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 * 4. 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 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char sccsid[] = "@(#)bt_put.c 8.8 (Berkeley) 7/26/94"; 35 #endif /* LIBC_SCCS and not lint */ 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include <sys/types.h> 40 41 #include <errno.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 46 #include <db.h> 47 #include "btree.h" 48 49 static EPG *bt_fast(BTREE *, const DBT *, const DBT *, int *); 50 51 /* 52 * __BT_PUT -- Add a btree item to the tree. 53 * 54 * Parameters: 55 * dbp: pointer to access method 56 * key: key 57 * data: data 58 * flag: R_NOOVERWRITE, R_SETCURSOR, R_CURSOR 59 * 60 * Returns: 61 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the 62 * tree and R_NOOVERWRITE specified. 63 */ 64 int 65 __bt_put(const DB *dbp, DBT *key, const DBT *data, u_int flags) 66 { 67 BTREE *t; 68 DBT tkey, tdata; 69 EPG *e; 70 PAGE *h; 71 indx_t idx, nxtindex; 72 pgno_t pg; 73 u_int32_t nbytes, tmp; 74 int dflags, exact, status; 75 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 76 77 t = dbp->internal; 78 79 /* Toss any page pinned across calls. */ 80 if (t->bt_pinned != NULL) { 81 mpool_put(t->bt_mp, t->bt_pinned, 0); 82 t->bt_pinned = NULL; 83 } 84 85 /* Check for change to a read-only tree. */ 86 if (F_ISSET(t, B_RDONLY)) { 87 errno = EPERM; 88 return (RET_ERROR); 89 } 90 91 switch (flags) { 92 case 0: 93 case R_NOOVERWRITE: 94 case R_SETCURSOR: 95 break; 96 case R_CURSOR: 97 /* 98 * If flags is R_CURSOR, put the cursor. Must already 99 * have started a scan and not have already deleted it. 100 */ 101 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 102 !F_ISSET(&t->bt_cursor, 103 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 104 break; 105 /* FALLTHROUGH */ 106 default: 107 errno = EINVAL; 108 return (RET_ERROR); 109 } 110 111 /* 112 * If the key/data pair won't fit on a page, store it on overflow 113 * pages. Only put the key on the overflow page if the pair are 114 * still too big after moving the data to an overflow page. 115 * 116 * XXX 117 * If the insert fails later on, the overflow pages aren't recovered. 118 */ 119 dflags = 0; 120 if (key->size + data->size > t->bt_ovflsize) { 121 if (key->size > t->bt_ovflsize) { 122 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 123 return (RET_ERROR); 124 tkey.data = kb; 125 tkey.size = NOVFLSIZE; 126 memmove(kb, &pg, sizeof(pgno_t)); 127 tmp = key->size; 128 memmove(kb + sizeof(pgno_t), 129 &tmp, sizeof(u_int32_t)); 130 dflags |= P_BIGKEY; 131 key = &tkey; 132 } 133 if (key->size + data->size > t->bt_ovflsize) { 134 if (__ovfl_put(t, data, &pg) == RET_ERROR) 135 return (RET_ERROR); 136 tdata.data = db; 137 tdata.size = NOVFLSIZE; 138 memmove(db, &pg, sizeof(pgno_t)); 139 tmp = data->size; 140 memmove(db + sizeof(pgno_t), 141 &tmp, sizeof(u_int32_t)); 142 dflags |= P_BIGDATA; 143 data = &tdata; 144 } 145 if (key->size + data->size > t->bt_ovflsize) 146 goto storekey; 147 } 148 149 /* Replace the cursor. */ 150 if (flags == R_CURSOR) { 151 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 152 return (RET_ERROR); 153 idx = t->bt_cursor.pg.index; 154 goto delete; 155 } 156 157 /* 158 * Find the key to delete, or, the location at which to insert. 159 * Bt_fast and __bt_search both pin the returned page. 160 */ 161 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 162 if ((e = __bt_search(t, key, &exact)) == NULL) 163 return (RET_ERROR); 164 h = e->page; 165 idx = e->index; 166 167 /* 168 * Add the key/data pair to the tree. If an identical key is already 169 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 170 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 171 * permitted) or an error is returned. 