Load the CollectionWrapper from a factory method

This allows a class implementing CollectionWrapper's interface to be
added from config

ankisyncd/collection.py

@@ -2,6 +2,10 @@ import anki
 import anki.storage
 
 import os, errno
+import logging
+
+logger = logging.getLogger("ankisyncd.collection")
+
 
 class CollectionWrapper:
     """A simple wrapper around an anki.storage.Collection object.
@@ -9,12 +13,12 @@ class CollectionWrapper:
     This allows us to manage and refer to the collection, whether it's open or not. It
     also provides a special "continuation passing" interface for executing functions
     on the collection, which makes it easy to switch to a threading mode.
-    
+
     See ThreadingCollectionWrapper for a version that maintains a seperate thread for
     interacting with the collection.
     """
 
-    def __init__(self, path, setup_new_collection=None):
+    def __init__(self, _config, path, setup_new_collection=None):
         self.path = os.path.realpath(path)
         self.username = os.path.basename(os.path.dirname(self.path))
         self.setup_new_collection = setup_new_collection
@@ -50,7 +54,7 @@ class CollectionWrapper:
         # mkdir -p the path, because it might not exist
         os.makedirs(os.path.dirname(self.path), exist_ok=True)
 
-        col = anki.storage.Collection(self.path)
+        col = self._get_collection()
 
         # Do any special setup
         if self.setup_new_collection is not None:
@@ -58,11 +62,14 @@ class CollectionWrapper:
 
         return col
 
+    def _get_collection(self):
+        return anki.storage.Collection(self.path)
+
     def open(self):
         """Open the collection, or create it if it doesn't exist."""
         if self.__col is None:
             if os.path.exists(self.path):
-                self.__col = anki.storage.Collection(self.path)
+                self.__col = self._get_collection()
             else:
                 self.__col = self.__create_collection()
 
@@ -83,8 +90,9 @@ class CollectionManager:
 
     collection_wrapper = CollectionWrapper
 
-    def __init__(self):
+    def __init__(self, config):
         self.collections = {}
+        self.config = config
 
     def get_collection(self, path, setup_new_collection=None):
         """Gets a CollectionWrapper for the given path."""
@@ -94,7 +102,7 @@ class CollectionManager:
         try:
             col = self.collections[path]
         except KeyError:
-            col = self.collections[path] = self.collection_wrapper(path, setup_new_collection)
+            col = self.collections[path] = self.collection_wrapper(self.config, path, setup_new_collection)
 
         return col
 
@@ -104,3 +112,19 @@ class CollectionManager:
             del self.collections[path]
             col.close()
 
+def get_collection_wrapper(config, path, setup_new_collection = None):
+    if "collection_wrapper" in config and config["collection_wrapper"]:
+        logger.info("Found collection_wrapper in config, using {} for "
+                     "user data persistence".format(config['collection_wrapper']))
+        import importlib
+        import inspect
+        module_name, class_name = config['collection_wrapper'].rsplit('.', 1)
+        module = importlib.import_module(module_name.strip())
+        class_ = getattr(module, class_name.strip())
+
+        if not CollectionWrapper in inspect.getmro(class_):
+            raise TypeError('''"collection_wrapper" found in the conf file but it doesn''t
+                            inherit from CollectionWrapper''')
+        return class_(config, path, setup_new_collection)
+    else:
+        return CollectionWrapper(config, path, setup_new_collection)

ankisyncd/sync_app.py

@@ -388,7 +388,7 @@ class SyncApp:
     valid_urls = SyncCollectionHandler.operations + SyncMediaHandler.operations + ['hostKey', 'upload', 'download']
 
     def __init__(self, config):
-        from ankisyncd.thread import getCollectionManager
+        from ankisyncd.thread import get_collection_manager
 
         self.data_root = os.path.abspath(config['data_root'])
         self.base_url  = config['base_url']
@@ -401,7 +401,7 @@ class SyncApp:
         self.user_manager = get_user_manager(config)
         self.session_manager = get_session_manager(config)
         self.full_sync_manager = get_full_sync_manager(config)
-        self.collection_manager = getCollectionManager()
+        self.collection_manager = get_collection_manager(config)
 
