# -*- coding: utf-8 -*-
# Licensed under the MIT license
# http://opensource.org/licenses/mit-license.php
import time
from functools import cmp_to_key
from abc import ABCMeta, abstractmethod
# Copyright 2007,, Frank Scholz <coherence@beebits.net>
from lxml import etree
import coherence.extern.louie as louie
from coherence import log
from coherence.extern.simple_plugin import Plugin
from coherence.upnp.core import DIDLLite
from coherence.upnp.core.utils import getPage
[docs]class Backend(log.LogAble, Plugin):
""" the base class for all backends
if there are any UPnP service actions, that can't
be handled by the service classes itself, or need some
special adjustments for the backend, they need to be
defined here.
Like maybe upnp_Browse for the CDS Browse action.
"""
# list the device classes below, like ['MediaServer','MediaRenderer']
implements = []
logCategory = 'backend'
[docs] def __init__(self, server, **kwargs):
""" the init method for a backend,
should probably most of the time be overwritten
when the init is done, send a signal to its device
the device will then setup and announce itself,
after that it calls the backends upnp_init method
"""
self.config = kwargs
self.server = server # the UPnP device that's hosting that backend
""" do whatever is necessary with the stuff we can
extract from the config dict,
connect maybe to an external data-source and
start up the backend
after that's done, tell Coherence about it
"""
log.LogAble.__init__(self)
Plugin.__init__(self)
""" this has to be done in the actual backend, maybe it has
to wait for an answer from an external data-source first
"""
# self.init_completed()
[docs] def init_completed(self, *args, **kwargs):
""" inform Coherence that this backend is ready for
announcement
this method just accepts any form of arguments
as we don't under which circumstances it is called
"""
louie.send('Coherence.UPnP.Backend.init_completed',
None, backend=self)
[docs] def upnp_init(self):
""" this method gets called after the device is fired,
here all initializations of service related state variables
should happen, as the services aren't available before that point
"""
pass
[docs]class BackendStore(Backend):
""" the base class for all MediaServer backend stores
"""
__metaclass__ = ABCMeta
logCategory = 'backend_store'
[docs] def __init__(self, server, *args, **kwargs):
""" the init method for a MediaServer backend,
should probably most of the time be overwritten
when the init is done, send a signal to its device
the device will then setup and announce itself,
after that it calls the backends upnp_init method
"""
Backend.__init__(self, server, *args)
self.config = kwargs
self.server = server # the UPnP device that's hosting that backend
self.update_id = 0
""" do whatever is necessary with the stuff we can
extract from the config dict
"""
""" in case we want so serve something via
the MediaServer web backend
the BackendItem should pass an URI assembled
of urlbase + '/' + id to the DIDLLite.Resource
"""
self.urlbase = kwargs.get('urlbase', '')
if not self.urlbase.endswith('/'):
self.urlbase += '/'
self.wmc_mapping = {'4': '4', '5': '5', '6': '6', '7': '7', '14': '14',
'F': 'F',
'11': '11', '16': '16', 'B': 'B', 'C': 'C',
'D': 'D',
'13': '13', '17': '17',
'8': '8', '9': '9', '10': '10', '15': '15',
'A': 'A', 'E': 'E'}
self.wmc_mapping.update({'4': lambda: self._get_all_items(0),
'8': lambda: self._get_all_items(0),
'B': lambda: self._get_all_items(0),
})
""" and send out the signal when ready
"""
# louie.send('Coherence.UPnP.Backend.init_completed',
# None, backend=self)
[docs] def release(self):
""" if anything needs to be cleaned up upon
shutdown of this backend, this is the place
for it
"""
pass
[docs] def _get_all_items(self, id):
""" a helper method to get all items as a response
to some XBox 360 UPnP Search action
probably never be used as the backend will overwrite
the wmc_mapping with more appropriate methods
"""
items = []
item = self.get_by_id(id)
if item is not None:
containers = [item]
while len(containers) > 0:
container = containers.pop()
if container.mimetype not in ['root', 'directory']:
continue
for child in container.get_children(0, 0):
if child.mimetype in ['root', 'directory']:
containers.append(child)
else:
items.append(child)
return items
[docs] @abstractmethod
def get_by_id(self, id):
""" called by the CDS or the MediaServer web
id is the id property of our DIDLLite item
if this MediaServer implements containers, that can
share their content, like 'all tracks', 'album' and
'album_of_artist' - they all have the same track item as content -
then the id may be passed by the CDS like this:
'id@container' or 'id@container@container@container...'
therefore a
if isinstance(id, basestring):
id = id.split('@',1)
id = id[0]
may be appropriate as the first thing to do
when entering this method
should return
- None when no matching item for that id is found,
- a BackendItem,
- or a Deferred
"""
return None
[docs]class BackendItem(log.LogAble):
""" the base class for all MediaServer backend items
"""
logCategory = 'backend_item'
[docs] def __init__(self, *args, **kwargs):
""" most of the time we collect the necessary data for
an UPnP ContentDirectoryService Container or Object
and instantiate it here
self.item = DIDLLite.Container(id,parent_id,name,...)
or
self.item = DIDLLite.MusicTrack(id,parent_id,name,...)
