Server Implementation

def server(thread_pool, handlers=None, interceptors=None, options=None, maximum_concurrent_rpcs=None, compression=None, xds=False) -> Server:
    """
    Creates a Server with which RPCs can be serviced.

    Parameters:
    - thread_pool: A futures.ThreadPoolExecutor for executing RPC handlers
    - handlers: Optional list of GenericRpcHandlers for initial service registration
    - interceptors: Optional list of ServerInterceptors for middleware
    - options: Optional list of key-value pairs for server configuration
    - maximum_concurrent_rpcs: Maximum concurrent RPCs before returning RESOURCE_EXHAUSTED
    - compression: Default compression algorithm for the server lifetime
    - xds: If True, retrieves server configuration via xDS (EXPERIMENTAL)

    Returns:
    Server: A Server object ready for service registration and startup
    """

from concurrent import futures

# Basic server with thread pool
server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))

# Server with interceptors
class LoggingInterceptor(grpc.ServerInterceptor):
    def intercept_service(self, continuation, handler_call_details):
        print(f"Handling {handler_call_details.method}")
        return continuation(handler_call_details)

server = grpc.server(
    futures.ThreadPoolExecutor(max_workers=10),
    interceptors=[LoggingInterceptor()]
)

# Server with advanced options
options = [
    ('grpc.keepalive_time_ms', 30000),
    ('grpc.max_concurrent_streams', 100),
]
server = grpc.server(
    futures.ThreadPoolExecutor(max_workers=20),
    options=options,
    maximum_concurrent_rpcs=1000,
    compression=grpc.compression.Gzip
)

class Server(abc.ABC):
    """Services RPCs with comprehensive lifecycle management."""
    
    def add_generic_rpc_handlers(self, generic_rpc_handlers):
        """
        Registers GenericRpcHandlers with this Server.
        Must be called before server is started.

        Parameters:
        - generic_rpc_handlers: Iterable of GenericRpcHandlers
        """
    
    def add_registered_method_handlers(self, service_name: str, method_handlers):
        """
        Registers method handlers for a specific service.
        Registered handlers take precedence over generic handlers.

        Parameters:
        - service_name: The service name
        - method_handlers: Dictionary mapping method names to RpcMethodHandlers
        """
    
    def add_insecure_port(self, address: str) -> int:
        """
        Opens an insecure port for accepting RPCs.
        Must be called before starting the server.

        Parameters:
        - address: Address to bind (e.g., '[::]:50051', 'localhost:0')

        Returns:
        int: The actual port number where server will accept requests
        """
    
    def add_secure_port(self, address: str, server_credentials: ServerCredentials) -> int:
        """
        Opens a secure port for accepting RPCs.
        Must be called before starting the server.

        Parameters:
        - address: Address to bind
        - server_credentials: ServerCredentials object for SSL/TLS

        Returns:
        int: The actual port number where server will accept requests
        """
    
    def start(self):
        """
        Starts this Server.
        May only be called once (not idempotent).
        """
    
    def stop(self, grace) -> threading.Event:
        """
        Stops this Server with optional grace period.

        Parameters:
        - grace: Duration in seconds to wait for active RPCs, or None for immediate stop

        Returns:
        threading.Event: Event that will be set when server completely stops
        """
    
    def wait_for_termination(self, timeout=None) -> bool:
        """
        Block current thread until the server stops.

