1 /*- 2 * See the file LICENSE for redistribution information. 3 * 4 * Copyright (c) 1996, 1997, 1998 5 * Sleepycat Software. All rights reserved. 6 */ 7 /* 8 * Copyright (c) 1990, 1993, 1994, 1995, 1996 9 * Keith Bostic. All rights reserved. 10 */ 11 /* 12 * Copyright (c) 1990, 1993, 1994, 1995 13 * The Regents of the University of California. All rights reserved. 14 * 15 * This code is derived from software contributed to Berkeley by 16 * Mike Olson. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 3. All advertising materials mentioning features or use of this software 27 * must display the following acknowledgement: 28 * This product includes software developed by the University of 29 * California, Berkeley and its contributors. 30 * 4. Neither the name of the University nor the names of its contributors 31 * may be used to endorse or promote products derived from this software 32 * without specific prior written permission. 33 * 34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 37 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 44 * SUCH DAMAGE. 45 * 46 * @(#)btree.h 10.26 (Sleepycat) 12/16/98 47 */ 48 49 /* Forward structure declarations. */ 50 struct __btree; typedef struct __btree BTREE; 51 struct __cursor; typedef struct __cursor CURSOR; 52 struct __epg; typedef struct __epg EPG; 53 struct __recno; typedef struct __recno RECNO; 54 55 #define DEFMINKEYPAGE (2) 56 57 #define ISINTERNAL(p) (TYPE(p) == P_IBTREE || TYPE(p) == P_IRECNO) 58 #define ISLEAF(p) (TYPE(p) == P_LBTREE || TYPE(p) == P_LRECNO) 59 60 /* 61 * If doing transactions we have to hold the locks associated with a data item 62 * from a page for the entire transaction. However, we don't have to hold the 63 * locks associated with walking the tree. Distinguish between the two so that 64 * we don't tie up the internal pages of the tree longer than necessary. 65 */ 66 #define __BT_LPUT(dbc, lock) \ 67 (F_ISSET((dbc)->dbp, DB_AM_LOCKING) ? \ 68 lock_put((dbc)->dbp->dbenv->lk_info, lock) : 0) 69 #define __BT_TLPUT(dbc, lock) \ 70 (F_ISSET((dbc)->dbp, DB_AM_LOCKING) && (dbc)->txn == NULL ? \ 71 lock_put((dbc)->dbp->dbenv->lk_info, lock) : 0) 72 73 /* 74 * Flags to __bam_search() and __bam_rsearch(). 75 * 76 * Note, internal page searches must find the largest record less than key in 77 * the tree so that descents work. Leaf page searches must find the smallest 78 * record greater than key so that the returned index is the record's correct 79 * position for insertion. 80 * 81 * The flags parameter to the search routines describes three aspects of the 82 * search: the type of locking required (including if we're locking a pair of 83 * pages), the item to return in the presence of duplicates and whether or not 84 * to return deleted entries. To simplify both the mnemonic representation 85 * and the code that checks for various cases, we construct a set of bitmasks. 86 */ 87 #define S_READ 0x00001 /* Read locks. */ 88 #define S_WRITE 0x00002 /* Write locks. */ 89 90 #define S_APPEND 0x00040 /* Append to the tree. */ 91 #define S_DELNO 0x00080 /* Don't return deleted items. */ 92 #define S_DUPFIRST 0x00100 /* Return first duplicate. */ 93 #define S_DUPLAST 0x00200 /* Return last duplicate. */ 94 #define S_EXACT 0x00400 /* Exact items only. */ 95 #define S_PARENT 0x00800 /* Lock page pair. */ 96 #define S_STACK 0x01000 /* Need a complete stack. */ 97 #define S_PAST_EOF 0x02000 /* If doing insert search (or keyfirst 98 * or keylast operations), or a split 99 * on behalf of an insert, it's okay to 100 * return an entry one past end-of-page. 101 */ 102 103 #define S_DELETE (S_WRITE | S_DUPFIRST | S_DELNO | S_EXACT | S_STACK) 104 #define S_FIND (S_READ | S_DUPFIRST | S_DELNO) 105 #define S_FIND_WR (S_WRITE | S_DUPFIRST | S_DELNO) 106 #define S_INSERT (S_WRITE | S_DUPLAST | S_PAST_EOF | S_STACK) 107 #define S_KEYFIRST (S_WRITE | S_DUPFIRST | S_PAST_EOF | S_STACK) 108 #define S_KEYLAST (S_WRITE | S_DUPLAST | S_PAST_EOF | S_STACK) 109 #define S_WRPAIR (S_WRITE | S_DUPLAST | S_PAST_EOF | S_PARENT) 110 111 /* 112 * Flags to __bam_iitem(). 