Implement download support for media_repository

5 files changed, 278 insertions, 12 deletions

diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 510f07dd7b..c7082b83a7 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -14,10 +14,11 @@
 # limitations under the License.
 
 
-from twisted.internet import defer, reactor
+from twisted.internet import defer, reactor, protocol
 from twisted.internet.error import DNSLookupError
 from twisted.web.client import readBody, _AgentBase, _URI
 from twisted.web.http_headers import Headers
+from twisted.web._newclient import ResponseDone
 
 from synapse.http.endpoint import matrix_federation_endpoint
 from synapse.util.async import sleep
@@ -227,7 +228,7 @@ class MatrixFederationHttpClient(object):
 
     @defer.inlineCallbacks
     def get_json(self, destination, path, args={}, retry_on_dns_fail=True):
-        """ Get's some json from the given host homeserver and path
+        """ GETs some json from the given host homeserver and path
 
         Args:
             destination (str): The remote server to send the HTTP request
@@ -235,9 +236,6 @@ class MatrixFederationHttpClient(object):
             path (str): The HTTP path.
             args (dict): A dictionary used to create query strings, defaults to
                 None.
-                **Note**: The value of each key is assumed to be an iterable
-                and *not* a string.
-
         Returns:
             Deferred: Succeeds when we get *any* HTTP response.
 
@@ -272,6 +270,48 @@ class MatrixFederationHttpClient(object):
 
         defer.returnValue(json.loads(body))
 
+    @defer.inlineCallbacks
+    def get_file(self, destination, path, output_stream, args={},
+                 retry_on_dns_fail=True):
+        """GETs a file from a given homeserver
+        Args:
+            destination (str): The remote server to send the HTTP request to.
+            path (str): The HTTP path to GET.
+            output_stream (file): File to write the response body to.
+            args (dict): Optional dictionary used to create the query string.
+        Returns:
+            A (int,dict) tuple of the file length and a dict of the response
+            headers.
+        """
+
+        encoded_args = {}
+        for k, vs in args.items():
+            if isinstance(vs, basestring):
+                vs = [vs]
+            encoded_args[k] = [v.encode("UTF-8") for v in vs]
+
+        query_bytes = urllib.urlencode(encoded_args, True)
+        logger.debug("Query bytes: %s Retry DNS: %s", args, retry_on_dns_fail)
+
+        def body_callback(method, url_bytes, headers_dict):
+            self.sign_request(destination, method, url_bytes, headers_dict)
+            return None
+
+        response = yield self._create_request(
+            destination.encode("ascii"),
+            "GET",
+            path.encode("ascii"),
+            query_bytes=query_bytes,
+            body_callback=body_callback,
+            retry_on_dns_fail=retry_on_dns_fail
+        )
+
+        headers = dict(response.headers.getAllRawHeaders())
+
+        length = yield _readBodyToFile(response, output_stream)
+
+        defer.returnValue((length, headers))
+
     def _getEndpoint(self, reactor, destination):
         return matrix_federation_endpoint(
             reactor, destination, timeout=10,
@@ -279,6 +319,29 @@ class MatrixFederationHttpClient(object):
         )
 
