Main Page | Modules | Namespace List | Data Structures | File List | Data Fields | Globals | Related Pages

sdbm_private.h

00001 /* ====================================================================
00002  * The Apache Software License, Version 1.1
00003  *
00004  * Copyright (c) 2000-2003 The Apache Software Foundation.  All rights
00005  * reserved.
00006  *
00007  * Redistribution and use in source and binary forms, with or without
00008  * modification, are permitted provided that the following conditions
00009  * are met:
00010  *
00011  * 1. Redistributions of source code must retain the above copyright
00012  *    notice, this list of conditions and the following disclaimer.
00013  *
00014  * 2. Redistributions in binary form must reproduce the above copyright
00015  *    notice, this list of conditions and the following disclaimer in
00016  *    the documentation and/or other materials provided with the
00017  *    distribution.
00018  *
00019  * 3. The end-user documentation included with the redistribution,
00020  *    if any, must include the following acknowledgment:
00021  *       "This product includes software developed by the
00022  *        Apache Software Foundation (http://www.apache.org/)."
00023  *    Alternately, this acknowledgment may appear in the software itself,
00024  *    if and wherever such third-party acknowledgments normally appear.
00025  *
00026  * 4. The names "Apache" and "Apache Software Foundation" must
00027  *    not be used to endorse or promote products derived from this
00028  *    software without prior written permission. For written
00029  *    permission, please contact apache@apache.org.
00030  *
00031  * 5. Products derived from this software may not be called "Apache",
00032  *    nor may "Apache" appear in their name, without prior written
00033  *    permission of the Apache Software Foundation.
00034  *
00035  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
00036  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00037  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
00038  * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
00039  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00040  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00041  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
00042  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
00043  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00044  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
00045  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00046  * SUCH DAMAGE.
00047  * ====================================================================
00048  *
00049  * This software consists of voluntary contributions made by many
00050  * individuals on behalf of the Apache Software Foundation.  For more
00051  * information on the Apache Software Foundation, please see
00052  * <http://www.apache.org/>.
00053  */
00054 
00055 /*
00056  * sdbm - ndbm work-alike hashed database library
00057  * based on Per-Ake Larson's Dynamic Hashing algorithms. BIT 18 (1978).
00058  * author: oz@nexus.yorku.ca
00059  */
00060 
00061 #ifndef SDBM_PRIVATE_H
00062 #define SDBM_PRIVATE_H
00063 
00064 #include "apr.h"
00065 #include "apr_pools.h"
00066 #include "apr_file_io.h"
00067 #include "apr_errno.h" /* for apr_status_t */
00068 
00069 #if 0
00070 /* if the block/page size is increased, it breaks perl apr_sdbm_t compatibility */
00071 #define DBLKSIZ 16384
00072 #define PBLKSIZ 8192
00073 #define PAIRMAX 8008                    /* arbitrary on PBLKSIZ-N */
00074 #else
00075 #define DBLKSIZ 4096
00076 #define PBLKSIZ 1024
00077 #define PAIRMAX 1008                    /* arbitrary on PBLKSIZ-N */
00078 #endif
00079 #define SPLTMAX 10                      /* maximum allowed splits */
00080 
00081 /* for apr_sdbm_t.flags */
00082 #define SDBM_RDONLY             0x1    /* data base open read-only */
00083 #define SDBM_SHARED             0x2    /* data base open for sharing */
00084 #define SDBM_SHARED_LOCK        0x4    /* data base locked for shared read */
00085 #define SDBM_EXCLUSIVE_LOCK     0x8    /* data base locked for write */
00086 
00087 struct apr_sdbm_t {
00088     apr_pool_t *pool;
00089     apr_file_t *dirf;                  /* directory file descriptor */
00090     apr_file_t *pagf;                  /* page file descriptor */
00091     apr_int32_t flags;                 /* status/error flags, see below */
00092     long maxbno;                       /* size of dirfile in bits */
00093     long curbit;                       /* current bit number */
00094     long hmask;                        /* current hash mask */
00095     long blkptr;                       /* current block for nextkey */
00096     int  keyptr;                       /* current key for nextkey */
00097     long blkno;                        /* current page to read/write */
00098     long pagbno;                       /* current page in pagbuf */
00099     char pagbuf[PBLKSIZ];              /* page file block buffer */
00100     long dirbno;                       /* current block in dirbuf */
00101     char dirbuf[DBLKSIZ];              /* directory file block buffer */
00102     int  lckcnt;                       /* number of calls to sdbm_lock */
00103 };
00104 
00105 
00106 #define sdbm_hash apu__sdbm_hash
00107 #define sdbm_nullitem apu__sdbm_nullitem
00108 
00109 extern const apr_sdbm_datum_t sdbm_nullitem;
00110 
00111 long sdbm_hash(const char *str, int len);
00112 
00113 /*
00114  * zero the cache
00115  */
00116 #define SDBM_INVALIDATE_CACHE(db, finfo) \
00117     do { db->dirbno = (!finfo.size) ? 0 : -1; \
00118          db->pagbno = -1; \
00119          db->maxbno = (long)(finfo.size * BYTESIZ); \
00120     } while (0);
00121 
00122 #endif /* SDBM_PRIVATE_H */

Generated on Tue Dec 7 18:34:56 2010 for Apache Portable Runtime Utility Library by  doxygen 1.3.9.1