1 /*- 2 * Copyright (c) 1990, 1993 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 8.3 (Berkeley) 9/16/93"; 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 size_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 switch (flags) { 92 case R_CURSOR: 93 if (!ISSET(t, B_SEQINIT)) 94 goto einval; 95 if (ISSET(t, B_DELCRSR)) 96 goto einval; 97 break; 98 case 0: 99 case R_NOOVERWRITE: 100 break; 101 default: 102 einval: errno = EINVAL; 103 return (RET_ERROR); 104 } 105 106 if (ISSET(t, B_RDONLY)) { 107 errno = EPERM; 108 return (RET_ERROR); 109 } 110 111 /* 112 * If the key/data won't fit on a page, store it on indirect pages. 113 * Only store the key on the overflow page if it's too big after the 114 * data is on an overflow page. 115 * 116 * XXX 117 * If the insert fails later on, these 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 memmove(kb + sizeof(pgno_t), 128 &key->size, sizeof(size_t)); 129 dflags |= P_BIGKEY; 130 key = &tkey; 131 } 132 if (key->size + data->size > t->bt_ovflsize) { 133 if (__ovfl_put(t, data, &pg) == RET_ERROR) 134 return (RET_ERROR); 135 tdata.data = db; 136 tdata.size = NOVFLSIZE; 137 memmove(db, &pg, sizeof(pgno_t)); 138 memmove(db + sizeof(pgno_t), 139 &data->size, sizeof(size_t)); 140 dflags |= P_BIGDATA; 141 data = &tdata; 142 } 143 if (key->size + data->size > t->bt_ovflsize) 144 goto storekey; 145 } 146 147 /* Replace the cursor. */ 148 if (flags == R_CURSOR) { 149 if ((h = mpool_get(t->bt_mp, t->bt_bcursor.pgno, 0)) == NULL) 150 return (RET_ERROR); 151 index = t->bt_bcursor.index; 152 goto delete; 153 } 154 155 /* 156 * Find the key to delete, or, the location at which to insert. Bt_fast 157 * and __bt_search pin the returned page. 158 */ 159 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 160 if ((e = __bt_search(t, key, &exact)) == NULL) 161 return (RET_ERROR); 162 h = e->page; 163 index = e->index; 164 165 /* 166 * Add the specified key/data pair to the tree. If an identical key 167 * is already in the tree, and R_NOOVERWRITE is set, an error is 168 * returned. If R_NOOVERWRITE is not set, the key is either added (if 169 * duplicates are permitted) or an error is returned. 170 * 171 * Pages are split as required. 172 */ 173 switch (flags) { 174 case R_NOOVERWRITE: 175 if (!exact) 176 break; 177 /* 178 * One special case is if the cursor references the record and 179 * it's been flagged for deletion. Then, we delete the record, 180 * leaving the cursor there -- this means that the inserted 181 * record will not be seen in a cursor scan. 182 */ 183 if (ISSET(t, B_DELCRSR) && t->bt_bcursor.pgno == h->pgno && 184 t->bt_bcursor.index == index) { 185 CLR(t, B_DELCRSR); 186 goto delete; 187 } 188 mpool_put(t->bt_mp, h, 0); 189 return (RET_SPECIAL); 190 default: 191 if (!exact || !ISSET(t, B_NODUPS)) 192 break; 193 delete: if (__bt_dleaf(t, h, index) == RET_ERROR) { 194 mpool_put(t->bt_mp, h, 0); 195 return (RET_ERROR); 196 } 197 break; 198 } 199 200 /* 201 * If not enough room, or the user has put a ceiling on the number of 202 * keys permitted in the page, split the page. The split code will 203 * insert the key and data and unpin the current page. If inserting 204 * into the offset array, shift the pointers up. 205 */ 206 nbytes = NBLEAFDBT(key->size, data->size); 207 if (h->upper - h->lower < nbytes + sizeof(indx_t)) { 208 if ((status = __bt_split(t, h, key, 209 data, dflags, nbytes, index)) != RET_SUCCESS) 210 return (status); 211 goto success; 212 } 213 214 if (index < (nxtindex = NEXTINDEX(h))) 215 memmove(h->linp + index + 1, h->linp + index, 216 (nxtindex - index) * sizeof(indx_t)); 217 h->lower += sizeof(indx_t); 218 219 h->linp[index] = h->upper -= nbytes; 220 dest = (char *)h + h->upper; 221 WR_BLEAF(dest, key, data, dflags); 222 223 if (t->bt_order == NOT) 224 if (h->nextpg == P_INVALID) { 225 if (index == NEXTINDEX(h) - 1) { 226 t->bt_order = FORWARD; 227 t->bt_last.index = index; 228 t->bt_last.pgno = h->pgno; 229 } 230 } else if (h->prevpg == P_INVALID) { 231 if (index == 0) { 232 t->bt_order = BACK; 233 t->bt_last.index = 0; 234 t->bt_last.pgno = h->pgno; 235 } 236 } 237 238 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 239 240 success: 241 if (flags == R_SETCURSOR) { 242 t->bt_bcursor.pgno = e->page->pgno; 243 t->bt_bcursor.index = e->index; 244 } 245 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(t, key, data, exactp) 265 BTREE *t; 266 const DBT *key, *data; 267 int *exactp; 268 { 269 PAGE *h; 270 size_t nbytes; 271 int cmp; 272 273 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 274 t->bt_order = NOT; 275 return (NULL); 276 } 277 t->bt_cur.page = h; 278 t->bt_cur.index = t->bt_last.index; 279 280 /* 281 * If won't fit in this page or have too many keys in this page, have 282 * to search to get split stack. 283 */ 284 nbytes = NBLEAFDBT(key->size, data->size); 285 if (h->upper - h->lower < nbytes + sizeof(indx_t)) 286 goto miss; 287 288 if (t->bt_order == FORWARD) { 289 if (t->bt_cur.page->nextpg != P_INVALID) 290 goto miss; 291 if (t->bt_cur.index != NEXTINDEX(h) - 1) 292 goto miss; 293 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 294 goto miss; 295 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 296 } else { 297 if (t->bt_cur.page->prevpg != P_INVALID) 298 goto miss; 299 if (t->bt_cur.index != 0) 300 goto miss; 301 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 302 goto miss; 303 t->bt_last.index = 0; 304 } 305 *exactp = cmp == 0; 306 #ifdef STATISTICS 307 ++bt_cache_hit; 308 #endif 309 return (&t->bt_cur); 310 311 miss: 312 #ifdef STATISTICS 313 ++bt_cache_miss; 314 #endif 315 t->bt_order = NOT; 316 mpool_put(t->bt_mp, h, 0); 317 return (NULL); 318 } 319