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.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; 76 PAGE *h; 77 indx_t index, nxtindex; 78 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 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 128 return (RET_ERROR); 129 tkey.data = kb; 130 tkey.size = NOVFLSIZE; 131 memmove(kb, &pg, sizeof(pgno_t)); 132 memmove(kb + sizeof(pgno_t), 133 &key->size, sizeof(u_int32_t)); 134 dflags |= P_BIGKEY; 135 key = &tkey; 136 } 137 if (key->size + data->size > t->bt_ovflsize) { 138 if (__ovfl_put(t, data, &pg) == RET_ERROR) 139 return (RET_ERROR); 140 tdata.data = db; 141 tdata.size = NOVFLSIZE; 142 memmove(db, &pg, sizeof(pgno_t)); 143 memmove(db + sizeof(pgno_t), 144 &data->size, sizeof(u_int32_t)); 145 dflags |= P_BIGDATA; 146 data = &tdata; 147 } 148 if (key->size + data->size > t->bt_ovflsize) 149 goto storekey; 150 } 151 152 /* Replace the cursor. */ 153 if (flags == R_CURSOR) { 154 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 155 return (RET_ERROR); 156 index = t->bt_cursor.pg.index; 157 goto delete; 158 } 159 160 /* 161 * Find the key to delete, or, the location at which to insert. 162 * Bt_fast and __bt_search both pin the returned page. 163 */ 164 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 165 if ((e = __bt_search(t, key, &exact)) == NULL) 166 return (RET_ERROR); 167 h = e->page; 168 index = e->index; 169 170 /* 171 * Add the key/data pair to the tree. If an identical key is already 172 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 173 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 174 * permitted) or an error is returned. 175 */ 176 switch (flags) { 177 case R_NOOVERWRITE: 178 if (!exact) 179 break; 180 mpool_put(t->bt_mp, h, 0); 181 return (RET_SPECIAL); 182 default: 183 if (!exact || !F_ISSET(t, B_NODUPS)) 184 break; 185 /* 186 * !!! 187 * Note, the delete may empty the page, so we need to put a 188 * new entry into the page immediately. 189 */ 190 delete: if (__bt_dleaf(t, key, h, index) == RET_ERROR) { 191 mpool_put(t->bt_mp, h, 0); 192 return (RET_ERROR); 193 } 194 break; 195 } 196 197 /* 198 * If not enough room, or the user has put a ceiling on the number of 199 * keys permitted in the page, split the page. The split code will 200 * insert the key and data and unpin the current page. If inserting 201 * into the offset array, shift the pointers up. 202 */ 203 nbytes = NBLEAFDBT(key->size, data->size); 204 if (h->upper - h->lower < nbytes + sizeof(indx_t)) { 205 if ((status = __bt_split(t, h, key, 206 data, dflags, nbytes, index)) != RET_SUCCESS) 207 return (status); 208 goto success; 209 } 210 211 if (index < (nxtindex = NEXTINDEX(h))) 212 memmove(h->linp + index + 1, h->linp + index, 213 (nxtindex - index) * sizeof(indx_t)); 214 h->lower += sizeof(indx_t); 215 216 h->linp[index] = h->upper -= nbytes; 217 dest = (char *)h + h->upper; 218 WR_BLEAF(dest, key, data, dflags); 219 220 /* If the cursor is on this page, adjust it as necessary. */ 221 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 222 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 223 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= index) 224 ++t->bt_cursor.pg.index; 225 226 if (t->bt_order == NOT) 227 if (h->nextpg == P_INVALID) { 228 if (index == NEXTINDEX(h) - 1) { 229 t->bt_order = FORWARD; 230 t->bt_last.index = index; 231 t->bt_last.pgno = h->pgno; 232 } 233 } else if (h->prevpg == P_INVALID) { 234 if (index == 0) { 235 t->bt_order = BACK; 236 t->bt_last.index = 0; 237 t->bt_last.pgno = h->pgno; 238 } 239 } 240 241 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 242 243 success: 244 if (flags == R_SETCURSOR) 245 __bt_setcur(t, e->page->pgno, e->index); 246 247 F_SET(t, B_MODIFIED); 248 return (RET_SUCCESS); 249 } 250 251 #ifdef STATISTICS 252 u_long bt_cache_hit, bt_cache_miss; 253 #endif 254 255 /* 256 * BT_FAST -- Do a quick check for sorted data. 257 * 258 * Parameters: 259 * t: tree 260 * key: key to insert 261 * 262 * Returns: 263 * EPG for new record or NULL if not found. 264 */ 265 static EPG * 266 bt_fast(t, key, data, exactp) 267 BTREE *t; 268 const DBT *key, *data; 269 int *exactp; 270 { 271 PAGE *h; 272 u_int32_t nbytes; 273 int cmp; 274 275 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 276 t->bt_order = NOT; 277 return (NULL); 278 } 279 t->bt_cur.page = h; 280 t->bt_cur.index = t->bt_last.index; 281 282 /* 283 * If won't fit in this page or have too many keys in this page, 284 * have to search to get split stack. 285 */ 286 nbytes = NBLEAFDBT(key->size, data->size); 287 if (h->upper - h->lower < nbytes + sizeof(indx_t)) 288 goto miss; 289 290 if (t->bt_order == FORWARD) { 291 if (t->bt_cur.page->nextpg != P_INVALID) 292 goto miss; 293 if (t->bt_cur.index != NEXTINDEX(h) - 1) 294 goto miss; 295 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 296 goto miss; 297 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 298 } else { 299 if (t->bt_cur.page->prevpg != P_INVALID) 300 goto miss; 301 if (t->bt_cur.index != 0) 302 goto miss; 303 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 304 goto miss; 305 t->bt_last.index = 0; 306 } 307 *exactp = cmp == 0; 308 #ifdef STATISTICS 309 ++bt_cache_hit; 310 #endif 311 return (&t->bt_cur); 312 313 miss: 314 #ifdef STATISTICS 315 ++bt_cache_miss; 316 #endif 317 t->bt_order = NOT; 318 mpool_put(t->bt_mp, h, 0); 319 return (NULL); 320 } 321