msggen: introduce chain of responsibility pattern to make msggen extensible

Changelog-Added: msggen: introduce chain of responsibility pattern to make msggen extensible

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

contrib/msggen/msggen/__main__.py

@@ -1,153 +1,31 @@
-from msggen.model import Method, CompositeField, Service
-from msggen.grpc import GrpcGenerator, GrpcConverterGenerator, GrpcUnconverterGenerator, GrpcServerGenerator
-from msggen.rust import RustGenerator
-from pathlib import Path
-import subprocess
 import json
+from msggen.gen.grpc import GrpcGenerator, GrpcConverterGenerator, GrpcUnconverterGenerator, GrpcServerGenerator
+from msggen.gen.rust import RustGenerator
+from msggen.gen.generator import GeneratorChain
+from msggen.utils import repo_root, load_jsonrpc_service
 
 
-# Sometimes we want to rename a method, due to a name clash
-method_name_override = {
-    "Connect": "ConnectPeer",
-}
-
-
-def repo_root():
-    path = subprocess.check_output(["git", "rev-parse", "--show-toplevel"])
-    return Path(path.strip().decode('UTF-8'))
-
-
-def load_jsonrpc_method(name):
-    """Load a method based on the file naming conventions for the JSON-RPC.
-    """
-    base_path = (repo_root() / "doc" / "schemas").resolve()
-    req_file = base_path / f"{name.lower()}.request.json"
-    resp_file = base_path / f"{name.lower()}.schema.json"
-    request = CompositeField.from_js(json.load(open(req_file)), path=name)
-    response = CompositeField.from_js(json.load(open(resp_file)), path=name)
-
-    # Normalize the method request and response typename so they no
-    # longer conflict.
-    request.typename += "Request"
-    response.typename += "Response"
-
-    return Method(
-        name=method_name_override.get(name, name),
-        request=request,
-        response=response,
-    )
-
-
-def load_jsonrpc_service():
-    method_names = [
-        "Getinfo",
-        "ListPeers",
-        "ListFunds",
-        "SendPay",
-        "ListChannels",
-        "AddGossip",
-        "AutoCleanInvoice",
-        "CheckMessage",
-        "Close",
-        "Connect",
-        "CreateInvoice",
-        "Datastore",
-        "CreateOnion",
-        "DelDatastore",
-        "DelExpiredInvoice",
-        "DelInvoice",
-        "Invoice",
-        "ListDatastore",
-        "ListInvoices",
-        "SendOnion",
-        "ListSendPays",
-        "ListTransactions",
-        "Pay",
-        "ListNodes",
-        "WaitAnyInvoice",
-        "WaitInvoice",
-        "WaitSendPay",
-        "NewAddr",
-        "Withdraw",
-        "KeySend",
-        "FundPsbt",
-        "SendPsbt",
-        "SignPsbt",
-        "UtxoPsbt",
-        "TxDiscard",
-        "TxPrepare",
-        "TxSend",
-        # "decodepay",
-        # "decode",
-        # "delpay",
-        # "disableoffer",
-        "Disconnect",
-        "Feerates",
-        # "fetchinvoice",
-        # "fundchannel_cancel",
-        # "fundchannel_complete",
-        # "fundchannel",
-        # "fundchannel_start",
-        # "funderupdate",
-        # "getlog",
-        "GetRoute",
-        # "getsharedsecret",
-        "ListForwards",
-        # "listoffers",
-        "ListPays",
-        # "multifundchannel",
-        # "multiwithdraw",
-        # "offerout",
-        # "offer",
-        # "openchannel_abort",
-        # "openchannel_bump",
-        # "openchannel_init",
-        # "openchannel_signed",
-        # "openchannel_update",
-        # "parsefeerate",
-        "Ping",
-        # "plugin",
-        # "reserveinputs",
-        # "sendcustommsg",
-        # "sendinvoice",
-        # "sendonionmessage",
-        # "setchannelfee",
-        "SignMessage",
-        # "unreserveinputs",
-        # "waitblockheight",
-        # "ListConfigs",
-        # "check",  # No point in mapping this one
-        # "Stop",  # Breaks a core assumption (root is an object) can't map unless we change this
-        # "notifications",  # No point in mapping this
-        # "help",
-    ]
-    methods = [load_jsonrpc_method(name) for name in method_names]
-    service = Service(name="Node", methods=methods)
-    service.includes = ['primitives.proto']  # Make sure we have the primitives included.
-    return service
-
-
-def gengrpc(service, meta):
+def gengrpc(generator_chain: GeneratorChain, meta):
     """Load all mapped RPC methods, wrap them in a Service, and split them into messages.
     """
     fname = repo_root() / "cln-grpc" / "proto" / "node.proto"
     dest = open(fname, "w")
-    GrpcGenerator(dest, meta).generate(service)
+    generator_chain.add_generator(GrpcGenerator(dest, meta))
 
