1 #pragma ident "%Z%%M% %I% %E% SMI" 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #if defined(LIBC_SCCS) && !defined(lint) 40 static char sccsid[] = "@(#)bt_put.c 8.8 (Berkeley) 7/26/94"; 41 #endif /* LIBC_SCCS and not lint */ 42 43 #include <sys/types.h> 44 45 #include <errno.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 50 #include "db-int.h" 51 #include "btree.h" 52 53 static EPG *bt_fast __P((BTREE *, const DBT *, const DBT *, int *)); 54 55 /* 56 * __BT_PUT -- Add a btree item to the tree. 57 * 58 * Parameters: 59 * dbp: pointer to access method 60 * key: key 61 * data: data 62 * flag: R_NOOVERWRITE 63 * 64 * Returns: 65 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the 66 * tree and R_NOOVERWRITE specified. 67 */ 68 int 69 __bt_put(dbp, key, data, flags) 70 const DB *dbp; 71 DBT *key; 72 const DBT *data; 73 u_int flags; 74 { 75 BTREE *t; 76 DBT tkey, tdata; 77 EPG *e = 0; 78 PAGE *h; 79 indx_t idx, nxtindex; 80 db_pgno_t pg; 81 u_int32_t nbytes; 82 int dflags, exact, status; 83 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 84 85 t = dbp->internal; 86 87 /* Toss any page pinned across calls. */ 88 if (t->bt_pinned != NULL) { 89 mpool_put(t->bt_mp, t->bt_pinned, 0); 90 t->bt_pinned = NULL; 91 } 92 93 /* Check for change to a read-only tree. */ 94 if (F_ISSET(t, B_RDONLY)) { 95 errno = EPERM; 96 return (RET_ERROR); 97 } 98 99 switch (flags) { 100 case 0: 101 case R_NOOVERWRITE: 102 break; 103 case R_CURSOR: 104 /* 105 * If flags is R_CURSOR, put the cursor. Must already 106 * have started a scan and not have already deleted it. 107 */ 108 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 109 !F_ISSET(&t->bt_cursor, 110 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 111 break; 112 /* FALLTHROUGH */ 113 default: 114 errno = EINVAL; 115 return (RET_ERROR); 116 } 117 118 /* 119 * If the key/data pair won't fit on a page, store it on overflow 120 * pages. Only put the key on the overflow page if the pair are 121 * still too big after moving the data to an overflow page. 122 * 123 * XXX 124 * If the insert fails later on, the overflow pages aren't recovered. 125 */ 126 dflags = 0; 127 if (key->size + data->size > t->bt_ovflsize) { 128 if (key->size > t->bt_ovflsize) { 129 u_int32_t yuck_this_is_gross_code; 130 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 131 return (RET_ERROR); 132 tkey.data = kb; 133 tkey.size = NOVFLSIZE; 134 memmove(kb, &pg, sizeof(db_pgno_t)); 135 yuck_this_is_gross_code = key->size; 136 if (yuck_this_is_gross_code != key->size) 137 abort (); 138 memmove(kb + sizeof(db_pgno_t), 139 &yuck_this_is_gross_code, sizeof(u_int32_t)); 140 dflags |= P_BIGKEY; 141 key = &tkey; 142 } 143 if (key->size + data->size > t->bt_ovflsize) { 144 u_int32_t yuck_this_is_gross_code = data->size; 145 if (__ovfl_put(t, data, &pg) == RET_ERROR) 146 return (RET_ERROR); 147 tdata.data = db; 148 tdata.size = NOVFLSIZE; 149 memmove(db, &pg, sizeof(db_pgno_t)); 150 if (yuck_this_is_gross_code != data->size) 151 abort (); 152 memmove(db + sizeof(db_pgno_t), 153 &yuck_this_is_gross_code, sizeof(u_int32_t)); 154 dflags |= P_BIGDATA; 155 data = &tdata; 156 } 157 if (key->size + data->size > t->bt_ovflsize) 158 goto storekey; 159 } 160 161 /* Replace the cursor. */ 162 if (flags == R_CURSOR) { 163 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 164 return (RET_ERROR); 165 idx = t->bt_cursor.pg.index; 166 goto delete; 167 } 168 169 /* 170 * Find the key to delete, or, the location at which to insert. 171 * Bt_fast and __bt_search both pin the returned page. 172 */ 173 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 174 if ((e = __bt_search(t, key, &exact)) == NULL) 175 return (RET_ERROR); 176 h = e->page; 177 idx = e->index; 178 179 /* 180 * Add the key/data pair to the tree. If an identical key is already 181 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 182 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 183 * permitted) or an error is returned. 