1 /* $NetBSD: bt_put.c,v 1.19 2009/02/12 06:40:14 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Mike Olson. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #if HAVE_NBTOOL_CONFIG_H 36 #include "nbtool_config.h" 37 #endif 38 39 #include <sys/cdefs.h> 40 __RCSID("$NetBSD: bt_put.c,v 1.19 2009/02/12 06:40:14 lukem Exp $"); 41 42 #include "namespace.h" 43 #include <sys/types.h> 44 45 #include <assert.h> 46 #include <errno.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 51 #include <db.h> 52 #include "btree.h" 53 54 static EPG *bt_fast(BTREE *, const DBT *, const DBT *, int *); 55 56 /* 57 * __BT_PUT -- Add a btree item to the tree. 58 * 59 * Parameters: 60 * dbp: pointer to access method 61 * key: key 62 * data: data 63 * flag: R_NOOVERWRITE 64 * 65 * Returns: 66 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the 67 * tree and R_NOOVERWRITE specified. 68 */ 69 int 70 __bt_put(const DB *dbp, DBT *key, const DBT *data, u_int flags) 71 { 72 BTREE *t; 73 DBT tkey, tdata; 74 EPG *e = NULL; /* pacify gcc */ 75 PAGE *h; 76 indx_t idx, nxtindex; 77 pgno_t pg; 78 uint32_t nbytes, temp; 79 int dflags, exact, status; 80 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 81 82 t = dbp->internal; 83 84 /* Toss any page pinned across calls. */ 85 if (t->bt_pinned != NULL) { 86 mpool_put(t->bt_mp, t->bt_pinned, 0); 87 t->bt_pinned = NULL; 88 } 89 90 /* Check for change to a read-only tree. */ 91 if (F_ISSET(t, B_RDONLY)) { 92 errno = EPERM; 93 return (RET_ERROR); 94 } 95 96 switch (flags) { 97 case 0: 98 case R_NOOVERWRITE: 99 break; 100 case R_CURSOR: 101 /* 102 * If flags is R_CURSOR, put the cursor. Must already 103 * have started a scan and not have already deleted it. 104 */ 105 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 106 !F_ISSET(&t->bt_cursor, 107 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 108 break; 109 /* FALLTHROUGH */ 110 default: 111 errno = EINVAL; 112 return (RET_ERROR); 113 } 114 115 /* 116 * If the key/data pair won't fit on a page, store it on overflow 117 * pages. Only put the key on the overflow page if the pair are 118 * still too big after moving the data to an overflow page. 119 * 120 * XXX 121 * If the insert fails later on, the overflow pages aren't recovered. 122 */ 123 dflags = 0; 124 if (key->size + data->size > t->bt_ovflsize) { 125 if (key->size > t->bt_ovflsize) { 126 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 127 return (RET_ERROR); 128 tkey.data = kb; 129 tkey.size = NOVFLSIZE; 130 memmove(kb, &pg, sizeof(pgno_t)); 131 memmove(kb + sizeof(pgno_t), 132 &key->size, sizeof(uint32_t)); 133 dflags |= P_BIGKEY; 134 key = &tkey; 135 } 136 if (key->size + data->size > t->bt_ovflsize) { 137 if (__ovfl_put(t, data, &pg) == RET_ERROR) 138 return (RET_ERROR); 139 tdata.data = db; 140 tdata.size = NOVFLSIZE; 141 memmove(db, &pg, sizeof(pgno_t)); 142 _DBFIT(data->size, uint32_t); 143 temp = (uint32_t)data->size; 144 (void)memmove(db + sizeof(pgno_t), 145 &temp, sizeof(uint32_t)); 146 dflags |= P_BIGDATA; 147 data = &tdata; 148 } 149 if (key->size + data->size > t->bt_ovflsize) 150 goto storekey; 151 } 152 153 /* Replace the cursor. */ 154 if (flags == R_CURSOR) { 155 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 156 return (RET_ERROR); 157 idx = t->bt_cursor.pg.index; 158 goto delete; 159 } 160 161 /* 162 * Find the key to delete, or, the location at which to insert. 163 * Bt_fast and __bt_search both pin the returned page. 164 */ 165 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 166 if ((e = __bt_search(t, key, &exact)) == NULL) 167 return (RET_ERROR); 168 h = e->page; 169 idx = e->index; 170 171 /* 172 * Add the key/data pair to the tree. If an identical key is already 173 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 174 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 175 * permitted) or an error is returned. 