Merge pull request #2767 from matrix-org/erikj/media_storage_refactor

Refactor MediaRepository to separate out storage

synapse/rest/media/v1/_base.py

@@ -70,38 +70,11 @@ def respond_with_file(request, media_type, file_path,
     logger.debug("Responding with %r", file_path)
 
     if os.path.isfile(file_path):
-        request.setHeader(b"Content-Type", media_type.encode("UTF-8"))
-        if upload_name:
-            if is_ascii(upload_name):
-                request.setHeader(
-                    b"Content-Disposition",
-                    b"inline; filename=%s" % (
-                        urllib.quote(upload_name.encode("utf-8")),
-                    ),
-                )
-            else:
-                request.setHeader(
-                    b"Content-Disposition",
-                    b"inline; filename*=utf-8''%s" % (
-                        urllib.quote(upload_name.encode("utf-8")),
-                    ),
-                )
-
-        # cache for at least a day.
-        # XXX: we might want to turn this off for data we don't want to
-        # recommend caching as it's sensitive or private - or at least
-        # select private. don't bother setting Expires as all our
-        # clients are smart enough to be happy with Cache-Control
-        request.setHeader(
-            b"Cache-Control", b"public,max-age=86400,s-maxage=86400"
-        )
         if file_size is None:
             stat = os.stat(file_path)
             file_size = stat.st_size
 
-        request.setHeader(
-            b"Content-Length", b"%d" % (file_size,)
-        )
+        add_file_headers(request, media_type, file_size, upload_name)
 
         with open(file_path, "rb") as f:
             yield logcontext.make_deferred_yieldable(
@@ -111,3 +84,118 @@ def respond_with_file(request, media_type, file_path,
         finish_request(request)
     else:
         respond_404(request)
+
+
+def add_file_headers(request, media_type, file_size, upload_name):
+    """Adds the correct response headers in preparation for responding with the
+    media.
+
+    Args:
+        request (twisted.web.http.Request)
+        media_type (str): The media/content type.
+        file_size (int): Size in bytes of the media, if known.
+        upload_name (str): The name of the requested file, if any.
+    """
+    request.setHeader(b"Content-Type", media_type.encode("UTF-8"))
+    if upload_name:
+        if is_ascii(upload_name):
+            request.setHeader(
+                b"Content-Disposition",
+                b"inline; filename=%s" % (
+                    urllib.quote(upload_name.encode("utf-8")),
+                ),
+            )
+        else:
+            request.setHeader(
+                b"Content-Disposition",
+                b"inline; filename*=utf-8''%s" % (
+                    urllib.quote(upload_name.encode("utf-8")),
+                ),
+            )
+
+    # cache for at least a day.
+    # XXX: we might want to turn this off for data we don't want to
+    # recommend caching as it's sensitive or private - or at least
+    # select private. don't bother setting Expires as all our
+    # clients are smart enough to be happy with Cache-Control
+    request.setHeader(
+        b"Cache-Control", b"public,max-age=86400,s-maxage=86400"
+    )
+
+    request.setHeader(
+        b"Content-Length", b"%d" % (file_size,)
+    )
+
+
+@defer.inlineCallbacks
+def respond_with_responder(request, responder, media_type, file_size, upload_name=None):
+    """Responds to the request with given responder. If responder is None then
+    returns 404.
+
+    Args:
+        request (twisted.web.http.Request)
+        responder (Responder|None)
+        media_type (str): The media/content type.
+        file_size (int|None): Size in bytes of the media. If not known it should be None
+        upload_name (str|None): The name of the requested file, if any.
+    """
+    if not responder:
+        respond_404(request)
+        return
+
+    add_file_headers(request, media_type, file_size, upload_name)
+    with responder:
+        yield responder.write_to_consumer(request)
+    finish_request(request)
+
+
+class Responder(object):
+    """Represents a response that can be streamed to the requester.
+
+    Responder is a context manager which *must* be used, so that any resources
+    held can be cleaned up.
+    """
+    def write_to_consumer(self, consumer):
+        """Stream response into consumer
+
+        Args:
+            consumer (IConsumer)
+
+        Returns:
+            Deferred: Resolves once the response has finished being written
+        """
+        pass
+
+    def __enter__(self):
+        pass
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        pass
+
+
+class FileInfo(object):
+    """Details about a requested/uploaded file.
+
+    Attributes:
+        server_name (str): The server name where the media originated from,
+            or None if local.
+        file_id (str): The local ID of the file. For local files this is the
+            same as the media_id
+        url_cache (bool): If the file is for the url preview cache
+        thumbnail (bool): Whether the file is a thumbnail or not.
+        thumbnail_width (int)
+        thumbnail_height (int)
+        thumbnail_method (str)
+        thumbnail_type (str): Content type of thumbnail, e.g. image/png
+    """
+    def __init__(self, server_name, file_id, url_cache=False,
+                 thumbnail=False, thumbnail_width=None, thumbnail_height=None,
+                 thumbnail_method=None, thumbnail_type=None):
+        self.server_name = server_name
+        self.file_id = file_id
+        self.url_cache = url_cache
+        self.thumbnail = thumbnail
+        self.thumbnail_width = thumbnail_width
+        self.thumbnail_height = thumbnail_height
+        self.thumbnail_method = thumbnail_method
+        self.thumbnail_type = thumbnail_type

