1 /*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Olson. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)bt_put.c 8.8 (Berkeley) 7/26/94 33 * $DragonFly: src/lib/libc/db/btree/bt_put.c,v 1.8 2005/11/12 23:01:54 swildner Exp $ 34 */ 35 36 #include <sys/types.h> 37 38 #include <errno.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 43 #include <db.h> 44 #include "btree.h" 45 46 static EPG *bt_fast (BTREE *, const DBT *, const DBT *, int *); 47 48 /* 49 * __BT_PUT -- Add a btree item to the tree. 50 * 51 * Parameters: 52 * dbp: pointer to access method 53 * key: key 54 * data: data 55 * flag: R_NOOVERWRITE 56 * 57 * Returns: 58 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the 59 * tree and R_NOOVERWRITE specified. 60 */ 61 int 62 __bt_put(const DB *dbp, DBT *key, const DBT *data, u_int flags) 63 { 64 BTREE *t; 65 DBT tkey, tdata; 66 EPG *e = NULL; 67 PAGE *h; 68 indx_t idx, nxtindex; 69 pgno_t pg; 70 u_int32_t nbytes; 71 int dflags, exact, status; 72 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 73 74 t = dbp->internal; 75 76 /* Toss any page pinned across calls. */ 77 if (t->bt_pinned != NULL) { 78 mpool_put(t->bt_mp, t->bt_pinned, 0); 79 t->bt_pinned = NULL; 80 } 81 82 /* Check for change to a read-only tree. */ 83 if (F_ISSET(t, B_RDONLY)) { 84 errno = EPERM; 85 return (RET_ERROR); 86 } 87 88 switch (flags) { 89 case 0: 90 case R_NOOVERWRITE: 91 break; 92 case R_CURSOR: 93 /* 94 * If flags is R_CURSOR, put the cursor. Must already 95 * have started a scan and not have already deleted it. 96 */ 97 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 98 !F_ISSET(&t->bt_cursor, 99 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 100 break; 101 /* FALLTHROUGH */ 102 default: 103 errno = EINVAL; 104 return (RET_ERROR); 105 } 106 107 /* 108 * If the key/data pair won't fit on a page, store it on overflow 109 * pages. Only put the key on the overflow page if the pair are 110 * still too big after moving the data to an overflow page. 111 * 112 * XXX 113 * If the insert fails later on, the overflow pages aren't recovered. 114 */ 115 dflags = 0; 116 if (key->size + data->size > t->bt_ovflsize) { 117 if (key->size > t->bt_ovflsize) { 118 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 119 return (RET_ERROR); 120 tkey.data = kb; 121 tkey.size = NOVFLSIZE; 122 memmove(kb, &pg, sizeof(pgno_t)); 123 memmove(kb + sizeof(pgno_t), 124 &key->size, sizeof(u_int32_t)); 125 dflags |= P_BIGKEY; 126 key = &tkey; 127 } 128 if (key->size + data->size > t->bt_ovflsize) { 129 if (__ovfl_put(t, data, &pg) == RET_ERROR) 130 return (RET_ERROR); 131 tdata.data = db; 132 tdata.size = NOVFLSIZE; 133 memmove(db, &pg, sizeof(pgno_t)); 134 memmove(db + sizeof(pgno_t), 135 &data->size, sizeof(u_int32_t)); 136 dflags |= P_BIGDATA; 137 data = &tdata; 138 } 139 if (key->size + data->size > t->bt_ovflsize) 140 goto storekey; 141 } 142 143 /* Replace the cursor. */ 144 if (flags == R_CURSOR) { 145 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 146 return (RET_ERROR); 147 idx = t->bt_cursor.pg.index; 148 goto delete; 149 } 150 151 /* 152 * Find the key to delete, or, the location at which to insert. 153 * Bt_fast and __bt_search both pin the returned page. 154 */ 155 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 156 if ((e = __bt_search(t, key, &exact)) == NULL) 157 return (RET_ERROR); 158 h = e->page; 159 idx = e->index; 160 161 /* 162 * Add the key/data pair to the tree. If an identical key is already 163 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 164 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 165 * permitted) or an error is returned. 