/*-
* 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
* 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. 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.
*
*/
/*****************************************************************************
* File: mcache.h
*
* This is a modfied version of the original Berkley code for
* manipulating a memory pool. This version however is not
* compatible with the original Berkley version.
*
* This version uses HDF number types.
*
* AUTHOR - George V.- 1996/08/22
*****************************************************************************/
/* $Id: mcache.h 5146 2009-01-14 17:46:57Z fbaker $ */
/*
* NOTE:
* Here pagesize is the same thing as chunk size and pages refer to chunks.
* I just didn't bother to change all references from pages to chunks.
*
* -georgev
*/
#ifndef _MCACHE_H
#define _MCACHE_H
/* Required include */
#include "hqueue.h" /* Circluar queue functions(Macros) */
/* Set return/succeed values */
#ifdef SUCCEED
#define RET_SUCCESS SUCCEED
#define RET_ERROR FAIL
#else
#define RET_SUCCESS 0
#define RET_ERROR -1
#endif
/*
* The memory pool scheme is a simple one. Each in-memory page is referenced
* by a bucket which is threaded in up to two (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.
*/
/* Current Hash table size. Page numbers start with 1
* (i.e 0 will denote invalid page number) */
#define HASHSIZE 128
#define HASHKEY(pgno) ((pgno -1) % HASHSIZE)
/* Default pagesize and max # of pages to cache */
#define DEF_PAGESIZE 8192
#define DEF_MAXCACHE 1
#define MAX_PAGE_NUMBER 0xffffffff /* >= # of pages in a object */
/* 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 */
int32 pgno; /* page number */
#define MCACHE_DIRTY 0x01 /* page needs to be written */
#define MCACHE_PINNED 0x02 /* page is pinned into memory */
uint8 flags; /* flags */
} BKT;
/* The element structure for every page referenced(read/written) in object */
typedef struct _lelem
{
CIRCLEQ_ENTRY(_lelem) hl; /* hash list */
int32 pgno; /* page number */
#ifdef STATISTICS
int32 elemhit; /* # of hits on page */
#endif
#define ELEM_READ 0x01
#define ELEM_WRITTEN 0x02
#define ELEM_SYNC 0x03
uint8 eflags; /* 1= read, 2=written, 3=synced */
} L_ELEM;
#define MCACHE_EXTEND 0x10 /* increase number of pages
i.e extend object */
/* Memory pool cache */
typedef struct MCACHE
{
CIRCLEQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */
CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE]; /* hash queue array */
CIRCLEQ_HEAD(_lhqh, _lelem) lhqh[HASHSIZE]; /* hash of all elements */
int32 curcache; /* current num of cached pages */
int32 maxcache; /* max number of cached pages */
int32 npages; /* number of pages in the object */
int32 pagesize; /* cache page size */
int32 object_id; /* access ID of object this cache is for */
int32 object_size; /* size of object to cache
must be multiple of pagesize for now */
int32 (*pgin) (VOID *cookie, int32 pgno, VOID *page); /* page in conversion routine */
int32 (*pgout) (VOID *cookie, int32 pgno, const VOID *page);/* page out conversion routine*/
VOID *pgcookie; /* cookie for page in/out routines */
#ifdef STATISTICS
int32 listhit; /* # of list hits */
int32 listalloc; /* # of list elems allocated */
int32 cachehit; /* # of cache hits */
int32 cachemiss; /* # of cache misses */
int32 pagealloc; /* # of pages allocated */
int32 pageflush; /* # of pages flushed */
int32 pageget; /* # of pages requested from pool */
int32 pagenew; /* # of new pages */
int32 pageput; /* # of pages put back into pool */
int32 pageread; /* # of pages read from object */
int32 pagewrite; /* # of pages written to object */
#endif /* STATISTICS */
} MCACHE;
#if defined c_plusplus || defined __cplusplus
extern "C"
{
#endif /* c_plusplus || __cplusplus */
extern MCACHE *mcache_open (
VOID *key, /* IN:byte string used as handle to share buffers */
int32 object_id, /* IN: object handle */
int32 pagesize, /* IN: chunk size in bytes */
int32 maxcache, /* IN: maximum number of pages to cache at any time */
int32 npages, /* IN: number of chunks currently in object */
int32 flags /* IN: 0= object exists, 1= does not exist */);
extern VOID mcache_filter (
MCACHE *mp, /* IN: MCACHE cookie */
int32 (*pgin)(VOID *cookie, int32 pgno, VOID *page) ,/* IN: page in filter */
int32 (*pgout)(VOID *cookie, int32 pgno, const VOID *page) , /* IN: page out filter */
VOID *pgcookie /* IN: filter cookie */);
extern VOID *mcache_new (
MCACHE *mp, /* IN: MCACHE cookie */
int32 *pgnoaddr, /* IN/OUT: address of newly create page */
int32 flags /* IN:MCACHE_EXTEND or 0 */);
extern VOID *mcache_get (
MCACHE *mp, /* IN: MCACHE cookie */
int32 pgno, /* IN: page number */
int32 flags /* IN: XXX not used? */);
extern intn mcache_put (
MCACHE *mp, /* IN: MCACHE cookie */
VOID *page, /* IN: page to put */
int32 flags /* IN: flags = 0, MCACHE_DIRTY */);
extern intn mcache_sync (
MCACHE *mp /* IN: MCACHE cookie */);
extern intn mcache_close (
MCACHE *mp /* IN: MCACHE cookie */);
extern int32 mcache_get_pagesize (
MCACHE *mp /* IN: MCACHE cookie */);
extern int32 mcache_get_maxcache (
MCACHE *mp /* IN: MCACHE cookie */);
extern int32 mcache_set_maxcache (
MCACHE *mp, /* IN: MCACHE cookie */
int32 maxcache /* IN: max pages to cache */);
extern int32 mcache_get_npages (
MCACHE *mp /* IN: MCACHE cookie */);
#ifdef STATISTICS
extern VOID mcache_stat(
MCACHE *mp /* IN: MCACHE cookie */);
#endif /* STATISTICS */
#if 0 /* NOT USED */
extern intn mcache_page_sync (
MCACHE *mp, /* IN: MCACHE cookie */
int32 pgno, /* IN: page to sync */
int32 flags /* IN: flags */);
#endif
#if defined c_plusplus || defined __cplusplus
}
#endif /* c_plusplus || __cplusplus */
#endif /* _MCACHE_H */