synapse/rest/media/v1/download_resource.py

@@ -14,7 +14,7 @@
 # limitations under the License.
 import synapse.http.servlet
 
-from ._base import parse_media_id, respond_with_file, respond_404
+from ._base import parse_media_id, respond_404
 from twisted.web.resource import Resource
 from synapse.http.server import request_handler, set_cors_headers
 
@@ -32,12 +32,12 @@ class DownloadResource(Resource):
     def __init__(self, hs, media_repo):
         Resource.__init__(self)
 
-        self.filepaths = media_repo.filepaths
         self.media_repo = media_repo
         self.server_name = hs.hostname
-        self.store = hs.get_datastore()
-        self.version_string = hs.version_string
+
+        # Both of these are expected by @request_handler()
         self.clock = hs.get_clock()
+        self.version_string = hs.version_string
 
     def render_GET(self, request):
         self._async_render_GET(request)
@@ -57,59 +57,16 @@ class DownloadResource(Resource):
         )
         server_name, media_id, name = parse_media_id(request)
         if server_name == self.server_name:
-            yield self._respond_local_file(request, media_id, name)
+            yield self.media_repo.get_local_media(request, media_id, name)
         else:
-            yield self._respond_remote_file(
-                request, server_name, media_id, name
-            )
-
-    @defer.inlineCallbacks
-    def _respond_local_file(self, request, media_id, name):
-        media_info = yield self.store.get_local_media(media_id)
-        if not media_info or media_info["quarantined_by"]:
-            respond_404(request)
-            return
-
-        media_type = media_info["media_type"]
-        media_length = media_info["media_length"]
-        upload_name = name if name else media_info["upload_name"]
-        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,
-            upload_name=upload_name,
-        )
-
-    @defer.inlineCallbacks
-    def _respond_remote_file(self, request, server_name, media_id, name):
-        # don't forward requests for remote media if allow_remote is false
-        allow_remote = synapse.http.servlet.parse_boolean(
-            request, "allow_remote", default=True)
-        if not allow_remote:
-            logger.info(
-                "Rejecting request for remote media %s/%s due to allow_remote",
-                server_name, media_id,
-            )
-            respond_404(request)
-            return
-
-        media_info = yield self.media_repo.get_remote_media(server_name, media_id)
-
-        media_type = media_info["media_type"]
-        media_length = media_info["media_length"]
-        filesystem_id = media_info["filesystem_id"]
-        upload_name = name if name else media_info["upload_name"]
-
-        file_path = self.filepaths.remote_media_filepath(
-            server_name, filesystem_id
-        )
-
-        yield respond_with_file(
-            request, media_type, file_path, media_length,
-            upload_name=upload_name,
-        )
+            allow_remote = synapse.http.servlet.parse_boolean(
+                request, "allow_remote", default=True)
+            if not allow_remote:
+                logger.info(
+                    "Rejecting request for remote media %s/%s due to allow_remote",
+                    server_name, media_id,
+                )
+                respond_404(request)
+                return
+
+            yield self.media_repo.get_remote_media(request, server_name, media_id, name)

