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264 lines
9.2 KiB
C
264 lines
9.2 KiB
C
/*-
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* See the file LICENSE for redistribution information.
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*
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* Copyright (c) 1996, 1997, 1998
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* Sleepycat Software. All rights reserved.
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*/
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/*
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* Copyright (c) 1990, 1993, 1994, 1995, 1996
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* Keith Bostic. All rights reserved.
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*/
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/*
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* Copyright (c) 1990, 1993, 1994, 1995
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Mike Olson.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)btree.h 10.26 (Sleepycat) 12/16/98
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*/
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/* Forward structure declarations. */
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struct __btree; typedef struct __btree BTREE;
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struct __cursor; typedef struct __cursor CURSOR;
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struct __epg; typedef struct __epg EPG;
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struct __recno; typedef struct __recno RECNO;
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#define DEFMINKEYPAGE (2)
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#define ISINTERNAL(p) (TYPE(p) == P_IBTREE || TYPE(p) == P_IRECNO)
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#define ISLEAF(p) (TYPE(p) == P_LBTREE || TYPE(p) == P_LRECNO)
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/*
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* If doing transactions we have to hold the locks associated with a data item
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* from a page for the entire transaction. However, we don't have to hold the
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* locks associated with walking the tree. Distinguish between the two so that
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* we don't tie up the internal pages of the tree longer than necessary.
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*/
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#define __BT_LPUT(dbc, lock) \
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(F_ISSET((dbc)->dbp, DB_AM_LOCKING) ? \
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lock_put((dbc)->dbp->dbenv->lk_info, lock) : 0)
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#define __BT_TLPUT(dbc, lock) \
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(F_ISSET((dbc)->dbp, DB_AM_LOCKING) && (dbc)->txn == NULL ? \
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lock_put((dbc)->dbp->dbenv->lk_info, lock) : 0)
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/*
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* Flags to __bam_search() and __bam_rsearch().
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*
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* Note, internal page searches must find the largest record less than key in
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* the tree so that descents work. Leaf page searches must find the smallest
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* record greater than key so that the returned index is the record's correct
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* position for insertion.
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*
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* The flags parameter to the search routines describes three aspects of the
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* search: the type of locking required (including if we're locking a pair of
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* pages), the item to return in the presence of duplicates and whether or not
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* to return deleted entries. To simplify both the mnemonic representation
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* and the code that checks for various cases, we construct a set of bitmasks.
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*/
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#define S_READ 0x00001 /* Read locks. */
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#define S_WRITE 0x00002 /* Write locks. */
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#define S_APPEND 0x00040 /* Append to the tree. */
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#define S_DELNO 0x00080 /* Don't return deleted items. */
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#define S_DUPFIRST 0x00100 /* Return first duplicate. */
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#define S_DUPLAST 0x00200 /* Return last duplicate. */
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#define S_EXACT 0x00400 /* Exact items only. */
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#define S_PARENT 0x00800 /* Lock page pair. */
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#define S_STACK 0x01000 /* Need a complete stack. */
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#define S_PAST_EOF 0x02000 /* If doing insert search (or keyfirst
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* or keylast operations), or a split
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* on behalf of an insert, it's okay to
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* return an entry one past end-of-page.
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*/
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#define S_DELETE (S_WRITE | S_DUPFIRST | S_DELNO | S_EXACT | S_STACK)
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#define S_FIND (S_READ | S_DUPFIRST | S_DELNO)
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#define S_FIND_WR (S_WRITE | S_DUPFIRST | S_DELNO)
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#define S_INSERT (S_WRITE | S_DUPLAST | S_PAST_EOF | S_STACK)
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#define S_KEYFIRST (S_WRITE | S_DUPFIRST | S_PAST_EOF | S_STACK)
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#define S_KEYLAST (S_WRITE | S_DUPLAST | S_PAST_EOF | S_STACK)
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#define S_WRPAIR (S_WRITE | S_DUPLAST | S_PAST_EOF | S_PARENT)
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/*
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* Flags to __bam_iitem().
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*/
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#define BI_DELETED 0x01 /* Key/data pair only placeholder. */
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#define BI_DOINCR 0x02 /* Increment the record count. */
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#define BI_NEWKEY 0x04 /* New key. */
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/*
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* Various routines pass around page references. A page reference can be a
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* pointer to the page or a page number; for either, an indx can designate
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* an item on the page.
