Store URL cache preview downloads seperately

This makes it easier to clear old media out at a later date

7 files changed, 94 insertions, 20 deletions

diff --git a/synapse/rest/media/v1/download_resource.py b/synapse/rest/media/v1/download_resource.py
index 39a286b83c..6879249c8a 100644
--- a/synapse/rest/media/v1/download_resource.py
+++ b/synapse/rest/media/v1/download_resource.py
@@ -73,7 +73,12 @@ class DownloadResource(Resource):
         media_type = media_info["media_type"]
         media_length = media_info["media_length"]
         upload_name = name if name else media_info["upload_name"]
-        file_path = self.filepaths.local_media_filepath(media_id)
+        if media_info["url_cache"]:
+            # TODO: Check the file still exists, if it doesn't we can redownload
+            # it from the url `media_info["url_cache"]`
+            file_path = self.filepaths.url_cache_filepath(media_id)
+        else:
+            file_path = self.filepaths.local_media_filepath(media_id)
 
         yield respond_with_file(
             request, media_type, file_path, media_length,
diff --git a/synapse/rest/media/v1/filepath.py b/synapse/rest/media/v1/filepath.py
index 0137458f71..d92b7ff337 100644
--- a/synapse/rest/media/v1/filepath.py
+++ b/synapse/rest/media/v1/filepath.py
@@ -71,3 +71,21 @@ class MediaFilePaths(object):
             self.base_path, "remote_thumbnail", server_name,
             file_id[0:2], file_id[2:4], file_id[4:],
         )
+
+    def url_cache_filepath(self, media_id):
+        return os.path.join(
+            self.base_path, "url_cache",
+            media_id[0:2], media_id[2:4], media_id[4:]
+        )
+
+    def url_cache_thumbnail(self, media_id, width, height, content_type,
+                            method):
+        top_level_type, sub_type = content_type.split("/")
+        file_name = "%i-%i-%s-%s-%s" % (
+            width, height, top_level_type, sub_type, method
+        )
+        return os.path.join(
+            self.base_path, "url_cache_thumbnails",
+            media_id[0:2], media_id[2:4], media_id[4:],
+            file_name
+        )
diff --git a/synapse/rest/media/v1/media_repository.py b/synapse/rest/media/v1/media_repository.py
index 0718f75241..0ea1248ce6 100644
--- a/synapse/rest/media/v1/media_repository.py
+++ b/synapse/rest/media/v1/media_repository.py
@@ -326,13 +326,17 @@ class MediaRepository(object):
             defer.returnValue(t_path)
 
     @defer.inlineCallbacks
-    def _generate_local_thumbnails(self, media_id, media_info):
+    def _generate_local_thumbnails(self, media_id, media_info, url_cache=False):
         media_type = media_info["media_type"]
         requirements = self._get_thumbnail_requirements(media_type)
         if not requirements:
             return
 
-        input_path = self.filepaths.local_media_filepath(media_id)
+        if url_cache:
+            input_path = self.filepaths.url_cache_filepath(media_id)
+        else:
+            input_path = self.filepaths.local_media_filepath(media_id)
+
         thumbnailer = Thumbnailer(input_path)
         m_width = thumbnailer.width
         m_height = thumbnailer.height
@@ -360,9 +364,14 @@ class MediaRepository(object):
 
             for t_width, t_height, t_type in scales:
                 t_method = "scale"
-                t_path = self.filepaths.local_media_thumbnail(
-                    media_id, t_width, t_height, t_type, t_method
-                )
+                if url_cache:
+                    t_path = self.filepaths.url_cache_thumbnail(
+                        media_id, t_width, t_height, t_type, t_method
+                    )
+                else:
+                    t_path = self.filepaths.local_media_thumbnail(
+                        media_id, t_width, t_height, t_type, t_method
+                    )
                 self._makedirs(t_path)
                 t_len = thumbnailer.scale(t_path, t_width, t_height, t_type)
 
@@ -377,9 +386,14 @@ class MediaRepository(object):
                     # thumbnail.
                     continue
                 t_method = "crop"
-                t_path = self.filepaths.local_media_thumbnail(
-                    media_id, t_width, t_height, t_type, t_method
-                )
+                if url_cache:
+                    t_path = self.filepaths.url_cache_thumbnail(
+                        media_id, t_width, t_height, t_type, t_method
+                    )
+                else:
+                    t_path = self.filepaths.local_media_thumbnail(
+                        media_id, t_width, t_height, t_type, t_method
+                    )
                 self._makedirs(t_path)
                 t_len = thumbnailer.crop(t_path, t_width, t_height, t_type)
                 local_thumbnails.append((
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index c680fddab5..b81a336c5d 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -164,7 +164,7 @@ class PreviewUrlResource(Resource):
 
