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Add new playlist handling functions.

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git-svn-id: https://svn.xiph.org/trunk/ezstream@12525 0101bb08-14d6-0310-b084-bc0e0c8e3800
This commit is contained in:
moritz 2007-02-24 20:50:33 +00:00
parent 5d932e4191
commit 2b0c3e6149
2 changed files with 526 additions and 0 deletions
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422
src/playlist.c Normal file
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/*
* Copyright (c) 2007 Moritz Grimm <gtgbr@gmx.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "playlist.h"
#include "util.h"
#ifdef WIN32
# define snprintf _snprintf
#endif
#ifndef SIZE_T_MAX
# define SIZE_T_MAX UINT_MAX
#endif
#ifndef PATH_MAX
# define PATH_MAX 256
#endif
extern int errno;
extern char *__progname;
struct playlist {
char *filename;
char **list;
size_t size;
size_t num;
size_t index;
};
playlist_t * playlist_create(const char *);
int playlist_add(playlist_t *, const char *);
unsigned int playlist_random(void);
playlist_t *
playlist_create(const char *filename)
{
playlist_t *pl;
pl = xcalloc(1, sizeof(playlist_t));
pl->filename = xstrdup(filename);
return (pl);
}
int
playlist_add(playlist_t *pl, const char *entry)
{
size_t num;
if (pl == NULL || entry == NULL) {
printf("%s: playlist_add(): Internal error: Bad arguments\n",
__progname);
exit(1);
}
num = pl->num + 1;
if (pl->size == 0) {
pl->list = xcalloc(2, sizeof(char *));
pl->size = 2 * sizeof(char *);
}
if (pl->size / sizeof(char *) <= num) {
unsigned long i;
pl->list = xrealloc(pl->list, 2, pl->size);
pl->size = 2 * pl->size;
for (i = num; i < pl->size / sizeof(char *); i++)
pl->list[i] = NULL;
}
pl->list[num - 1] = xstrdup(entry);
pl->num = num;
return (1);
}
unsigned int
playlist_random(void)
{
unsigned int ret = 0;
#ifdef HAVE_ARC4RANDOM
ret = arc4random();
#elif HAVE_RANDOM
ret = (unsigned int)random();
#else
/*
* Throw away the lower 12 bits; they go through a cyclic pattern.
* While this means that items in gigantic playlists won't be put
* beyond a certain distance from their original place in the list,
* it still improves the quality of the shuffler if this PRNG has
* to be used.
*/
ret = (unsigned int)rand() >> 12;
#endif
return (ret);
}
void
playlist_init(void)
{
#ifdef HAVE_RANDOM
# ifdef HAVE_SRANDOMDEV
srandomdev();
# else
srandom((unsigned int)time(NULL));
# endif /* HAVE_SRANDOMDEV */
#else
srand((unsigned int)time(NULL));
#endif /* HAVE_RANDOM */
}
void playlist_shutdown(void) {}
playlist_t *
playlist_read(const char *filename)
{
playlist_t *pl;
unsigned long line;
FILE *filep;
char buf[PATH_MAX + 1];
pl = playlist_create(filename);
if ((filep = fopen(filename, "r")) == NULL) {
printf("%s: playlist_read(): %s: %s\n", __progname, filename,
strerror(errno));
playlist_free(pl);
return (NULL);
}
line = 0;
while (fgets(buf, sizeof(buf), filep) != NULL) {
line++;
if (strlen(buf) == sizeof(buf) - 1) {
char skip_buf[2];
printf("%s[%lu]: File or path name too long\n",
filename, line);
/* Discard any excess chars in that line. */
while (fgets(skip_buf, sizeof(skip_buf), filep) != NULL) {
if (skip_buf[0] == '\n')
break;
}
continue;
}
/*
* fgets() would happily fill a buffer with
* { '\0', ..., '\n', '\0' }. Also skip lines that begin with
* a '#', which is considered a comment.
*/
if (buf[0] == '\0' || buf[0] == '#')
continue;
/* Trim any trailing newlines and carriage returns. */
if (buf[strlen(buf) - 1] == '\n')
buf[strlen(buf) - 1] = '\0';
if (buf[0] != '\0' && buf[strlen(buf) - 1] == '\r')
buf[strlen(buf) - 1] = '\0';
/* Skip lines that are empty after the trimming. */
if (buf[0] == '\0')
continue;
/* We got one. */
if (!playlist_add(pl, buf)) {
fclose(filep);
playlist_free(pl);
return (NULL);
}
}
if (ferror(filep)) {
printf("%s: playlist_read(): Error while reading %s: %s\n",
__progname, filename, strerror(errno));
fclose(filep);
playlist_free(pl);
return (NULL);
}
fclose(filep);
return (pl);
}
void
playlist_free(playlist_t *pl)
{
size_t i;
if (pl != NULL) {
if (pl->filename != NULL) {
xfree(pl->filename);
pl->filename = NULL;
}
if (pl->list != NULL) {
if (pl->size > 0) {
for (i = 0; i < pl->size / sizeof(char *); i++) {
if (pl->list[i] != NULL) {
xfree(pl->list[i]);
pl->list[i] = NULL;
} else
break;
}
}
xfree(pl->list);
pl->list = NULL;
}
xfree(pl);
pl = NULL;
}
}
const char *
playlist_get_next(playlist_t *pl)
{
if (pl == NULL) {
printf("%s: playlist_get_next(): Internal error: NULL argument\n",
__progname);
exit(1);
}
return ((const char *)pl->list[pl->index++]);
}
const char *
playlist_peek_next(playlist_t *pl)
{
if (pl == NULL) {
printf("%s: playlist_peek_next(): Internal error: NULL argument\n",
__progname);
exit(1);
}
return ((const char *)pl->list[pl->index]);
}
void
playlist_skip_next(playlist_t *pl)
{
if (pl == NULL) {
