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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char sccsid[] = "@(#)bt_put.c 8.8 (Berkeley) 7/26/94"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/types.h> 42 43 #include <errno.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 48 #include "db-int.h" 49 #include "btree.h" 50 51 static EPG *bt_fast __P((BTREE *, const DBT *, const DBT *, int *)); 52 53 /* 54 * __BT_PUT -- Add a btree item to the tree. 55 * 56 * Parameters: 57 * dbp: pointer to access method 58 * key: key 59 * data: data 60 * flag: R_NOOVERWRITE 61 * 62 * Returns: 63 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the 64 * tree and R_NOOVERWRITE specified. 65 */ 66 int 67 __bt_put(dbp, key, data, flags) 68 const DB *dbp; 69 DBT *key; 70 const DBT *data; 71 u_int flags; 72 { 73 BTREE *t; 74 DBT tkey, tdata; 75 EPG *e = 0; 76 PAGE *h; 77 indx_t idx, nxtindex; 78 db_pgno_t pg; 79 u_int32_t nbytes; 80 int dflags, exact, status; 81 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 82 83 t = dbp->internal; 84 85 /* Toss any page pinned across calls. */ 86 if (t->bt_pinned != NULL) { 87 mpool_put(t->bt_mp, t->bt_pinned, 0); 88 t->bt_pinned = NULL; 89 } 90 91 /* Check for change to a read-only tree. */ 92 if (F_ISSET(t, B_RDONLY)) { 93 errno = EPERM; 94 return (RET_ERROR); 95 } 96 97 switch (flags) { 98 case 0: 99 case R_NOOVERWRITE: 100 break; 101 case R_CURSOR: 102 /* 103 * If flags is R_CURSOR, put the cursor. Must already 104 * have started a scan and not have already deleted it. 105 */ 106 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 107 !F_ISSET(&t->bt_cursor, 108 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 109 break; 110 /* FALLTHROUGH */ 111 default: 112 errno = EINVAL; 113 return (RET_ERROR); 114 } 115 116 /* 117 * If the key/data pair won't fit on a page, store it on overflow 118 * pages. Only put the key on the overflow page if the pair are 119 * still too big after moving the data to an overflow page. 120 * 121 * XXX 122 * If the insert fails later on, the overflow pages aren't recovered. 123 */ 124 dflags = 0; 125 if (key->size + data->size > t->bt_ovflsize) { 126 if (key->size > t->bt_ovflsize) { 127 u_int32_t yuck_this_is_gross_code; 128 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 129 return (RET_ERROR); 130 tkey.data = kb; 131 tkey.size = NOVFLSIZE; 132 memmove(kb, &pg, sizeof(db_pgno_t)); 133 yuck_this_is_gross_code = key->size; 134 if (yuck_this_is_gross_code != key->size) 135 abort (); 136 memmove(kb + sizeof(db_pgno_t), 137 &yuck_this_is_gross_code, sizeof(u_int32_t)); 138 dflags |= P_BIGKEY; 139 key = &tkey; 140 } 141 if (key->size + data->size > t->bt_ovflsize) { 142 u_int32_t yuck_this_is_gross_code = data->size; 143 if (__ovfl_put(t, data, &pg) == RET_ERROR) 144 return (RET_ERROR); 145 tdata.data = db; 146 tdata.size = NOVFLSIZE; 147 memmove(db, &pg, sizeof(db_pgno_t)); 148 if (yuck_this_is_gross_code != data->size) 149 abort (); 150 memmove(db + sizeof(db_pgno_t), 151 &yuck_this_is_gross_code, sizeof(u_int32_t)); 152 dflags |= P_BIGDATA; 153 data = &tdata; 154 } 155 if (key->size + data->size > t->bt_ovflsize) 156 goto storekey; 157 } 158 159 /* Replace the cursor. */ 160 if (flags == R_CURSOR) { 161 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 162 return (RET_ERROR); 163 idx = t->bt_cursor.pg.index; 164 goto delete; 165 } 166 167 /* 168 * Find the key to delete, or, the location at which to insert. 169 * Bt_fast and __bt_search both pin the returned page. 170 */ 171 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 172 if ((e = __bt_search(t, key, &exact)) == NULL) 173 return (RET_ERROR); 174 h = e->page; 175 idx = e->index; 176 177 /* 178 * Add the key/data pair to the tree. If an identical key is already 179 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 180 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 181 * permitted) or an error is returned. 