     fname = repo_root() / "cln-grpc" / "src" / "convert.rs"
     dest = open(fname, "w")
-    GrpcConverterGenerator(dest).generate(service)
-    GrpcUnconverterGenerator(dest).generate(service)
+    generator_chain.add_generator(GrpcConverterGenerator(dest))
+    generator_chain.add_generator(GrpcUnconverterGenerator(dest))
 
     fname = repo_root() / "cln-grpc" / "src" / "server.rs"
     dest = open(fname, "w")
-    GrpcServerGenerator(dest).generate(service)
+    generator_chain.add_generator(GrpcServerGenerator(dest))
 
 
-def genrustjsonrpc(service):
+def genrustjsonrpc(generator_chain: GeneratorChain):
     fname = repo_root() / "cln-rpc" / "src" / "model.rs"
     dest = open(fname, "w")
-    RustGenerator(dest).generate(service)
+    generator_chain.add_generator(RustGenerator(dest))
 
 
 def load_msggen_meta():
@@ -163,8 +41,13 @@ def write_msggen_meta(meta):
 def run():
     service = load_jsonrpc_service()
     meta = load_msggen_meta()
-    gengrpc(service, meta)
-    genrustjsonrpc(service)
+    generator_chain = GeneratorChain()
+
+    gengrpc(generator_chain, meta)
+    genrustjsonrpc(generator_chain)
+
+    generator_chain.generate(service)
+
     write_msggen_meta(meta)
 
 

contrib/msggen/msggen/gen/__init__.py

@@ -0,0 +1,3 @@
+from .generator import IGenerator, GeneratorChain # noqa
+from .grpc import GrpcGenerator, GrpcConverterGenerator, GrpcUnconverterGenerator, GrpcServerGenerator # noqa
+from .rust import RustGenerator # noqa

contrib/msggen/msggen/gen/generator.py

@@ -0,0 +1,36 @@
+"""
+Generator interface!
+
+author: https://github.com/vincenzopalazzo
+"""
+from abc import ABC, abstractmethod
+
+from msggen.model import Service
+
+
+class IGenerator(ABC):
+    """
+    Change of responsibility handler that need to be
+    implemented by all the generators.
+    """
+
+    @abstractmethod
+    def generate(self, service: Service):
+        pass
+
+
+class GeneratorChain:
+    """
+    Chain responsibility patter implementation to generalize
+    the generation method.
+    """
+
+    def __init__(self):
+        self.generators = []
+
+    def add_generator(self, generator: IGenerator) -> None:
+        self.generators.append(generator)
+
+    def generate(self, service: Service) -> None:
+        for _, generator in enumerate(self.generators):
+            generator.generate(service)

contrib/msggen/msggen/gen/grpc.py

@@ -1,5 +1,6 @@
 # A grpc model
-from .model import ArrayField, Field, CompositeField, EnumField, PrimitiveField, Service
+from msggen.model import ArrayField, Field, CompositeField, EnumField, PrimitiveField, Service
+from msggen.gen import IGenerator
 from typing import TextIO, List, Dict, Any
 from textwrap import indent, dedent
 import re
@@ -51,7 +52,7 @@ method_name_overrides = {
 }
 
 
-class GrpcGenerator:
+class GrpcGenerator(IGenerator):
     """A generator that generates protobuf files.
     """
 
@@ -235,7 +236,7 @@ class GrpcGenerator:
             self.generate_message(message)
 
 
-class GrpcConverterGenerator:
+class GrpcConverterGenerator(IGenerator):
     def __init__(self, dest: TextIO):
         self.dest = dest
         self.logger = logging.getLogger("msggen.grpc.GrpcConversionGenerator")

contrib/msggen/msggen/gen/rust.py

@@ -5,8 +5,9 @@ import logging
 import sys
 import re
 
-from .model import (ArrayField, CompositeField, EnumField,
-                    PrimitiveField, Service)
+from msggen.model import (ArrayField, CompositeField, EnumField,
+                          PrimitiveField, Service)
+from msggen.gen.generator import IGenerator
 
 logger = logging.getLogger(__name__)
 
