db/recno/FreeBSD/rec_get.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)rec_get.c   8.9 (Berkeley) 8/18/94";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/db/recno/rec_get.c,v 1.5 2002/03/22 21:52:02 obrien Exp $");
  39
  40 #include <sys/types.h>
  41
  42 #include <errno.h>
  43 #include <stddef.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48
  49 #include <db.h>
  50 #include "recno.h"
  51
  52 /*
  53  * __REC_GET -- Get a record from the btree.
  54  *
  55  * Parameters:
  56  *      dbp:    pointer to access method
  57  *      key:    key to find
  58  *      data:   data to return
  59  *      flag:   currently unused
  60  *
  61  * Returns:
  62  *      RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
  63  */
  64 int
  65 __rec_get(dbp, key, data, flags)
  66         const DB *dbp;
  67         const DBT *key;
  68         DBT *data;
  69         u_int flags;
  70 {
  71         BTREE *t;
  72         EPG *e;
  73         recno_t nrec;
  74         int status;
  75
  76         t = dbp->internal;
  77
  78         /* Toss any page pinned across calls. */
  79         if (t->bt_pinned != NULL) {
  80                 mpool_put(t->bt_mp, t->bt_pinned, 0);
  81                 t->bt_pinned = NULL;
  82         }
  83
  84         /* Get currently doesn't take any flags, and keys of 0 are illegal. */
  85         if (flags || (nrec = *(recno_t *)key->data) == 0) {
  86                 errno = EINVAL;
  87                 return (RET_ERROR);
  88         }
  89
  90         /*
  91          * If we haven't seen this record yet, try to find it in the
  92          * original file.
  93          */
  94         if (nrec > t->bt_nrecs) {
  95                 if (F_ISSET(t, R_EOF | R_INMEM))
  96                         return (RET_SPECIAL);
  97                 if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
  98                         return (status);
  99         }
 100
 101         --nrec;
 102         if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
 103                 return (RET_ERROR);
 104
 105         status = __rec_ret(t, e, 0, NULL, data);
 106         if (F_ISSET(t, B_DB_LOCK))
 107                 mpool_put(t->bt_mp, e->page, 0);
 108         else
 109                 t->bt_pinned = e->page;
 110         return (status);
 111 }
 112
 113 /*
 114  * __REC_FPIPE -- Get fixed length records from a pipe.
 115  *
 116  * Parameters:
 117  *      t:      tree
 118  *      cnt:    records to read
 119  *
 120  * Returns:
 121  *      RET_ERROR, RET_SUCCESS
 122  */
 123 int
 124 __rec_fpipe(t, top)
 125         BTREE *t;
 126         recno_t top;
 127 {
 128         DBT data;
 129         recno_t nrec;
 130         size_t len;
 131         int ch;
 132         u_char *p;
 133
 134         if (t->bt_rdata.size < t->bt_reclen) {
 135                 t->bt_rdata.data = t->bt_rdata.data == NULL ?
 136                     malloc(t->bt_reclen) :
 137                     reallocf(t->bt_rdata.data, t->bt_reclen);
 138                 if (t->bt_rdata.data == NULL)
 139                         return (RET_ERROR);
 140                 t->bt_rdata.size = t->bt_reclen;
 141         }
 142         data.data = t->bt_rdata.data;
 143         data.size = t->bt_reclen;
 144
 145         for (nrec = t->bt_nrecs; nrec < top;) {
 146                 len = t->bt_reclen;
 147                 for (p = t->bt_rdata.data;; *p++ = ch)
 148                         if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
 149                                 if (ch != EOF)
 150                                         *p = ch;
 151                                 if (len != 0)
 152                                         memset(p, t->bt_bval, len);
 153                                 if (__rec_iput(t,
 154                                     nrec, &data, 0) != RET_SUCCESS)
 155                                         return (RET_ERROR);
 156                                 ++nrec;
 157                                 break;
 158                         }
 159                 if (ch == EOF)
 160                         break;
 161         }
 162         if (nrec < top) {
 163                 F_SET(t, R_EOF);
 164                 return (RET_SPECIAL);
 165         }
 166         return (RET_SUCCESS);
 167 }
 168
 169 /*
 170  * __REC_VPIPE -- Get variable length records from a pipe.