113 */ 114 #define BI_DELETED 0x01 /* Key/data pair only placeholder. */ 115 #define BI_DOINCR 0x02 /* Increment the record count. */ 116 #define BI_NEWKEY 0x04 /* New key. */ 117 118 /* 119 * Various routines pass around page references. A page reference can be a 120 * pointer to the page or a page number; for either, an indx can designate 121 * an item on the page. 122 */ 123 struct __epg { 124 PAGE *page; /* The page. */ 125 db_indx_t indx; /* The index on the page. */ 126 DB_LOCK lock; /* The page's lock. */ 127 }; 128 129 /* 130 * We maintain a stack of the pages that we're locking in the tree. Btree's 131 * (currently) only save two levels of the tree at a time, so the default 132 * stack is always large enough. Recno trees have to lock the entire tree to 133 * do inserts/deletes, however. Grow the stack as necessary. 134 */ 135 #define BT_STK_CLR(c) \ 136 ((c)->csp = (c)->sp) 137 138 #define BT_STK_ENTER(c, pagep, page_indx, lock, ret) do { \ 139 if ((ret = \ 140 (c)->csp == (c)->esp ? __bam_stkgrow(c) : 0) == 0) { \ 141 (c)->csp->page = pagep; \ 142 (c)->csp->indx = page_indx; \ 143 (c)->csp->lock = lock; \ 144 } \ 145 } while (0) 146 147 #define BT_STK_PUSH(c, pagep, page_indx, lock, ret) do { \ 148 BT_STK_ENTER(c, pagep, page_indx, lock, ret); \ 149 ++(c)->csp; \ 150 } while (0) 151 152 #define BT_STK_POP(c) \ 153 ((c)->csp == (c)->stack ? NULL : --(c)->csp) 154 155 /* 156 * Arguments passed to __bam_ca_replace(). 157 */ 158 typedef enum { 159 REPLACE_SETUP, 160 REPLACE_SUCCESS, 161 REPLACE_FAILED 162 } ca_replace_arg; 163 164 /* Arguments passed to __ram_ca(). */ 165 typedef enum { 166 CA_DELETE, 167 CA_IAFTER, 168 CA_IBEFORE 169 } ca_recno_arg; 170 171 #define RECNO_OOB 0 /* Illegal record number. */ 172 173 /* Btree/Recno cursor. */ 174 struct __cursor { 175 DBC *dbc; /* Enclosing DBC. */ 176 177 /* Per-thread information: shared by btree/recno. */ 178 EPG *sp; /* Stack pointer. */ 179 EPG *csp; /* Current stack entry. */ 180 EPG *esp; /* End stack pointer. */ 181 EPG stack[5]; 182 183 /* Per-thread information: btree private. */ 184 PAGE *page; /* Cursor page. */ 185 186 db_pgno_t pgno; /* Page. */ 187 db_indx_t indx; /* Page item ref'd by the cursor. */ 188 189 db_pgno_t dpgno; /* Duplicate page. */ 190 db_indx_t dindx; /* Page item ref'd by the cursor. */ 191 192 DB_LOCK lock; /* Cursor read lock. */ 193 db_lockmode_t mode; /* Lock mode. */ 194 195 /* Per-thread information: recno private. */ 196 db_recno_t recno; /* Current record number. */ 197 198 /* 199 * Btree: 200 * We set a flag in the cursor structure if the underlying object has 201 * been deleted. It's not strictly necessary, we could get the same 202 * information by looking at the page itself. 203 * 204 * Recno: 205 * When renumbering recno databases during deletes, cursors referencing 206 * "deleted" records end up positioned between two records, and so must 207 * be specially adjusted on the next operation. 208 */ 209 #define C_DELETED 0x0001 /* Record was deleted. */ 210 u_int32_t flags; 211 }; 212 213 /* 214 * The in-memory recno data structure. 215 * 216 * !!! 217 * These fields are ignored as far as multi-threading is concerned. There 218 * are no transaction semantics associated with backing files, nor is there 219 * any thread protection. 220 */ 221 struct __recno { 222 int re_delim; /* Variable-length delimiting byte. */ 223 int re_pad; /* Fixed-length padding byte. */ 224 u_int32_t re_len; /* Length for fixed-length records. */ 225 226 char *re_source; /* Source file name. */ 227 int re_fd; /* Source file descriptor */ 228 db_recno_t re_last; /* Last record number read. */ 229 void *re_cmap; /* Current point in mapped space. */ 230 void *re_smap; /* Start of mapped space. */ 231 void *re_emap; /* End of mapped space. */ 232 size_t re_msize; /* Size of mapped region. */ 233 /* Recno input function. */ 234 int (*re_irec) __P((DBC *, db_recno_t)); 235 236 #define RECNO_EOF 0x0001 /* EOF on backing source file. */ 237 #define RECNO_MODIFIED 0x0002 /* Tree was modified. */ 238 u_int32_t flags; 239 }; 240 241 /* 242 * The in-memory, per-tree btree data structure. 243 */ 244 struct __btree { 245 db_pgno_t bt_lpgno; /* Last insert location. */ 246 247 db_indx_t bt_maxkey; /* Maximum keys per page. */ 248 db_indx_t bt_minkey; /* Minimum keys per page. */ 249 250 int (*bt_compare) /* Comparison function. */ 251 __P((const DBT *, const DBT *)); 252 size_t(*bt_prefix) /* Prefix function. */ 253 __P((const DBT *, const DBT *)); 254 255 db_indx_t bt_ovflsize; /* Maximum key/data on-page size. */ 256 257 RECNO *recno; /* Private recno structure. */ 258 }; 259 260 #include "btree_auto.h" 261 #include "btree_ext.h" 262 #include "db_am.h" 263 #include "common_ext.h" 264