python: Introduce a new connection API that is a bit less stateful.

python/dazl/__init__.py

@@ -14,6 +14,7 @@
 from .prim import FrozenDict as frozendict
 from .pretty.table import write_acs
 
+from .protocols.ledgerapi import connect, Connection
 
 try:
     # This method is undocumented, but is required to read large size of model files when using

python/dazl/protocols/config/__init__.py

@@ -0,0 +1,65 @@
+# Copyright (c) 2017-2021 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+from os import PathLike
+from typing import Collection, Optional, Union
+
+from ...prim import Party, TimeDeltaLike
+from .access import AccessConfig, create_access
+from .ssl import SSLConfig
+from .url import URLConfig
+
+__all__ = ["Config", "AccessConfig", "SSLConfig", "URLConfig"]
+
+
+class Config:
+    @classmethod
+    def create(
+        cls,
+        url: str = None,
+        read_as: "Union[None, Party, Collection[Party]]" = None,
+        act_as: "Union[None, Party, Collection[Party]]" = None,
+        party: "Union[None, Party, Collection[Party]]" = None,
+        admin: "Optional[bool]" = False,
+        ledger_id: "Optional[str]" = None,
+        application_name: "Optional[str]" = None,
+        oauth_token: "Optional[str]" = None,
+        ca: "Optional[bytes]" = None,
+        ca_file: "Optional[PathLike]" = None,
+        cert: "Optional[bytes]" = None,
+        cert_file: "Optional[PathLike]" = None,
+        cert_key: "Optional[bytes]" = None,
+        cert_key_file: "Optional[PathLike]" = None,
+        connect_timeout: "Optional[TimeDeltaLike]" = None,
+        enable_http_proxy: "bool" = True,
+    ) -> "Config":
+        url_config = URLConfig(
+            url=url,
+            connect_timeout=connect_timeout,
+            enable_http_proxy=enable_http_proxy,
+        )
+
+        access_config = create_access(
+            read_as=read_as,
+            act_as=act_as,
+            party=party,
+            admin=admin,
+            ledger_id=ledger_id,
+            application_name=application_name,
+            oauth_token=oauth_token,
+        )
+
+        ssl_config = SSLConfig(
+            ca=ca,
+            ca_file=ca_file,
+            cert=cert,
+            cert_file=cert_file,
+            cert_key=cert_key,
+            cert_key_file=cert_key_file,
+        )
+
+        return cls(access_config, ssl_config, url_config)
+
+    def __init__(self, access: "AccessConfig", ssl: "SSLConfig", url: "URLConfig"):
+        self.access = access
+        self.ssl = ssl
+        self.url = url