182 */ 183 switch (flags) { 184 case R_NOOVERWRITE: 185 if (!exact) 186 break; 187 mpool_put(t->bt_mp, h, 0); 188 return (RET_SPECIAL); 189 default: 190 if (!exact || !F_ISSET(t, B_NODUPS)) 191 break; 192 /* 193 * !!! 194 * Note, the delete may empty the page, so we need to put a 195 * new entry into the page immediately. 196 */ 197 delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) { 198 mpool_put(t->bt_mp, h, 0); 199 return (RET_ERROR); 200 } 201 break; 202 } 203 204 /* 205 * If not enough room, or the user has put a ceiling on the number of 206 * keys permitted in the page, split the page. The split code will 207 * insert the key and data and unpin the current page. If inserting 208 * into the offset array, shift the pointers up. 209 */ 210 nbytes = NBLEAFDBT(key->size, data->size); 211 if (h->upper - h->lower < nbytes + sizeof(indx_t)) { 212 if ((status = __bt_split(t, h, key, 213 data, dflags, nbytes, idx)) != RET_SUCCESS) 214 return (status); 215 goto success; 216 } 217 218 if (idx < (nxtindex = NEXTINDEX(h))) 219 memmove(h->linp + idx + 1, h->linp + idx, 220 (nxtindex - idx) * sizeof(indx_t)); 221 h->lower += sizeof(indx_t); 222 223 h->linp[idx] = h->upper -= nbytes; 224 dest = (char *)h + h->upper; 225 WR_BLEAF(dest, key, data, dflags); 226 227 /* If the cursor is on this page, adjust it as necessary. */ 228 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 229 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 230 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) 231 ++t->bt_cursor.pg.index; 232 233 if (t->bt_order == NOT) { 234 if (h->nextpg == P_INVALID) { 235 if (idx == NEXTINDEX(h) - 1) { 236 t->bt_order = FORWARD; 237 t->bt_last.index = idx; 238 t->bt_last.pgno = h->pgno; 239 } 240 } else if (h->prevpg == P_INVALID) { 241 if (idx == 0) { 242 t->bt_order = BACK; 243 t->bt_last.index = 0; 244 t->bt_last.pgno = h->pgno; 245 } 246 } 247 } 248 249 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 250 251 success: 252 if (flags == R_SETCURSOR) 253 __bt_setcur(t, e->page->pgno, e->index); 254 255 F_SET(t, B_MODIFIED); 256 return (RET_SUCCESS); 257 } 258 259 #ifdef STATISTICS 260 u_long bt_cache_hit, bt_cache_miss; 261 #endif 262 263 /* 264 * BT_FAST -- Do a quick check for sorted data. 265 * 266 * Parameters: 267 * t: tree 268 * key: key to insert 269 * 270 * Returns: 271 * EPG for new record or NULL if not found. 272 */ 273 static EPG * 274 bt_fast(t, key, data, exactp) 275 BTREE *t; 276 const DBT *key, *data; 277 int *exactp; 278 { 279 PAGE *h; 280 u_int32_t nbytes; 281 int cmp; 282 283 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 284 t->bt_order = NOT; 285 return (NULL); 286 } 287 t->bt_cur.page = h; 288 t->bt_cur.index = t->bt_last.index; 289 290 /* 291 * If won't fit in this page or have too many keys in this page, 292 * have to search to get split stack. 293 */ 294 nbytes = NBLEAFDBT(key->size, data->size); 295 if (h->upper - h->lower < nbytes + sizeof(indx_t)) 296 goto miss; 297 298 if (t->bt_order == FORWARD) { 299 if (t->bt_cur.page->nextpg != P_INVALID) 300 goto miss; 301 if (t->bt_cur.index != NEXTINDEX(h) - 1) 302 goto miss; 303 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 304 goto miss; 305 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 306 } else { 307 if (t->bt_cur.page->prevpg != P_INVALID) 308 goto miss; 309 if (t->bt_cur.index != 0) 310 goto miss; 311 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 312 goto miss; 313 t->bt_last.index = 0; 314 } 315 *exactp = cmp == 0; 316 #ifdef STATISTICS 317 ++bt_cache_hit; 318 #endif 319 return (&t->bt_cur); 320 321 miss: 322 #ifdef STATISTICS 323 ++bt_cache_miss; 324 #endif 325 t->bt_order = NOT; 326 mpool_put(t->bt_mp, h, 0); 327 return (NULL); 328 } 329