 
+class _ReadBodyToFileProtocol(protocol.Protocol):
+    def __init__(self, stream, deferred):
+        self.stream = stream
+        self.deferred = deferred
+        self.length = 0
+
+    def dataReceived(self, data):
+        self.stream.write(data)
+        self.length += len(data)
+
+    def connectionLost(self, reason):
+        if reason.check(ResponseDone):
+            self.deferred.callback(self.length)
+        else:
+            self.deferred.errback(reason)
+
+
+def _readBodyToFile(response, stream):
+    d = defer.Deferred()
+    response.deliverBody(_ReadBodyToFileProtocol(stream, d))
+    return d
+
+
 def _print_ex(e):
     if hasattr(e, "reasons") and e.reasons:
         for ex in e.reasons:
diff --git a/synapse/media/v1/download_resource.py b/synapse/media/v1/download_resource.py
new file mode 100644
index 0000000000..c243f16a74
--- /dev/null
+++ b/synapse/media/v1/download_resource.py
@@ -0,0 +1,194 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 OpenMarket 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 synapse.http.server import respond_with_json
+from synapse.util.stringutils import random_string
+from synapse.api.errors import (
+    cs_exception, CodeMessageException, cs_error, Codes
+)
+
+from twisted.protocols.basic import FileSender
+from twisted.web.resource import Resource
+from twisted.web.server import NOT_DONE_YET
+from twisted.internet import defer
+
+import os
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class DownloadResource(Resource):
+    isLeaf = True
+
+    def __init__(self, hs, filepaths):
+        Resource.__init__(self)
+        self.client = hs.get_http_client()
+        self.clock = hs.get_clock()
+        self.server_name = hs.hostname
+        self.store = hs.get_datastore()
+        self.filepaths = filepaths
+
+    def render_GET(self, request):
+        self._async_render_GET(request)
+        return NOT_DONE_YET
+
+    def _respond_404(self, request):
+        respond_with_json(
+            request, 404,
+            cs_error(
+                "Not found %r" % (request.postpath,),
+                code=Codes.NOT_FOUND,
+            ),
+            send_cors=True
+        )
+
+    @defer.inlineCallbacks
+    def _async_render_GET(self, request):
+
+        try:
+            server_name, media_id = request.postpath
+        except:
+            self._respond_404(request)
+            return
+
+        try:
+            if server_name == self.server_name:
+                yield self._respond_local_file(request, media_id)
+            else:
+                yield self._respond_remote_file(request, server_name, media_id)
+        except CodeMessageException as e:
+            logger.exception(e)
+            respond_with_json(request, e.code, cs_exception(e), send_cors=True)
+        except:
+            logger.exception("Failed to serve file")
+            respond_with_json(
+                request,
+                500,
+                {"error": "Internal server error"},
+                send_cors=True
+            )
+
+    @defer.inlineCallbacks
+    def _download_remote_file(self, server_name, media_id):
+        filesystem_id = random_string(24)
+
+        fname = self.filepaths.remote_media_filepath(
+            server_name, filesystem_id
+        )
+        os.makedirs(os.path.dirname(fname))
+
+        try:
+            with open(fname, "wb") as f:
+                length, headers = yield self.client.get_file(
+                    server_name,
+                    "/".join((
+                        "/_matrix/media/v1/download", server_name, media_id,
+                    )),
+                    output_stream=f,
+                )
+        except:
+            os.remove(fname)
+            raise
+
+        media_type = headers["Content-Type"][0]
+        time_now_ms = self.clock.time_msec()
+
+        yield self.store.store_cached_remote_media(
+            origin=server_name,
+            media_id=media_id,
+            media_type=media_type,
+            time_now_ms=self.clock.time_msec(),
+            upload_name=None,
+            media_length=length,
+            filesystem_id=filesystem_id,
+        )
+
+        defer.returnValue({
+            "media_type": media_type,
+            "media_length": length,
+            "upload_name": None,
+            "created_ts": time_now_ms,
+            "filesystem_id": filesystem_id,
+        })
+
+    @defer.inlineCallbacks
+    def _respond_remote_file(self, request, server_name, media_id):
+        media_info = yield self.store.get_cached_remote_media(
+            server_name, media_id
+        )
+
+        if not media_info:
+            media_info = yield self._download_remote_file(
+                server_name, media_id
+            )
+
+        filesystem_id = media_info["filesystem_id"]
+
+        file_path = self.filepaths.remote_media_filepath(
+            server_name, filesystem_id
+        )
+
+        if os.path.isfile(file_path):
+            media_type = media_info["media_type"]
+            request.setHeader(b"Content-Type", media_type.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"
+            )
+
+            with open(file_path, "rb") as f:
+                yield FileSender().beginFileTransfer(f, request)
+
+            request.finish()
+        else:
+            self._respond_404()
+
+    @defer.inlineCallbacks
+    def _respond_local_file(self, request, media_id):
+        media_info = yield self.store.get_local_media(media_id)
+        if not media_info:
+            self._respond_404()
+            return
+
+        file_path = self.filepaths.local_media_filepath(media_id)
+
+        logger.debug("Searching for %s", file_path)
+
+        if os.path.isfile(file_path):
+            media_type = media_info["media_type"]
+            request.setHeader(b"Content-Type", media_type.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"
+            )
+
+            with open(file_path, "rb") as f:
+                yield FileSender().beginFileTransfer(f, request)
+
+            request.finish()
+        else:
+            self._respond_404()
diff --git a/synapse/media/v1/media_repository.py b/synapse/media/v1/media_repository.py
index afd92874cf..e0a4cd01ee 100644
--- a/synapse/media/v1/media_repository.py
+++ b/synapse/media/v1/media_repository.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 from .upload_resource import UploadResource
+from .download_resource import DownloadResource
 from .filepath import MediaFilePaths
 
