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+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997
+ * 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. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. 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.
+ *
+ * @(#)hash.h 10.6 (Sleepycat) 8/18/97
+ */
+
+/* Cursor structure definitions. */
+typedef struct cursor_t {
+ DBC *db_cursor;
+ db_pgno_t bucket; /* Bucket we are traversing. */
+ DB_LOCK lock; /* Lock held on the current bucket. */
+ PAGE *pagep; /* The current page. */
+ db_pgno_t pgno; /* Current page number. */
+ db_indx_t bndx; /* Index within the current page. */
+ PAGE *dpagep; /* Duplicate page pointer. */
+ db_pgno_t dpgno; /* Duplicate page number. */
+ db_indx_t dndx; /* Index within a duplicate set. */
+ 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 big_keylen; /* Length of big_key buffer. */
+ void *big_key; /* Temporary buffer for big keys. */
+ u_int32_t big_datalen; /* Length of big_data buffer. */
+ void *big_data; /* Temporary buffer for big data. */
+#define H_OK 0x0001
+#define H_NOMORE 0x0002
+#define H_DELETED 0x0004
+#define H_ISDUP 0x0008
+#define H_EXPAND 0x0020
+ u_int32_t flags; /* Is cursor inside a dup set. */
+} HASH_CURSOR;
+
+#define IS_VALID(C) ((C)->bucket != BUCKET_INVALID)
+
+
+typedef struct htab { /* Memory resident data structure. */
+ DB *dbp; /* Pointer to parent db structure. */
+ DB_LOCK hlock; /* Metadata page lock. */
+ HASHHDR *hdr; /* Pointer to meta-data page. */
+ u_int32_t (*hash) __P((const void *, u_int32_t)); /* Hash Function */
+ PAGE *split_buf; /* Temporary buffer for splits. */
+ int local_errno; /* Error Number -- for DBM compatability */
+ u_long hash_accesses; /* Number of accesses to this table. */
+ u_long hash_collisions; /* Number of collisions on search. */
+ u_long hash_expansions; /* Number of times we added a bucket. */
+ u_long hash_overflows; /* Number of overflow pages. */
+ u_long hash_bigpages; /* Number of big key/data pages. */
+} HTAB;
+
+/*
+ * Macro used for interface functions to set the txnid in the DBP.
+ */
+#define SET_LOCKER(D, T) ((D)->txn = (T))
+
+/*
+ * More interface macros used to get/release the meta data page.
+ */
+#define GET_META(D, H) { \
+ int _r; \
+ if (F_ISSET(D, DB_AM_LOCKING) && !F_ISSET(D, DB_AM_RECOVER)) { \
+ (D)->lock.pgno = BUCKET_INVALID; \
+ if ((_r = lock_get((D)->dbenv->lk_info, \
+ (D)->txn == NULL ? (D)->locker : (D)->txn->txnid, \
+ 0, &(D)->lock_dbt, DB_LOCK_READ, \
+ &(H)->hlock)) != 0) \
+ return (_r < 0 ? EAGAIN : _r); \
+ } \
+ if ((_r = __ham_get_page(D, 0, (PAGE **)&((H)->hdr))) != 0) { \
+ if ((H)->hlock) { \
+ (void)lock_put((D)->dbenv->lk_info, (H)->hlock);\
+ (H)->hlock = 0; \
+ } \
+ return (_r); \
+ } \
+}
+
+#define RELEASE_META(D, H) { \
+ if (!F_ISSET(D, DB_AM_RECOVER) && \
+ (D)->txn == NULL && (H)->hlock) \
+ (void)lock_put((H)->dbp->dbenv->lk_info, (H)->hlock); \
+ (H)->hlock = 0; \
+ if ((H)->hdr) \
+ (void)__ham_put_page(D, (PAGE *)(H)->hdr, \
+ F_ISSET(D, DB_HS_DIRTYMETA) ? 1 : 0); \
+ (H)->hdr = NULL; \
+ F_CLR(D, DB_HS_DIRTYMETA); \
+}
+
+#define DIRTY_META(H, R) { \
+ if (F_ISSET((H)->dbp, DB_AM_LOCKING) && \
+ !F_ISSET((H)->dbp, DB_AM_RECOVER)) { \
+ DB_LOCK _tmp; \
+ (H)->dbp->lock.pgno = BUCKET_INVALID; \
+ if (((R) = lock_get((H)->dbp->dbenv->lk_info, \
+ (H)->dbp->txn ? (H)->dbp->txn->txnid : \
+ (H)->dbp->locker, 0, &(H)->dbp->lock_dbt, \
+ DB_LOCK_WRITE, &_tmp)) == 0) \
+ (R) = lock_put((H)->dbp->dbenv->lk_info, \
+ (H)->hlock); \
+ else if ((R) < 0) \
+ (R) = EAGAIN; \
+ (H)->hlock = _tmp; \
+ } \
+ F_SET((H)->dbp, DB_HS_DIRTYMETA); \
+}
+
+/* Allocate and discard thread structures. */
+#define H_GETHANDLE(dbp, dbpp, ret) \
+ if (F_ISSET(dbp, DB_AM_THREAD)) \
+ ret = __db_gethandle(dbp, __ham_hdup, dbpp); \
+ else { \
+ ret = 0; \
+ *dbpp = dbp; \
+ }
+
+#define H_PUTHANDLE(dbp) { \
+ if (F_ISSET(dbp, DB_AM_THREAD)) \
+ __db_puthandle(dbp); \
+}
+
+/* Test string. */
+#define CHARKEY "%$sniglet^&"
+
+/* Overflow management */
+/*
+ * Overflow page numbers are allocated per split point. At each doubling of
+ * the table, we can allocate extra pages. We keep track of how many pages
+ * we've allocated at each point to calculate bucket to page number mapping.
+ */
+#define BUCKET_TO_PAGE(H, B) \
+ ((B) + 1 + ((B) ? (H)->hdr->spares[__db_log2((B)+1)-1] : 0))
+
+#define PGNO_OF(H, S, O) (BUCKET_TO_PAGE((H), (1 << (S)) - 1) + (O))
+
+/* Constraints about number of pages and how much data goes on a page. */
+
+#define MAX_PAGES(H) UINT32_T_MAX
+#define MINFILL 0.25
+#define ISBIG(H, N) (((N) > ((H)->hdr->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_ISKEYBIG(N) (N & PAIR_KEYMASK)
+#define PAIR_ISDATABIG(N) (N & PAIR_DATAMASK)
+#define OPCODE_OF(N) (N & ~(PAIR_KEYMASK | PAIR_DATAMASK))
+
+#define PUTPAIR 0x20
+#define DELPAIR 0x30
+#define PUTOVFL 0x40
+#define DELOVFL 0x50
+#define ALLOCPGNO 0x60
+#define DELPGNO 0x70
+#define SPLITOLD 0x80
+#define SPLITNEW 0x90
+
+#include "hash_auto.h"
+#include "hash_ext.h"
+#include "db_am.h"
+#include "common_ext.h"