cc-4105: added wrapper around pyinotify. added some stubs and todos

python_apps/media-monitor2/media/monitor/mm_manager.py

@@ -0,0 +1,90 @@
+import pyinotify
+
+from media.monitor.log import Loggable
+from media.monitor.listeners import StoreWatchListener, OrganizeListener
+from media.monitor.organizer import Organizer
+
+class Manager(Loggable):
+    """
+    An abstraction over media monitors core pyinotify functions. These include
+    adding watched,store, organize directories, etc. Basically composes over
+    WatchManager from pyinotify
+    """
+    all_signals = set(['add_watch', 'remove_watch'])
+    # TODO : get rid of config object being passed? It's not actually being
+    # used
+    def __init__(self,config):
+
+        self.wm = pyinotify.WatchManager()
+        # These two instance variables are assumed to be constant
+        self.watch_channel = 'watch'
+        self.organize_channel = 'organize'
+
+        self.watch_listener = StoreWatchListener(self.watch_channel)
+
+        self.organize = {
+            'organize_path' : None,
+            'store_path' : None,
+            # This guy doesn't need to be changed, always the same.
+            # Gets hooked by wm to different directories
+            'organize_listener' : OrganizeListener(self.organize_channel),
+            # Also stays the same as long as its target, the directory
+            # which the "organized" files go to, isn't changed.
+            'organizer' : None,
+        }
+
+        self.watched_directories = set([])
+
+    def __remove_watch(self,path):
+        old_watch = self.wm.get_wd(path)
+        if old_watch: # only delete if dir is actually being watched
+            self.rm_watch(old_watch, rec=True)
+
+    def __create_organizer(self, target_path):
+        return Organizer(channel=self.organize_channel,target_path=target_path)
+
+    def set_organize_path(self, new_path):
+        # if we are already organizing a particular directory we remove the
+        # watch from it first before organizing another directory
+        self.__remove_watch(self.organize['organize_path'])
+        self.organize['organize_path'] = new_path
+        # the OrganizeListener instance will walk path and dispatch an organize
+        # event for every file in that directory
+        self.organize['organize_listener'].flush_events(new_path)
+        self.wm.add_watch(new_path, pyinotify.ALL_EVENTS, rec=True, auto_add=True,
+                proc_fun=self.organize['organize_listener'])
+
+    def set_store_path(self,new_path):
+        """set the directory where organized files go to"""
+        self.__remove_watch(self.organize['store_path'])
+        self.organize['store_path'] = new_path
+        self.organize['organizer'] = self.__create_organizer(new_path)
+        # flush all the files in the new store_directory. this is done so that
+        # new files are added to the database. Note that we are not responsible
+        # for removing songs in the old store directory from the database
+        # we assume that this is already done for us.
+        self.watch_listener.flush_events(new_path)
+        self.wm.add_watch(new_path, pyinotify.ALL_EVENTS, rec=True, auto_add=True,
+                proc_fun=self.watch_listener)
+
+    def add_watch_directory(self, new_dir):
+        if new_dir in self.watched_directories:
+            self.logger.info("Cannot add '%s' to watched directories. It's \
+                    already being watched" % new_dir)
+        else:
+            self.logger.info("Adding watched directory: '%s'" % new_dir)
+            self.watched_directories.add(new_dir)
+            self.wm.add_watch(new_dir, pyinotify.ALL_EVENTS, rec=True, auto_add=True,
+                    proc_fun=self.watch_listener)
+
+    def remove_watch_directory(self, watch_dir):
+        if watch_dir in self.watched_directories:
+            self.watched_directories.remove(watch_dir)
+            self.logger.info("Removing watched directory: '%s'", watch_dir)
+            self.__remove_watch(watch_dir)
+        else:
+            self.logger.info("'%s' is not being watched, henced cannot be removed"
+                    % watch_dir)
+
+    def loop(self):
+        pyinotify.Notifier(self.wm).loop()