        Parameters:
        - timeout: Optional timeout in seconds

        Returns:
        bool: True if server stopped normally, False if timeout occurred
        """

from concurrent import futures
import time

# Complete server lifecycle
def run_server():
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
    
    # Register services
    add_MyServiceServicer_to_server(MyServiceServicer(), server)
    
    # Add ports
    insecure_port = server.add_insecure_port('[::]:0')
    print(f"Server will listen on insecure port: {insecure_port}")
    
    # Start server
    server.start()
    print("Server started")
    
    try:
        # Keep server running
        server.wait_for_termination()
    except KeyboardInterrupt:
        print("Shutting down server...")
        server.stop(grace=5.0).wait()
        print("Server stopped")

# Secure server setup
def run_secure_server():
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
    
    # Load SSL credentials
    with open('server.key', 'rb') as f:
        private_key = f.read()
    with open('server.crt', 'rb') as f:
        certificate_chain = f.read()
    
    credentials = grpc.ssl_server_credentials([(private_key, certificate_chain)])
    
    # Add secure port
    secure_port = server.add_secure_port('[::]:50051', credentials)
    print(f"Secure server listening on port: {secure_port}")
    
    server.start()
    server.wait_for_termination()

class ServicerContext(RpcContext):
    """Context object passed to method implementations."""
    
    def invocation_metadata(self):
        """
        Accesses the metadata sent by the client.

        Returns:
        Metadata: The invocation metadata key-value pairs
        """
    
    def peer(self) -> str:
        """
        Identifies the peer that invoked the RPC.

        Returns:
        str: String identifying the peer (format determined by gRPC runtime)
        """
    
    def peer_identities(self):
        """
        Gets one or more peer identity(s).

        Returns:
        Iterable of bytes or None: Peer identities if authenticated, None otherwise
        """
    
    def peer_identity_key(self):
        """
        The auth property used to identify the peer.

        Returns:
        str or None: Auth property name or None if not authenticated
        """
    
    def auth_context(self):
        """
        Gets the auth context for the call.

        Returns:
        dict: Map of auth properties to iterables of bytes
        """
    
    def send_initial_metadata(self, initial_metadata):
        """
        Sends the initial metadata value to the client.

        Parameters:
        - initial_metadata: The initial metadata key-value pairs
        """
    
    def set_trailing_metadata(self, trailing_metadata):
        """
        Sets the trailing metadata for the RPC.

        Parameters:
        - trailing_metadata: The trailing metadata key-value pairs
        """
    
    def abort(self, code: StatusCode, details: str):
        """
        Raises an exception to terminate the RPC with a non-OK status.

        Parameters:
        - code: A StatusCode object (must not be StatusCode.OK)
        - details: A UTF-8-encodable string for the client

        Raises:
        Exception: Always raised to signal RPC abortion
        """
    
    def abort_with_status(self, status):
        """
        Raises an exception to terminate the RPC with a status object.

        Parameters:
        - status: A grpc.Status object (EXPERIMENTAL)

        Raises:
        Exception: Always raised to signal RPC abortion
        """
    
    def set_code(self, code: StatusCode):
        """
        Sets the value to be used as status code upon RPC completion.

        Parameters:
        - code: A StatusCode object to be sent to the client
        """
    
    def set_details(self, details: str):
        """
        Sets the value to be used as detail string upon RPC completion.

        Parameters:
        - details: A UTF-8-encodable string to be sent to the client
        """
    
    def set_compression(self, compression):
        """
        Set the compression algorithm to be used for the entire call.

        Parameters:
        - compression: An element of grpc.compression (e.g., grpc.compression.Gzip)
        """
    
    def disable_next_message_compression(self):
        """
        Disables compression for the next response message.
        Overrides any compression configuration.
        """

class MyServiceServicer(my_service_pb2_grpc.MyServiceServicer):
    def UnaryMethod(self, request, context):
        # Access client metadata
        metadata = dict(context.invocation_metadata())
        user_agent = metadata.get('user-agent', 'unknown')
        
        # Check authentication
        if not self.is_authenticated(context):
            context.abort(grpc.StatusCode.UNAUTHENTICATED, 'Authentication required')
        
