2019-10-23 21:28:31 -07:00

407 lines
15 KiB
Python
Executable File

#!/usr/bin/env python
import itertools
import json
import os.path
import re
import sys
import textwrap
from typing import Any, List, Tuple
try:
import jinja2
except ImportError:
print(
"Unable to import `jinja2`. Did you install the compiler feature with `pip install betterproto[compiler]`?"
)
raise SystemExit(1)
import stringcase
from google.protobuf.compiler import plugin_pb2 as plugin
from google.protobuf.descriptor_pb2 import (
DescriptorProto,
EnumDescriptorProto,
FieldDescriptorProto,
FileDescriptorProto,
ServiceDescriptorProto,
)
from betterproto.casing import safe_snake_case
def get_ref_type(package: str, imports: set, type_name: str) -> str:
"""
Return a Python type name for a proto type reference. Adds the import if
necessary.
"""
type_name = type_name.lstrip(".")
if type_name.startswith(package):
# This is the current package, which has nested types flattened.
# foo.bar_thing => FooBarThing
parts = type_name.lstrip(package).lstrip(".").split(".")
cased = [stringcase.pascalcase(part) for part in parts]
type_name = f'"{"".join(cased)}"'
if "." in type_name:
# This is imported from another package. No need
# to use a forward ref and we need to add the import.
parts = type_name.split(".")
parts[-1] = stringcase.pascalcase(parts[-1])
imports.add(f"from .{'.'.join(parts[:-2])} import {parts[-2]}")
type_name = f"{parts[-2]}.{parts[-1]}"
return type_name
def py_type(
package: str,
imports: set,
message: DescriptorProto,
descriptor: FieldDescriptorProto,
) -> str:
if descriptor.type in [1, 2, 6, 7, 15, 16]:
return "float"
elif descriptor.type in [3, 4, 5, 13, 17, 18]:
return "int"
elif descriptor.type == 8:
return "bool"
elif descriptor.type == 9:
return "str"
elif descriptor.type in [11, 14]:
# Type referencing another defined Message or a named enum
return get_ref_type(package, imports, descriptor.type_name)
elif descriptor.type == 12:
return "bytes"
else:
raise NotImplementedError(f"Unknown type {descriptor.type}")
def get_py_zero(type_num: int) -> str:
zero = 0
if type_num in []:
zero = 0.0
elif type_num == 8:
zero = "False"
elif type_num == 9:
zero = '""'
elif type_num == 11:
zero = "None"
elif type_num == 12:
zero = 'b""'
return zero
def traverse(proto_file):
def _traverse(path, items):
for i, item in enumerate(items):
yield item, path + [i]
if isinstance(item, DescriptorProto):
for enum in item.enum_type:
enum.name = item.name + enum.name
yield enum, path + [i, 4]
if item.nested_type:
for n, p in _traverse(path + [i, 3], item.nested_type):
# Adjust the name since we flatten the heirarchy.
n.name = item.name + n.name
yield n, p
return itertools.chain(
_traverse([5], proto_file.enum_type), _traverse([4], proto_file.message_type)
)
def get_comment(proto_file, path: List[int]) -> str:
for sci in proto_file.source_code_info.location:
# print(list(sci.path), path, file=sys.stderr)
if list(sci.path) == path and sci.leading_comments:
lines = textwrap.wrap(
sci.leading_comments.strip().replace("\n", ""), width=75
)
if path[-2] == 2 and path[-4] != 6:
# This is a field
return " # " + " # ".join(lines)
else:
# This is a message, enum, service, or method
if len(lines) == 1 and len(lines[0]) < 70:
lines[0] = lines[0].strip('"')
return f' """{lines[0]}"""'
else:
joined = "\n ".join(lines)
return f' """\n {joined}\n """'
return ""
def generate_code(request, response):
env = jinja2.Environment(
trim_blocks=True,
lstrip_blocks=True,
loader=jinja2.FileSystemLoader("%s/templates/" % os.path.dirname(__file__)),
)
template = env.get_template("template.py")
output_map = {}
for proto_file in request.proto_file:
out = proto_file.package
if not out:
out = os.path.splitext(proto_file.name)[0].replace(os.path.sep, ".")
if out not in output_map:
output_map[out] = {"package": proto_file.package, "files": []}
output_map[out]["files"].append(proto_file)
# TODO: Figure out how to handle gRPC request/response messages and add
# processing below for Service.
for filename, options in output_map.items():
package = options["package"]
# print(package, filename, file=sys.stderr)
output = {
"package": package,
"files": [f.name for f in options["files"]],
"imports": set(),
"typing_imports": set(),
"messages": [],
"enums": [],
"services": [],
}
type_mapping = {}
for proto_file in options["files"]:
# print(proto_file.message_type, file=sys.stderr)
# print(proto_file.service, file=sys.stderr)
# print(proto_file.source_code_info, file=sys.stderr)
for item, path in traverse(proto_file):
# print(item, file=sys.stderr)
# print(path, file=sys.stderr)
data = {"name": item.name, "py_name": stringcase.pascalcase(item.name)}
if isinstance(item, DescriptorProto):
# print(item, file=sys.stderr)
if item.options.map_entry:
# Skip generated map entry messages since we just use dicts
continue
data.update(
{
"type": "Message",
"comment": get_comment(proto_file, path),
"properties": [],
}
)
for i, f in enumerate(item.field):
t = py_type(package, output["imports"], item, f)
zero = get_py_zero(f.type)
repeated = False
packed = False
field_type = f.Type.Name(f.type).lower()[5:]
map_types = None
if f.type == 11:
# This might be a map...
message_type = f.type_name.split(".").pop().lower()
# message_type = py_type(package)
map_entry = f"{f.name.replace('_', '').lower()}entry"
if message_type == map_entry:
for nested in item.nested_type:
if (
nested.name.replace("_", "").lower()
== map_entry
):
if nested.options.map_entry:
# print("Found a map!", file=sys.stderr)
k = py_type(
package,
output["imports"],
item,
nested.field[0],
)
v = py_type(
package,
output["imports"],
item,
nested.field[1],
)
t = f"Dict[{k}, {v}]"
field_type = "map"
map_types = (
f.Type.Name(nested.field[0].type),
f.Type.Name(nested.field[1].type),
)
output["typing_imports"].add("Dict")
if f.label == 3 and field_type != "map":
# Repeated field
repeated = True
t = f"List[{t}]"
zero = "[]"
output["typing_imports"].add("List")
if f.type in [1, 2, 3, 4, 5, 6, 7, 8, 13, 15, 16, 17, 18]:
packed = True
one_of = ""
if f.HasField("oneof_index"):
one_of = item.oneof_decl[f.oneof_index].name
data["properties"].append(
{
"name": f.name,
"py_name": safe_snake_case(f.name),
"number": f.number,
"comment": get_comment(proto_file, path + [2, i]),
"proto_type": int(f.type),
"field_type": field_type,
"map_types": map_types,
"type": t,
"zero": zero,
"repeated": repeated,
"packed": packed,
"one_of": one_of,
}
)
# print(f, file=sys.stderr)
output["messages"].append(data)
elif isinstance(item, EnumDescriptorProto):
# print(item.name, path, file=sys.stderr)
data.update(
{
"type": "Enum",
"comment": get_comment(proto_file, path),
"entries": [
{
"name": v.name,
"value": v.number,
"comment": get_comment(proto_file, path + [2, i]),
}
for i, v in enumerate(item.value)
],
}
)
output["enums"].append(data)
for i, service in enumerate(proto_file.service):
# print(service, file=sys.stderr)
data = {
"name": service.name,
"py_name": stringcase.pascalcase(service.name),
"comment": get_comment(proto_file, [6, i]),
"methods": [],
}
for j, method in enumerate(service.method):
if method.client_streaming:
raise NotImplementedError("Client streaming not yet supported")
input_message = None
input_type = get_ref_type(
package, output["imports"], method.input_type
).strip('"')
for msg in output["messages"]:
if msg["name"] == input_type:
input_message = msg
for field in msg["properties"]:
if field["zero"] == "None":
output["typing_imports"].add("Optional")
break
data["methods"].append(
{
"name": method.name,
"py_name": stringcase.snakecase(method.name),
"comment": get_comment(proto_file, [6, i, 2, j]),
"route": f"/{package}.{service.name}/{method.name}",
"input": get_ref_type(
package, output["imports"], method.input_type
).strip('"'),
"input_message": input_message,
"output": get_ref_type(
package, output["imports"], method.output_type
).strip('"'),
"client_streaming": method.client_streaming,
"server_streaming": method.server_streaming,
}
)
if method.server_streaming:
output["typing_imports"].add("AsyncGenerator")
output["services"].append(data)
output["imports"] = sorted(output["imports"])
output["typing_imports"] = sorted(output["typing_imports"])
# Fill response
f = response.file.add()
# print(filename, file=sys.stderr)
f.name = filename.replace(".", os.path.sep) + ".py"
# f.content = json.dumps(output, indent=2)
f.content = template.render(description=output).rstrip("\n") + "\n"
inits = set([""])
for f in response.file:
# Ensure output paths exist
# print(f.name, file=sys.stderr)
dirnames = os.path.dirname(f.name)
if dirnames:
os.makedirs(dirnames, exist_ok=True)
base = ""
for part in dirnames.split(os.path.sep):
base = os.path.join(base, part)
inits.add(base)
for base in inits:
name = os.path.join(base, "__init__.py")
if os.path.exists(name):
# Never overwrite inits as they may have custom stuff in them.
continue
init = response.file.add()
init.name = name
init.content = b""
filenames = sorted([f.name for f in response.file])
for fname in filenames:
print(f"Writing {fname}", file=sys.stderr)
def main():
"""The plugin's main entry point."""
# Read request message from stdin
data = sys.stdin.buffer.read()
# Parse request
request = plugin.CodeGeneratorRequest()
request.ParseFromString(data)
# Create response
response = plugin.CodeGeneratorResponse()
# Generate code
generate_code(request, response)
# Serialise response message
output = response.SerializeToString()
# Write to stdout
sys.stdout.buffer.write(output)
if __name__ == "__main__":
main()