To make that a valid UPnP CDS Object it needs one or
more DIDLLite.Resource(uri,protocolInfo)
self.item.res = []
res = DIDLLite.Resource(url, 'http-get:*:%s:*' % mimetype)
url : the urlbase of our backend + '/' + our id
res.size = size
self.item.res.append(res)
"""
log.LogAble.__init__(self)
self.store = None
self.storage_id = None
# the basename of a file, the album title, the artists name...
# is expected to be unicode
self.name = 'my_name'
self.item = None
self.update_id = 0 # the update id of that item,
# when an UPnP ContentDirectoryService Container
# this should be incremented on every modification
# the filepath of our media file, or alternatively
# a FilePath or a ReverseProxyResource object
self.location = None
self.cover = None # if we have some album art image, let's put
# the filepath or link into here
[docs] def get_children(self, start=0, end=0):
""" called by the CDS and the MediaServer web
should return
- a list of its childs[start:end]
- or a Deferred
if end == 0, the request is for all childs
after start - childs[start:]
"""
pass
[docs] def get_child_count(self):
""" called by the CDS
should return
- the number of its childs - len(childs)
- or a Deferred
"""
[docs] def get_item(self):
""" called by the CDS and the MediaServer web
should return
- an UPnP ContentDirectoryServer DIDLLite object
- or a Deferred
"""
return self.item
[docs] def get_name(self):
""" called by the MediaServer web
should return
- the name of the item,
it is always expected to be in unicode
"""
return self.name
[docs] def get_path(self):
""" called by the MediaServer web
should return
- the filepath where to find the media file
that this item does refer to
"""
return self.location
[docs] def get_cover(self):
""" called by the MediaServer web
should return
- the filepath where to find the album art file
only needed when we have created for that item
an albumArtURI property that does point back to us
"""
return self.cover
def __repr__(self):
return "%s[%s]" % (self.__class__.__name__, self.get_name())
[docs]class Container(BackendItem):
def __init__(self, parent, title):
BackendItem.__init__(self)
self.parent = parent
if self.parent is not None:
self.parent_id = self.parent.get_id()
else:
self.parent_id = -1
self.name = title
self.mimetype = 'directory'
self.children = []
self.children_ids = {}
self.children_by_external_id = {}
self.update_id = 0
self.item = None
self.sorted = False
def childs_sort(x, y):
return cmp_to_key(x.name, y.name)
self.sorting_method = childs_sort
[docs] def register_child(self, child, external_id=None):
id = self.store.append_item(child)
child.url = self.store.urlbase + str(id)
child.parent = self
if external_id is not None:
child.external_id = external_id
self.children_by_external_id[external_id] = child
[docs] def add_child(self, child, external_id=None, update=True):
self.register_child(child, external_id)
if self.children is None:
self.children = []
self.children.append(child)
self.sorted = False
if update:
self.update_id += 1
[docs] def remove_child(self, child, external_id=None, update=True):
self.children.remove(child)
self.store.remove_item(child)
if update:
self.update_id += 1
if external_id is not None:
child.external_id = None
del self.children_by_external_id[external_id]
[docs] def get_children(self, start=0, end=0):
if not self.sorted:
self.children = sorted(
self.children.sort, key=cmp_to_key(self.sorting_method))
self.sorted = True
if end != 0:
return self.children[start:end]
return self.children[start:]
[docs] def get_child_count(self):
if self.children is None:
return 0
return len(self.children)
[docs] def get_path(self):
return self.store.urlbase + str(self.storage_id)
[docs] def get_item(self):
if self.item is None:
self.item = DIDLLite.Container(self.storage_id, self.parent_id,
self.name)
self.item.childCount = len(self.children)
return self.item
[docs] def get_name(self):
return self.name
[docs] def get_id(self):
return self.storage_id
[docs] def get_update_id(self):
return self.update_id
[docs]class LazyContainer(Container):
logCategory = 'lazyContainer'
def __init__(self, parent, title, external_id=None, refresh=0,
childrenRetriever=None, **kwargs):
Container.__init__(self, parent, title)
self.childrenRetrievingNeeded = True
self.childrenRetrievingDeferred = None
self.childrenRetriever = childrenRetriever
self.children_retrieval_campaign_in_progress = False
self.childrenRetriever_params = kwargs
self.childrenRetriever_params['parent'] = self
self.has_pages = ('per_page' in self.childrenRetriever_params)
self.external_id = None
self.external_id = external_id
self.retrieved_children = {}
self.last_updated = 0
self.refresh = refresh
[docs] def replace_by(self, item):
if self.external_id is not None and item.external_id is not None:
return self.external_id == item.external_id
return True
[docs] def add_child(self, child, external_id=None, update=True):
if self.children_retrieval_campaign_in_progress is True:
self.retrieved_children[external_id] = child
