core: Add core.library.get_images

mopidy/backend/__init__.py

@@ -92,6 +92,14 @@ class LibraryProvider(object):
         """
         return []
 
+    def get_images(self, uris):
+        """
+        See :meth:`mopidy.core.LibraryController.get_images`.
+
+        *MAY be implemented by subclass.*
+        """
+        return {}
+
     # TODO: replace with search(query, exact=True, ...)
     def find_exact(self, query=None, uris=None):
         """

mopidy/core/library.py

@@ -72,6 +72,22 @@ class LibraryController(object):
             return []
         return backend.library.browse(uri).get()
 
+    def get_images(self, uris):
+        """Lookup the images for the given URIs
+
+        :param list uris: list of uris to find images for
+        :rtype: dict mapping uris to :class:`mopidy.models.Image` instances
+        """
+        futures = [
+            backend.library.get_images(backend_uris)
+            for (backend, backend_uris)
+            in self._get_backends_to_uris(uris).items() if backend_uris]
+
+        images = {}
+        for result in pykka.get_all(futures):
+            images.update(result)
+        return images
+
     def find_exact(self, query=None, uris=None, **kwargs):
         """
         Search the library for tracks where ``field`` is ``values``.

tests/core/test_library.py

@@ -5,7 +5,7 @@ import unittest
 import mock
 
 from mopidy import backend, core
-from mopidy.models import Ref, SearchResult, Track
+from mopidy.models import Image, Ref, SearchResult, Track
 
 
 class CoreLibraryTest(unittest.TestCase):
@@ -14,6 +14,8 @@ class CoreLibraryTest(unittest.TestCase):
         self.backend1 = mock.Mock()
         self.backend1.uri_schemes.get.return_value = ['dummy1']
         self.library1 = mock.Mock(spec=backend.LibraryProvider)
+        self.library1.get_images().get.return_value = {}
+        self.library1.get_images.reset_mock()
         self.library1.root_directory.get.return_value = dummy1_root
         self.backend1.library = self.library1
 
@@ -21,6 +23,8 @@ class CoreLibraryTest(unittest.TestCase):
         self.backend2 = mock.Mock()
         self.backend2.uri_schemes.get.return_value = ['dummy2', 'du2']
         self.library2 = mock.Mock(spec=backend.LibraryProvider)
+        self.library2.get_images().get.return_value = {}
+        self.library2.get_images.reset_mock()
         self.library2.root_directory.get.return_value = dummy2_root
         self.backend2.library = self.library2
 
@@ -33,6 +37,46 @@ class CoreLibraryTest(unittest.TestCase):
         self.core = core.Core(mixer=None, backends=[
             self.backend1, self.backend2, self.backend3])
 
+    def test_get_images_returns_empty_dict_for_no_uris(self):
+        self.assertEqual({}, self.core.library.get_images([]))
+
+    def test_get_images_returns_empty_dict_for_unknown_uri(self):
+        self.assertEqual({}, self.core.library.get_images(['dummy4:bar']))
+
+    def test_get_images_returns_empty_dict_for_library_less_uri(self):
+        self.assertEqual({}, self.core.library.get_images(['dummy3:foo']))
+
+    def test_get_images_maps_uri_to_backend(self):
+        self.core.library.get_images(['dummy1:track'])
+        self.library1.get_images.assert_called_once_with(['dummy1:track'])
+        self.library2.get_images.assert_not_called()
+
+    def test_get_images_maps_uri_to_backends(self):
+        self.core.library.get_images(['dummy1:track', 'dummy2:track'])
+        self.library1.get_images.assert_called_once_with(['dummy1:track'])
+        self.library2.get_images.assert_called_once_with(['dummy2:track'])
+
+    def test_get_images_returns_images(self):
+        self.library1.get_images().get.return_value = {
+            'dummy1:track': Image(uri='uri')}
+        self.library1.get_images.reset_mock()
+
+        result = self.core.library.get_images(['dummy1:track'])
+        self.assertEqual({'dummy1:track': Image(uri='uri')}, result)
+
+    def test_get_images_merges_results(self):
+        self.library1.get_images().get.return_value = {
+            'dummy1:track': Image(uri='uri1')}
+        self.library1.get_images.reset_mock()
+        self.library2.get_images().get.return_value = {
+            'dummy2:track': Image(uri='uri2')}
+        self.library2.get_images.reset_mock()
+
+        result = self.core.library.get_images(['dummy1:track', 'dummy2:track'])
+        expected = {'dummy1:track': Image(uri='uri1'),
+                    'dummy2:track': Image(uri='uri2')}
+        self.assertEqual(expected, result)
+
     def test_browse_root_returns_dir_ref_for_each_lib_with_root_dir_name(self):
         result = self.core.library.browse(None)