lib/libc/db/recno/rec_get.c

   1 /*      $NetBSD: rec_get.c,v 1.16 2008/09/11 12:58:00 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 #if HAVE_NBTOOL_CONFIG_H
  33 #include "nbtool_config.h"
  34 #endif
  35
  36 #include <sys/cdefs.h>
  37 __RCSID("$NetBSD: rec_get.c,v 1.16 2008/09/11 12:58:00 joerg Exp $");
  38
  39 #include "namespace.h"
  40 #include <sys/types.h>
  41
  42 #include <assert.h>
  43 #include <errno.h>
  44 #include <stddef.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 #include <db.h>
  51 #include "recno.h"
  52
  53 /*
  54  * __REC_GET -- Get a record from the btree.
  55  *
  56  * Parameters:
  57  *      dbp:    pointer to access method
  58  *      key:    key to find
  59  *      data:   data to return
  60  *      flag:   currently unused
  61  *
  62  * Returns:
  63  *      RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
  64  */
  65 int
  66 __rec_get(const DB *dbp, const DBT *key, DBT *data, u_int flags)
  67 {
  68         BTREE *t;
  69         EPG *e;
  70         recno_t nrec;
  71         int status;
  72
  73         t = dbp->internal;
  74
  75         /* Toss any page pinned across calls. */
  76         if (t->bt_pinned != NULL) {
  77                 mpool_put(t->bt_mp, t->bt_pinned, 0);
  78                 t->bt_pinned = NULL;
  79         }
  80
  81         /* Get currently doesn't take any flags, and keys of 0 are illegal. */
  82         if (flags || (nrec = *(recno_t *)key->data) == 0) {
  83                 errno = EINVAL;
  84                 return (RET_ERROR);
  85         }
  86
  87         /*
  88          * If we haven't seen this record yet, try to find it in the
  89          * original file.
  90          */
  91         if (nrec > t->bt_nrecs) {
  92                 if (F_ISSET(t, R_EOF | R_INMEM))
  93                         return (RET_SPECIAL);
  94                 if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
  95                         return (status);
  96         }
  97
  98         --nrec;
  99         if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
 100                 return (RET_ERROR);
 101
 102         status = __rec_ret(t, e, 0, NULL, data);
 103         if (F_ISSET(t, B_DB_LOCK))
 104                 mpool_put(t->bt_mp, e->page, 0);
 105         else
 106                 t->bt_pinned = e->page;
 107         return (status);
 108 }
 109
 110 /*
 111  * __REC_FPIPE -- Get fixed length records from a pipe.
 112  *
 113  * Parameters:
 114  *      t:      tree
 115  *      cnt:    records to read
 116  *
 117  * Returns:
 118  *      RET_ERROR, RET_SUCCESS
 119  */
 120 int
 121 __rec_fpipe(BTREE *t, recno_t top)
 122 {
 123         DBT data;
 124         recno_t nrec;
 125         size_t len;
 126         int ch;
 127         uint8_t *p;
 128
 129         if (t->bt_rdata.size < t->bt_reclen) {
 130                 t->bt_rdata.data = t->bt_rdata.data == NULL ?
 131                     malloc(t->bt_reclen) :
 132                     realloc(t->bt_rdata.data, t->bt_reclen);
 133                 if (t->bt_rdata.data == NULL)
 134                         return (RET_ERROR);
 135                 t->bt_rdata.size = t->bt_reclen;
 136         }
 137         data.data = t->bt_rdata.data;
 138         data.size = t->bt_reclen;
 139
 140         for (nrec = t->bt_nrecs; nrec < top;) {
 141                 len = t->bt_reclen;
 142                 for (p = t->bt_rdata.data;; *p++ = ch)
 143                         if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
 144                                 if (ch != EOF)
 145                                         *p = ch;
 146                                 if (len != 0)
 147                                         memset(p, t->bt_bval, len);
 148                                 if (__rec_iput(t,
 149                                     nrec, &data, 0) != RET_SUCCESS)
 150                                         return (RET_ERROR);
 151                                 ++nrec;
 152                                 break;
 153                         }
 154                 if (ch == EOF)
 155                         break;
 156         }
 157         if (nrec < top) {
 158                 F_SET(t, R_EOF);
 159                 return (RET_SPECIAL);
 160         }
 161         return (RET_SUCCESS);
 162 }
 163
 164 /*
 165  * __REC_VPIPE -- Get variable length records from a pipe.
