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 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(dbp, key, data, flags) 66 const DB *dbp; 67 DBT *key; 68 const DBT *data; 69 u_int flags; 70 { 71 BTREE *t; 72 DBT tkey, tdata; 73 EPG *e; 74 PAGE *h; 75 indx_t index, nxtindex; 76 pgno_t pg; 77 u_int32_t nbytes, tmp; 78 int dflags, exact, status; 79 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 80 81 t = dbp->internal; 82 83 /* Toss any page pinned across calls. */ 84 if (t->bt_pinned != NULL) { 85 mpool_put(t->bt_mp, t->bt_pinned, 0); 86 t->bt_pinned = NULL; 87 } 88 89 /* Check for change to a read-only tree. */ 90 if (F_ISSET(t, B_RDONLY)) { 91 errno = EPERM; 92 return (RET_ERROR); 93 } 94 95 switch (flags) { 96 case 0: 97 case R_NOOVERWRITE: 98 break; 99 case R_CURSOR: 100 /* 101 * If flags is R_CURSOR, put the cursor. Must already 102 * have started a scan and not have already deleted it. 103 */ 104 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 105 !F_ISSET(&t->bt_cursor, 106 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 107 break; 108 /* FALLTHROUGH */ 109 default: 110 errno = EINVAL; 111 return (RET_ERROR); 112 } 113 114 /* 115 * If the key/data pair won't fit on a page, store it on overflow 116 * pages. Only put the key on the overflow page if the pair are 117 * still too big after moving the data to an overflow page. 118 * 119 * XXX 120 * If the insert fails later on, the overflow pages aren't recovered. 121 */ 122 dflags = 0; 123 if (key->size + data->size > t->bt_ovflsize) { 124 if (key->size > t->bt_ovflsize) { 125 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 126 return (RET_ERROR); 127 tkey.data = kb; 128 tkey.size = NOVFLSIZE; 129 memmove(kb, &pg, sizeof(pgno_t)); 130 tmp = key->size; 131 memmove(kb + sizeof(pgno_t), 132 &tmp, sizeof(u_int32_t)); 133 dflags |= P_BIGKEY; 134 key = &tkey; 135 } 136 if (key->size + data->size > t->bt_ovflsize) { 137 if (__ovfl_put(t, data, &pg) == RET_ERROR) 138 return (RET_ERROR); 139 tdata.data = db; 140 tdata.size = NOVFLSIZE; 141 memmove(db, &pg, sizeof(pgno_t)); 142 tmp = data->size; 143 memmove(db + sizeof(pgno_t), 144 &tmp, 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 } 241 242 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 243 244 success: 245 if (flags == R_SETCURSOR) 246 __bt_setcur(t, e->page->pgno, e->index); 247 248 F_SET(t, B_MODIFIED); 249 return (RET_SUCCESS); 250 } 251 252 #ifdef STATISTICS 253 u_long bt_cache_hit, bt_cache_miss; 254 #endif 255 256 /* 257 * BT_FAST -- Do a quick check for sorted data. 258 * 259 * Parameters: 260 * t: tree 261 * key: key to insert 262 * 263 * Returns: 264 * EPG for new record or NULL if not found. 265 */ 266 static EPG * 267 bt_fast(t, key, data, exactp) 268 BTREE *t; 269 const DBT *key, *data; 270 int *exactp; 271 { 272 PAGE *h; 273 u_int32_t nbytes; 274 int cmp; 275 276 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 277 t->bt_order = NOT; 278 return (NULL); 279 } 280 t->bt_cur.page = h; 281 t->bt_cur.index = t->bt_last.index; 282 283 /* 284 * If won't fit in this page or have too many keys in this page, 285 * have to search to get split stack. 286 */ 287 nbytes = NBLEAFDBT(key->size, data->size); 288 if (h->upper - h->lower < nbytes + sizeof(indx_t)) 289 goto miss; 290 291 if (t->bt_order == FORWARD) { 292 if (t->bt_cur.page->nextpg != P_INVALID) 293 goto miss; 294 if (t->bt_cur.index != NEXTINDEX(h) - 1) 295 goto miss; 296 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 297 goto miss; 298 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 299 } else { 300 if (t->bt_cur.page->prevpg != P_INVALID) 301 goto miss; 302 if (t->bt_cur.index != 0) 303 goto miss; 304 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 305 goto miss; 306 t->bt_last.index = 0; 307 } 308 *exactp = cmp == 0; 309 #ifdef STATISTICS 310 ++bt_cache_hit; 311 #endif 312 return (&t->bt_cur); 313 314 miss: 315 #ifdef STATISTICS 316 ++bt_cache_miss; 317 #endif 318 t->bt_order = NOT; 319 mpool_put(t->bt_mp, h, 0); 320 return (NULL); 321 } 322