rec_get.c revision 1.14
1 /* $NetBSD: rec_get.c,v 1.14 2008/08/26 21:18:38 joerg Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)rec_get.c 8.9 (Berkeley) 8/18/94"; 36 #else 37 __RCSID("$NetBSD: rec_get.c,v 1.14 2008/08/26 21:18:38 joerg Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 #include <sys/types.h> 43 44 #include <assert.h> 45 #include <errno.h> 46 #include <stddef.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #include <db.h> 53 #include "recno.h" 54 55 /* 56 * __REC_GET -- Get a record from the btree. 57 * 58 * Parameters: 59 * dbp: pointer to access method 60 * key: key to find 61 * data: data to return 62 * flag: currently unused 63 * 64 * Returns: 65 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found. 66 */ 67 int 68 __rec_get(const DB *dbp, const DBT *key, DBT *data, u_int flags) 69 { 70 BTREE *t; 71 EPG *e; 72 recno_t nrec; 73 int status; 74 75 t = dbp->internal; 76 77 /* Toss any page pinned across calls. */ 78 if (t->bt_pinned != NULL) { 79 mpool_put(t->bt_mp, t->bt_pinned, 0); 80 t->bt_pinned = NULL; 81 } 82 83 /* Get currently doesn't take any flags, and keys of 0 are illegal. */ 84 if (flags || (nrec = *(recno_t *)key->data) == 0) { 85 errno = EINVAL; 86 return (RET_ERROR); 87 } 88 89 /* 90 * If we haven't seen this record yet, try to find it in the 91 * original file. 92 */ 93 if (nrec > t->bt_nrecs) { 94 if (F_ISSET(t, R_EOF | R_INMEM)) 95 return (RET_SPECIAL); 96 if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS) 97 return (status); 98 } 99 100 --nrec; 101 if ((e = __rec_search(t, nrec, SEARCH)) == NULL) 102 return (RET_ERROR); 103 104 status = __rec_ret(t, e, 0, NULL, data); 105 if (F_ISSET(t, B_DB_LOCK)) 106 mpool_put(t->bt_mp, e->page, 0); 107 else 108 t->bt_pinned = e->page; 109 return (status); 110 } 111 112 /* 113 * __REC_FPIPE -- Get fixed length records from a pipe. 114 * 115 * Parameters: 116 * t: tree 117 * cnt: records to read 118 * 119 * Returns: 120 * RET_ERROR, RET_SUCCESS 121 */ 122 int 123 __rec_fpipe(BTREE *t, recno_t top) 124 { 125 DBT data; 126 recno_t nrec; 127 size_t len; 128 int ch; 129 uint8_t *p; 130 131 if (t->bt_rdata.size < t->bt_reclen) { 132 t->bt_rdata.data = t->bt_rdata.data == NULL ? 133 malloc(t->bt_reclen) : 134 realloc(t->bt_rdata.data, t->bt_reclen); 135 if (t->bt_rdata.data == NULL) 136 return (RET_ERROR); 137 t->bt_rdata.size = t->bt_reclen; 138 } 139 data.data = t->bt_rdata.data; 140 data.size = t->bt_reclen; 141 142 for (nrec = t->bt_nrecs; nrec < top;) { 143 len = t->bt_reclen; 144 for (p = t->bt_rdata.data;; *p++ = ch) 145 if ((ch = getc(t->bt_rfp)) == EOF || !--len) { 146 if (ch != EOF) 147 *p = ch; 148 if (len != 0) 149 memset(p, t->bt_bval, len); 150 if (__rec_iput(t, 151 nrec, &data, 0) != RET_SUCCESS) 152 return (RET_ERROR); 153 ++nrec; 154 break; 155 } 156 if (ch == EOF) 157 break; 158 } 159 if (nrec < top) { 160 F_SET(t, R_EOF); 161 return (RET_SPECIAL); 162 } 163 return (RET_SUCCESS); 164 } 165 166 /* 167 * __REC_VPIPE -- Get variable length records from a pipe. 168 * 169 * Parameters: 170 * t: tree 171 * cnt: records to read 172 * 173 * Returns: 174 * RET_ERROR, RET_SUCCESS 175 */ 176 int 177 __rec_vpipe(BTREE *t, recno_t top) 178 { 179 DBT data; 180 recno_t nrec; 181 ptrdiff_t len; 182 size_t sz; 183 int bval, ch; 184 uint8_t *p; 185 186 bval = t->bt_bval; 187 for (nrec = t->bt_nrecs; nrec < top; ++nrec) { 188 for (p = t->bt_rdata.data, 189 sz = t->bt_rdata.size;; *p++ = ch, --sz) { 190 if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) { 191 data.data = t->bt_rdata.data; 192 data.size = p - (uint8_t *)t->bt_rdata.data; 193 if (ch == EOF && data.size == 0) 194 break; 195 if (__rec_iput(t, nrec, &data, 0) 196 != RET_SUCCESS) 197 return (RET_ERROR); 198 break; 199 } 200 if (sz == 0) { 201 len = p - (uint8_t *)t->bt_rdata.data; 202 t->bt_rdata.size += (sz = 256); 203 t->bt_rdata.data = t->bt_rdata.data == NULL ? 204 malloc(t->bt_rdata.size) : 205 realloc(t->bt_rdata.data, t->bt_rdata.size); 206 if (t->bt_rdata.data == NULL) 207 return (RET_ERROR); 208 p = (uint8_t *)t->bt_rdata.data + len; 209 } 210 } 211 if (ch == EOF) 212 break; 213 } 214 if (nrec < top) { 215 F_SET(t, R_EOF); 216 return (RET_SPECIAL); 217 } 218 return (RET_SUCCESS); 219 } 220 221 /* 222 * __REC_FMAP -- Get fixed length records from a file. 223 * 224 * Parameters: 225 * t: tree 226 * cnt: records to read 227 * 228 * Returns: 229 * RET_ERROR, RET_SUCCESS 230 */ 231 int 232 __rec_fmap(BTREE *t, recno_t top) 233 { 234 DBT data; 235 recno_t nrec; 236 uint8_t *sp, *ep, *p; 237 size_t len; 238 239 if (t->bt_rdata.size < t->bt_reclen) { 240 t->bt_rdata.data = t->bt_rdata.data == NULL ? 241 malloc(t->bt_reclen) : 242 realloc(t->bt_rdata.data, t->bt_reclen); 243 if (t->bt_rdata.data == NULL) 244 return (RET_ERROR); 245 t->bt_rdata.size = t->bt_reclen; 246 } 247 data.data = t->bt_rdata.data; 248 data.size = t->bt_reclen; 249 250 sp = (uint8_t *)t->bt_cmap; 251 ep = (uint8_t *)t->bt_emap; 252 for (nrec = t->bt_nrecs; nrec < top; ++nrec) { 253 if (sp >= ep) { 254 F_SET(t, R_EOF); 255 return (RET_SPECIAL); 256 } 257 len = t->bt_reclen; 258 for (p = t->bt_rdata.data; 259 sp < ep && len > 0; *p++ = *sp++, --len); 260 if (len != 0) 261 memset(p, t->bt_bval, len); 262 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS) 263 return (RET_ERROR); 264 } 265 t->bt_cmap = (caddr_t)sp; 266 return (RET_SUCCESS); 267 } 268 269 /* 270 * __REC_VMAP -- Get variable length records from a file. 271 * 272 * Parameters: 273 * t: tree 274 * cnt: records to read 275 * 276 * Returns: 277 * RET_ERROR, RET_SUCCESS 278 */ 279 int 280 __rec_vmap(BTREE *t, recno_t top) 281 { 282 DBT data; 283 uint8_t *sp, *ep; 284 recno_t nrec; 285 int bval; 286 287 sp = (uint8_t *)t->bt_cmap; 288 ep = (uint8_t *)t->bt_emap; 289 bval = t->bt_bval; 290 291 for (nrec = t->bt_nrecs; nrec < top; ++nrec) { 292 if (sp >= ep) { 293 F_SET(t, R_EOF); 294 return (RET_SPECIAL); 295 } 296 for (data.data = sp; sp < ep && *sp != bval; ++sp); 297 data.size = sp - (uint8_t *)data.data; 298 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS) 299 return (RET_ERROR); 300 ++sp; 301 } 302 t->bt_cmap = (caddr_t)sp; 303 return (RET_SUCCESS); 304 } 305
Indexes created Sun Oct 19 02:09:48 GMT 2025