michael@0: /*-
michael@0:  * Copyright (c) 1991, 1993, 1994
michael@0:  *	The Regents of the University of California.  All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 1. Redistributions of source code must retain the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer.
michael@0:  * 2. Redistributions in binary form must reproduce the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer in the
michael@0:  *    documentation and/or other materials provided with the distribution.
michael@0:  * 3. ***REMOVED*** - see 
michael@0:  *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
michael@0:  * 4. Neither the name of the University nor the names of its contributors
michael@0:  *    may be used to endorse or promote products derived from this software
michael@0:  *    without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
michael@0:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
michael@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
michael@0:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
michael@0:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
michael@0:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
michael@0:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
michael@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
michael@0:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
michael@0:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
michael@0:  * SUCH DAMAGE.
michael@0:  *
michael@0:  *	@(#)mpool.h	8.2 (Berkeley) 7/14/94
michael@0:  */
michael@0: 
michael@0: #include <sys/queue.h>
michael@0: 
michael@0: /*
michael@0:  * The memory pool scheme is a simple one.  Each in-memory page is referenced
michael@0:  * by a bucket which is threaded in up to two of three ways.  All active pages
michael@0:  * are threaded on a hash chain (hashed by page number) and an lru chain.
michael@0:  * Inactive pages are threaded on a free chain.  Each reference to a memory
michael@0:  * pool is handed an opaque MPOOL cookie which stores all of this information.
michael@0:  */
michael@0: #define	HASHSIZE	128
michael@0: #define	HASHKEY(pgno)	((pgno - 1) % HASHSIZE)
michael@0: 
michael@0: /* The BKT structures are the elements of the queues. */
michael@0: typedef struct _bkt {
michael@0: 	CIRCLEQ_ENTRY(_bkt) hq;		/* hash queue */
michael@0: 	CIRCLEQ_ENTRY(_bkt) q;		/* lru queue */
michael@0: 	void    *page;			/* page */
michael@0: 	pgno_t   pgno;			/* page number */
michael@0: 
michael@0: #define	MPOOL_DIRTY	0x01		/* page needs to be written */
michael@0: #define	MPOOL_PINNED	0x02		/* page is pinned into memory */
michael@0: 	uint8 flags;			/* flags */
michael@0: } BKT;
michael@0: 
michael@0: typedef struct MPOOL {
michael@0: 	CIRCLEQ_HEAD(_lqh, _bkt) lqh;	/* lru queue head */
michael@0: 					/* hash queue array */
michael@0: 	CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];
michael@0: 	pgno_t	curcache;		/* current number of cached pages */
michael@0: 	pgno_t	maxcache;		/* max number of cached pages */
michael@0: 	pgno_t	npages;			/* number of pages in the file */
michael@0: 	uint32	pagesize;		/* file page size */
michael@0: 	int	fd;			/* file descriptor */
michael@0: 					/* page in conversion routine */
michael@0: 	void    (*pgin) (void *, pgno_t, void *);
michael@0: 					/* page out conversion routine */
michael@0: 	void    (*pgout) (void *, pgno_t, void *);
michael@0: 	void	*pgcookie;		/* cookie for page in/out routines */
michael@0: #ifdef STATISTICS
michael@0: 	uint32	cachehit;
michael@0: 	uint32	cachemiss;
michael@0: 	uint32	pagealloc;
michael@0: 	uint32	pageflush;
michael@0: 	uint32	pageget;
michael@0: 	uint32	pagenew;
michael@0: 	uint32	pageput;
michael@0: 	uint32	pageread;
michael@0: 	uint32	pagewrite;
michael@0: #endif
michael@0: } MPOOL;
michael@0: 
michael@0: __BEGIN_DECLS
michael@0: MPOOL	*mpool_open (void *, int, pgno_t, pgno_t);
michael@0: void	 mpool_filter (MPOOL *, void (*)(void *, pgno_t, void *),
michael@0: 	    void (*)(void *, pgno_t, void *), void *);
michael@0: void	*mpool_new (MPOOL *, pgno_t *);
michael@0: void	*mpool_get (MPOOL *, pgno_t, uint);
michael@0: int	 mpool_put (MPOOL *, void *, uint);
michael@0: int	 mpool_sync (MPOOL *);
michael@0: int	 mpool_close (MPOOL *);
michael@0: #ifdef STATISTICS
michael@0: void	 mpool_stat (MPOOL *);
michael@0: #endif
michael@0: __END_DECLS