@@ -196,7 +197,7 @@ def gen_composite(c) -> Tuple[str, str]:
     return ("", r)
 
 
-class RustGenerator:
+class RustGenerator(IGenerator):
     def __init__(self, dest: TextIO):
         self.dest = dest
 

contrib/msggen/msggen/utils/__init__.py

@@ -0,0 +1 @@
+from .utils import load_jsonrpc_method, load_jsonrpc_service, repo_root # noqa

contrib/msggen/msggen/utils/utils.py

@@ -0,0 +1,129 @@
+import subprocess
+import json
+from pathlib import Path
+
+from msggen.model import Method, CompositeField, Service
+
+# Sometimes we want to rename a method, due to a name clash
+# FIXME: need to be generalized?
+method_name_override = {
+    "Connect": "ConnectPeer",
+}
+
+
+def repo_root():
+    path = subprocess.check_output(["git", "rev-parse", "--show-toplevel"])
+    return Path(path.strip().decode('UTF-8'))
+
+
+def load_jsonrpc_method(name, schema_dir: str = None):
+    """Load a method based on the file naming conventions for the JSON-RPC.
+    """
+    if schema_dir is None:
+        base_path = (repo_root() / "doc" / "schemas").resolve()
+    else:
+        base_path = schema_dir
+    req_file = base_path / f"{name.lower()}.request.json"
+    resp_file = base_path / f"{name.lower()}.schema.json"
+    request = CompositeField.from_js(json.load(open(req_file)), path=name)
+    response = CompositeField.from_js(json.load(open(resp_file)), path=name)
+
+    # Normalize the method request and response typename so they no
+    # longer conflict.
+    request.typename += "Request"
+    response.typename += "Response"
+
+    return Method(
+        name=method_name_override.get(name, name),
+        request=request,
+        response=response,
+    )
+
+
+def load_jsonrpc_service(schema_dir: str = None):
+    method_names = [
+        "Getinfo",
+        "ListPeers",
+        "ListFunds",
+        "SendPay",
+        "ListChannels",
+        "AddGossip",
+        "AutoCleanInvoice",
+        "CheckMessage",
+        "Close",
+        "Connect",
+        "CreateInvoice",
+        "Datastore",
+        "CreateOnion",
+        "DelDatastore",
+        "DelExpiredInvoice",
+        "DelInvoice",
+        "Invoice",
+        "ListDatastore",
+        "ListInvoices",
+        "SendOnion",
+        "ListSendPays",
+        "ListTransactions",
+        "Pay",
+        "ListNodes",
+        "WaitAnyInvoice",
+        "WaitInvoice",
+        "WaitSendPay",
+        "NewAddr",
+        "Withdraw",
+        "KeySend",
+        "FundPsbt",
+        "SendPsbt",
+        "SignPsbt",
+        "UtxoPsbt",
+        "TxDiscard",
+        "TxPrepare",
+        "TxSend",
+        # "decodepay",
+        # "decode",
+        # "delpay",
+        # "disableoffer",
+        "Disconnect",
+        "Feerates",
+        # "fetchinvoice",
+        # "fundchannel_cancel",
+        # "fundchannel_complete",
+        # "fundchannel",
+        # "fundchannel_start",
+        # "funderupdate",
+        # "getlog",
+        "GetRoute",
+        # "getsharedsecret",
+        "ListForwards",
+        # "listoffers",
+        "ListPays",
+        # "multifundchannel",
+        # "multiwithdraw",
+        # "offerout",
+        # "offer",
+        # "openchannel_abort",
+        # "openchannel_bump",
+        # "openchannel_init",
+        # "openchannel_signed",
+        # "openchannel_update",
+        # "parsefeerate",
+        "Ping",
+        # "plugin",
+        # "reserveinputs",
+        # "sendcustommsg",
+        # "sendinvoice",
+        # "sendonionmessage",
+        # "setchannelfee",
+        "SignMessage",
+        # "unreserveinputs",
+        # "waitblockheight",
+        # "ListConfigs",
+        # "check",  # No point in mapping this one
+        # "Stop",  # Breaks a core assumption (root is an object) can't map unless we change this
+        # "notifications",  # No point in mapping this
+        # "help",
+    ]
+    methods = [load_jsonrpc_method(name, schema_dir=schema_dir) for name in method_names]
+    service = Service(name="Node", methods=methods)
+    service.includes = ['primitives.proto']  # Make sure we have the primitives included.
+    return service