1 /* $NetBSD: bt_put.c,v 1.7 1995/02/27 13:20:40 cgd Exp $ */ 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 #if 0 41 static char sccsid[] = "@(#)bt_put.c 8.4 (Berkeley) 5/31/94"; 42 #else 43 static char rcsid[] = "$NetBSD: bt_put.c,v 1.7 1995/02/27 13:20:40 cgd Exp $"; 44 #endif 45 #endif /* LIBC_SCCS and not lint */ 46 47 #include <sys/types.h> 48 49 #include <errno.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 54 #include <db.h> 55 #include "btree.h" 56 57 static EPG *bt_fast __P((BTREE *, const DBT *, const DBT *, int *)); 58 59 /* 60 * __BT_PUT -- Add a btree item to the tree. 61 * 62 * Parameters: 63 * dbp: pointer to access method 64 * key: key 65 * data: data 66 * flag: R_NOOVERWRITE 67 * 68 * Returns: 69 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the 70 * tree and R_NOOVERWRITE specified. 71 */ 72 int 73 __bt_put(dbp, key, data, flags) 74 const DB *dbp; 75 DBT *key; 76 const DBT *data; 77 u_int flags; 78 { 79 BTREE *t; 80 DBT tkey, tdata; 81 EPG *e; 82 PAGE *h; 83 indx_t index, nxtindex; 84 pgno_t pg; 85 u_int32_t nbytes; 86 int dflags, exact, status; 87 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 88 89 t = dbp->internal; 90 91 /* Toss any page pinned across calls. */ 92 if (t->bt_pinned != NULL) { 93 mpool_put(t->bt_mp, t->bt_pinned, 0); 94 t->bt_pinned = NULL; 95 } 96 97 switch (flags) { 98 case R_CURSOR: 99 if (!ISSET(t, B_SEQINIT)) 100 goto einval; 101 if (ISSET(t, B_DELCRSR)) 102 goto einval; 103 break; 104 case 0: 105 case R_NOOVERWRITE: 106 break; 107 default: 108 einval: errno = EINVAL; 109 return (RET_ERROR); 110 } 111 112 if (ISSET(t, B_RDONLY)) { 113 errno = EPERM; 114 return (RET_ERROR); 115 } 116 117 /* 118 * If the key/data won't fit on a page, store it on indirect pages. 119 * Only store the key on the overflow page if it's too big after the 120 * data is on an overflow page. 121 * 122 * XXX 123 * If the insert fails later on, these pages aren't recovered. 124 */ 125 dflags = 0; 126 if (key->size + data->size > t->bt_ovflsize) { 127 if (key->size > t->bt_ovflsize) { 128 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 129 return (RET_ERROR); 130 tkey.data = kb; 131 tkey.size = NOVFLSIZE; 132 memmove(kb, &pg, sizeof(pgno_t)); 133 memmove(kb + sizeof(pgno_t), 134 &key->size, sizeof(u_int32_t)); 135 dflags |= P_BIGKEY; 136 key = &tkey; 137 } 138 if (key->size + data->size > t->bt_ovflsize) { 139 if (__ovfl_put(t, data, &pg) == RET_ERROR) 140 return (RET_ERROR); 141 tdata.data = db; 142 tdata.size = NOVFLSIZE; 143 memmove(db, &pg, sizeof(pgno_t)); 144 memmove(db + sizeof(pgno_t), 145 &data->size, sizeof(u_int32_t)); 146 dflags |= P_BIGDATA; 147 data = &tdata; 148 } 149 if (key->size + data->size > t->bt_ovflsize) 150 goto storekey; 151 } 152 153 /* Replace the cursor. */ 154 if (flags == R_CURSOR) { 155 if ((h = mpool_get(t->bt_mp, t->bt_bcursor.pgno, 0)) == NULL) 156 return (RET_ERROR); 157 index = t->bt_bcursor.index; 158 goto delete; 159 } 160 161 /* 162 * Find the key to delete, or, the location at which to insert. Bt_fast 163 * and __bt_search pin the returned page. 164 */ 165 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 166 if ((e = __bt_search(t, key, &exact)) == NULL) 167 return (RET_ERROR); 168 h = e->page; 169 index = e->index; 170 171 /* 172 * Add the specified key/data pair to the tree. If an identical key 173 * is already in the tree, and R_NOOVERWRITE is set, an error is 174 * returned. If R_NOOVERWRITE is not set, the key is either added (if 175 * duplicates are permitted) or an error is returned. 