Add the abliity to send a schema write request

datajack/__init__.py

@@ -1,7 +1,7 @@
 import enum
 import logging
 import socket
-from typing import Tuple
+from typing import Mapping, Tuple, Type
 import urllib.parse
 
 from proto import control_pb2
@@ -21,6 +21,11 @@ DATA_FORMATS = ",".join([
 	"json",
 ])
 
+PYTHON_TYPE_TO_SCHEMA_TYPE = {
+	str: control_pb2.SchemaEntry.STRING,
+	int:  control_pb2.SchemaEntry.INT,
+}
+
 # The types of access that are allowed with this connection
 class Permissions(enum.Enum):
 	pass
@@ -62,6 +67,18 @@ class Connection:
 	def send(self, data):
 		self.socket.send(data)
 
+	def write_schema(self, table_name: str, schema: Mapping[str, Type]) -> None:
+		"Send a command to write the given schema."
+		command = control_pb2.Command(
+			type=control_pb2.Command.Type.SCHEMA_WRITE,
+			table_name=table_name,
+		)
+		for k, v in schema.items():
+			entry = command.schema_entry.add()
+			entry.name = k
+			entry.type = PYTHON_TYPE_TO_SCHEMA_TYPE[v]
+		self.socket.send(command.SerializeToString())
+		
 	def _handshake(self):
 		"Handshake with the server, ensure we have all the data we need."
 		fields = [MAGIC, DATA_FORMATS, self.namespace, self.app_name, self.app_version, self.public_key,]