db release 1.85

src/include/mpool.h

@@ -1,7 +1,7 @@
-/*	$NetBSD: mpool.h,v 1.6 1994/10/26 00:56:07 cgd Exp $	*/
+/*	$NetBSD: mpool.h,v 1.7 1996/05/03 21:13:41 cgd Exp $	*/
 
 /*-
- * Copyright (c) 1991, 1993
+ * 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
@@ -32,98 +32,62 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)mpool.h	8.1 (Berkeley) 6/2/93
+ *	@(#)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 three ways.  All active pages are threaded
- * on a hash chain (hashed by the page number) and an lru chain.  Inactive
- * pages are threaded on a free chain.  Each reference to a memory pool is
- * handed an MPOOL which is the opaque cookie passed to all of the memory
- * routines.
+ * 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 lists. */
-typedef struct BKT {
-	struct BKT	*hnext;		/* next hash bucket */
-	struct BKT	*hprev;		/* previous hash bucket */
-	struct BKT	*cnext;		/* next free/lru bucket */
-	struct BKT	*cprev;		/* previous free/lru bucket */
-	void		*page;		/* page */
-	pgno_t		pgno;		/* page number */
+/* 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 */
-	unsigned long	flags;		/* flags */
+	u_int8_t flags;			/* flags */
 } BKT;
 
-/* The BKTHDR structures are the heads of the lists. */
-typedef struct BKTHDR {
-	struct BKT	*hnext;		/* next hash bucket */
-	struct BKT	*hprev;		/* previous hash bucket */
-	struct BKT	*cnext;		/* next free/lru bucket */
-	struct BKT	*cprev;		/* previous free/lru bucket */
-} BKTHDR;
-
 typedef struct MPOOL {
-	BKTHDR	free;			/* The free list. */
-	BKTHDR	lru;			/* The LRU list. */
-	BKTHDR	hashtable[HASHSIZE];	/* Hashed list by page number. */
-	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. */
-	u_long	pagesize;		/* File page size. */
-	int	fd;			/* File descriptor. */
-					/* Page in conversion routine. */
+	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 */
+	u_long	pagesize;		/* file page size */
+	int	fd;			/* file descriptor */
+					/* page in conversion routine */
 	void    (*pgin) __P((void *, pgno_t, void *));
-					/* Page out conversion routine. */
+					/* page out conversion routine */
 	void    (*pgout) __P((void *, pgno_t, void *));
-	void	*pgcookie;		/* Cookie for page in/out routines. */
+	void	*pgcookie;		/* cookie for page in/out routines */
 #ifdef STATISTICS
-	unsigned long	cachehit;
-	unsigned long	cachemiss;
-	unsigned long	pagealloc;
-	unsigned long	pageflush;
-	unsigned long	pageget;
-	unsigned long	pagenew;
-	unsigned long	pageput;
-	unsigned long	pageread;
-	unsigned long	pagewrite;
+	u_long	cachehit;
+	u_long	cachemiss;
+	u_long	pagealloc;
+	u_long	pageflush;
+	u_long	pageget;
+	u_long	pagenew;
+	u_long	pageput;
+	u_long	pageread;
+	u_long	pagewrite;
 #endif
 } MPOOL;
 
-#ifdef __MPOOLINTERFACE_PRIVATE
-/* Macros to insert/delete into/from hash chain. */
-#define rmhash(bp) { \
-        (bp)->hprev->hnext = (bp)->hnext; \
-        (bp)->hnext->hprev = (bp)->hprev; \
-}
-#define inshash(bp, pg) { \
-	hp = &mp->hashtable[HASHKEY(pg)]; \
-        (bp)->hnext = hp->hnext; \
-        (bp)->hprev = (struct BKT *)hp; \
-        hp->hnext->hprev = (bp); \
-        hp->hnext = (bp); \
-}
-
-/* Macros to insert/delete into/from lru and free chains. */
-#define	rmchain(bp) { \
-        (bp)->cprev->cnext = (bp)->cnext; \
-        (bp)->cnext->cprev = (bp)->cprev; \
-}
-#define inschain(bp, dp) { \
-        (bp)->cnext = (dp)->cnext; \
-        (bp)->cprev = (struct BKT *)(dp); \
-        (dp)->cnext->cprev = (bp); \
-        (dp)->cnext = (bp); \
-}
-#endif
-
 __BEGIN_DECLS
-MPOOL	*mpool_open __P((DBT *, int, pgno_t, pgno_t));
+MPOOL	*mpool_open __P((void *, int, pgno_t, pgno_t));
 void	 mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *),
 	    void (*)(void *, pgno_t, void *), void *));
 void	*mpool_new __P((MPOOL *, pgno_t *));