176 * 177 * Pages are split as required. 178 */ 179 switch (flags) { 180 case R_NOOVERWRITE: 181 if (!exact) 182 break; 183 /* 184 * One special case is if the cursor references the record and 185 * it's been flagged for deletion. Then, we delete the record, 186 * leaving the cursor there -- this means that the inserted 187 * record will not be seen in a cursor scan. 188 */ 189 if (ISSET(t, B_DELCRSR) && t->bt_bcursor.pgno == h->pgno && 190 t->bt_bcursor.index == index) { 191 CLR(t, B_DELCRSR); 192 goto delete; 193 } 194 mpool_put(t->bt_mp, h, 0); 195 return (RET_SPECIAL); 196 default: 197 if (!exact || !ISSET(t, B_NODUPS)) 198 break; 199 delete: if (__bt_dleaf(t, h, index) == 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, index)) != RET_SUCCESS) 216 return (status); 217 goto success; 218 } 219 220 if (index < (nxtindex = NEXTINDEX(h))) 221 memmove(h->linp + index + 1, h->linp + index, 222 (nxtindex - index) * sizeof(indx_t)); 223 h->lower += sizeof(indx_t); 224 225 h->linp[index] = h->upper -= nbytes; 226 dest = (char *)h + h->upper; 227 WR_BLEAF(dest, key, data, dflags); 228 229 if (t->bt_order == NOT) 230 if (h->nextpg == P_INVALID) { 231 if (index == NEXTINDEX(h) - 1) { 232 t->bt_order = FORWARD; 233 t->bt_last.index = index; 234 t->bt_last.pgno = h->pgno; 235 } 236 } else if (h->prevpg == P_INVALID) { 237 if (index == 0) { 238 t->bt_order = BACK; 239 t->bt_last.index = 0; 240 t->bt_last.pgno = h->pgno; 241 } 242 } 243 244 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 245 246 success: 247 if (flags == R_SETCURSOR) { 248 t->bt_bcursor.pgno = e->page->pgno; 249 t->bt_bcursor.index = e->index; 250 } 251 SET(t, B_MODIFIED); 252 return (RET_SUCCESS); 253 } 254 255 #ifdef STATISTICS 256 u_long bt_cache_hit, bt_cache_miss; 257 #endif 258 259 /* 260 * BT_FAST -- Do a quick check for sorted data. 261 * 262 * Parameters: 263 * t: tree 264 * key: key to insert 265 * 266 * Returns: 267 * EPG for new record or NULL if not found. 268 */ 269 static EPG * 270 bt_fast(t, key, data, exactp) 271 BTREE *t; 272 const DBT *key, *data; 273 int *exactp; 274 { 275 PAGE *h; 276 u_int32_t nbytes; 277 int cmp; 278 279 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 280 t->bt_order = NOT; 281 return (NULL); 282 } 283 t->bt_cur.page = h; 284 t->bt_cur.index = t->bt_last.index; 285 286 /* 287 * If won't fit in this page or have too many keys in this page, have 288 * to search to get split stack. 289 */ 290 nbytes = NBLEAFDBT(key->size, data->size); 291 if (h->upper - h->lower < nbytes + sizeof(indx_t)) 292 goto miss; 293 294 if (t->bt_order == FORWARD) { 295 if (t->bt_cur.page->nextpg != P_INVALID) 296 goto miss; 297 if (t->bt_cur.index != NEXTINDEX(h) - 1) 298 goto miss; 299 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 300 goto miss; 301 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 302 } else { 303 if (t->bt_cur.page->prevpg != P_INVALID) 304 goto miss; 305 if (t->bt_cur.index != 0) 306 goto miss; 307 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 308 goto miss; 309 t->bt_last.index = 0; 310 } 311 *exactp = cmp == 0; 312 #ifdef STATISTICS 313 ++bt_cache_hit; 314 #endif 315 return (&t->bt_cur); 316 317 miss: 318 #ifdef STATISTICS 319 ++bt_cache_miss; 320 #endif 321 t->bt_order = NOT; 322 mpool_put(t->bt_mp, h, 0); 323 return (NULL); 324 } 325