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* Copyright (c) 1991, 1993, 1994
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* The Regents of the University of California. All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* @(#)mpool.h 8.4 (Berkeley) 11/2/95
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* The memory pool scheme is a simple one. Each in-memory page is referenced
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* by a bucket which is threaded in up to two of three ways. All active pages
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* are threaded on a hash chain (hashed by page number) and an lru chain.
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* Inactive pages are threaded on a free chain. Each reference to a memory
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* pool is handed an opaque MPOOL cookie which stores all of this information.
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#define HASHKEY(pgno) ((pgno - 1) % HASHSIZE)
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/* The BKT structures are the elements of the queues. */
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CIRCLEQ_ENTRY(_bkt) hq; /* hash queue */
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CIRCLEQ_ENTRY(_bkt) q; /* lru queue */
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void *page; /* page */
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db_pgno_t pgno; /* page number */
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#define MPOOL_DIRTY 0x01 /* page needs to be written */
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#define MPOOL_PINNED 0x02 /* page is pinned into memory */
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#define MPOOL_INUSE 0x04 /* page address is valid */
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u_int8_t flags; /* flags */
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typedef struct MPOOL {
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CIRCLEQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */
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/* hash queue array */
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CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];
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db_pgno_t curcache; /* current number of cached pages */
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db_pgno_t maxcache; /* max number of cached pages */
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db_pgno_t npages; /* number of pages in the file */
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u_long pagesize; /* file page size */
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int fd; /* file descriptor */
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/* page in conversion routine */
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void (*pgin) __P((void *, db_pgno_t, void *));
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/* page out conversion routine */
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void (*pgout) __P((void *, db_pgno_t, void *));
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void *pgcookie; /* cookie for page in/out routines */
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#define MPOOL_IGNOREPIN 0x01 /* Ignore if the page is pinned. */
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#define MPOOL_PAGE_REQUEST 0x01 /* Allocate a new page with a
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specific page number. */
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#define MPOOL_PAGE_NEXT 0x02 /* Allocate a new page with the next
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#define mpool_open kdb2_mpool_open
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#define mpool_filter kdb2_mpool_filter
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#define mpool_new kdb2_mpool_new
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#define mpool_get kdb2_mpool_get
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#define mpool_delete kdb2_mpool_delete
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#define mpool_put kdb2_mpool_put
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#define mpool_sync kdb2_mpool_sync
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#define mpool_close kdb2_mpool_close
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#define mpool_stat kdb2_mpool_stat
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MPOOL *mpool_open __P((void *, int, db_pgno_t, db_pgno_t));
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void mpool_filter __P((MPOOL *, void (*)(void *, db_pgno_t, void *),
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void (*)(void *, db_pgno_t, void *), void *));
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void *mpool_new __P((MPOOL *, db_pgno_t *, u_int));
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void *mpool_get __P((MPOOL *, db_pgno_t, u_int));
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int mpool_delete __P((MPOOL *, void *));
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int mpool_put __P((MPOOL *, void *, u_int));
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int mpool_sync __P((MPOOL *));
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int mpool_close __P((MPOOL *));
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void mpool_stat __P((MPOOL *));