📄 hash.h
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/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996-2002 * 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 11.26 2002/03/27 04:34:54 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 0x90typedef 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_ */
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