printf("%s: playlist_skip_next(): Internal error: NULL argument\n",
__progname);
exit(1);
}
if (pl->list[pl->index] != NULL)
pl->index++;
}
unsigned long
playlist_get_num_items(playlist_t *pl)
{
if (pl == NULL) {
printf("%s: playlist_get_position(): Internal error: NULL argument\n",
__progname);
exit(1);
}
return ((unsigned long)pl->num);
}
unsigned long
playlist_get_position(playlist_t *pl)
{
if (pl == NULL) {
printf("%s: playlist_get_position(): Internal error: NULL argument\n",
__progname);
exit(1);
}
return ((unsigned long)pl->index);
}
int
playlist_set_position(playlist_t *pl, unsigned long index)
{
if (pl == NULL) {
printf("%s: playlist_set_position(): Internal error: NULL argument\n",
__progname);
exit(1);
}
if (index > pl->num - 1)
return (0);
pl->index = (size_t)index;
return (1);
}
int
playlist_goto_entry(playlist_t *pl, const char *entry)
{
unsigned long i;
if (pl == NULL || entry == NULL) {
printf("%s: playlist_goto_entry(): Internal error: Bad arguments\n",
__progname);
exit(1);
}
if (pl->num == 0)
return (0);
for (i = 0; i < pl->num; i++) {
if (strcmp(pl->list[i], entry) == 0) {
pl->index = (size_t)i;
return (1);
}
}
return (0);
}
void
playlist_rewind(playlist_t *pl)
{
if (pl == NULL) {
printf("%s: playlist_rewind(): Internal error: NULL argument\n",
__progname);
exit(1);
}
pl->index = 0;
}
int
playlist_reread(playlist_t **plist)
{
playlist_t *new_pl, *pl;
if (plist == NULL || *plist == NULL) {
printf("%s: playlist_reread(): Internal error: NULL argument\n",
__progname);
exit(1);
}
pl = *plist;
if ((new_pl = playlist_read(pl->filename)) == NULL)
return (0);
playlist_free(pl);
*plist = new_pl;
return (1);
}
/*
* Yet another implementation of the "Knuth Shuffle":
*/
void
playlist_shuffle(playlist_t *pl)
{
unsigned long d, i, range;
char *temp;
if (pl == NULL) {
printf("%s: playlist_shuffle(): Internal error: NULL argument\n",
__progname);
exit(1);
}
if (pl->num < 2)
return;
for (i = 0; i < pl->num; i++) {
range = pl->num - i;
/*
* Only accept a random number if it is smaller than the
* largest multiple of our range. This reduces PRNG bias.
*/
do {
d = (unsigned long)playlist_random();
} while (d > RAND_MAX - (RAND_MAX % range));
/*
* The range starts at the item we want to shuffle, excluding
* already shuffled items.
*/
d = i + (d % range);
temp = pl->list[d];
pl->list[d] = pl->list[i];
pl->list[i] = temp;
}
}

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/*
* Copyright (c) 2007 Moritz Grimm <gtgbr@gmx.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef __PLAYLIST_H__
#define __PLAYLIST_H__
typedef struct playlist playlist_t;
/*
* Initialize the playlist routines. Should be called before any of the other
* playlist functions.
*/
void playlist_init(void);
/*
* Clean up for clean shutdowns. No-op at the moment.
*/
void playlist_shutdown(void);
/*
* Read a playlist file (in .M3U format), and return a new playlist handler
* on success, or NULL on failure.
*/
playlist_t * playlist_read(const char * /* filename */);
/*
* Free all memory used by a playlist handler that was created with
* playlist_read().
*/
void playlist_free(playlist_t *);
/*
* Get the next item in the playlist. Returns a NUL-terminated string of a
* playlist entry, or NULL if the end of the list has been reached.
*/
const char * playlist_get_next(playlist_t *);
/*
* Get the next item in the playlist without moving on to the following entry.
* Returns a NUL-terminated string of the next playlist entry, or NULL if the
* currently playing song is the last one in the list.
*/
const char * playlist_peek_next(playlist_t *);
/*
* Skip the playlist item that would be played next.
*/
void playlist_skip_next(playlist_t *);
/*
* Get the number of items in the playlist.
*/
unsigned long playlist_get_num_items(playlist_t *);
/*
* Get the current position in the playlist.
*/
unsigned long playlist_get_position(playlist_t *);
/*
* Set a position in the playlist. Returns 1 on success, and 0 on failure.
*/
int playlist_set_position(playlist_t *, unsigned long /* index */);
/*
* Search for a given entry in the playlist and reposition to it. Returns 1 on
* success and 0 on failure. A subsequent call to playlist_get_next() will
* return this list item again.
*/
int playlist_goto_entry(playlist_t *, const char * /* name */);
/*
* Rewind the playlist to the beginning, so that it can be replayed. Does
* not reread the playlist file.
*/
void playlist_rewind(playlist_t *);
/*
* Reread the playlist file and rewind to the beginning. Equivalent to calling
* playlist_free() and playlist_read(). Entries will no longer be shuffled
* after calling this function.
* Returns 1 on success, and 0 on error.
*/
int playlist_reread(playlist_t **);
/*
* Shuffle the entries of the playlist randomly.
*/
void playlist_shuffle(playlist_t *);
#endif /* __PLAYLIST_H__ */