sintonia/python_apps/media-monitor2/media/monitor/events.py

192 lines
6.6 KiB
Python

# -*- coding: utf-8 -*-
import os
import abc
import media.monitor.pure as mmp
from media.monitor.pure import LazyProperty
from media.monitor.metadata import Metadata
from media.monitor.log import Loggable
from media.monitor.exceptions import BadSongFile
class PathChannel(object):
def __init__(self, signal, path):
self.signal = signal
self.path = path
class EventRegistry(object):
"""
This class's main use is to keep track all events with a cookie attribute.
This is done mainly because some events must be 'morphed' into other events
because we later detect that they are move events instead of delete events.
"""
registry = {}
@staticmethod
def register(evt): EventRegistry.registry[evt.cookie] = evt
@staticmethod
def unregister(evt): del EventRegistry.registry[evt.cookie]
@staticmethod
def registered(evt): return evt.cookie in EventRegistry.registry
@staticmethod
def matching(evt):
event = EventRegistry.registry[evt.cookie]
# Want to disallow accessing the same event twice
EventRegistry.unregister(event)
return event
def __init__(self,*args,**kwargs):
raise Exception("You can instantiate this class. Must only use class \
methods")
class HasMetaData(object):
"""
Any class that inherits from this class gains the metadata attribute that
loads metadata from the class's 'path' attribute. This is done lazily so
there is no performance penalty to inheriting from this and subsequent
calls to metadata are cached
"""
__metaclass__ = abc.ABCMeta
@LazyProperty
def metadata(self): return Metadata(self.path)
class BaseEvent(Loggable):
__metaclass__ = abc.ABCMeta
def __init__(self, raw_event):
# TODO : clean up this idiotic hack
# we should use keyword constructors instead of this behaviour checking
# bs to initialize BaseEvent
if hasattr(raw_event,"pathname"):
self._raw_event = raw_event
self.path = os.path.normpath(raw_event.pathname)
else: self.path = raw_event
self._pack_hook = lambda: None # no op
# into another event
def reset_hook(self):
self._pack_hook()
self._pack_hook = lambda: None
def exists(self): return os.path.exists(self.path)
@LazyProperty
def cookie(self): return getattr( self._raw_event, 'cookie', None )
def __str__(self):
return "Event(%s). Path(%s)" % ( self.path, self.__class__.__name__)
def add_safe_pack_hook(self,k):
"""
adds a callable object (function) that will be called after the event
has been "safe_packed"
"""
self._pack_hook = k
# As opposed to unsafe_pack...
def safe_pack(self):
"""
returns exceptions instead of throwing them to be consistent with
events that must catch their own BadSongFile exceptions since generate
a set of exceptions instead of a single one
"""
# pack will only throw an exception if it processes one file but this
# is a little bit hacky
try:
self._pack_hook()
ret = self.pack()
return ret
except BadSongFile as e: return [e]
# nothing to see here, please move along
def morph_into(self, evt):
self.logger.info("Morphing %s into %s" % ( str(self), str(evt) ) )
self._raw_event = evt
self.path = evt.path
self.__class__ = evt.__class__
# We don't transfer the _pack_hook over to the new event
return self
class FakePyinotify(object):
"""
sometimes we must create our own pyinotify like objects to
instantiate objects from the classes below whenever we want to turn
a single event into multiple events
"""
def __init__(self, path): self.pathname = path
class OrganizeFile(BaseEvent, HasMetaData):
def __init__(self, *args, **kwargs):
super(OrganizeFile, self).__init__(*args, **kwargs)
def pack(self):
raise AttributeError("You can't send organize events to airtime!!!")
class NewFile(BaseEvent, HasMetaData):
def __init__(self, *args, **kwargs):
super(NewFile, self).__init__(*args, **kwargs)
def pack(self):
"""
packs turns an event into a media monitor request
"""
req_dict = self.metadata.extract()
req_dict['mode'] = u'create'
req_dict['MDATA_KEY_FILEPATH'] = unicode( self.path )
return [req_dict]
class DeleteFile(BaseEvent):
def __init__(self, *args, **kwargs):
super(DeleteFile, self).__init__(*args, **kwargs)
def pack(self):
req_dict = {}
req_dict['mode'] = u'delete'
req_dict['MDATA_KEY_FILEPATH'] = unicode( self.path )
return [req_dict]
class MoveFile(BaseEvent, HasMetaData):
"""
Path argument should be the new path of the file that was moved
"""
def __init__(self, *args, **kwargs):
super(MoveFile, self).__init__(*args, **kwargs)
def pack(self):
req_dict = {}
req_dict['mode'] = u'moved'
req_dict['MDATA_KEY_MD5'] = self.metadata.extract()['MDATA_KEY_MD5']
req_dict['MDATA_KEY_FILEPATH'] = unicode( self.path )
return [req_dict]
class ModifyFile(BaseEvent, HasMetaData):
def __init__(self, *args, **kwargs):
super(ModifyFile, self).__init__(*args, **kwargs)
def pack(self):
req_dict = self.metadata.extract()
req_dict['mode'] = u'modify'
# path to directory that is to be removed
req_dict['MDATA_KEY_FILEPATH'] = unicode( self.path )
return [req_dict]
def map_events(directory, constructor):
# -unknown-path should not appear in the path here but more testing
# might be necessary
for f in mmp.walk_supported(directory, clean_empties=False):
try:
for e in constructor( FakePyinotify(f) ).pack(): yield e
except BadSongFile as e: yield e
class DeleteDir(BaseEvent):
def __init__(self, *args, **kwargs):
super(DeleteDir, self).__init__(*args, **kwargs)
def pack(self):
return map_events( self.path, DeleteFile )
class MoveDir(BaseEvent):
def __init__(self, *args, **kwargs):
super(MoveDir, self).__init__(*args, **kwargs)
def pack(self):
return map_events( self.path, MoveFile )
class DeleteDirWatch(BaseEvent):
def __init__(self, *args, **kwargs):
super(DeleteDirWatch, self).__init__(*args, **kwargs)
def pack(self):
req_dict = {}
req_dict['mode'] = u'delete_dir'
req_dict['MDATA_KEY_FILEPATH'] = unicode( self.path + "/" )
return [req_dict]