIRCLEQ_ENTRY(_bkt) q;		/* lru queue */
+	void    *page;			/* page */
+	pgno_t   pgno;			/* page number */
+
+#define	MPOOL_DIRTY	0x01		/* page needs to be written */
+#define	MPOOL_PINNED	0x02		/* page is pinned into memory */
+	uint8 flags;			/* flags */
+} BKT;
+
+typedef struct MPOOL {
+	CIRCLEQ_HEAD(_lqh, _bkt) lqh;	/* lru queue head */
+					/* hash queue array */
+	CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];
+	pgno_t	curcache;		/* current number of cached pages */
+	pgno_t	maxcache;		/* max number of cached pages */
+	pgno_t	npages;			/* number of pages in the file */
+	uint32	pagesize;		/* file page size */
+	int	fd;			/* file descriptor */
+					/* page in conversion routine */
+	void    (*pgin) (void *, pgno_t, void *);
+					/* page out conversion routine */
+	void    (*pgout) (void *, pgno_t, void *);
+	void	*pgcookie;		/* cookie for page in/out routines */
+#ifdef STATISTICS
+	uint32	cachehit;
+	uint32	cachemiss;
+	uint32	pagealloc;
+	uint32	pageflush;
+	uint32	pageget;
+	uint32	pagenew;
+	uint32	pageput;
+	uint32	pageread;
+	uint32	pagewrite;
+#endif
+} MPOOL;
+
+__BEGIN_DECLS
+MPOOL	*mpool_open (void *, int, pgno_t, pgno_t);
+void	 mpool_filter (MPOOL *, void (*)(void *, pgno_t, void *),
+	    void (*)(void *, pgno_t, void *), void *);
+void	*mpool_new (MPOOL *, pgno_t *);
+void	*mpool_get (MPOOL *, pgno_t, uint);
+int	 mpool_put (MPOOL *, void *, uint);
+int	 mpool_sync (MPOOL *);
+int	 mpool_close (MPOOL *);
+#ifdef STATISTICS
+void	 mpool_stat (MPOOL *);
+#endif
+__END_DECLS