From 25b9cf4c996b6b107fbfb45536c8741158091a96 Mon Sep 17 00:00:00 2001
From: Michael Hudson-Doyle <michael.hudson@canonical.com>
Date: Wed, 23 Sep 2020 09:56:56 +1200
Subject: [PATCH] make serialization api a touch easier to use

---
 subiquity/common/api/client.py |  8 +++-----
 subiquity/common/api/server.py |  9 +++------
 subiquity/common/serialize.py  | 12 ++++++++++++
 3 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/subiquity/common/api/client.py b/subiquity/common/api/client.py
index cd05457e..868a52c4 100644
--- a/subiquity/common/api/client.py
+++ b/subiquity/common/api/client.py
@@ -14,7 +14,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import inspect
-import json
 
 import aiohttp
 
@@ -42,9 +41,8 @@ def _wrap(make_request, path, meth, serializer):
             if arg_name == payload_arg:
                 data = serializer.serialize(payload_ann, value)
             else:
-                query_args[arg_name] = json.dumps(
-                    serializer.serialize(
-                        meth_params[arg_name].annotation, value))
+                query_args[arg_name] = serializer.to_json(
+                        meth_params[arg_name].annotation, value)
         async with make_request(
                 meth.__name__, path, json=data, params=query_args) as resp:
             resp.raise_for_status()
@@ -77,7 +75,7 @@ def make_client_for_conn(
             # session.request needs a full URL with scheme and host
             # even though that's in some ways a bit silly with a unix
             # socket, so we just hardcode something here (I guess the
-            # "a" gets sent a long to the server inthe Host: header
+            # "a" gets sent along to the server in the Host: header
             # and the server could in principle do something like
             # virtual host based selection but well....)
             url = 'http://a' + path
diff --git a/subiquity/common/api/server.py b/subiquity/common/api/server.py
index 7a44c8ce..8b5aeb75 100644
--- a/subiquity/common/api/server.py
+++ b/subiquity/common/api/server.py
@@ -14,7 +14,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import inspect
-import json
 
 from aiohttp import web
 
@@ -104,13 +103,11 @@ def _make_handler(controller, definition, implementation, serializer):
             args = {}
             try:
                 if data_annotation is not None:
-                    payload = json.loads(await request.text())
-                    args[data_arg] = serializer.deserialize(
-                        data_annotation, payload)
+                    args[data_arg] = serializer.from_json(
+                        data_annotation, await request.text())
                 for arg, ann, default in query_args_anns:
                     if arg in request.query:
-                        v = serializer.deserialize(
-                            ann, json.loads(request.query[arg]))
+                        v = serializer.from_json(ann, request.query[arg])
                     elif default != inspect._empty:
                         v = default
                     else:
diff --git a/subiquity/common/serialize.py b/subiquity/common/serialize.py
index be907a9f..d94ee7e9 100644
--- a/subiquity/common/serialize.py
+++ b/subiquity/common/serialize.py
@@ -15,6 +15,7 @@
 
 import datetime
 import enum
+import json
 import inspect
 import typing
 
@@ -124,3 +125,14 @@ class Serializer:
         if isinstance(annotation, type) and issubclass(annotation, enum.Enum):
             return getattr(annotation, value)
         return self.type_deserializers[annotation](annotation, value, metadata)
+
+    def to_json(self, annotation, value):
+        return json.dumps(self.serialize(annotation, value))
+
+    def from_json(self, annotation, value):
+        return self.deserialize(annotation, json.loads(value))
+
+
+_serializer = Serializer()
+to_json = _serializer.to_json
+from_json = _serializer.from_json