1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #if defined(LIBC_SCCS) && !defined(lint) 36 static char sccsid[] = "@(#)bt_put.c 8.8 (Berkeley) 7/26/94"; 37 #endif /* LIBC_SCCS and not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 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(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, R_SETCURSOR, R_CURSOR 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(const DB *dbp, DBT *key, const DBT *data, u_int flags) 68 { 69 BTREE *t; 70 DBT tkey, tdata; 71 EPG *e; 72 PAGE *h; 73 indx_t idx, nxtindex; 74 pgno_t pg; 75 u_int32_t nbytes, tmp; 76 int dflags, exact, status; 77 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 78 79 t = dbp->internal; 80 81 /* Toss any page pinned across calls. */ 82 if (t->bt_pinned != NULL) { 83 mpool_put(t->bt_mp, t->bt_pinned, 0); 84 t->bt_pinned = NULL; 85 } 86 87 /* Check for change to a read-only tree. */ 88 if (F_ISSET(t, B_RDONLY)) { 89 errno = EPERM; 90 return (RET_ERROR); 91 } 92 93 switch (flags) { 94 case 0: 95 case R_NOOVERWRITE: 96 case R_SETCURSOR: 97 break; 98 case R_CURSOR: 99 /* 100 * If flags is R_CURSOR, put the cursor. Must already 101 * have started a scan and not have already deleted it. 102 */ 103 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 104 !F_ISSET(&t->bt_cursor, 105 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 106 break; 107 /* FALLTHROUGH */ 108 default: 109 errno = EINVAL; 110 return (RET_ERROR); 111 } 112 113 /* 114 * If the key/data pair won't fit on a page, store it on overflow 115 * pages. Only put the key on the overflow page if the pair are 116 * still too big after moving the data to an overflow page. 117 * 118 * XXX 119 * If the insert fails later on, the overflow pages aren't recovered. 120 */ 121 dflags = 0; 122 if (key->size + data->size > t->bt_ovflsize) { 123 if (key->size > t->bt_ovflsize) { 124 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 125 return (RET_ERROR); 126 tkey.data = kb; 127 tkey.size = NOVFLSIZE; 128 memmove(kb, &pg, sizeof(pgno_t)); 129 tmp = key->size; 130 memmove(kb + sizeof(pgno_t), 131 &tmp, sizeof(u_int32_t)); 132 dflags |= P_BIGKEY; 133 key = &tkey; 134 } 135 if (key->size + data->size > t->bt_ovflsize) { 136 if (__ovfl_put(t, data, &pg) == RET_ERROR) 137 return (RET_ERROR); 138 tdata.data = db; 139 tdata.size = NOVFLSIZE; 140 memmove(db, &pg, sizeof(pgno_t)); 141 tmp = data->size; 142 memmove(db + sizeof(pgno_t), 143 &tmp, sizeof(u_int32_t)); 144 dflags |= P_BIGDATA; 145 data = &tdata; 146 } 147 if (key->size + data->size > t->bt_ovflsize) 148 goto storekey; 149 } 150 151 /* Replace the cursor. */ 152 if (flags == R_CURSOR) { 153 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 154 return (RET_ERROR); 155 idx = t->bt_cursor.pg.index; 156 goto delete; 157 } 158 159 /* 160 * Find the key to delete, or, the location at which to insert. 161 * Bt_fast and __bt_search both pin the returned page. 162 */ 163 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 164 if ((e = __bt_search(t, key, &exact)) == NULL) 165 return (RET_ERROR); 166 h = e->page; 167 idx = e->index; 168 169 /* 170 * Add the key/data pair to the tree. If an identical key is already 171 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 172 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 173 * permitted) or an error is returned. 174 */ 175 switch (flags) { 176 case R_NOOVERWRITE: 177 if (!exact) 178 break; 179 mpool_put(t->bt_mp, h, 0); 180 return (RET_SPECIAL); 181 default: 182 if (!exact || !F_ISSET(t, B_NODUPS)) 183 break; 184 /* 185 * !!! 186 * Note, the delete may empty the page, so we need to put a 187 * new entry into the page immediately. 188 */ 189 delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) { 190 mpool_put(t->bt_mp, h, 0); 191 return (RET_ERROR); 192 } 193 break; 194 } 195 196 /* 197 * If not enough room, or the user has put a ceiling on the number of 198 * keys permitted in the page, split the page. The split code will 199 * insert the key and data and unpin the current page. If inserting 200 * into the offset array, shift the pointers up. 201 */ 202 nbytes = NBLEAFDBT(key->size, data->size); 203 if ((u_int32_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) { 204 if ((status = __bt_split(t, h, key, 205 data, dflags, nbytes, idx)) != RET_SUCCESS) 206 return (status); 207 goto success; 208 } 209 210 if (idx < (nxtindex = NEXTINDEX(h))) 211 memmove(h->linp + idx + 1, h->linp + idx, 212 (nxtindex - idx) * sizeof(indx_t)); 213 h->lower += sizeof(indx_t); 214 215 h->linp[idx] = h->upper -= nbytes; 216 dest = (char *)h + h->upper; 217 WR_BLEAF(dest, key, data, dflags); 218 219 /* If the cursor is on this page, adjust it as necessary. */ 220 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 221 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 222 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) 223 ++t->bt_cursor.pg.index; 224 225 if (t->bt_order == NOT) { 226 if (h->nextpg == P_INVALID) { 227 if (idx == NEXTINDEX(h) - 1) { 228 t->bt_order = FORWARD; 229 t->bt_last.index = idx; 230 t->bt_last.pgno = h->pgno; 231 } 232 } else if (h->prevpg == P_INVALID) { 233 if (idx == 0) { 234 t->bt_order = BACK; 235 t->bt_last.index = 0; 236 t->bt_last.pgno = h->pgno; 237 } 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(BTREE *t, const DBT *key, const DBT *data, int *exactp) 267 { 268 PAGE *h; 269 u_int32_t nbytes; 270 int cmp; 271 272 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 273 t->bt_order = NOT; 274 return (NULL); 275 } 276 t->bt_cur.page = h; 277 t->bt_cur.index = t->bt_last.index; 278 279 /* 280 * If won't fit in this page or have too many keys in this page, 281 * have to search to get split stack. 282 */ 283 nbytes = NBLEAFDBT(key->size, data->size); 284 if ((u_int32_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) 285 goto miss; 286 287 if (t->bt_order == FORWARD) { 288 if (t->bt_cur.page->nextpg != P_INVALID) 289 goto miss; 290 if (t->bt_cur.index != NEXTINDEX(h) - 1) 291 goto miss; 292 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 293 goto miss; 294 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 295 } else { 296 if (t->bt_cur.page->prevpg != P_INVALID) 297 goto miss; 298 if (t->bt_cur.index != 0) 299 goto miss; 300 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 301 goto miss; 302 t->bt_last.index = 0; 303 } 304 *exactp = cmp == 0; 305 #ifdef STATISTICS 306 ++bt_cache_hit; 307 #endif 308 return (&t->bt_cur); 309 310 miss: 311 #ifdef STATISTICS 312 ++bt_cache_miss; 313 #endif 314 t->bt_order = NOT; 315 mpool_put(t->bt_mp, h, 0); 316 return (NULL); 317 } 318