1/* gdbmfetch.c - Find a key and return the associated data.  */
2
3/*  This file is part of GDBM, the GNU data base manager, by Philip A. Nelson.
4    Copyright (C) 1990, 1991, 1993  Free Software Foundation, Inc.
5
6    GDBM is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 2, or (at your option)
9    any later version.
10
11    GDBM is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15
16    You should have received a copy of the GNU General Public License
17    along with GDBM; see the file COPYING.  If not, write to
18    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
19
20    You may contact the author by:
21       e-mail:  phil@cs.wwu.edu
22      us-mail:  Philip A. Nelson
23                Computer Science Department
24                Western Washington University
25                Bellingham, WA 98226
26
27*************************************************************************/
28
29
30/* include system configuration before all else. */
31#include "autoconf.h"
32
33#include "gdbmdefs.h"
34#include "gdbmerrno.h"
35
36/* Look up a given KEY and return the information associated with that KEY.
37   The pointer in the structure that is  returned is a pointer to dynamically
38   allocated memory block.  */
39
40datum
41gdbm_fetch (dbf, key)
42     gdbm_file_info *dbf;
43     datum key;
44{
45  datum  return_val;		/* The return value. */
46  int    elem_loc;		/* The location in the bucket. */
47  char  *find_data;		/* Returned from find_key. */
48  int    hash_val;		/* Returned from find_key. */
49
50  /* Set the default return value. */
51  return_val.dptr  = NULL;
52  return_val.dsize = 0;
53
54  /* Initialize the gdbm_errno variable. */
55  gdbm_errno = GDBM_NO_ERROR;
56
57  /* Find the key and return a pointer to the data. */
58  elem_loc = _gdbm_findkey (dbf, key, &find_data, &hash_val);
59
60  /* Copy the data if the key was found.  */
61  if (elem_loc >= 0)
62    {
63      /* This is the item.  Return the associated data. */
64      return_val.dsize = dbf->bucket->h_table[elem_loc].data_size;
65      if (return_val.dsize == 0)
66	return_val.dptr = (char *) malloc (1);
67      else
68	return_val.dptr = (char *) malloc (return_val.dsize);
69      if (return_val.dptr == NULL) _gdbm_fatal (dbf, "malloc error");
70      bcopy (find_data, return_val.dptr, return_val.dsize);
71    }
72
73  /* Check for an error and return. */
74  if (return_val.dptr == NULL) gdbm_errno = GDBM_ITEM_NOT_FOUND;
75  return return_val;
76}
77