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tdemultimedia/kscd/libwm/index.c

384 lines
8.0 KiB

/*
* $Id$
*
* This file is part of WorkMan, the civilized CD player library
* (c) 1991-1997 by Steven Grimm (original author)
* (c) by Dirk F<EFBFBD>rsterling (current 'author' = maintainer)
* The maintainer can be contacted by his e-mail address:
* milliByte@DeathsDoor.com
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*
* Maintain an external index file for a WorkMan CD database.
* Uses the Berkeley libdb library, available from ftp.cs.berkeley.edu.
*/
#ifdef LIBDB
#include <stdio.h>
#include <stdlib.h>
#include <db.h>
#include <fcntl.h>
#include <string.h>
#include <netinet/in.h> /* for htonl() */
#include "include/wm_config.h"
#include "include/wm_index.h"
extern int suppress_locking;
/*
* idx_find_entry()
*
* Find an entry in the index file.
*
* Input:
* file Name of database file (text version).
* ntracks Number of tracks on the CD we're looking for.
* tracks Array of track start times.
* len CD length in frames.
* fuzz Fuzz factor (tolerance value).
* pos Pointer to return value.
*
* Output:
* 1 No matching record found.
* 0 Record found; *pos contains offset into text file.
* -1 Index file out of date or inaccessible, or another error.
*/
int
idx_find_entry( char *file, int ntracks, int *tracks,
int len, int fuzz, unsigned long *pos )
{
unsigned long dbpos;
char *indexname = NULL, keyval[8];
int c;
FILE *text;
DB *index;
DBT key, data;
BTREEINFO bti;
/*
* First, see if the text file is accessible. Lock it if so.
*/
text = fopen(file, "r");
if (text == NULL)
return (-1);
if ((c = getc(text)) == EOF)
{
fclose(text);
return (-1);
}
if (! suppress_locking)
if (lockit(fileno(text), F_RDLCK))
{
fclose(text);
return (-1);
}
/*
* Open the index file.
*/
indexname = malloc(strlen(file) + sizeof(".ind"));
if (indexname == NULL)
{
fclose(text);
return (-1);
}
strcpy(indexname, file);
strcat(indexname, ".ind");
bti.flags = 0;
bti.cachesize = 0;
bti.minkeypage = bti.maxkeypage = 0;
bti.psize = bti.lorder = 0;
bti.compare = NULL;
bti.prefix = NULL;
index = dbopen(indexname, O_RDONLY, 0666, DB_BTREE, &bti);
free(indexname);
if (index == NULL)
{
fclose(text);
return (-1);
}
/*
* Search for the first matching entry.
*/
sprintf(keyval, "%07d", tracks[ntracks - 1] - fuzz);
key.data = keyval;
key.size = 7;
if (c = (index->seq)(index, &key, &data, R_CURSOR))
{
(index->close)(index);
fclose(text);
return (c);
}
/*
* Now loop through all the possible matches, collecting them into
* memory.
*/
do {
char tracksline[750], *s;
int i, val;
/* Hit the end of the valid entries? */
sscanf(key.data, "%d", &val);
if (val > tracks[ntracks - 1] + fuzz)
break;
dbpos = ntohl(*((unsigned long *) data.data));
if (fseek(text, dbpos, 0))
break;
fgets(tracksline, sizeof(tracksline), text);
if (strncmp(tracksline, "tracks ", 7))
break;
(void) strtok(tracksline, " \t");
/* Got a valid tracks line. See if it matches the CD. */
s = strtok(NULL, " \t");
if (s == NULL)
break;
if (atoi(s) != ntracks)
continue;
for (i = 0; i < ntracks; i++)
{
s = strtok(NULL, " \t");
if (s == NULL)
break;
val = atoi(s);
if (val + fuzz < tracks[i] || val - fuzz > tracks[i])
break;
}
if (i != ntracks)
continue;
s = strtok(NULL, " \t");
if (s == NULL)
continue;
val = atoi(s);
if (val + fuzz / 75 < len / 75 || val + fuzz / 75 > len / 75)
continue;
/* XXX - add to sorted list! */
*pos = dbpos;
(index->close)(index);
fclose(text);
return (0);
} while ((c = (index->seq)(index, &key, &data, R_NEXT)) == 0);
if (c == 0)
{
/* An error. */
(index->close)(index);
fclose(text);
return (-1);
}
(index->close)(index);
fclose(text);
return (1);
}
/*
* idx_delete_entry()
*
* Delete an entry from the index file.