         if _is_media(media_info['media_type']):
             dims = yield self.media_repo._generate_local_thumbnails(
-                media_info['filesystem_id'], media_info
+                media_info['filesystem_id'], media_info, url_cache=True,
             )
 
             og = {
@@ -210,7 +210,7 @@ class PreviewUrlResource(Resource):
                 if _is_media(image_info['media_type']):
                     # TODO: make sure we don't choke on white-on-transparent images
                     dims = yield self.media_repo._generate_local_thumbnails(
-                        image_info['filesystem_id'], image_info
+                        image_info['filesystem_id'], image_info, url_cache=True,
                     )
                     if dims:
                         og["og:image:width"] = dims['width']
@@ -256,7 +256,7 @@ class PreviewUrlResource(Resource):
         # XXX: horrible duplication with base_resource's _download_remote_file()
         file_id = random_string(24)
 
-        fname = self.filepaths.local_media_filepath(file_id)
+        fname = self.filepaths.url_cache_filepath(file_id)
         self.media_repo._makedirs(fname)
 
         try:
@@ -303,6 +303,7 @@ class PreviewUrlResource(Resource):
                 upload_name=download_name,
                 media_length=length,
                 user_id=user,
+                url_cache=url,
             )
 
         except Exception as e:
diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py
index 59b2c39b2f..68d56b2b10 100644
--- a/synapse/rest/media/v1/thumbnail_resource.py
+++ b/synapse/rest/media/v1/thumbnail_resource.py
@@ -101,9 +101,16 @@ class ThumbnailResource(Resource):
             t_type = thumbnail_info["thumbnail_type"]
             t_method = thumbnail_info["thumbnail_method"]
 
-            file_path = self.filepaths.local_media_thumbnail(
-                media_id, t_width, t_height, t_type, t_method,
-            )
+            if media_info["url_cache"]:
+                # TODO: Check the file still exists, if it doesn't we can redownload
+                # it from the url `media_info["url_cache"]`
+                file_path = self.filepaths.url_cache_thumbnail(
+                    media_id, t_width, t_height, t_type, t_method,
+                )
+            else:
+                file_path = self.filepaths.local_media_thumbnail(
+                    media_id, t_width, t_height, t_type, t_method,
+                )
             yield respond_with_file(request, t_type, file_path)
 
         else:
@@ -134,9 +141,18 @@ class ThumbnailResource(Resource):
             t_type = info["thumbnail_type"] == desired_type
 
             if t_w and t_h and t_method and t_type:
-                file_path = self.filepaths.local_media_thumbnail(
-                    media_id, desired_width, desired_height, desired_type, desired_method,
-                )
+                if media_info["url_cache"]:
+                    # TODO: Check the file still exists, if it doesn't we can redownload
+                    # it from the url `media_info["url_cache"]`
+                    file_path = self.filepaths.url_cache_thumbnail(
+                        media_id, desired_width, desired_height, desired_type,
+                        desired_method,
+                    )
+                else:
+                    file_path = self.filepaths.local_media_thumbnail(
+                        media_id, desired_width, desired_height, desired_type,
+                        desired_method,
+                    )
                 yield respond_with_file(request, desired_type, file_path)
                 return
 
diff --git a/synapse/storage/media_repository.py b/synapse/storage/media_repository.py
index 5f0f18ee66..82bb61b811 100644
--- a/synapse/storage/media_repository.py
+++ b/synapse/storage/media_repository.py
@@ -30,13 +30,16 @@ class MediaRepositoryStore(SQLBaseStore):
         return self._simple_select_one(
             "local_media_repository",
             {"media_id": media_id},
-            ("media_type", "media_length", "upload_name", "created_ts", "quarantined_by"),
+            (
+                "media_type", "media_length", "upload_name", "created_ts",
+                "quarantined_by", "url_cache",
+            ),
             allow_none=True,
             desc="get_local_media",
         )
 
     def store_local_media(self, media_id, media_type, time_now_ms, upload_name,
-                          media_length, user_id):
+                          media_length, user_id, url_cache=None):
         return self._simple_insert(
             "local_media_repository",
             {
@@ -46,6 +49,7 @@ class MediaRepositoryStore(SQLBaseStore):
                 "upload_name": upload_name,
                 "media_length": media_length,
                 "user_id": user_id.to_string(),
+                "url_cache": url_cache,
             },
             desc="store_local_media",
         )
diff --git a/synapse/storage/schema/delta/43/url_cache.sql b/synapse/storage/schema/delta/43/url_cache.sql
new file mode 100644
index 0000000000..45ebe020da
--- /dev/null
+++ b/synapse/storage/schema/delta/43/url_cache.sql
@@ -0,0 +1,16 @@
+/* Copyright 2017 Vector Creations 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.
+ */
+
+ALTER TABLE local_media_repository ADD COLUMN url_cache TEXT;