176 */ 177 switch (flags) { 178 case R_NOOVERWRITE: 179 if (!exact) 180 break; 181 mpool_put(t->bt_mp, h, 0); 182 return (RET_SPECIAL); 183 default: 184 if (!exact || !F_ISSET(t, B_NODUPS)) 185 break; 186 /* 187 * !!! 188 * Note, the delete may empty the page, so we need to put a 189 * new entry into the page immediately. 190 */ 191 delete: if (__bt_dleaf(t, key, h, (u_int)idx) == RET_ERROR) { 192 mpool_put(t->bt_mp, h, 0); 193 return (RET_ERROR); 194 } 195 break; 196 } 197 198 /* 199 * If not enough room, or the user has put a ceiling on the number of 200 * keys permitted in the page, split the page. The split code will 201 * insert the key and data and unpin the current page. If inserting 202 * into the offset array, shift the pointers up. 203 */ 204 nbytes = NBLEAFDBT(key->size, data->size); 205 if ((uint32_t)h->upper - (uint32_t)h->lower < nbytes + sizeof(indx_t)) { 206 if ((status = __bt_split(t, h, key, 207 data, dflags, nbytes, (u_int)idx)) != RET_SUCCESS) 208 return (status); 209 goto success; 210 } 211 212 if (idx < (nxtindex = NEXTINDEX(h))) 213 memmove(h->linp + idx + 1, h->linp + idx, 214 (nxtindex - idx) * sizeof(indx_t)); 215 h->lower += sizeof(indx_t); 216 217 h->linp[idx] = h->upper -= nbytes; 218 dest = (char *)(void *)h + h->upper; 219 WR_BLEAF(dest, key, data, dflags); 220 221 /* If the cursor is on this page, adjust it as necessary. */ 222 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 223 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 224 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) 225 ++t->bt_cursor.pg.index; 226 227 if (t->bt_order == NOT) { 228 if (h->nextpg == P_INVALID) { 229 if (idx == NEXTINDEX(h) - 1) { 230 t->bt_order = FORWARD; 231 t->bt_last.index = idx; 232 t->bt_last.pgno = h->pgno; 233 } 234 } else if (h->prevpg == P_INVALID) { 235 if (idx == 0) { 236 t->bt_order = BACK; 237 t->bt_last.index = 0; 238 t->bt_last.pgno = h->pgno; 239 } 240 } 241 } 242 243 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 244 245 success: 246 if (flags == R_SETCURSOR) 247 __bt_setcur(t, e->page->pgno, (u_int)e->index); 248 249 F_SET(t, B_MODIFIED); 250 return (RET_SUCCESS); 251 } 252 253 #ifdef STATISTICS 254 unsigned long bt_cache_hit, bt_cache_miss; 255 #endif 256 257 /* 258 * BT_FAST -- Do a quick check for sorted data. 259 * 260 * Parameters: 261 * t: tree 262 * key: key to insert 263 * 264 * Returns: 265 * EPG for new record or NULL if not found. 266 */ 267 static EPG * 268 bt_fast(BTREE *t, const DBT *key, const DBT *data, int *exactp) 269 { 270 PAGE *h; 271 uint32_t nbytes; 272 int cmp; 273 274 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 275 t->bt_order = NOT; 276 return (NULL); 277 } 278 t->bt_cur.page = h; 279 t->bt_cur.index = t->bt_last.index; 280 281 /* 282 * If won't fit in this page or have too many keys in this page, 283 * have to search to get split stack. 284 */ 285 nbytes = NBLEAFDBT(key->size, data->size); 286 if ((uint32_t)h->upper - (uint32_t)h->lower < nbytes + sizeof(indx_t)) 287 goto miss; 288 289 if (t->bt_order == FORWARD) { 290 if (t->bt_cur.page->nextpg != P_INVALID) 291 goto miss; 292 if (t->bt_cur.index != NEXTINDEX(h) - 1) 293 goto miss; 294 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 295 goto miss; 296 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 297 } else { 298 if (t->bt_cur.page->prevpg != P_INVALID) 299 goto miss; 300 if (t->bt_cur.index != 0) 301 goto miss; 302 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 303 goto miss; 304 t->bt_last.index = 0; 305 } 306 *exactp = cmp == 0; 307 #ifdef STATISTICS 308 ++bt_cache_hit; 309 #endif 310 return (&t->bt_cur); 311 312 miss: 313 #ifdef STATISTICS 314 ++bt_cache_miss; 315 #endif 316 t->bt_order = NOT; 317 mpool_put(t->bt_mp, h, 0); 318 return (NULL); 319 } 320