184 */ 185 switch (flags) { 186 case R_NOOVERWRITE: 187 if (!exact) 188 break; 189 mpool_put(t->bt_mp, h, 0); 190 return (RET_SPECIAL); 191 default: 192 if (!exact || !F_ISSET(t, B_NODUPS)) 193 break; 194 /* 195 * !!! 196 * Note, the delete may empty the page, so we need to put a 197 * new entry into the page immediately. 198 */ 199 delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) { 200 mpool_put(t->bt_mp, h, 0); 201 return (RET_ERROR); 202 } 203 break; 204 } 205 206 /* 207 * If not enough room, or the user has put a ceiling on the number of 208 * keys permitted in the page, split the page. The split code will 209 * insert the key and data and unpin the current page. If inserting 210 * into the offset array, shift the pointers up. 211 */ 212 nbytes = NBLEAFDBT(key->size, data->size); 213 if (h->upper - h->lower < nbytes + sizeof(indx_t)) { 214 if ((status = __bt_split(t, h, key, 215 data, dflags, nbytes, idx)) != RET_SUCCESS) 216 return (status); 217 goto success; 218 } 219 220 if (idx < (nxtindex = NEXTINDEX(h))) 221 memmove(h->linp + idx + 1, h->linp + idx, 222 (nxtindex - idx) * sizeof(indx_t)); 223 h->lower += sizeof(indx_t); 224 225 h->linp[idx] = h->upper -= nbytes; 226 dest = (char *)h + h->upper; 227 WR_BLEAF(dest, key, data, dflags); 228 229 /* If the cursor is on this page, adjust it as necessary. */ 230 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 231 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 232 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) 233 ++t->bt_cursor.pg.index; 234 235 if (t->bt_order == NOT) { 236 if (h->nextpg == P_INVALID) { 237 if (idx == NEXTINDEX(h) - 1) { 238 t->bt_order = FORWARD; 239 t->bt_last.index = idx; 240 t->bt_last.pgno = h->pgno; 241 } 242 } else if (h->prevpg == P_INVALID) { 243 if (idx == 0) { 244 t->bt_order = BACK; 245 t->bt_last.index = 0; 246 t->bt_last.pgno = h->pgno; 247 } 248 } 249 } 250 251 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 252 253 success: 254 if (flags == R_SETCURSOR) 255 __bt_setcur(t, e->page->pgno, e->index); 256 257 F_SET(t, B_MODIFIED); 258 return (RET_SUCCESS); 259 } 260 261 #ifdef STATISTICS 262 u_long bt_cache_hit, bt_cache_miss; 263 #endif 264 265 /* 266 * BT_FAST -- Do a quick check for sorted data. 267 * 268 * Parameters: 269 * t: tree 270 * key: key to insert 271 * 272 * Returns: 273 * EPG for new record or NULL if not found. 274 */ 275 static EPG * 276 bt_fast(t, key, data, exactp) 277 BTREE *t; 278 const DBT *key, *data; 279 int *exactp; 280 { 281 PAGE *h; 282 u_int32_t nbytes; 283 int cmp; 284 285 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 286 t->bt_order = NOT; 287 return (NULL); 288 } 289 t->bt_cur.page = h; 290 t->bt_cur.index = t->bt_last.index; 291 292 /* 293 * If won't fit in this page or have too many keys in this page, 294 * have to search to get split stack. 295 */ 296 nbytes = NBLEAFDBT(key->size, data->size); 297 if (h->upper - h->lower < nbytes + sizeof(indx_t)) 298 goto miss; 299 300 if (t->bt_order == FORWARD) { 301 if (t->bt_cur.page->nextpg != P_INVALID) 302 goto miss; 303 if (t->bt_cur.index != NEXTINDEX(h) - 1) 304 goto miss; 305 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 306 goto miss; 307 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 308 } else { 309 if (t->bt_cur.page->prevpg != P_INVALID) 310 goto miss; 311 if (t->bt_cur.index != 0) 312 goto miss; 313 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 314 goto miss; 315 t->bt_last.index = 0; 316 } 317 *exactp = cmp == 0; 318 #ifdef STATISTICS 319 ++bt_cache_hit; 320 #endif 321 return (&t->bt_cur); 322 323 miss: 324 #ifdef STATISTICS 325 ++bt_cache_miss; 326 #endif 327 t->bt_order = NOT; 328 mpool_put(t->bt_mp, h, 0); 329 return (NULL); 330 } 331