 171  *
 172  * Parameters:
 173  *      t:      tree
 174  *      cnt:    records to read
 175  *
 176  * Returns:
 177  *      RET_ERROR, RET_SUCCESS
 178  */
 179 int
 180 __rec_vpipe(t, top)
 181         BTREE *t;
 182         recno_t top;
 183 {
 184         DBT data;
 185         recno_t nrec;
 186         size_t len;
 187         size_t sz;
 188         int bval, ch;
 189         u_char *p;
 190
 191         bval = t->bt_bval;
 192         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 193                 for (p = t->bt_rdata.data,
 194                     sz = t->bt_rdata.size;; *p++ = ch, --sz) {
 195                         if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
 196                                 data.data = t->bt_rdata.data;
 197                                 data.size = p - (u_char *)t->bt_rdata.data;
 198                                 if (ch == EOF && data.size == 0)
 199                                         break;
 200                                 if (__rec_iput(t, nrec, &data, 0)
 201                                     != RET_SUCCESS)
 202                                         return (RET_ERROR);
 203                                 break;
 204                         }
 205                         if (sz == 0) {
 206                                 len = p - (u_char *)t->bt_rdata.data;
 207                                 t->bt_rdata.size += (sz = 256);
 208                                 t->bt_rdata.data = t->bt_rdata.data == NULL ?
 209                                     malloc(t->bt_rdata.size) :
 210                                     reallocf(t->bt_rdata.data, t->bt_rdata.size);
 211                                 if (t->bt_rdata.data == NULL)
 212                                         return (RET_ERROR);
 213                                 p = (u_char *)t->bt_rdata.data + len;
 214                         }
 215                 }
 216                 if (ch == EOF)
 217                         break;
 218         }
 219         if (nrec < top) {
 220                 F_SET(t, R_EOF);
 221                 return (RET_SPECIAL);
 222         }
 223         return (RET_SUCCESS);
 224 }
 225
 226 /*
 227  * __REC_FMAP -- Get fixed length records from a file.
 228  *
 229  * Parameters:
 230  *      t:      tree
 231  *      cnt:    records to read
 232  *
 233  * Returns:
 234  *      RET_ERROR, RET_SUCCESS
 235  */
 236 int
 237 __rec_fmap(t, top)
 238         BTREE *t;
 239         recno_t top;
 240 {
 241         DBT data;
 242         recno_t nrec;
 243         u_char *sp, *ep, *p;
 244         size_t len;
 245
 246         if (t->bt_rdata.size < t->bt_reclen) {
 247                 t->bt_rdata.data = t->bt_rdata.data == NULL ?
 248                     malloc(t->bt_reclen) :
 249                     reallocf(t->bt_rdata.data, t->bt_reclen);
 250                 if (t->bt_rdata.data == NULL)
 251                         return (RET_ERROR);
 252                 t->bt_rdata.size = t->bt_reclen;
 253         }
 254         data.data = t->bt_rdata.data;
 255         data.size = t->bt_reclen;
 256
 257         sp = (u_char *)t->bt_cmap;
 258         ep = (u_char *)t->bt_emap;
 259         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 260                 if (sp >= ep) {
 261                         F_SET(t, R_EOF);
 262                         return (RET_SPECIAL);
 263                 }
 264                 len = t->bt_reclen;
 265                 for (p = t->bt_rdata.data;
 266                     sp < ep && len > 0; *p++ = *sp++, --len);
 267                 if (len != 0)
 268                         memset(p, t->bt_bval, len);
 269                 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
 270                         return (RET_ERROR);
 271         }
 272         t->bt_cmap = (caddr_t)sp;
 273         return (RET_SUCCESS);
 274 }
 275
 276 /*
 277  * __REC_VMAP -- Get variable length records from a file.
 278  *
 279  * Parameters:
 280  *      t:      tree
 281  *      cnt:    records to read
 282  *
 283  * Returns:
 284  *      RET_ERROR, RET_SUCCESS
 285  */
 286 int
 287 __rec_vmap(t, top)
 288         BTREE *t;
 289         recno_t top;
 290 {
 291         DBT data;
 292         u_char *sp, *ep;
 293         recno_t nrec;
 294         int bval;
 295
 296         sp = (u_char *)t->bt_cmap;
 297         ep = (u_char *)t->bt_emap;
 298         bval = t->bt_bval;
 299
 300         for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
 301                 if (sp >= ep) {
 302                         F_SET(t, R_EOF);
 303                         return (RET_SPECIAL);
 304                 }
 305                 for (data.data = sp; sp < ep && *sp != bval; ++sp);
 306                 data.size = sp - (u_char *)data.data;
 307                 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
 308                         return (RET_ERROR);
 309                 ++sp;
 310         }
 311         t->bt_cmap = (caddr_t)sp;
 312         return (RET_SUCCESS);
 313 }