else:
Container.add_child(self, child, external_id=external_id,
update=update)
[docs] def update_children(self, new_children, old_children):
children_to_be_removed = {}
children_to_be_replaced = {}
children_to_be_added = {}
# Phase 1
# let's classify the item between items to be removed,
# to be updated or to be added
self.debug("Refresh pass 1:%d %d",
len(new_children), len(old_children))
for id, item in list(old_children.items()):
children_to_be_removed[id] = item
for id, item in list(new_children.items()):
if id in old_children:
# print(id, "already there")
children_to_be_replaced[id] = old_children[id]
del children_to_be_removed[id]
else:
children_to_be_added[id] = new_children[id]
# Phase 2
# Now, we remove, update or add the relevant items
# to the list of items
self.debug("Refresh pass 2: %d %d %d", len(children_to_be_removed),
len(children_to_be_replaced), len(children_to_be_added))
# Remove relevant items from Container children
for id, item in list(children_to_be_removed.items()):
self.remove_child(item, external_id=id, update=False)
# Update relevant items from Container children
for id, item in list(children_to_be_replaced.items()):
old_item = item
new_item = new_children[id]
replaced = False
if hasattr(old_item, 'replace_by'):
replaced = old_item.replace_by(new_item)
if replaced is False:
# print("No replacement possible:
# we remove and add the item again")
self.remove_child(old_item, external_id=id, update=False)
self.add_child(new_item, external_id=id, update=False)
# Add relevant items to COntainer children
for id, item in list(children_to_be_added.items()):
self.add_child(item, external_id=id, update=False)
self.update_id += 1
[docs] def start_children_retrieval_campaign(self):
self.last_updated = time.time()
self.retrieved_children = {}
self.children_retrieval_campaign_in_progress = True
[docs] def end_children_retrieval_campaign(self, success=True):
self.children_retrieval_campaign_in_progress = False
if success is True:
self.update_children(self.retrieved_children,
self.children_by_external_id)
self.update_id += 1
self.last_updated = time.time()
self.retrieved_children = {}
[docs] def retrieve_children(self, start=0, page=0):
def items_retrieved(result, page, start_offset):
if self.childrenRetrievingNeeded is True:
new_offset = len(self.retrieved_children)
return self.retrieve_children(
new_offset, page + 1) # we try the next page
return self.retrieved_children
self.childrenRetrievingNeeded = False
if self.has_pages is True:
self.childrenRetriever_params['offset'] = start
self.childrenRetriever_params['page'] = page
d = self.childrenRetriever(**self.childrenRetriever_params)
d.addCallback(items_retrieved, page, start)
return d
[docs] def retrieve_all_children(self, start=0, request_count=0):
def all_items_retrieved(result):
self.end_children_retrieval_campaign(True)
return super(LazyContainer, self).get_children(
start, request_count)
def error_while_retrieving_items(error):
self.end_children_retrieval_campaign(False)
return super(LazyContainer, self).get_children(
start, request_count)
self.start_children_retrieval_campaign()
if self.childrenRetriever is not None:
d = self.retrieve_children(start)
if start == 0:
d.addCallbacks(all_items_retrieved,
error_while_retrieving_items)
return d
else:
self.end_children_retrieval_campaign()
return self.children
[docs] def get_children(self, start=0, request_count=0):
# Check if an update is needed since last update
current_time = time.time()
delay_since_last_updated = current_time - self.last_updated
period = self.refresh
if (period > 0) and (delay_since_last_updated > period):
self.info("Last update is older than %d s -> update data", period)
self.childrenRetrievingNeeded = True
if self.childrenRetrievingNeeded is True:
return self.retrieve_all_children(start, request_count)
return Container.get_children(self, start, request_count)
ROOT_CONTAINER_ID = 0
SEED_ITEM_ID = 1000
[docs]class AbstractBackendStore(BackendStore):
def __init__(self, server, **kwargs):
BackendStore.__init__(self, server, **kwargs)
self.next_id = SEED_ITEM_ID
self.store = {}
[docs] def len(self):
return len(self.store)
[docs] def set_root_item(self, item):
return self.append_item(item, storage_id=ROOT_CONTAINER_ID)
[docs] def get_root_id(self):
return ROOT_CONTAINER_ID
[docs] def get_root_item(self):
return self.get_by_id(ROOT_CONTAINER_ID)
[docs] def append_item(self, item, storage_id=None):
if storage_id is None:
storage_id = self.getnextID()
self.store[storage_id] = item
item.storage_id = storage_id
item.store = self
return storage_id
[docs] def remove_item(self, item):
del self.store[item.storage_id]
item.storage_id = -1
item.store = None
[docs] def get_by_id(self, id):
if isinstance(id, str):
id = id.split('@', 1)
id = id[0].split('.')[0]
try:
return self.store[int(id)]
except (ValueError, KeyError):
pass
return None
[docs] def getnextID(self):
ret = self.next_id
self.next_id += 1
return ret
def __repr__(self):
return self.__class__.__name__