synapse/rest/media/v1/media_storage.py

+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vecotr 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, threads
+from twisted.protocols.basic import FileSender
+
+from ._base import Responder
+
+from synapse.util.logcontext import make_deferred_yieldable
+
+import contextlib
+import os
+import logging
+import shutil
+import sys
+
+logger = logging.getLogger(__name__)
+
+
+class MediaStorage(object):
+    """Responsible for storing/fetching files from local sources.
+
+    Args:
+        local_media_directory (str): Base path where we store media on disk
+        filepaths (MediaFilePaths)
+        storage_providers ([StorageProvider]): List of StorageProvider that are
+            used to fetch and store files.
+    """
+
+    def __init__(self, local_media_directory, filepaths, storage_providers):
+        self.local_media_directory = local_media_directory
+        self.filepaths = filepaths
+        self.storage_providers = storage_providers
+
+    @defer.inlineCallbacks
+    def store_file(self, source, file_info):
+        """Write `source` to the on disk media store, and also any other
+        configured storage providers
+
+        Args:
+            source: A file like object that should be written
+            file_info (FileInfo): Info about the file to store
+
+        Returns:
+            Deferred[str]: the file path written to in the primary media store
+        """
+        path = self._file_info_to_path(file_info)
+        fname = os.path.join(self.local_media_directory, path)
+
+        dirname = os.path.dirname(fname)
+        if not os.path.exists(dirname):
+            os.makedirs(dirname)
+
+        # Write to the main repository
+        yield make_deferred_yieldable(threads.deferToThread(
+            _write_file_synchronously, source, fname,
+        ))
+
+        defer.returnValue(fname)
+
+    @contextlib.contextmanager
+    def store_into_file(self, file_info):
+        """Context manager used to get a file like object to write into, as
+        described by file_info.
+
+        Actually yields a 3-tuple (file, fname, finish_cb), where file is a file
+        like object that can be written to, fname is the absolute path of file
+        on disk, and finish_cb is a function that returns a Deferred.
+
+        fname can be used to read the contents from after upload, e.g. to
+        generate thumbnails.
+
+        finish_cb must be called and waited on after the file has been
+        successfully been written to. Should not be called if there was an
+        error.
+
+        Args:
+            file_info (FileInfo): Info about the file to store
+
+        Example:
+
+            with media_storage.store_into_file(info) as (f, fname, finish_cb):
+                # .. write into f ...
+                yield finish_cb()
+        """
+
+        path = self._file_info_to_path(file_info)
+        fname = os.path.join(self.local_media_directory, path)
+
+        dirname = os.path.dirname(fname)
+        if not os.path.exists(dirname):
+            os.makedirs(dirname)
+
+        finished_called = [False]
+
+        @defer.inlineCallbacks
+        def finish():
+            for provider in self.storage_providers:
+                yield provider.store_file(path, file_info)
+
+            finished_called[0] = True
+
+        try:
+            with open(fname, "wb") as f:
+                yield f, fname, finish
+        except Exception:
+            t, v, tb = sys.exc_info()
+            try:
+                os.remove(fname)
+            except Exception:
+                pass
+            raise t, v, tb
+
+        if not finished_called:
+            raise Exception("Finished callback not called")
+
+    @defer.inlineCallbacks
+    def fetch_media(self, file_info):
+        """Attempts to fetch media described by file_info from the local cache
+        and configured storage providers.
+
+        Args:
+            file_info (FileInfo)
+
+        Returns:
+            Deferred[Responder|None]: Returns a Responder if the file was found,
+                otherwise None.
+        """
+
+        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(FileResponder(open(local_path, "rb")))
+
+        for provider in self.storage_providers:
+            res = yield provider.fetch(path, file_info)
+            if res:
+                defer.returnValue(res)
+
+        defer.returnValue(None)
+
+    def _file_info_to_path(self, file_info):
+        """Converts file_info into a relative path.
+
+        The path is suitable for storing files under a directory, e.g. used to
+        store files on local FS under the base media repository directory.
+
+        Args:
+            file_info (FileInfo)
+
+        Returns:
+            str
+        """
+        if file_info.url_cache:
+            return self.filepaths.url_cache_filepath_rel(file_info.file_id)
+
+        if file_info.server_name:
+            if file_info.thumbnail:
+                return self.filepaths.remote_media_thumbnail_rel(
+                    server_name=file_info.server_name,
+                    file_id=file_info.file_id,
+                    width=file_info.thumbnail_width,
+                    height=file_info.thumbnail_height,
+                    content_type=file_info.thumbnail_type,
+                    method=file_info.thumbnail_method
+                )
+            return self.filepaths.remote_media_filepath_rel(
+                file_info.server_name, file_info.file_id,
+            )
+
+        if file_info.thumbnail:
+            return self.filepaths.local_media_thumbnail_rel(
+                media_id=file_info.file_id,
+                width=file_info.thumbnail_width,
+                height=file_info.thumbnail_height,
+                content_type=file_info.thumbnail_type,
+                method=file_info.thumbnail_method
+            )
+        return self.filepaths.local_media_filepath_rel(
+            file_info.file_id,
+        )
+
+
+def _write_file_synchronously(source, fname):
+    """Write `source` to the path `fname` synchronously. Should be called
+    from a thread.
+
+    Args:
+        source: A file like object to be written
+        fname (str): Path to write to
+    """
+    dirname = os.path.dirname(fname)
+    if not os.path.exists(dirname):
+        os.makedirs(dirname)
+
+    source.seek(0)  # Ensure we read from the start of the file
+    with open(fname, "wb") as f:
+        shutil.copyfileobj(source, f)
+
+
+class FileResponder(Responder):
+    """Wraps an open file that can be sent to a request.
+
+    Args:
+        open_file (file): A file like object to be streamed ot the client,
+            is closed when finished streaming.
+    """
+    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)
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.open_file.close()

