From a6ce65d368e623088a4c1a29865889f431b15420 Mon Sep 17 00:00:00 2001 From: rgrimes Date: Tue, 24 May 1994 09:57:34 +0000 Subject: BSD 4.4 Lite Include Sources --- include/mpool.h | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 include/mpool.h (limited to 'include/mpool.h') diff --git a/include/mpool.h b/include/mpool.h new file mode 100644 index 0000000..910e078 --- /dev/null +++ b/include/mpool.h @@ -0,0 +1,135 @@ +/*- + * Copyright (c) 1991, 1993 + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 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 8.1 (Berkeley) 6/2/93 + */ + +/* + * 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. + */ +#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 */ + +#define MPOOL_DIRTY 0x01 /* page needs to be written */ +#define MPOOL_PINNED 0x02 /* page is pinned into memory */ + unsigned long 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. */ + void (*pgin) __P((void *, pgno_t, void *)); + /* Page out conversion routine. */ + void (*pgout) __P((void *, pgno_t, void *)); + 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; +#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)); +void mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *), + void (*)(void *, pgno_t, void *), void *)); +void *mpool_new __P((MPOOL *, pgno_t *)); +void *mpool_get __P((MPOOL *, pgno_t, u_int)); +int mpool_put __P((MPOOL *, void *, u_int)); +int mpool_sync __P((MPOOL *)); +int mpool_close __P((MPOOL *)); +#ifdef STATISTICS +void mpool_stat __P((MPOOL *)); +#endif +__END_DECLS -- cgit v1.1