82 lines
3.1 KiB
Python
82 lines
3.1 KiB
Python
# requires: grpc, grpc_tools
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"""gRPC 演示：从 user.proto 生成代码 → 启动服务端 → 客户端调用（一元、服务端流、超时、错误码）。
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运行：pip install grpcio grpcio-tools && python demo.py
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生成的代码放在临时目录，不污染仓库。
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"""
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import importlib
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import sys
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import tempfile
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import time
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from concurrent import futures
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from pathlib import Path
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import grpc
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from grpc_tools import protoc
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HERE = Path(__file__).resolve().parent
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def generate(out: Path):
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rc = protoc.main(["protoc", f"-I{HERE}", f"--python_out={out}", f"--grpc_python_out={out}", str(HERE / "user.proto")])
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assert rc == 0, "protoc 生成失败"
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sys.path.insert(0, str(out))
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return importlib.import_module("user_pb2"), importlib.import_module("user_pb2_grpc")
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def main() -> None:
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with tempfile.TemporaryDirectory() as tmp:
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pb, pb_grpc = generate(Path(tmp))
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users = {i: pb.User(id=i, name=f"用户{i}", email=f"u{i}@example.com") for i in range(1, 6)}
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class UserService(pb_grpc.UserServiceServicer):
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def GetUser(self, request, context):
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if request.id == 99:
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time.sleep(0.5) # 模拟慢请求
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user = users.get(request.id)
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if user is None:
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context.abort(grpc.StatusCode.NOT_FOUND, f"用户 {request.id} 不存在")
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return user
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def ListUsers(self, request, context):
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for i, u in enumerate(users.values()):
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if i >= request.page_size:
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break
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yield u
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server = grpc.server(futures.ThreadPoolExecutor(max_workers=4))
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pb_grpc.add_UserServiceServicer_to_server(UserService(), server)
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port = server.add_insecure_port("127.0.0.1:0") # 0 = 随机可用端口
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server.start()
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try:
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with grpc.insecure_channel(f"127.0.0.1:{port}") as ch:
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stub = pb_grpc.UserServiceStub(ch)
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u = stub.GetUser(pb.GetUserRequest(id=1), timeout=1.0) # 每次调用都带超时
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print("一元调用：", u.id, u.name)
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assert u.name == "用户1"
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names = [x.name for x in stub.ListUsers(pb.ListUsersRequest(page_size=3), timeout=1.0)]
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print("服务端流：", names)
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assert len(names) == 3
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try:
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stub.GetUser(pb.GetUserRequest(id=42), timeout=1.0)
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raise AssertionError("应该返回 NOT_FOUND")
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except grpc.RpcError as e:
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print("错误码：", e.code().name, e.details())
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assert e.code() == grpc.StatusCode.NOT_FOUND
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try:
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stub.GetUser(pb.GetUserRequest(id=99), timeout=0.1)
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raise AssertionError("应该超时")
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except grpc.RpcError as e:
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print("超时：", e.code().name)
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assert e.code() == grpc.StatusCode.DEADLINE_EXCEEDED
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finally:
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server.stop(grace=None)
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print("gRPC 演示通过")
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if __name__ == "__main__":
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main()
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