synapse/rest/media/v1/preview_url_resource.py

@@ -17,6 +17,8 @@ from twisted.web.server import NOT_DONE_YET
 from twisted.internet import defer
 from twisted.web.resource import Resource
 
+from ._base import FileInfo
+
 from synapse.api.errors import (
     SynapseError, Codes,
 )
@@ -49,7 +51,7 @@ logger = logging.getLogger(__name__)
 class PreviewUrlResource(Resource):
     isLeaf = True
 
-    def __init__(self, hs, media_repo):
+    def __init__(self, hs, media_repo, media_storage):
         Resource.__init__(self)
 
         self.auth = hs.get_auth()
@@ -62,6 +64,7 @@ class PreviewUrlResource(Resource):
         self.client = SpiderHttpClient(hs)
         self.media_repo = media_repo
         self.primary_base_path = media_repo.primary_base_path
+        self.media_storage = media_storage
 
         self.url_preview_url_blacklist = hs.config.url_preview_url_blacklist
 
@@ -273,19 +276,21 @@ class PreviewUrlResource(Resource):
 
         file_id = datetime.date.today().isoformat() + '_' + random_string(16)
 
-        fpath = self.filepaths.url_cache_filepath_rel(file_id)
-        fname = os.path.join(self.primary_base_path, fpath)
-        self.media_repo._makedirs(fname)
+        file_info = FileInfo(
+            server_name=None,
+            file_id=file_id,
+            url_cache=True,
+        )
 
         try:
-            with open(fname, "wb") as f:
+            with self.media_storage.store_into_file(file_info) as (f, fname, finish):
                 logger.debug("Trying to get url '%s'" % url)
                 length, headers, uri, code = yield self.client.get_file(
                     url, output_stream=f, max_size=self.max_spider_size,
                 )
                 # FIXME: pass through 404s and other error messages nicely
 
-            yield self.media_repo.copy_to_backup(fpath)
+                yield finish()
 
             media_type = headers["Content-Type"][0]
             time_now_ms = self.clock.time_msec()
@@ -327,7 +332,6 @@ class PreviewUrlResource(Resource):
             )
 
         except Exception as e:
-            os.remove(fname)
             raise SynapseError(
                 500, ("Failed to download content: %s" % e),
                 Codes.UNKNOWN

