1 /* $OpenBSD: rec_get.c,v 1.11 2007/08/08 07:16:50 ray 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/types.h> 33 34 #include <errno.h> 35 #include <stddef.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 41 #include <db.h> 42 #include "recno.h" 43 44 /* 45 * __REC_GET -- Get a record from the btree. 46 * 47 * Parameters: 48 * dbp: pointer to access method 49 * key: key to find 50 * data: data to return 51 * flag: currently unused 52 * 53 * Returns: 54 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found. 55 */ 56 int 57 __rec_get(const DB *dbp, const DBT *key, DBT *data, u_int flags) 58 { 59 BTREE *t; 60 EPG *e; 61 recno_t nrec; 62 int status; 63 64 t = dbp->internal; 65 66 /* Toss any page pinned across calls. */ 67 if (t->bt_pinned != NULL) { 68 mpool_put(t->bt_mp, t->bt_pinned, 0); 69 t->bt_pinned = NULL; 70 } 71 72 /* Get currently doesn't take any flags, and keys of 0 are illegal. */ 73 if (flags || (nrec = *(recno_t *)key->data) == 0) { 74 errno = EINVAL; 75 return (RET_ERROR); 76 } 77 78 /* 79 * If we haven't seen this record yet, try to find it in the 80 * original file. 81 */ 82 if (nrec > t->bt_nrecs) { 83 if (F_ISSET(t, R_EOF | R_INMEM)) 84 return (RET_SPECIAL); 85 if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS) 86 return (status); 87 } 88 89 --nrec; 90 if ((e = __rec_search(t, nrec, SEARCH)) == NULL) 91 return (RET_ERROR); 92 93 status = __rec_ret(t, e, 0, NULL, data); 94 if (F_ISSET(t, B_DB_LOCK)) 95 mpool_put(t->bt_mp, e->page, 0); 96 else 97 t->bt_pinned = e->page; 98 return (status); 99 } 100 101 /* 102 * __REC_FPIPE -- Get fixed length records from a pipe. 103 * 104 * Parameters: 105 * t: tree 106 * cnt: records to read 107 * 108 * Returns: 109 * RET_ERROR, RET_SUCCESS 110 */ 111 int 112 __rec_fpipe(BTREE *t, recno_t top) 113 { 114 DBT data; 115 recno_t nrec; 116 size_t len; 117 int ch; 118 u_char *p; 119 void *tp; 120 121 if (t->bt_rdata.size < t->bt_reclen) { 122 tp = realloc(t->bt_rdata.data, t->bt_reclen); 123 if (tp == NULL) 124 return (RET_ERROR); 125 t->bt_rdata.data = tp; 126 t->bt_rdata.size = t->bt_reclen; 127 } 128 data.data = t->bt_rdata.data; 129 data.size = t->bt_reclen; 130 131 for (nrec = t->bt_nrecs; nrec < top;) { 132 len = t->bt_reclen; 133 for (p = t->bt_rdata.data;; *p++ = ch) 134 if ((ch = getc(t->bt_rfp)) == EOF || !--len) { 135 if (ch != EOF) 136 *p = ch; 137 if (len != 0) 138 memset(p, t->bt_bval, len); 139 if (__rec_iput(t, 140 nrec, &data, 0) != RET_SUCCESS) 141 return (RET_ERROR); 142 ++nrec; 143 break; 144 } 145 if (ch == EOF) 146 break; 147 } 148 if (nrec < top) { 149 F_SET(t, R_EOF); 150 return (RET_SPECIAL); 151 } 152 return (RET_SUCCESS); 153 } 154 155 /* 156 * __REC_VPIPE -- Get variable length records from a pipe. 157 * 158 * Parameters: 159 * t: tree 160 * cnt: records to read 161 * 162 * Returns: 163 * RET_ERROR, RET_SUCCESS 164 */ 165 int 166 __rec_vpipe(BTREE *t, recno_t top) 167 { 168 DBT data; 169 recno_t nrec; 170 size_t len; 171 size_t sz; 172 int bval, ch; 173 u_char *p; 174 void *tp; 175 176 bval = t->bt_bval; 177 for (nrec = t->bt_nrecs; nrec < top; ++nrec) { 178 for (p = t->bt_rdata.data, 179 sz = t->bt_rdata.size;; *p++ = ch, --sz) { 180 if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) { 181 data.data = t->bt_rdata.data; 182 data.size = p - (u_char *)t->bt_rdata.data; 183 if (ch == EOF && data.size == 0) 184 break; 185 if (__rec_iput(t, nrec, &data, 0) 186 != RET_SUCCESS) 187 return (RET_ERROR); 188 break; 189 } 190 if (sz == 0) { 191 len = p - (u_char *)t->bt_rdata.data; 192 t->bt_rdata.size += (sz = 256); 193 tp = realloc(t->bt_rdata.data, t->bt_rdata.size); 194 if (tp == NULL) 195 return (RET_ERROR); 196 t->bt_rdata.data = tp; 197 p = (u_char *)t->bt_rdata.data + len; 198 } 199 } 200 if (ch == EOF) 201 break; 202 } 203 if (nrec < top) { 204 F_SET(t, R_EOF); 205 return (RET_SPECIAL); 206 } 207 return (RET_SUCCESS); 208 } 209 210 /* 211 * __REC_FMAP -- Get fixed length records from a file. 212 * 213 * Parameters: 214 * t: tree 215 * cnt: records to read 216 * 217 * Returns: 218 * RET_ERROR, RET_SUCCESS 219 */ 220 int 221 __rec_fmap(BTREE *t, recno_t top) 222 { 223 DBT data; 224 recno_t nrec; 225 u_char *sp, *ep, *p; 226 size_t len; 227 void *tp; 228 229 if (t->bt_rdata.size < t->bt_reclen) { 230 tp = realloc(t->bt_rdata.data, t->bt_reclen); 231 if (tp == NULL) 232 return (RET_ERROR); 233 t->bt_rdata.data = tp; 234 t->bt_rdata.size = t->bt_reclen; 235 } 236 data.data = t->bt_rdata.data; 237 data.size = t->bt_reclen; 238 239 sp = (u_char *)t->bt_cmap; 240 ep = (u_char *)t->bt_emap; 241 for (nrec = t->bt_nrecs; nrec < top; ++nrec) { 242 if (sp >= ep) { 243 F_SET(t, R_EOF); 244 return (RET_SPECIAL); 245 } 246 len = t->bt_reclen; 247 for (p = t->bt_rdata.data; 248 sp < ep && len > 0; *p++ = *sp++, --len); 249 if (len != 0) 250 memset(p, t->bt_bval, len); 251 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS) 252 return (RET_ERROR); 253 } 254 t->bt_cmap = (caddr_t)sp; 255 return (RET_SUCCESS); 256 } 257 258 /* 259 * __REC_VMAP -- Get variable length records from a file. 260 * 261 * Parameters: 262 * t: tree 263 * cnt: records to read 264 * 265 * Returns: 266 * RET_ERROR, RET_SUCCESS 267 */ 268 int 269 __rec_vmap(BTREE *t, recno_t top) 270 { 271 DBT data; 272 u_char *sp, *ep; 273 recno_t nrec; 274 int bval; 275 276 sp = (u_char *)t->bt_cmap; 277 ep = (u_char *)t->bt_emap; 278 bval = t->bt_bval; 279 280 for (nrec = t->bt_nrecs; nrec < top; ++nrec) { 281 if (sp >= ep) { 282 F_SET(t, R_EOF); 283 return (RET_SPECIAL); 284 } 285 for (data.data = sp; sp < ep && *sp != bval; ++sp); 286 data.size = sp - (u_char *)data.data; 287 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS) 288 return (RET_ERROR); 289 ++sp; 290 } 291 t->bt_cmap = (caddr_t)sp; 292 return (RET_SUCCESS); 293 } 294