[feature] working naive implementation of the backend

- Resolves: #8757, #8771, #8772

2 files changed, 141 insertions, 5 deletions

diff --git a/server/src/leap/soledad/server/_blobs.py b/server/src/leap/soledad/server/_blobs.py
index cacabbdf..03d37059 100644
--- a/server/src/leap/soledad/server/_blobs.py
+++ b/server/src/leap/soledad/server/_blobs.py
@@ -14,27 +14,147 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
+
 """
 Blobs Server implementation.
+
+This is a very simplistic implementation for the time being.
+Clients should be able to opt-in util the feature is complete.
+
+A more performant BlobsBackend can (and should) be implemented for production
+environments.
 """
+
+import os
+
+from twisted.web import static
 from twisted.web import resource
+from twisted.web.client import FileBodyProducer
+from twisted.web.server import NOT_DONE_YET
 
+from zope.interface import Interface, implementer
 from ._config import get_config
 
 
 __all__ = ['BlobsResource', 'blobs_resource']
 
 
+# TODO some error handling needed
+# [ ] make path configurable
+# [ ] sanitize path
+# [ ] implement basic quota (and raise a QuotaExceeded if limit reached!)
+
+# for the future:
+# [ ] isolate user avatar in a safer way
+# [ ] catch timeout in the server (and delete incomplete upload)
+# p [ chunking (should we do it on the client or on the server?)
+
+
+class BlobAlreadyExists(Exception):
+    pass
+
+
+class IBlobsBackend(Interface):
+
+    """
+    An interface for a BlobsBackend.
+    """
+
+    def read_blob(user, blob_id, request):
+        """
+        Read blob with a given blob_id, and write it to the passed request.
+
+        :returns: a deferred that fires upon finishing.
+        """
+
+    def write_blob(user, blob_id, request):
+        """
+        Write blob to the storage, reading it from the passed request.
+
+        :returns: a deferred that fires upon finishing.
+        """
+
+    # other stuff for the API
+
+    def delete_blob(user, blob_id):
+        pass
+
+    def get_blob_size(user, blob_id):
+        pass
+
+    def get_total_storage(user):
+        pass
+
+
+@implementer(IBlobsBackend)
+class FilesystemBlobsBackend(object):
+
+    path = '/tmp/blobs/'
+
+    def read_blob(self, user, blob_id, request):
+        print "USER", user
+        print "BLOB_ID", blob_id
+        path = self.get_path(user, blob_id)
+        print "READ FROM", path
+        _file = static.File(path, defaultType='application/octet-stream')
+        return _file.render_GET(request)
+
+    def write_blob(self, user, blob_id, request):
+        path = self.get_path(user, blob_id)
+        if os.path.isfile(path):
+            raise BlobAlreadyExists()
+        try:
+            os.makedirs(os.path.split(path)[0])
+        except:
+            pass
+        print "WRITE TO", path
+        fbp = FileBodyProducer(request.content)
+        d = fbp.startProducing(open(path, 'wb'))
+        d.addCallback(lambda _: request.finish())
+        return NOT_DONE_YET
+
+    def get_path(self, user, blob_id):
+        parts = [user]
+        parts += [blob_id[0], blob_id[0:3], blob_id[0:6]]
+        parts += [blob_id]
+        return os.path.join(self.path, *parts)
+
+
 class BlobsResource(resource.Resource):
 
     isLeaf = True
 
+    # Allowed factory classes are defined here
+    blobsFactoryClass = FilesystemBlobsBackend
+
     def __init__(self, blobs_path):
-        resource.Resource.__init__(self)
-        self._blobs_path = blobs_path
+        # TODO pass the backend as configurable option
+        """
+        __init__(self, backend, opts={})
+        factorykls = getattr(self, backend + 'Class')(**opts)
+        self._handler = kls()
+        """
+	resource.Resource.__init__(self)
+	self._blobs_path = blobs_path
+        self._handler = self.blobsFactoryClass()
+        assert IBlobsBackend.providedBy(self._handler)
+
+    # TODO double check credentials, we can have then
+    # under request.
 
     def render_GET(self, request):
-        return 'blobs is not implemented yet!'
+        user, blob_id = self._split_path(request.path)
+        return self._handler.read_blob(user, blob_id, request)
+
+    def render_PUT(self, request):
+        user, blob_id = self._split_path(request.path)
+        return self._handler.write_blob(user, blob_id, request)
+
+    def _split_path(self, blob_id):
+        # FIXME catch errors here
+        parts = blob_id.split('/')
+        _, user, blobname = parts
+        return user, blobname
 
 
 # provide a configured instance of the resource
@@ -42,3 +162,19 @@ _config = get_config()
 _path = _config['blobs_path']
 
 blobs_resource = BlobsResource(_path)
+if __name__ == '__main__':
+    # A dummy blob server
+    # curl -X PUT --data-binary @/tmp/book.pdf localhost:9000/user/somerandomstring
+    # curl -X GET -o /dev/null localhost:9000/user/somerandomstring
+
+    from twisted.web.server import Site
+    from twisted.internet import reactor
+
+    # XXX pass the path here
+    root = BlobsResource()
+    # I picture somethink like
+    # BlobsResource(backend="filesystem", backend_opts={'path': '/tmp/blobs'})
+
+    factory = Site(root)
+    reactor.listenTCP(9000, factory)
+    reactor.run()
diff --git a/server/src/leap/soledad/server/_resource.py b/server/src/leap/soledad/server/_resource.py
index 7a00ad9a..04bb4fba 100644
--- a/server/src/leap/soledad/server/_resource.py
+++ b/server/src/leap/soledad/server/_resource.py
@@ -19,7 +19,7 @@ A twisted resource that serves the Soledad Server.
 """
 from twisted.web.resource import Resource
 
-from ._blobs import blobs_resource
+from ._blobs import BlobsResource
 from ._server_info import ServerInfo
 from ._wsgi import get_sync_resource
 
@@ -74,7 +74,7 @@ class SoledadResource(Resource):
 
         # requests to /blobs will serve blobs if enabled
         if enable_blobs:
-            self.putChild('blobs', blobs_resource)
+            self.putChild('blobs', BlobsResource())
 
         # other requests are routed to legacy sync resource
         self._sync_resource = get_sync_resource(sync_pool)