synapse/rest/media/v1/storage_provider.py

+# -*- 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, threads
+
+from .media_storage import FileResponder
+
+from synapse.util.logcontext import preserve_fn
+
+import logging
+import os
+import shutil
+
+
+logger = logging.getLogger(__name__)
+
+
+class StorageProvider(object):
+    """A storage provider is a service that can store uploaded media and
+    retrieve them.
+    """
+    def store_file(self, path, file_info):
+        """Store the file described by file_info. The actual contents can be
+        retrieved by reading the file in file_info.upload_path.
+
+        Args:
+            path (str): Relative path of file in local cache
+            file_info (FileInfo)
+
+        Returns:
+            Deferred
+        """
+        pass
+
+    def fetch(self, path, file_info):
+        """Attempt to fetch the file described by file_info and stream it
+        into writer.
+
+        Args:
+            path (str): Relative path of file in local cache
+            file_info (FileInfo)
+
+        Returns:
+            Deferred(Responder): Returns a Responder if the provider has the file,
+                otherwise returns None.
+        """
+        pass
+
+
+class StorageProviderWrapper(StorageProvider):
+    """Wraps a storage provider and provides various config options
+
+    Args:
+        backend (StorageProvider)
+        store (bool): Whether to store new files or not.
+        store_synchronous (bool): Whether to wait for file to be successfully
+            uploaded, or todo the upload in the backgroud.
+        store_remote (bool): Whether remote media should be uploaded
+    """
+    def __init__(self, backend, store, store_synchronous, store_remote):
+        self.backend = backend
+        self.store = store
+        self.store_synchronous = store_synchronous
+        self.store_remote = store_remote
+
+    def store_file(self, path, file_info):
+        if not self.store:
+            return defer.succeed(None)
+
+        if file_info.server_name and not self.store_remote:
+            return defer.succeed(None)
+
+        if self.store_synchronous:
+            return self.backend.store_file(path, file_info)
+        else:
+            # TODO: Handle errors.
+            preserve_fn(self.backend.store_file)(path, file_info)
+            return defer.succeed(None)
+
+    def fetch(self, path, file_info):
+        return self.backend.fetch(path, file_info)
+
+
+class FileStorageProviderBackend(StorageProvider):
+    """A storage provider that stores files in a directory on a filesystem.
+
+    Args:
+        cache_directory (str): Base path of the local media repository
+        base_directory (str): Base path to store new files
+    """
+
+    def __init__(self, cache_directory, base_directory):
+        self.cache_directory = cache_directory
+        self.base_directory = base_directory
+
+    def store_file(self, path, file_info):
+        """See StorageProvider.store_file"""
+
+        primary_fname = os.path.join(self.cache_directory, path)
+        backup_fname = os.path.join(self.base_directory, path)
+
+        dirname = os.path.dirname(backup_fname)
+        if not os.path.exists(dirname):
+            os.makedirs(dirname)
+
+        return threads.deferToThread(
+            shutil.copyfile, primary_fname, backup_fname,
+        )
+
+    def fetch(self, path, file_info):
+        """See StorageProvider.fetch"""
+
+        backup_fname = os.path.join(self.base_directory, path)
+        if os.path.isfile(backup_fname):
+            return FileResponder(open(backup_fname, "rb"))

synapse/rest/media/v1/thumbnail_resource.py

@@ -14,7 +14,10 @@
 # limitations under the License.
 
 
-from ._base import parse_media_id, respond_404, respond_with_file
+from ._base import (
+    parse_media_id, respond_404, respond_with_file, FileInfo,
+    respond_with_responder,
+)
 from twisted.web.resource import Resource
 from synapse.http.servlet import parse_string, parse_integer
 from synapse.http.server import request_handler, set_cors_headers
@@ -30,12 +33,12 @@ logger = logging.getLogger(__name__)
 class ThumbnailResource(Resource):
     isLeaf = True
 
-    def __init__(self, hs, media_repo):
+    def __init__(self, hs, media_repo, media_storage):
         Resource.__init__(self)
 
         self.store = hs.get_datastore()
-        self.filepaths = media_repo.filepaths
         self.media_repo = media_repo
+        self.media_storage = media_storage
         self.dynamic_thumbnails = hs.config.dynamic_thumbnails
         self.server_name = hs.hostname
         self.version_string = hs.version_string
@@ -91,23 +94,22 @@ class ThumbnailResource(Resource):
             thumbnail_info = self._select_thumbnail(
                 width, height, method, m_type, thumbnail_infos
             )
-            t_width = thumbnail_info["thumbnail_width"]
-            t_height = thumbnail_info["thumbnail_height"]
-            t_type = thumbnail_info["thumbnail_type"]
-            t_method = thumbnail_info["thumbnail_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)
 