172 */ 173 switch (flags) { 174 case R_NOOVERWRITE: 175 if (!exact) 176 break; 177 mpool_put(t->bt_mp, h, 0); 178 return (RET_SPECIAL); 179 default: 180 if (!exact || !F_ISSET(t, B_NODUPS)) 181 break; 182 /* 183 * !!! 184 * Note, the delete may empty the page, so we need to put a 185 * new entry into the page immediately. 186 */ 187 delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) { 188 mpool_put(t->bt_mp, h, 0); 189 return (RET_ERROR); 190 } 191 break; 192 } 193 194 /* 195 * If not enough room, or the user has put a ceiling on the number of 196 * keys permitted in the page, split the page. The split code will 197 * insert the key and data and unpin the current page. If inserting 198 * into the offset array, shift the pointers up. 199 */ 200 nbytes = NBLEAFDBT(key->size, data->size); 201 if ((u_int32_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) { 202 if ((status = __bt_split(t, h, key, 203 data, dflags, nbytes, idx)) != RET_SUCCESS) 204 return (status); 205 goto success; 206 } 207 208 if (idx < (nxtindex = NEXTINDEX(h))) 209 memmove(h->linp + idx + 1, h->linp + idx, 210 (nxtindex - idx) * sizeof(indx_t)); 211 h->lower += sizeof(indx_t); 212 213 h->linp[idx] = h->upper -= nbytes; 214 dest = (char *)h + h->upper; 215 WR_BLEAF(dest, key, data, dflags); 216 217 /* If the cursor is on this page, adjust it as necessary. */ 218 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 219 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 220 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) 221 ++t->bt_cursor.pg.index; 222 223 if (t->bt_order == NOT) { 224 if (h->nextpg == P_INVALID) { 225 if (idx == NEXTINDEX(h) - 1) { 226 t->bt_order = FORWARD; 227 t->bt_last.index = idx; 228 t->bt_last.pgno = h->pgno; 229 } 230 } else if (h->prevpg == P_INVALID) { 231 if (idx == 0) { 232 t->bt_order = BACK; 233 t->bt_last.index = 0; 234 t->bt_last.pgno = h->pgno; 235 } 236 } 237 } 238 239 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 240 241 success: 242 if (flags == R_SETCURSOR) 243 __bt_setcur(t, e->page->pgno, e->index); 244 245 F_SET(t, B_MODIFIED); 246 return (RET_SUCCESS); 247 } 248 249 #ifdef STATISTICS 250 u_long bt_cache_hit, bt_cache_miss; 251 #endif 252 253 /* 254 * BT_FAST -- Do a quick check for sorted data. 255 * 256 * Parameters: 257 * t: tree 258 * key: key to insert 259 * 260 * Returns: 261 * EPG for new record or NULL if not found. 262 */ 263 static EPG * 264 bt_fast(BTREE *t, const DBT *key, const DBT *data, int *exactp) 265 { 266 PAGE *h; 267 u_int32_t nbytes; 268 int cmp; 269 270 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 271 t->bt_order = NOT; 272 return (NULL); 273 } 274 t->bt_cur.page = h; 275 t->bt_cur.index = t->bt_last.index; 276 277 /* 278 * If won't fit in this page or have too many keys in this page, 279 * have to search to get split stack. 280 */ 281 nbytes = NBLEAFDBT(key->size, data->size); 282 if ((u_int32_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) 283 goto miss; 284 285 if (t->bt_order == FORWARD) { 286 if (t->bt_cur.page->nextpg != P_INVALID) 287 goto miss; 288 if (t->bt_cur.index != NEXTINDEX(h) - 1) 289 goto miss; 290 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 291 goto miss; 292 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 293 } else { 294 if (t->bt_cur.page->prevpg != P_INVALID) 295 goto miss; 296 if (t->bt_cur.index != 0) 297 goto miss; 298 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 299 goto miss; 300 t->bt_last.index = 0; 301 } 302 *exactp = cmp == 0; 303 #ifdef STATISTICS 304 ++bt_cache_hit; 305 #endif 306 return (&t->bt_cur); 307 308 miss: 309 #ifdef STATISTICS 310 ++bt_cache_miss; 311 #endif 312 t->bt_order = NOT; 313 mpool_put(t->bt_mp, h, 0); 314 return (NULL); 315 } 316