 from twisted.web.resource import Resource
@@ -62,3 +63,4 @@ class MediaRepositoryResource(Resource):
         Resource.__init__(self)
         filepaths = MediaFilePaths(hs.config.media_store_path)
         self.putChild("upload", UploadResource(hs, filepaths))
+        self.putChild("download", DownloadResource(hs, filepaths))
diff --git a/synapse/media/v1/upload_resource.py b/synapse/media/v1/upload_resource.py
index 2919fee12f..91bcc5caff 100644
--- a/synapse/media/v1/upload_resource.py
+++ b/synapse/media/v1/upload_resource.py
@@ -20,7 +20,8 @@ from synapse.api.errors import (
     cs_exception, SynapseError, CodeMessageException
 )
 
-from twisted.web import server, resource
+from twisted.web.resource import Resource
+from twisted.web.server import NOT_DONE_YET
 from twisted.internet import defer
 
 import os
@@ -30,9 +31,11 @@ import logging
 logger = logging.getLogger(__name__)
 
 
-class UploadResource(resource.Resource):
+class UploadResource(Resource):
+    isLeaf = True
 
     def __init__(self, hs, filepaths):
+        Resource.__init__(self)
         self.auth = hs.get_auth()
         self.clock = hs.get_clock()
         self.store = hs.get_datastore()
@@ -41,11 +44,11 @@ class UploadResource(resource.Resource):
 
     def render_POST(self, request):
         self._async_render_POST(request)
-        return server.NOT_DONE_YET
+        return NOT_DONE_YET
 
     def render_OPTIONS(self, request):
         respond_with_json(request, 200, {}, send_cors=True)
-        return server.NOT_DONE_YET
+        return NOT_DONE_YET
 
     @defer.inlineCallbacks
     def _async_render_POST(self, request):
diff --git a/synapse/storage/media_repository.py b/synapse/storage/media_repository.py
index eda191ad5b..2d3a2d1ccb 100644
--- a/synapse/storage/media_repository.py
+++ b/synapse/storage/media_repository.py
@@ -22,13 +22,13 @@ class MediaRepositoryStore(SQLBaseStore):
     def get_local_media(self, media_id):
         """Get the metadata for a local piece of media
         Returns:
-            None if the media_id doesn't exist.
+            None if the meia_id doesn't exist.
         """
         return self._simple_select_one(
             "local_media_repository",
             {"media_id": media_id},
             ("media_type", "media_length", "upload_name", "created_ts"),
-            True,
+            allow_none=True,
         )
 
     def store_local_media(self, media_id, media_type, time_now_ms, upload_name,
@@ -73,7 +73,11 @@ class MediaRepositoryStore(SQLBaseStore):
         return self._simple_select_one(
             "remote_media_cache",
             {"media_origin": origin, "media_id": media_id},
-            ("media_type", "media_length", "upload_name", "created_ts"),
+            (
+                "media_type", "media_length", "upload_name", "created_ts",
+                "filesystem_id",
+            ),
+            allow_none=True,
         )
 
     def store_cached_remote_media(self, origin, media_id, media_type,