+            file_info = FileInfo(
+                server_name=None, file_id=media_id,
+                url_cache=media_info["url_cache"],
+                thumbnail=True,
+                thumbnail_width=thumbnail_info["thumbnail_width"],
+                thumbnail_height=thumbnail_info["thumbnail_height"],
+                thumbnail_type=thumbnail_info["thumbnail_type"],
+                thumbnail_method=thumbnail_info["thumbnail_method"],
+            )
+
+            t_type = file_info.thumbnail_type
+            t_length = thumbnail_info["thumbnail_length"]
+
+            responder = yield self.media_storage.fetch_media(file_info)
+            yield respond_with_responder(request, responder, t_type, t_length)
         else:
             respond_404(request)
 
@@ -129,20 +131,23 @@ class ThumbnailResource(Resource):
             t_type = info["thumbnail_type"] == desired_type
 
             if t_w and t_h and t_method and t_type:
-                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
+                file_info = FileInfo(
+                    server_name=None, file_id=media_id,
+                    url_cache=media_info["url_cache"],
+                    thumbnail=True,
+                    thumbnail_width=info["thumbnail_width"],
+                    thumbnail_height=info["thumbnail_height"],
+                    thumbnail_type=info["thumbnail_type"],
+                    thumbnail_method=info["thumbnail_method"],
+                )
+
+                t_type = file_info.thumbnail_type
+                t_length = info["thumbnail_length"]
+
+                responder = yield self.media_storage.fetch_media(file_info)
+                if responder:
+                    yield respond_with_responder(request, responder, t_type, t_length)
+                    return
 
         logger.debug("We don't have a local thumbnail of that size. Generating")
 
@@ -175,12 +180,22 @@ 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.remote_media_thumbnail(
-                    server_name, file_id, desired_width, desired_height,
-                    desired_type, desired_method,
+                file_info = FileInfo(
+                    server_name=None, file_id=media_id,
+                    thumbnail=True,
+                    thumbnail_width=info["thumbnail_width"],
+                    thumbnail_height=info["thumbnail_height"],
+                    thumbnail_type=info["thumbnail_type"],
+                    thumbnail_method=info["thumbnail_method"],
                 )
-                yield respond_with_file(request, desired_type, file_path)
-                return
+
+                t_type = file_info.thumbnail_type
+                t_length = info["thumbnail_length"]
+
+                responder = yield self.media_storage.fetch_media(file_info)
+                if responder:
+                    yield respond_with_responder(request, responder, t_type, t_length)
+                    return
 
         logger.debug("We don't have a local thumbnail of that size. Generating")
 
@@ -211,17 +226,20 @@ class ThumbnailResource(Resource):
             thumbnail_info = self._select_thumbnail(
                 width, height, method, m_type, thumbnail_infos
             )
-            t_width = thumbnail_info["thumbnail_width"]
-            t_height = thumbnail_info["thumbnail_height"]
-            t_type = thumbnail_info["thumbnail_type"]
-            t_method = thumbnail_info["thumbnail_method"]
-            file_id = thumbnail_info["filesystem_id"]
+            file_info = FileInfo(
+                server_name=None, file_id=media_id,
+                thumbnail=True,
+                thumbnail_width=thumbnail_info["thumbnail_width"],
+                thumbnail_height=thumbnail_info["thumbnail_height"],
+                thumbnail_type=thumbnail_info["thumbnail_type"],
+                thumbnail_method=thumbnail_info["thumbnail_method"],
+            )
+
+            t_type = file_info.thumbnail_type
             t_length = thumbnail_info["thumbnail_length"]
 
-            file_path = self.filepaths.remote_media_thumbnail(
-                server_name, file_id, t_width, t_height, t_type, t_method,
-            )
-            yield respond_with_file(request, t_type, file_path, t_length)
+            responder = yield self.media_storage.fetch_media(file_info)
+            yield respond_with_responder(request, responder, t_type, t_length)
         else:
             respond_404(request)