 166  *
 167  * Parameters:
 168  *      t:      tree
 169  *      cnt:    records to read
 170  *
 171  * Returns:
 172  *      RET_ERROR, RET_SUCCESS
 173  */
 174 int
 175 __rec_vpipe(BTREE *t, recno_t top)
 176 {
 177         DBT data;
 178         recno_t nrec;
 179         ptrdiff_t len;
 180         size_t sz;
 181         int bval, ch;
 182         uint8_t *p;
 183
 184         bval = t->bt_bval;
 185         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 186                 for (p = t->bt_rdata.data,
 187                     sz = t->bt_rdata.size;; *p++ = ch, --sz) {
 188                         if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
 189                                 data.data = t->bt_rdata.data;
 190                                 data.size = p - (uint8_t *)t->bt_rdata.data;
 191                                 if (ch == EOF && data.size == 0)
 192                                         break;
 193                                 if (__rec_iput(t, nrec, &data, 0)
 194                                     != RET_SUCCESS)
 195                                         return (RET_ERROR);
 196                                 break;
 197                         }
 198                         if (sz == 0) {
 199                                 len = p - (uint8_t *)t->bt_rdata.data;
 200                                 t->bt_rdata.size += (sz = 256);
 201                                 t->bt_rdata.data = t->bt_rdata.data == NULL ?
 202                                     malloc(t->bt_rdata.size) :
 203                                     realloc(t->bt_rdata.data, t->bt_rdata.size);
 204                                 if (t->bt_rdata.data == NULL)
 205                                         return (RET_ERROR);
 206                                 p = (uint8_t *)t->bt_rdata.data + len;
 207                         }
 208                 }
 209                 if (ch == EOF)
 210                         break;
 211         }
 212         if (nrec < top) {
 213                 F_SET(t, R_EOF);
 214                 return (RET_SPECIAL);
 215         }
 216         return (RET_SUCCESS);
 217 }
 218
 219 /*
 220  * __REC_FMAP -- Get fixed length records from a file.
 221  *
 222  * Parameters:
 223  *      t:      tree
 224  *      cnt:    records to read
 225  *
 226  * Returns:
 227  *      RET_ERROR, RET_SUCCESS
 228  */
 229 int
 230 __rec_fmap(BTREE *t, recno_t top)
 231 {
 232         DBT data;
 233         recno_t nrec;
 234         uint8_t *sp, *ep, *p;
 235         size_t len;
 236
 237         if (t->bt_rdata.size < t->bt_reclen) {
 238                 t->bt_rdata.data = t->bt_rdata.data == NULL ?
 239                     malloc(t->bt_reclen) :
 240                     realloc(t->bt_rdata.data, t->bt_reclen);
 241                 if (t->bt_rdata.data == NULL)
 242                         return (RET_ERROR);
 243                 t->bt_rdata.size = t->bt_reclen;
 244         }
 245         data.data = t->bt_rdata.data;
 246         data.size = t->bt_reclen;
 247
 248         sp = (uint8_t *)t->bt_cmap;
 249         ep = (uint8_t *)t->bt_emap;
 250         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 251                 if (sp >= ep) {
 252                         F_SET(t, R_EOF);
 253                         return (RET_SPECIAL);
 254                 }
 255                 len = t->bt_reclen;
 256                 for (p = t->bt_rdata.data;
 257                     sp < ep && len > 0; *p++ = *sp++, --len);
 258                 if (len != 0)
 259                         memset(p, t->bt_bval, len);
 260                 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
 261                         return (RET_ERROR);
 262         }
 263         t->bt_cmap = (caddr_t)sp;
 264         return (RET_SUCCESS);
 265 }
 266
 267 /*
 268  * __REC_VMAP -- Get variable length records from a file.
 269  *
 270  * Parameters:
 271  *      t:      tree
 272  *      cnt:    records to read
 273  *
 274  * Returns:
 275  *      RET_ERROR, RET_SUCCESS
 276  */
 277 int
 278 __rec_vmap(BTREE *t, recno_t top)
 279 {
 280         DBT data;
 281         uint8_t *sp, *ep;
 282         recno_t nrec;
 283         int bval;
 284
 285         sp = (uint8_t *)t->bt_cmap;
 286         ep = (uint8_t *)t->bt_emap;
 287         bval = t->bt_bval;
 288
 289         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 290                 if (sp >= ep) {
 291                         F_SET(t, R_EOF);
 292                         return (RET_SPECIAL);
 293                 }
 294                 for (data.data = sp; sp < ep && *sp != bval; ++sp);
 295                 data.size = sp - (uint8_t *)data.data;
 296                 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
 297                         return (RET_ERROR);
 298                 ++sp;
 299         }
 300         t->bt_cmap = (caddr_t)sp;
 301         return (RET_SUCCESS);
 302 }