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*/
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struct __epg {
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PAGE *page; /* The page. */
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db_indx_t indx; /* The index on the page. */
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DB_LOCK lock; /* The page's lock. */
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};
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/*
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* We maintain a stack of the pages that we're locking in the tree. Btree's
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* (currently) only save two levels of the tree at a time, so the default
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* stack is always large enough. Recno trees have to lock the entire tree to
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* do inserts/deletes, however. Grow the stack as necessary.
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*/
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#define BT_STK_CLR(c) \
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((c)->csp = (c)->sp)
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#define BT_STK_ENTER(c, pagep, page_indx, lock, ret) do { \
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if ((ret = \
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(c)->csp == (c)->esp ? __bam_stkgrow(c) : 0) == 0) { \
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(c)->csp->page = pagep; \
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(c)->csp->indx = page_indx; \
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(c)->csp->lock = lock; \
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} \
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} while (0)
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#define BT_STK_PUSH(c, pagep, page_indx, lock, ret) do { \
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BT_STK_ENTER(c, pagep, page_indx, lock, ret); \
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++(c)->csp; \
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} while (0)
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#define BT_STK_POP(c) \
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((c)->csp == (c)->stack ? NULL : --(c)->csp)
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/*
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* Arguments passed to __bam_ca_replace().
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*/
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typedef enum {
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REPLACE_SETUP,
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REPLACE_SUCCESS,
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REPLACE_FAILED
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} ca_replace_arg;
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/* Arguments passed to __ram_ca(). */
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typedef enum {
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CA_DELETE,
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CA_IAFTER,
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CA_IBEFORE
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} ca_recno_arg;
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#define RECNO_OOB 0 /* Illegal record number. */
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/* Btree/Recno cursor. */
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struct __cursor {
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DBC *dbc; /* Enclosing DBC. */
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/* Per-thread information: shared by btree/recno. */
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EPG *sp; /* Stack pointer. */
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EPG *csp; /* Current stack entry. */
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EPG *esp; /* End stack pointer. */
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EPG stack[5];
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/* Per-thread information: btree private. */
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PAGE *page; /* Cursor page. */
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db_pgno_t pgno; /* Page. */
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db_indx_t indx; /* Page item ref'd by the cursor. */
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db_pgno_t dpgno; /* Duplicate page. */
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db_indx_t dindx; /* Page item ref'd by the cursor. */
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DB_LOCK lock; /* Cursor read lock. */
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db_lockmode_t mode; /* Lock mode. */
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/* Per-thread information: recno private. */
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db_recno_t recno; /* Current record number. */
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/*
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* Btree:
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* We set a flag in the cursor structure if the underlying object has
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* been deleted. It's not strictly necessary, we could get the same
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* information by looking at the page itself.
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*
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* Recno:
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* When renumbering recno databases during deletes, cursors referencing
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* "deleted" records end up positioned between two records, and so must
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* be specially adjusted on the next operation.
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*/
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#define C_DELETED 0x0001 /* Record was deleted. */
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u_int32_t flags;
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};
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/*
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* The in-memory recno data structure.
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*
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* !!!
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* These fields are ignored as far as multi-threading is concerned. There
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* are no transaction semantics associated with backing files, nor is there
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* any thread protection.
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*/
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struct __recno {
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int re_delim; /* Variable-length delimiting byte. */
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int re_pad; /* Fixed-length padding byte. */
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u_int32_t re_len; /* Length for fixed-length records. */
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char *re_source; /* Source file name. */
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int re_fd; /* Source file descriptor */
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db_recno_t re_last; /* Last record number read. */
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void *re_cmap; /* Current point in mapped space. */
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void *re_smap; /* Start of mapped space. */
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void *re_emap; /* End of mapped space. */
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size_t re_msize; /* Size of mapped region. */
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/* Recno input function. */
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int (*re_irec) __P((DBC *, db_recno_t));
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#define RECNO_EOF 0x0001 /* EOF on backing source file. */
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#define RECNO_MODIFIED 0x0002 /* Tree was modified. */
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u_int32_t flags;
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};
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/*
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* The in-memory, per-tree btree data structure.
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*/
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struct __btree {
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db_pgno_t bt_lpgno; /* Last insert location. */
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db_indx_t bt_maxkey; /* Maximum keys per page. */
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db_indx_t bt_minkey; /* Minimum keys per page. */
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int (*bt_compare) /* Comparison function. */
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__P((const DBT *, const DBT *));
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size_t(*bt_prefix) /* Prefix function. */
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__P((const DBT *, const DBT *));
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db_indx_t bt_ovflsize; /* Maximum key/data on-page size. */
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RECNO *recno; /* Private recno structure. */
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};
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#include "btree_auto.h"
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#include "btree_ext.h"
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#include "db_am.h"
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#include "common_ext.h"
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