*
* Input:
* file Name of database file (text version).
* track Last track's start time (database key).
* fuzz Fuzz factor (tolerance value).
* pos Position of CD in database file.
*
* Output:
* 1 No matching record found.
* 0 Record deleted.
* -1 Index file out of date or inaccessible, or another error.
*
* Note: it is the caller's responsibility to do locking, as it's assumed
* that this operation will accompany a modification of the main database
* file and will need to be atomic with that modification.
*/
int
idx_delete_entry(char *file, int track, int fuzz, unsigned long pos )
{
unsigned long dbpos;
char *indexname = NULL, keyval[8];
int c, status;
DB *index;
DBT key, data;
BTREEINFO bti;
/*
* Open the index file.
*/
indexname = malloc(strlen(file) + sizeof(".ind"));
if (indexname == NULL)
return (-1);
strcpy(indexname, file);
strcat(indexname, ".ind");
bti.flags = 0;
bti.cachesize = 0;
bti.minkeypage = bti.maxkeypage = 0;
bti.psize = bti.lorder = 0;
bti.compare = NULL;
bti.prefix = NULL;
index = dbopen(indexname, O_RDWR, 0666, DB_BTREE, &bti);
free(indexname);
if (index == NULL)
return (-1);
/*
* Search for the first matching entry.
*/
sprintf(keyval, "%07d", track - fuzz);
key.data = keyval;
key.size = 7;
if (c = (index->seq)(index, &key, &data, R_CURSOR))
{
/*
* Nothing matched!
*/
(index->close)(index);
return (c);
}
/*
* Look for the entry the user wants to delete.
*/
do {
int val;
/* Hit the end of the valid entries? */
sscanf(key.data, "%d", &val);
if (val > track + fuzz)
break;
/* Is this the entry we want? */
if (pos == ntohl(*((unsigned long *) data.data)))
{
/*
* Yep! Delete it.
*/
status = (index->del)(index, &key, R_CURSOR);
(index->close)(index);
return (status);
}
} while ((c = (index->seq)(index, &key, &data, R_NEXT)) == 0);
if (c == 0)
{
/* An error. */
(index->close)(index);
return (-1);
}
(index->close)(index);
return (1);
}
/*
* idx_write_entry()
*
* Write out an index file entry.
*
* Input:
* file Name of database file (text version).
* track Start time of last track (database key).
* pos Position of entry in text file.
*
* Output:
* 0 Record written.
* -1 Index file inaccessible, or another error.
*
* Note: it is the caller's responsibility to do locking, as it's assumed
* that this operation will accompany a modification of the main database
* file and will need to be atomic with that modification.
*/
int
idx_write_entry( char *file, int track, unsigned long pos )
{
char *indexname, keyval[8];
int status;
DB *index;
DBT key, data;
BTREEINFO bti;
/*
* Open the index file.
*/
indexname = malloc(strlen(file) + sizeof(".ind"));
if (indexname == NULL)
return (-1);
strcpy(indexname, file);
strcat(indexname, ".ind");
bti.flags = R_DUP;
bti.cachesize = 0;
bti.minkeypage = 0;
bti.maxkeypage = 0;
bti.psize = 0;
bti.lorder = 4321; /* network byte order */
bti.compare = NULL;
bti.prefix = NULL;
index = dbopen(indexname, O_RDWR, 0666, DB_BTREE, &bti);
free(indexname);
if (index == NULL)
return (-1);
/*
* Create a new key and value.
*/
pos = htonl(pos);
data.data = &pos;
data.size = sizeof(pos);
key.data = keyval;
key.size = 7;
sprintf(keyval, "%07d", track);
status = (index->put)(index, &key, &data, 0);
(index->close)(index);
return (status);
}
#else /* LIBDB */
int
idx_find_entry()
{
return (1); /* no record found; text file will be searched. */
}
int
idx_delete_entry()
{
return (0);
}
int
idx_write_entry()
{
return (0);
}
#endif /* LIBDB */