mdw@git.distorted.org.uk Git - disorder/blob - disobedience/lookup.c

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2008 Richard Kettlewell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 #include "disobedience.h"
  21
  22 static int namepart_lookups_outstanding;
  23 static const struct cache_type cachetype_string = { 3600 };
  24 static const struct cache_type cachetype_integer = { 3600 };
  25
  26 /** @brief Called when a namepart lookup has completed or failed
  27  *
  28  * When there are no lookups in flight a redraw is provoked.  This might well
  29  * provoke further lookups.
  30  */
  31 static void namepart_completed_or_failed(void) {
  32   --namepart_lookups_outstanding;
  33   if(!namepart_lookups_outstanding)
  34     /* When all lookups complete, we update any displays that care */
  35     event_raise("lookups-completed", 0);
  36 }
  37
  38 /** @brief Called when a namepart lookup has completed */
  39 static void namepart_completed(void *v, const char *error, const char *value) {
  40   D(("namepart_completed"));
  41   if(error) {
  42     gtk_label_set_text(GTK_LABEL(report_label), error);
  43     value = "?";
  44   }
  45   const char *key = v;
  46
  47   cache_put(&cachetype_string, key, value);
  48   namepart_completed_or_failed();
  49 }
  50
  51 /** @brief Called when a length lookup has completed */
  52 static void length_completed(void *v, const char *error, long l) {
  53   D(("length_completed"));
  54   if(error) {
  55     gtk_label_set_text(GTK_LABEL(report_label), error);
  56     l = -1;
  57   }
  58   const char *key = v;
  59   long *value;
  60
  61   D(("namepart_completed"));
  62   value = xmalloc(sizeof *value);
  63   *value = l;
  64   cache_put(&cachetype_integer, key, value);
  65   namepart_completed_or_failed();
  66 }
  67
  68 /** @brief Arrange to fill in a namepart cache entry */
  69 static void namepart_fill(const char *track,
  70                           const char *context,
  71                           const char *part,
  72                           const char *key) {
  73   D(("namepart_fill %s %s %s %s", track, context, part, key));
  74   /* We limit the total number of lookups in flight */
  75   ++namepart_lookups_outstanding;
  76   D(("namepart_lookups_outstanding -> %d\n", namepart_lookups_outstanding));
  77   disorder_eclient_namepart(client, namepart_completed,
  78                             track, context, part, (void *)key);
  79 }
  80
  81 /** @brief Look up a namepart
  82  * @param track Track name
  83  * @param context Context
  84  * @param part Name part
  85  * @param lookup If nonzero, will schedule a lookup for unknown values
  86  *
  87  * If it is in the cache then just return its value.  If not then look it up
  88  * and arrange for the queues to be updated when its value is available. */
  89 const char *namepart(const char *track,
  90                      const char *context,
  91                      const char *part) {
  92   char *key;
  93   const char *value;
  94
  95   D(("namepart %s %s %s", track, context, part));
  96   byte_xasprintf(&key, "namepart context=%s part=%s track=%s",
  97                  context, part, track);
  98   value = cache_get(&cachetype_string, key);
  99   if(!value) {
 100     D(("deferring..."));
 101     namepart_fill(track, context, part, key);
 102     value = "?";
 103   }
 104   return value;
 105 }
 106
 107 /** @brief Called from @ref disobedience/properties.c when we know a name part has changed */
 108 void namepart_update(const char *track,
 109                      const char *context,
 110                      const char *part) {
 111   char *key;
 112
 113   byte_xasprintf(&key, "namepart context=%s part=%s track=%s",
 114                  context, part, track);
 115   /* Only refetch if it's actually in the cache. */
 116   if(cache_get(&cachetype_string, key))
 117     namepart_fill(track, context, part, key);
 118 }
 119
 120 /** @brief Look up a track length
 121  *
 122  * If it is in the cache then just return its value.  If not then look it up
 123  * and arrange for the queues to be updated when its value is available. */
 124 long namepart_length(const char *track) {
 125   char *key;
 126   const long *value;
 127
 128   D(("getlength %s", track));
 129   byte_xasprintf(&key, "length track=%s", track);
 130   value = cache_get(&cachetype_integer, key);
 131   if(value)
 132     return *value;
 133   D(("deferring..."));;
 134   ++namepart_lookups_outstanding;
 135   D(("namepart_lookups_outstanding -> %d\n", namepart_lookups_outstanding));
 136   disorder_eclient_length(client, length_completed, track, key);
 137   return -1;
 138 }
 139
 140
 141 /*
 142 Local Variables:
 143 c-basic-offset:2
 144 comment-column:40
 145 fill-column:79
 146 indent-tabs-mode:nil
 147 End:
 148 */