mpool.h revision 1.6
1 /* $NetBSD: mpool.h,v 1.6 1994/10/26 00:56:07 cgd Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)mpool.h 8.1 (Berkeley) 6/2/93 36 */ 37 38 /* 39 * The memory pool scheme is a simple one. Each in memory page is referenced 40 * by a bucket which is threaded in three ways. All active pages are threaded 41 * on a hash chain (hashed by the page number) and an lru chain. Inactive 42 * pages are threaded on a free chain. Each reference to a memory pool is 43 * handed an MPOOL which is the opaque cookie passed to all of the memory 44 * routines. 45 */ 46 #define HASHSIZE 128 47 #define HASHKEY(pgno) ((pgno - 1) % HASHSIZE) 48 49 /* The BKT structures are the elements of the lists. */ 50 typedef struct BKT { 51 struct BKT *hnext; /* next hash bucket */ 52 struct BKT *hprev; /* previous hash bucket */ 53 struct BKT *cnext; /* next free/lru bucket */ 54 struct BKT *cprev; /* previous free/lru bucket */ 55 void *page; /* page */ 56 pgno_t pgno; /* page number */ 57 58 #define MPOOL_DIRTY 0x01 /* page needs to be written */ 59 #define MPOOL_PINNED 0x02 /* page is pinned into memory */ 60 unsigned long flags; /* flags */ 61 } BKT; 62 63 /* The BKTHDR structures are the heads of the lists. */ 64 typedef struct BKTHDR { 65 struct BKT *hnext; /* next hash bucket */ 66 struct BKT *hprev; /* previous hash bucket */ 67 struct BKT *cnext; /* next free/lru bucket */ 68 struct BKT *cprev; /* previous free/lru bucket */ 69 } BKTHDR; 70 71 typedef struct MPOOL { 72 BKTHDR free; /* The free list. */ 73 BKTHDR lru; /* The LRU list. */ 74 BKTHDR hashtable[HASHSIZE]; /* Hashed list by page number. */ 75 pgno_t curcache; /* Current number of cached pages. */ 76 pgno_t maxcache; /* Max number of cached pages. */ 77 pgno_t npages; /* Number of pages in the file. */ 78 u_long pagesize; /* File page size. */ 79 int fd; /* File descriptor. */ 80 /* Page in conversion routine. */ 81 void (*pgin) __P((void *, pgno_t, void *)); 82 /* Page out conversion routine. */ 83 void (*pgout) __P((void *, pgno_t, void *)); 84 void *pgcookie; /* Cookie for page in/out routines. */ 85 #ifdef STATISTICS 86 unsigned long cachehit; 87 unsigned long cachemiss; 88 unsigned long pagealloc; 89 unsigned long pageflush; 90 unsigned long pageget; 91 unsigned long pagenew; 92 unsigned long pageput; 93 unsigned long pageread; 94 unsigned long pagewrite; 95 #endif 96 } MPOOL; 97 98 #ifdef __MPOOLINTERFACE_PRIVATE 99 /* Macros to insert/delete into/from hash chain. */ 100 #define rmhash(bp) { \ 101 (bp)->hprev->hnext = (bp)->hnext; \ 102 (bp)->hnext->hprev = (bp)->hprev; \ 103 } 104 #define inshash(bp, pg) { \ 105 hp = &mp->hashtable[HASHKEY(pg)]; \ 106 (bp)->hnext = hp->hnext; \ 107 (bp)->hprev = (struct BKT *)hp; \ 108 hp->hnext->hprev = (bp); \ 109 hp->hnext = (bp); \ 110 } 111 112 /* Macros to insert/delete into/from lru and free chains. */ 113 #define rmchain(bp) { \ 114 (bp)->cprev->cnext = (bp)->cnext; \ 115 (bp)->cnext->cprev = (bp)->cprev; \ 116 } 117 #define inschain(bp, dp) { \ 118 (bp)->cnext = (dp)->cnext; \ 119 (bp)->cprev = (struct BKT *)(dp); \ 120 (dp)->cnext->cprev = (bp); \ 121 (dp)->cnext = (bp); \ 122 } 123 #endif 124 125 __BEGIN_DECLS 126 MPOOL *mpool_open __P((DBT *, int, pgno_t, pgno_t)); 127 void mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *), 128 void (*)(void *, pgno_t, void *), void *)); 129 void *mpool_new __P((MPOOL *, pgno_t *)); 130 void *mpool_get __P((MPOOL *, pgno_t, u_int)); 131 int mpool_put __P((MPOOL *, void *, u_int)); 132 int mpool_sync __P((MPOOL *)); 133 int mpool_close __P((MPOOL *)); 134 #ifdef STATISTICS 135 void mpool_stat __P((MPOOL *)); 136 #endif 137 __END_DECLS 138
Indexes created Wed Sep 24 22:09:59 GMT 2025