6 files changed, 156 insertions, 12 deletions
diff --git a/synapse/rest/media/v1/media_repository.py b/synapse/rest/media/v1/media_repository.py
index 485db8577a..bb79599379 100644
--- a/synapse/rest/media/v1/media_repository.py
+++ b/synapse/rest/media/v1/media_repository.py
@@ -472,8 +472,10 @@ class MediaRepository(object):
 
     @defer.inlineCallbacks
     def generate_local_exact_thumbnail(self, media_id, t_width, t_height,
-                                       t_method, t_type):
-        input_path = self.filepaths.local_media_filepath(media_id)
+                                       t_method, t_type, url_cache):
+        input_path = yield self.media_storage.ensure_media_is_in_local_cache(FileInfo(
+            None, media_id, url_cache=url_cache,
+        ))
 
         thumbnailer = Thumbnailer(input_path)
         t_byte_source = yield make_deferred_yieldable(threads.deferToThread(
@@ -486,6 +488,7 @@ class MediaRepository(object):
                 file_info = FileInfo(
                     server_name=None,
                     file_id=media_id,
+                    url_cache=url_cache,
                     thumbnail=True,
                     thumbnail_width=t_width,
                     thumbnail_height=t_height,
@@ -512,7 +515,9 @@ class MediaRepository(object):
     @defer.inlineCallbacks
     def generate_remote_exact_thumbnail(self, server_name, file_id, media_id,
                                         t_width, t_height, t_method, t_type):
-        input_path = self.filepaths.remote_media_filepath(server_name, file_id)
+        input_path = yield self.media_storage.ensure_media_is_in_local_cache(FileInfo(
+            server_name, file_id, url_cache=False,
+        ))
 
         thumbnailer = Thumbnailer(input_path)
         t_byte_source = yield make_deferred_yieldable(threads.deferToThread(
@@ -570,12 +575,9 @@ class MediaRepository(object):
         if not requirements:
             return
 
-        if server_name:
-            input_path = self.filepaths.remote_media_filepath(server_name, file_id)
-        elif url_cache:
-            input_path = self.filepaths.url_cache_filepath(media_id)
-        else:
-            input_path = self.filepaths.local_media_filepath(media_id)
+        input_path = yield self.media_storage.ensure_media_is_in_local_cache(FileInfo(
+            server_name, file_id, url_cache=url_cache,
+        ))
 
         thumbnailer = Thumbnailer(input_path)
         m_width = thumbnailer.width
diff --git a/synapse/rest/media/v1/media_storage.py b/synapse/rest/media/v1/media_storage.py
index 041ae396cd..e8e8b3986d 100644
--- a/synapse/rest/media/v1/media_storage.py
+++ b/synapse/rest/media/v1/media_storage.py
@@ -18,6 +18,7 @@ from twisted.protocols.basic import FileSender
 
 from ._base import Responder
 
+from synapse.util.file_consumer import BackgroundFileConsumer
 from synapse.util.logcontext import make_deferred_yieldable
 
 import contextlib
@@ -26,6 +27,7 @@ import logging
 import shutil
 import sys
 
+
 logger = logging.getLogger(__name__)
 
 
@@ -151,6 +153,37 @@ class MediaStorage(object):
 
         defer.returnValue(None)
 
+    @defer.inlineCallbacks
+    def ensure_media_is_in_local_cache(self, file_info):
+        """Ensures that the given file is in the local cache. Attempts to
+        download it from storage providers if it isn't.
+
+        Args:
+            file_info (FileInfo)
+
+        Returns:
+            Deferred[str]: Full path to local file
+        """
+        path = self._file_info_to_path(file_info)
+        local_path = os.path.join(self.local_media_directory, path)
+        if os.path.exists(local_path):
+            defer.returnValue(local_path)
+
+        dirname = os.path.dirname(local_path)
+        if not os.path.exists(dirname):
+            os.makedirs(dirname)
+
+        for provider in self.storage_providers:
+            res = yield provider.fetch(path, file_info)
+            if res:
+                with res:
+                    consumer = BackgroundFileConsumer(open(local_path, "w"))
+                    yield res.write_to_consumer(consumer)
+                    yield consumer.wait()
+                defer.returnValue(local_path)
+
+        raise Exception("file could not be found")
+
     def _file_info_to_path(self, file_info):
         """Converts file_info into a relative path.
 
