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