166 */ 167 switch (flags) { 168 case R_NOOVERWRITE: 169 if (!exact) 170 break; 171 mpool_put(t->bt_mp, h, 0); 172 return (RET_SPECIAL); 173 default: 174 if (!exact || !F_ISSET(t, B_NODUPS)) 175 break; 176 /* 177 * !!! 178 * Note, the delete may empty the page, so we need to put a 179 * new entry into the page immediately. 180 */ 181 delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) { 182 mpool_put(t->bt_mp, h, 0); 183 return (RET_ERROR); 184 } 185 break; 186 } 187 188 /* 189 * If not enough room, or the user has put a ceiling on the number of 190 * keys permitted in the page, split the page. The split code will 191 * insert the key and data and unpin the current page. If inserting 192 * into the offset array, shift the pointers up. 193 */ 194 nbytes = NBLEAFDBT(key->size, data->size); 195 if ((size_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) { 196 if ((status = __bt_split(t, h, key, 197 data, dflags, nbytes, idx)) != RET_SUCCESS) 198 return (status); 199 goto success; 200 } 201 202 if (idx < (nxtindex = NEXTINDEX(h))) 203 memmove(h->linp + idx + 1, h->linp + idx, 204 (nxtindex - idx) * sizeof(indx_t)); 205 h->lower += sizeof(indx_t); 206 207 h->linp[idx] = h->upper -= nbytes; 208 dest = (char *)h + h->upper; 209 WR_BLEAF(dest, key, data, dflags); 210 211 /* If the cursor is on this page, adjust it as necessary. */ 212 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 213 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 214 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) 215 ++t->bt_cursor.pg.index; 216 217 if (t->bt_order == NOT) { 218 if (h->nextpg == P_INVALID) { 219 if (idx == NEXTINDEX(h) - 1) { 220 t->bt_order = FORWARD; 221 t->bt_last.index = idx; 222 t->bt_last.pgno = h->pgno; 223 } 224 } else if (h->prevpg == P_INVALID) { 225 if (idx == 0) { 226 t->bt_order = BACK; 227 t->bt_last.index = 0; 228 t->bt_last.pgno = h->pgno; 229 } 230 } 231 } 232 233 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 234 235 success: 236 if (flags == R_SETCURSOR) 237 __bt_setcur(t, e->page->pgno, e->index); 238 239 F_SET(t, B_MODIFIED); 240 return (RET_SUCCESS); 241 } 242 243 #ifdef STATISTICS 244 u_long bt_cache_hit, bt_cache_miss; 245 #endif 246 247 /* 248 * BT_FAST -- Do a quick check for sorted data. 249 * 250 * Parameters: 251 * t: tree 252 * key: key to insert 253 * 254 * Returns: 255 * EPG for new record or NULL if not found. 256 */ 257 static EPG * 258 bt_fast(BTREE *t, const DBT *key, const DBT *data, int *exactp) 259 { 260 PAGE *h; 261 u_int32_t nbytes; 262 int cmp; 263 264 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 265 t->bt_order = NOT; 266 return (NULL); 267 } 268 t->bt_cur.page = h; 269 t->bt_cur.index = t->bt_last.index; 270 271 /* 272 * If won't fit in this page or have too many keys in this page, 273 * have to search to get split stack. 274 */ 275 nbytes = NBLEAFDBT(key->size, data->size); 276 if ((size_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) 277 goto miss; 278 279 if (t->bt_order == FORWARD) { 280 if (t->bt_cur.page->nextpg != P_INVALID) 281 goto miss; 282 if (t->bt_cur.index != NEXTINDEX(h) - 1) 283 goto miss; 284 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 285 goto miss; 286 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 287 } else { 288 if (t->bt_cur.page->prevpg != P_INVALID) 289 goto miss; 290 if (t->bt_cur.index != 0) 291 goto miss; 292 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 293 goto miss; 294 t->bt_last.index = 0; 295 } 296 *exactp = cmp == 0; 297 #ifdef STATISTICS 298 ++bt_cache_hit; 299 #endif 300 return (&t->bt_cur); 301 302 miss: 303 #ifdef STATISTICS 304 ++bt_cache_miss; 305 #endif 306 t->bt_order = NOT; 307 mpool_put(t->bt_mp, h, 0); 308 return (NULL); 309 } 310