         # make sure the base_url has a trailing slash
         if not self.base_url.endswith('/'):

ankisyncd/thread.py

@@ -1,4 +1,4 @@
-from ankisyncd.collection import CollectionWrapper, CollectionManager
+from ankisyncd.collection import CollectionManager, get_collection_wrapper
 
 from threading import Thread
 from queue import Queue
@@ -29,12 +29,12 @@ def short_repr(obj, logger=logging.getLogger(), maxlen=80):
     return repr(o)
 
 class ThreadingCollectionWrapper:
-    """Provides the same interface as CollectionWrapper, but it creates a new Thread to 
+    """Provides the same interface as CollectionWrapper, but it creates a new Thread to
     interact with the collection."""
 
-    def __init__(self, path, setup_new_collection=None):
+    def __init__(self, config, path, setup_new_collection=None):
         self.path = path
-        self.wrapper = CollectionWrapper(path, setup_new_collection)
+        self.wrapper = get_collection_wrapper(config, path, setup_new_collection)
         self.logger = logging.getLogger("ankisyncd." + str(self))
 
         self._queue = Queue()
@@ -156,8 +156,8 @@ class ThreadingCollectionManager(CollectionManager):
 
     collection_wrapper = ThreadingCollectionWrapper
 
-    def __init__(self):
+    def __init__(self, config):
-        super(ThreadingCollectionManager, self).__init__()
+        super(ThreadingCollectionManager, self).__init__(config)
 
         self.monitor_frequency = 15
         self.monitor_inactivity = 90
@@ -202,11 +202,11 @@ class ThreadingCollectionManager(CollectionManager):
 
 collection_manager = None
 
-def getCollectionManager():
+def get_collection_manager(config):
     """Return the global ThreadingCollectionManager for this process."""
     global collection_manager
     if collection_manager is None:
-        collection_manager = ThreadingCollectionManager()
+        collection_manager = ThreadingCollectionManager(config)
     return collection_manager
 
 def shutdown():

tests/test_collection_wrappers.py

@@ -0,0 +1,47 @@
+# -*- coding: utf-8 -*-
+
+import os
+import unittest
+import configparser
+
+from ankisyncd.collection import CollectionWrapper
+from ankisyncd.collection import get_collection_wrapper
+
+import helpers.server_utils
+
+class FakeCollectionWrapper(CollectionWrapper):
+    def __init__(self, config, path, setup_new_collection=None):
+        self. _CollectionWrapper__col = None
+        pass
+
+class BadCollectionWrapper:
+    pass
+
+class CollectionWrapperFactoryTest(unittest.TestCase):
+    def test_get_collection_wrapper(self):
+        # Get absolute path to development ini file.
+        script_dir = os.path.dirname(os.path.realpath(__file__))
+        ini_file_path = os.path.join(script_dir,
+                                     "assets",
+                                     "test.conf")
+
+        # Create temporary files and dirs the server will use.
+        server_paths = helpers.server_utils.create_server_paths()
+
+        config = configparser.ConfigParser()
+        config.read(ini_file_path)
+        path = os.path.realpath('fake/collection.anki2')
+
+        # Use custom files and dirs in settings. Should be CollectionWrapper
+        config['sync_app'].update(server_paths)
+        self.assertTrue(type(get_collection_wrapper(config['sync_app'], path) == CollectionWrapper))
+
+        # A conf-specified CollectionWrapper is loaded
+        config.set("sync_app", "collection_wrapper", 'test_collection_wrappers.FakeCollectionWrapper')
+        self.assertTrue(type(get_collection_wrapper(config['sync_app'], path)) == FakeCollectionWrapper)
+
+        # Should fail at load time if the class doesn't inherit from CollectionWrapper
+        config.set("sync_app", "collection_wrapper", 'test_collection_wrappers.BadCollectionWrapper')
+        with self.assertRaises(TypeError):
+            pm = get_collection_wrapper(config['sync_app'], path)
+