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/* gdbmseq.c - Routines to visit all keys. Not in sorted order. */
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/* This file is part of GDBM, the GNU data base manager, by Philip A. Nelson.
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Copyright (C) 1990, 1991, 1993 Free Software Foundation, Inc.
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GDBM is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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GDBM is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GDBM; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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You may contact the author by:
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e-mail: phil@cs.wwu.edu
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us-mail: Philip A. Nelson
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Computer Science Department
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Western Washington University
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*************************************************************************/
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/* include system configuration before all else. */
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#include "gdbmerrno.h"
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/* Special extern for this file. */
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extern char *_gdbm_read_entry _ARGS((gdbm_file_info *, int));
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/* Find and read the next entry in the hash structure for DBF starting
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at ELEM_LOC of the current bucket and using RETURN_VAL as the place to
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put the data that is found. */
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get_next_key (dbf, elem_loc, return_val)
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int found; /* Have we found the next key. */
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char *find_data; /* Data pointer returned by find_key. */
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/* Find the next key. */
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/* Advance to the next location in the bucket. */
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if (elem_loc == dbf->header->bucket_elems)
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/* We have finished the current bucket, get the next bucket. */
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/* Find the next bucket. It is possible several entries in
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the bucket directory point to the same bucket. */
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while (dbf->bucket_dir < dbf->header->dir_size / sizeof (off_t)
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&& dbf->cache_entry->ca_adr == dbf->dir[dbf->bucket_dir])
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/* Check to see if there was a next bucket. */
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if (dbf->bucket_dir < dbf->header->dir_size / sizeof (off_t))
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_gdbm_get_bucket (dbf, dbf->bucket_dir);
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/* No next key, just return. */
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found = dbf->bucket->h_table[elem_loc].hash_value != -1;
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/* Found the next key, read it into return_val. */
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find_data = _gdbm_read_entry (dbf, elem_loc);
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return_val->dsize = dbf->bucket->h_table[elem_loc].key_size;
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if (return_val->dsize == 0)
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return_val->dptr = (char *) malloc (1);
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return_val->dptr = (char *) malloc (return_val->dsize);
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if (return_val->dptr == NULL) _gdbm_fatal (dbf, "malloc error");
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bcopy (find_data, return_val->dptr, return_val->dsize);
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/* Start the visit of all keys in the database. This produces something in
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hash order, not in any sorted order. */
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datum return_val; /* To return the first key. */
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/* Set the default return value for not finding a first entry. */
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return_val.dptr = NULL;
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/* Initialize the gdbm_errno variable. */
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gdbm_errno = GDBM_NO_ERROR;
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/* Get the first bucket. */
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_gdbm_get_bucket (dbf, 0);
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/* Look for first entry. */
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get_next_key (dbf, -1, &return_val);
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/* Continue visiting all keys. The next key following KEY is returned. */
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gdbm_nextkey (dbf, key)
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datum return_val; /* The return value. */
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int elem_loc; /* The location in the bucket. */
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char *find_data; /* Data pointer returned by _gdbm_findkey. */
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word_t hash_val; /* Returned by _gdbm_findkey. */
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/* Initialize the gdbm_errno variable. */
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gdbm_errno = GDBM_NO_ERROR;
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/* Set the default return value for no next entry. */
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return_val.dptr = NULL;
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/* Do we have a valid key? */
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if (key.dptr == NULL) return return_val;
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elem_loc = _gdbm_findkey (dbf, key, &find_data, &hash_val);
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if (elem_loc == -1) return return_val;
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/* Find the next key. */
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get_next_key (dbf, elem_loc, &return_val);
added
removed
gdbmseq.c
