acl/lib_dict/bdb/include/hash.h
2014-11-19 00:25:21 +08:00

148 lines
5.3 KiB
C

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996-2004
* Sleepycat Software. All rights reserved.
*/
/*
* Copyright (c) 1990, 1993, 1994
* Margo Seltzer. All rights reserved.
*/
/*
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Margo Seltzer.
*
* 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.
*
* $Id: hash.h,v 11.28 2004/01/28 03:36:02 bostic Exp $
*/
#ifndef _DB_HASH_H_
#define _DB_HASH_H_
/* Hash internal structure. */
typedef struct hash_t {
db_pgno_t meta_pgno; /* Page number of the meta data page. */
u_int32_t h_ffactor; /* Fill factor. */
u_int32_t h_nelem; /* Number of elements. */
/* Hash function. */
u_int32_t (*h_hash) __P((DB *, const void *, u_int32_t));
} HASH;
/* Cursor structure definitions. */
typedef struct cursor_t {
/* struct __dbc_internal */
__DBC_INTERNAL
/* Hash private part */
/* Per-thread information */
DB_LOCK hlock; /* Metadata page lock. */
HMETA *hdr; /* Pointer to meta-data page. */
PAGE *split_buf; /* Temporary buffer for splits. */
/* Hash cursor information */
db_pgno_t bucket; /* Bucket we are traversing. */
db_pgno_t lbucket; /* Bucket for which we are locked. */
db_indx_t dup_off; /* Offset within a duplicate set. */
db_indx_t dup_len; /* Length of current duplicate. */
db_indx_t dup_tlen; /* Total length of duplicate entry. */
u_int32_t seek_size; /* Number of bytes we need for add. */
db_pgno_t seek_found_page;/* Page on which we can insert. */
u_int32_t order; /* Relative order among deleted curs. */
#define H_CONTINUE 0x0001 /* Join--search strictly fwd for data */
#define H_DELETED 0x0002 /* Cursor item is deleted. */
#define H_DIRTY 0x0004 /* Meta-data page needs to be written */
#define H_DUPONLY 0x0008 /* Dups only; do not change key. */
#define H_EXPAND 0x0010 /* Table expanded. */
#define H_ISDUP 0x0020 /* Cursor is within duplicate set. */
#define H_NEXT_NODUP 0x0040 /* Get next non-dup entry. */
#define H_NOMORE 0x0080 /* No more entries in bucket. */
#define H_OK 0x0100 /* Request succeeded. */
u_int32_t flags;
} HASH_CURSOR;
/* Test string. */
#define CHARKEY "%$sniglet^&"
/* Overflow management */
/*
* The spares table indicates the page number at which each doubling begins.
* From this page number we subtract the number of buckets already allocated
* so that we can do a simple addition to calculate the page number here.
*/
#define BS_TO_PAGE(bucket, spares) \
((bucket) + (spares)[__db_log2((bucket) + 1)])
#define BUCKET_TO_PAGE(I, B) (BS_TO_PAGE((B), (I)->hdr->spares))
/* Constraints about much data goes on a page. */
#define MINFILL 4
#define ISBIG(I, N) (((N) > ((I)->hdr->dbmeta.pagesize / MINFILL)) ? 1 : 0)
/* Shorthands for accessing structure */
#define NDX_INVALID 0xFFFF
#define BUCKET_INVALID 0xFFFFFFFF
/* On page duplicates are stored as a string of size-data-size triples. */
#define DUP_SIZE(len) ((len) + 2 * sizeof(db_indx_t))
/* Log messages types (these are subtypes within a record type) */
#define PAIR_KEYMASK 0x1
#define PAIR_DATAMASK 0x2
#define PAIR_DUPMASK 0x4
#define PAIR_MASK 0xf
#define PAIR_ISKEYBIG(N) (N & PAIR_KEYMASK)
#define PAIR_ISDATABIG(N) (N & PAIR_DATAMASK)
#define PAIR_ISDATADUP(N) (N & PAIR_DUPMASK)
#define OPCODE_OF(N) (N & ~PAIR_MASK)
#define PUTPAIR 0x20
#define DELPAIR 0x30
#define PUTOVFL 0x40
#define DELOVFL 0x50
#define HASH_UNUSED1 0x60
#define HASH_UNUSED2 0x70
#define SPLITOLD 0x80
#define SPLITNEW 0x90
typedef enum {
DB_HAM_CHGPG = 1,
DB_HAM_DELFIRSTPG = 2,
DB_HAM_DELMIDPG = 3,
DB_HAM_DELLASTPG = 4,
DB_HAM_DUP = 5,
DB_HAM_SPLIT = 6
} db_ham_mode;
#include "dbinc_auto/hash_auto.h"
#include "dbinc_auto/hash_ext.h"
#include "dbinc/db_am.h"
#endif /* !_DB_HASH_H_ */