playlist.c

   1 #include "para.h"
   2 #include "error.h"
   3 #include "afs.h"
   4 #include "string.h"
   5
   6 /** \file playlist.c Functions for loading and saving playlists. */
   7
   8 /** Structure used for adding entries to a playlist. */
   9 struct playlist_info {
  10         /** The name of the playlist. */
  11         char *name;
  12         /** The number of entries currently in the playlist. */
  13         unsigned length;
  14 };
  15 static struct playlist_info playlist;
  16
  17 /**
  18  * Re-insert an audio file into the tree of admissible files.
  19  *
  20  * \param aft_row Determines the audio file.
  21  *
  22  * \return The return value of score_update().
  23  */
  24 int playlist_update_audio_file(struct osl_row *aft_row)
  25 {
  26         /* always re-insert to the top of the tree */
  27         return score_update(aft_row, 0);
  28 }
  29
  30 static int add_playlist_entry(char *line, void *private_data)
  31 {
  32         struct osl_row *aft_row;
  33         struct playlist_info *pli = private_data;
  34         int ret = aft_get_row_of_path(line, &aft_row);
  35
  36         if (ret < 0) {
  37                 PARA_NOTICE_LOG("path not found in audio file table: %s\n",
  38                         line);
  39                 return 1;
  40         }
  41         ret = score_add(aft_row, -pli->length);
  42         if (ret < 0) {
  43                 PARA_ERROR_LOG("failed to add %s: %d\n", line, ret);
  44                 return ret;
  45         }
  46         pli->length++;
  47         return 1;
  48 }
  49
  50 static int load_playlist(struct osl_row *row)
  51 {
  52         struct osl_object obj;
  53         int ret;
  54
  55         ret = osl_get_object(playlists_table, row, BLOBCOL_NAME, &obj);
  56         if (ret < 0)
  57                 return ret;
  58         playlist.name = para_strdup(obj.data);
  59         playlist.length = 0;
  60         ret = osl_open_disk_object(playlists_table, row, BLOBCOL_DEF, &obj);
  61         if (ret < 0)
  62                 goto err;
  63         ret = for_each_line_ro(obj.data, obj.size, add_playlist_entry,
  64                 &playlist);
  65         osl_close_disk_object(&obj);
  66         if (ret < 0)
  67                 goto err;
  68         ret = -E_PLAYLIST_EMPTY;
  69         if (!playlist.length)
  70                 goto err;
  71         PARA_NOTICE_LOG("loaded playlist %s (%u files)\n", playlist.name,
  72                 playlist.length);
  73         return 1;
  74 err:
  75         free(playlist.name);
  76         return ret;
  77 }
  78
  79 /* returns -E_PLAYLIST_LOADED on _success_ to terminate the loop */
  80 static int playlist_loop(struct osl_row *row, __a_unused void *private_data)
  81 {
  82         int ret = load_playlist(row);
  83         if (ret < 0) {
  84                 if (ret != -E_DUMMY_ROW)
  85                         PARA_NOTICE_LOG("unable to load playlist, trying next\n");
  86                 return 1;
  87         }
  88         return -E_PLAYLIST_LOADED;
  89 }
  90
  91 static int load_first_available_playlist(void)
  92 {
  93         int ret = osl_rbtree_loop(playlists_table, BLOBCOL_NAME, NULL,
  94                 playlist_loop);
  95         if (ret == -E_PLAYLIST_LOADED) /* success */
  96                 return 1;
  97         if (ret < 0)
  98                 return ret; /* error */
  99         PARA_NOTICE_LOG("no valid playlist found\n");
 100         return -E_NO_PLAYLIST;
 101 }
 102
 103 /**
 104  * Close the current playlist.
 105  *
 106  * \sa playlist_open().
 107  */
 108 void playlist_close(void)
 109 {
 110         free(playlist.name);
 111         playlist.name = NULL;
 112 }
 113
 114 /**
 115  * Open the given playlist.
 116  *
 117  * \param name The name of the playlist to open.
 118  *
 119  * If name is \p NULL, load the first available playlist. Files which are
 120  * listed in the playlist, but not contained in the database are ignored.
 121  * This is not considered an error.
 122  *
 123  * \return Positive on success, negative on errors. Possible errors
 124  * include: Given playlist not found, -E_NO_PLAYLIST (no playlist defined).
 125  */
 126 int playlist_open(char *name)
 127 {
 128         struct osl_object obj;
 129         int ret;
 130         struct osl_row *row;
 131
 132         if (!name)
 133                 return load_first_available_playlist();
 134         obj.data = name;
 135         obj.size = strlen(obj.data);
 136         ret = osl_get_row(playlists_table, BLOBCOL_NAME, &obj, &row);
 137         if (ret < 0) {
 138                 PARA_NOTICE_LOG("failed to load playlist %s\n", name);
 139                 return ret;
 140         }
 141         return load_playlist(row);
 142 }