@@ -228,9 +261,8 @@ class FileResponder(Responder):
     def __init__(self, open_file):
         self.open_file = open_file
 
-    @defer.inlineCallbacks
     def write_to_consumer(self, consumer):
-        yield FileSender().beginFileTransfer(self.open_file, consumer)
+        return FileSender().beginFileTransfer(self.open_file, consumer)
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         self.open_file.close()
diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py
index 12e84a2b7c..58ada49711 100644
--- a/synapse/rest/media/v1/thumbnail_resource.py
+++ b/synapse/rest/media/v1/thumbnail_resource.py
@@ -164,7 +164,8 @@ class ThumbnailResource(Resource):
 
         # Okay, so we generate one.
         file_path = yield self.media_repo.generate_local_exact_thumbnail(
-            media_id, desired_width, desired_height, desired_method, desired_type
+            media_id, desired_width, desired_height, desired_method, desired_type,
+            url_cache=media_info["url_cache"],
         )
 
         if file_path:
diff --git a/tests/rest/media/__init__.py b/tests/rest/media/__init__.py
new file mode 100644
index 0000000000..a354d38ca8
--- /dev/null
+++ b/tests/rest/media/__init__.py
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
diff --git a/tests/rest/media/v1/__init__.py b/tests/rest/media/v1/__init__.py
new file mode 100644
index 0000000000..a354d38ca8
--- /dev/null
+++ b/tests/rest/media/v1/__init__.py
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
diff --git a/tests/rest/media/v1/test_media_storage.py b/tests/rest/media/v1/test_media_storage.py
new file mode 100644
index 0000000000..c4de181579
--- /dev/null
+++ b/tests/rest/media/v1/test_media_storage.py
@@ -0,0 +1,81 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from twisted.internet import defer
+
+from synapse.rest.media.v1._base import FileInfo
+from synapse.rest.media.v1.media_storage import MediaStorage
+from synapse.rest.media.v1.filepath import MediaFilePaths
+from synapse.rest.media.v1.storage_provider import FileStorageProviderBackend
+
+from tests import unittest
+
+import os
+import shutil
+import tempfile
+
+
+class MediaStorageTests(unittest.TestCase):
+    def setUp(self):
+        self.test_dir = tempfile.mkdtemp(prefix="synapse-tests-")
+
+        self.primary_base_path = os.path.join(self.test_dir, "primary")
+        self.secondary_base_path = os.path.join(self.test_dir, "secondary")
+
+        storage_providers = [FileStorageProviderBackend(
+            self.primary_base_path, self.secondary_base_path
+        )]
+
+        self.filepaths = MediaFilePaths(self.primary_base_path)
+        self.media_storage = MediaStorage(
+            self.primary_base_path, self.filepaths, storage_providers,
+        )
+
+    def tearDown(self):
+        shutil.rmtree(self.test_dir)
+
+    @defer.inlineCallbacks
+    def test_ensure_media_is_in_local_cache(self):
+        media_id = "some_media_id"
+        test_body = "Test\n"
+
+        # First we create a file that is in a storage provider but not in the
+        # local primary media store
+        rel_path = self.filepaths.local_media_filepath_rel(media_id)
+        secondary_path = os.path.join(self.secondary_base_path, rel_path)
+
+        os.makedirs(os.path.dirname(secondary_path))
+
+        with open(secondary_path, "w") as f:
+            f.write(test_body)
+
+        # Now we run ensure_media_is_in_local_cache, which should copy the file
+        # to the local cache.
+        file_info = FileInfo(None, media_id)
+        local_path = yield self.media_storage.ensure_media_is_in_local_cache(file_info)
+
+        self.assertTrue(os.path.exists(local_path))
+
+        # Asserts the file is under the expected local cache directory
+        self.assertEquals(
+            os.path.commonprefix([self.primary_base_path, local_path]),
+            self.primary_base_path,
+        )
+
+        with open(local_path) as f:
+            body = f.read()
+
+        self.assertEqual(test_body, body)