lib/libc/db/recno/rec_get.c

   1 /*      $NetBSD: rec_get.c,v 1.18 2013/12/25 19:42:23 christos 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 1.18 2013/12/25 19:42:23 christos 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                 void *np = realloc(t->bt_rdata.data, t->bt_reclen);
 131                 if (np == NULL)
 132                         return (RET_ERROR);
 133                 t->bt_rdata.data = np;
 134                 t->bt_rdata.size = t->bt_reclen;
 135         }
 136         data.data = t->bt_rdata.data;
 137         data.size = t->bt_reclen;
 138
 139         for (nrec = t->bt_nrecs; nrec < top;) {
 140                 len = t->bt_reclen;
 141                 for (p = t->bt_rdata.data;; *p++ = ch)
 142                         if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
 143                                 if (ch != EOF)
 144                                         *p = ch;
 145                                 if (len != 0)
 146                                         memset(p, t->bt_bval, len);
 147                                 if (__rec_iput(t,
 148                                     nrec, &data, 0) != RET_SUCCESS)
 149                                         return (RET_ERROR);
 150                                 ++nrec;
 151                                 break;
 152                         }
 153                 if (ch == EOF)
 154                         break;
 155         }
 156         if (nrec < top) {
 157                 F_SET(t, R_EOF);
 158                 return (RET_SPECIAL);
 159         }
 160         return (RET_SUCCESS);
 161 }
 162
 163 /*
 164  * __REC_VPIPE -- Get variable length records from a pipe.
 165  *
 166  * Parameters:
 167  *      t:      tree
 168  *      cnt:    records to read
 169  *
 170  * Returns:
 171  *      RET_ERROR, RET_SUCCESS
 172  */
 173 int
 174 __rec_vpipe(BTREE *t, recno_t top)
 175 {
 176         DBT data;
 177         recno_t nrec;
 178         size_t sz;
 179         int bval, ch;
 180         uint8_t *p;
 181
 182         bval = t->bt_bval;
 183         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 184                 for (p = t->bt_rdata.data,
 185                     sz = t->bt_rdata.size;; *p++ = ch, --sz) {
 186                         if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
 187                                 data.data = t->bt_rdata.data;
 188                                 data.size = p - (uint8_t *)t->bt_rdata.data;
 189                                 if (ch == EOF && data.size == 0)
 190                                         break;
 191                                 if (__rec_iput(t, nrec, &data, 0)
 192                                     != RET_SUCCESS)
 193                                         return (RET_ERROR);
 194                                 break;
 195                         }
 196                         if (sz == 0) {
 197                                 ptrdiff_t len = p - (uint8_t *)t->bt_rdata.data;
 198                                 size_t tot = t->bt_rdata.size + (sz = 256);
 199                                 void *np = realloc(t->bt_rdata.data, tot);
 200                                 if (np == NULL)
 201                                         return (RET_ERROR);
 202                                 t->bt_rdata.size = tot;
 203                                 t->bt_rdata.data = np;
 204                                 p = (uint8_t *)t->bt_rdata.data + len;
 205                         }
 206                 }
 207                 if (ch == EOF)
 208                         break;
 209         }
 210         if (nrec < top) {
 211                 F_SET(t, R_EOF);
 212                 return (RET_SPECIAL);
 213         }
 214         return (RET_SUCCESS);
 215 }
 216
 217 /*
 218  * __REC_FMAP -- Get fixed length records from a file.
 219  *
 220  * Parameters:
 221  *      t:      tree
 222  *      cnt:    records to read
 223  *
 224  * Returns:
 225  *      RET_ERROR, RET_SUCCESS
 226  */
 227 int
 228 __rec_fmap(BTREE *t, recno_t top)
 229 {
 230         DBT data;
 231         recno_t nrec;
 232         uint8_t *sp, *ep, *p;
 233         size_t len;
 234
 235         if (t->bt_rdata.size < t->bt_reclen) {
 236                 void *np = realloc(t->bt_rdata.data, t->bt_reclen);
 237                 if (np == NULL)
 238                         return (RET_ERROR);
 239                 t->bt_rdata.data = np;
 240                 t->bt_rdata.size = t->bt_reclen;
 241         }
 242         data.data = t->bt_rdata.data;
 243         data.size = t->bt_reclen;
 244
 245         sp = (uint8_t *)t->bt_cmap;
 246         ep = (uint8_t *)t->bt_emap;
 247         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 248                 if (sp >= ep) {
 249                         F_SET(t, R_EOF);
 250                         return (RET_SPECIAL);
 251                 }
 252                 len = t->bt_reclen;
 253                 for (p = t->bt_rdata.data;
 254                     sp < ep && len > 0; *p++ = *sp++, --len);
 255                 if (len != 0)
 256                         memset(p, t->bt_bval, len);
 257                 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
 258                         return (RET_ERROR);
 259         }
 260         t->bt_cmap = (caddr_t)sp;
 261         return (RET_SUCCESS);
 262 }
 263
 264 /*
 265  * __REC_VMAP -- Get variable length records from a file.
 266  *
 267  * Parameters:
 268  *      t:      tree
 269  *      cnt:    records to read
 270  *
 271  * Returns:
 272  *      RET_ERROR, RET_SUCCESS
 273  */
 274 int
 275 __rec_vmap(BTREE *t, recno_t top)
 276 {
 277         DBT data;
 278         uint8_t *sp, *ep;
 279         recno_t nrec;
 280         int bval;
 281
 282         sp = (uint8_t *)t->bt_cmap;
 283         ep = (uint8_t *)t->bt_emap;
 284         bval = t->bt_bval;
 285
 286         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 287                 if (sp >= ep) {
 288                         F_SET(t, R_EOF);
 289                         return (RET_SPECIAL);
 290                 }
 291                 for (data.data = sp; sp < ep && *sp != bval; ++sp);
 292                 data.size = sp - (uint8_t *)data.data;
 293                 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
 294                         return (RET_ERROR);
 295                 ++sp;
 296         }
 297         t->bt_cmap = (caddr_t)sp;
 298         return (RET_SUCCESS);
 299 }