[gnome-music] albumArtCache: put album resolve threads in queue

[Vadim Rutkovsky <vrutkovsky src gnome org>]

commit 665c2f673e179ceff0bcf8e8caa90b047c19308e
Author: Vadim Rutkovsky <vrutkovs redhat com>
Date:   Fri Oct 3 13:43:01 2014 +0200

    albumArtCache: put album resolve threads in queue
    
    The queue is being processed in two workers, each resolve thread is
    being terminated if it takes more than 30 secs to finish
    
    https://bugzilla.gnome.org/show_bug.cgi?id=732151

 gnomemusic/albumArtCache.py |   35 +++++++++++++++++++++++++++++------
 1 files changed, 29 insertions(+), 6 deletions(-)
---
diff --git a/gnomemusic/albumArtCache.py b/gnomemusic/albumArtCache.py
index 2668f63..f2366b8 100644
--- a/gnomemusic/albumArtCache.py
+++ b/gnomemusic/albumArtCache.py
@@ -38,8 +38,11 @@ from time import sleep
 from gnomemusic import log
 from gnomemusic.grilo import grilo
 import logging
+from queue import Queue
 logger = logging.getLogger(__name__)
 
+WORKER_THREADS = 2
+
 
 @log
 def _make_icon_frame(pixbuf, path=None):
@@ -112,13 +115,33 @@ class AlbumArtCache:
 
         return title
 
+    def worker(self, id):
+        while True:
+            try:
+                item = self.thread_queue.get()
+                item.setDaemon(True)
+                item.start()
+                item.join(30)
+                self.thread_queue.task_done()
+            except Exception as e:
+                logger.warn("worker %d item %s: error %s" % (id, item, str(e)))
+
     @log
     def __init__(self):
         try:
             self.cacheDir = os.path.join(GLib.get_user_cache_dir(), 'media-art')
             Gio.file_new_for_path(self.cacheDir).make_directory(None)
-        except:
-            pass
+        except Exception as e:
+            logger.warn("Error: %s" % e)
+
+        try:
+            self.thread_queue = Queue()
+            for i in range(WORKER_THREADS):
+                t = Thread(target=self.worker, args=(i,))
+                t.setDaemon(True)
+                t.start()
+        except Exception as e:
+            logger.warn("Error: %s" % e)
 
     @log
     def get_default_icon(self, width, height):
@@ -147,9 +170,9 @@ class AlbumArtCache:
     def lookup(self, item, width, height, callback, itr, artist, album):
         try:
             t = Thread(target=self.lookup_worker, args=(item, width, height, callback, itr, artist, album))
-            t.start()
+            self.thread_queue.put(t)
         except Exception as e:
-            logger.warn("Error: %s" % e)
+            logger.warn("Error: %s" % e.__class__)
 
     @log
     def lookup_worker(self, item, width, height, callback, itr, artist, album):
@@ -202,7 +225,7 @@ class AlbumArtCache:
                 return
 
             t = Thread(target=self.download_worker, args=(item, width, height, path, callback, itr, artist, 
album, uri))
-            t.start()
+            self.thread_queue.put(t)
         except Exception as e:
             logger.warn("Error: %s" % e)
 
@@ -225,7 +248,7 @@ class AlbumArtCache:
                 return
 
             t = Thread(target=self.download_worker, args=(item, width, height, path, callback, itr, artist, 
album, uri))
-            t.start()
+            self.thread_queue.put(t)
         except Exception as e:
             logger.warn("Error: %s" % e)