Rewrite package serialization (#53)

royalnet/network/packages.py

@@ -1,28 +1,44 @@
-import pickle
+import json
 import uuid
+import typing
 
 
 class Package:
     """A Royalnet package, the data type with which a :py:class:`royalnet.network.RoyalnetLink` communicates with a :py:class:`royalnet.network.RoyalnetServer` or another link. """
 
-    def __init__(self, data, destination: str, source: str, *, source_conv_id: str = None, destination_conv_id: str = None):
+    def __init__(self,
+                 data: typing.Union[None, int, float, str, list, dict],
+                 *,
+                 source: str,
+                 destination: str,
+                 source_conv_id: typing.Optional[str] = None,
+                 destination_conv_id: typing.Optional[str] = None):
         """Create a Package.
 
         Parameters:
             data: The data that should be sent. Usually a :py:class:`royalnet.network.Message`.
-            destination: The ``link_type`` of the destination node, or alternatively, the ``nid`` of the node. Can also be the ``NULL`` value to send the message to nobody.
             source: The ``nid`` of the node that created this Package.
+            destination: The ``link_type`` of the destination node, or alternatively, the ``nid`` of the node. Can also be the ``NULL`` value to send the message to nobody.
             source_conv_id: The conversation id of the node that created this package. Akin to the sequence number on IP packets.
             destination_conv_id: The conversation id of the node that this Package is a reply to."""
         # TODO: something is not right in these type hints. Check them.
-        self.data = data
-        self.destination: str = destination
+        self.data: typing.Union[None, int, float, str, list, dict] = data
         self.source: str = source
         self.source_conv_id: str = source_conv_id or str(uuid.uuid4())
-        self.destination_conv_id: str = destination_conv_id
+        self.destination: str = destination
+        self.destination_conv_id: typing.Optional[str] = destination_conv_id
 
     def __repr__(self):
-        return f"<Package to {self.destination}: {self.data.__class__.__name__}>"
+        return f"<Package {self.source} ({self.source_conv_id}) to {self.destination} ({self.destination_conv_id}>"
+
+    def __eq__(self, other):
+        if isinstance(other, Package):
+            return (self.data == other.data) and \
+                   (self.source == other.source) and \
+                   (self.destination == other.destination) and \
+                   (self.source_conv_id == other.source_conv_id) and \
+                   (self.destination_conv_id == other.destination_conv_id)
+        return False
 
     def reply(self, data) -> "Package":
         """Reply to this Package with another Package.
@@ -32,13 +48,63 @@ class Package:
 
         Returns:
             The reply Package."""
-        return Package(data, self.source, self.destination,
-                       source_conv_id=str(uuid.uuid4()),
+        return Package(data,
+                       source=self.destination,
+                       destination=self.source,
+                       source_conv_id=self.destination_conv_id or str(uuid.uuid4()),
                        destination_conv_id=self.source_conv_id)
 
-    def pickle(self) -> bytes:
-        """:py:mod:`pickle` this Package.
+    @staticmethod
+    def from_dict(d) -> "Package":
+        """Create a Package from a dictionary."""
+        if "source" not in d:
+            raise ValueError("Missing source field")
+        if "nid" not in d["source"]:
+            raise ValueError("Missing source.nid field")
+        if "conv_id" not in d["source"]:
+            raise ValueError("Missing source.conv_id field")
+        if "destination" not in d:
+            raise ValueError("Missing destination field")
+        if "nid" not in d["destination"]:
+            raise ValueError("Missing destination.nid field")
+        if "conv_id" not in d["destination"]:
+            raise ValueError("Missing destination.conv_id field")
+        if "data" not in d:
+            raise ValueError("Missing data field")
+        return Package(d["data"],
+                       source=d["source"]["nid"],
+                       destination=d["destination"]["nid"],
+                       source_conv_id=d["source"]["conv_id"],
+                       destination_conv_id=d["destination"]["conv_id"])
 
-        Returns:
-            The pickled package in form of bytes."""
-        return pickle.dumps(self)
+    def to_dict(self) -> dict:
+        """Convert the Package into a dictionary."""
+        return {
+            "source": {
+                "nid": self.source,
+                "conv_id": self.source_conv_id
+            },
+            "destination": {
+                "nid": self.destination,
+                "conv_id": self.destination_conv_id
+            },
+            "data": self.data
+        }
+
+    @staticmethod
+    def from_json_string(string: str) -> "Package":
+        """Create a Package from a JSON string."""
+        return Package.from_dict(json.loads(string))
+
+    def to_json_string(self) -> str:
+        """Convert the Package into a JSON string."""
+        return json.dumps(self.to_dict())
+
+    @staticmethod
+    def from_json_bytes(b: bytes) -> "Package":
+        """Create a Package from UTF8-encoded JSON bytes."""
+        return Package.from_json_string(str(b, encoding="utf8"))
+
+    def to_json_bytes(self) -> bytes:
+        """Convert the Package into UTF8-encoded JSON bytes."""
+        return bytes(self.to_json_string(), encoding="utf8")

tests/test_network.py

@@ -0,0 +1,14 @@
+import pytest
+import uuid
+from royalnet.network.packages import Package
+
+
+def test_package_serialization():
+    pkg = Package("ciao",
+                  source=str(uuid.uuid4()),
+                  destination=str(uuid.uuid4()),
+                  source_conv_id=str(uuid.uuid4()),
+                  destination_conv_id=str(uuid.uuid4()))
+    assert pkg == Package.from_dict(pkg.to_dict())
+    assert pkg == Package.from_json_string(pkg.to_json_string())
+    assert pkg == Package.from_json_bytes(pkg.to_json_bytes())