        # Send initial metadata
        context.send_initial_metadata([('server-version', '1.0')])
        
        # Process request
        try:
            result = self.process_request(request)
            
            # Set trailing metadata
            context.set_trailing_metadata([('processed-count', str(len(result)))])
            
            return my_service_pb2.MyResponse(data=result)
        except ValueError as e:
            context.set_code(grpc.StatusCode.INVALID_ARGUMENT)
            context.set_details(f'Invalid request: {str(e)}')
            raise
        except Exception as e:
            context.abort(grpc.StatusCode.INTERNAL, 'Internal server error')
    
    def StreamingMethod(self, request_iterator, context):
        try:
            for request in request_iterator:
                # Check if client cancelled
                if not context.is_active():
                    break
                
                # Process and yield response
                response = self.process_item(request)
                yield my_service_pb2.MyResponse(data=response)
                
        except Exception as e:
            context.abort(grpc.StatusCode.INTERNAL, f'Processing error: {str(e)}')

def unary_unary_rpc_method_handler(behavior, request_deserializer=None, response_serializer=None) -> RpcMethodHandler:
    """
    Creates an RpcMethodHandler for a unary-unary RPC method.

    Parameters:
    - behavior: Implementation accepting one request and returning one response
    - request_deserializer: Optional deserializer for request deserialization
    - response_serializer: Optional serializer for response serialization

    Returns:
    RpcMethodHandler: Handler object for use with grpc.Server
    """

def unary_stream_rpc_method_handler(behavior, request_deserializer=None, response_serializer=None) -> RpcMethodHandler:
    """Creates an RpcMethodHandler for a unary-stream RPC method."""

def stream_unary_rpc_method_handler(behavior, request_deserializer=None, response_serializer=None) -> RpcMethodHandler:
    """Creates an RpcMethodHandler for a stream-unary RPC method."""

def stream_stream_rpc_method_handler(behavior, request_deserializer=None, response_serializer=None) -> RpcMethodHandler:
    """Creates an RpcMethodHandler for a stream-stream RPC method."""

def method_handlers_generic_handler(service: str, method_handlers) -> GenericRpcHandler:
    """
    Creates a GenericRpcHandler from RpcMethodHandlers.

    Parameters:
    - service: The name of the service implemented by the method handlers
    - method_handlers: Dictionary mapping method names to RpcMethodHandlers

    Returns:
    GenericRpcHandler: Handler for adding to grpc.Server
    """

def my_unary_unary(request, context):
    return my_service_pb2.MyResponse(message=f"Echo: {request.message}")

def my_unary_stream(request, context):
    for i in range(request.count):
        yield my_service_pb2.MyResponse(message=f"Item {i}")

# Create method handlers
handlers = {
    'UnaryMethod': grpc.unary_unary_rpc_method_handler(
        my_unary_unary,
        request_deserializer=my_service_pb2.MyRequest.FromString,
        response_serializer=my_service_pb2.MyResponse.SerializeToString,
    ),
    'StreamMethod': grpc.unary_stream_rpc_method_handler(
        my_unary_stream,
        request_deserializer=my_service_pb2.MyRequest.FromString,
        response_serializer=my_service_pb2.MyResponse.SerializeToString,
    ),
}

# Create generic handler
generic_handler = grpc.method_handlers_generic_handler('MyService', handlers)

# Add to server
server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
server.add_generic_rpc_handlers([generic_handler])

class RpcMethodHandler(abc.ABC):
    """
    An implementation of a single RPC method.
    
    Attributes:
    - request_streaming: Whether RPC supports multiple request messages
    - response_streaming: Whether RPC supports multiple response messages
    - request_deserializer: Callable for request deserialization
    - response_serializer: Callable for response serialization
    - unary_unary: Business logic for unary-unary pattern
    - unary_stream: Business logic for unary-stream pattern  
    - stream_unary: Business logic for stream-unary pattern
    - stream_stream: Business logic for stream-stream pattern
    """

class HandlerCallDetails(abc.ABC):
    """
    Describes an RPC that has just arrived for service.
    
    Attributes:
    - method: The method name of the RPC
    - invocation_metadata: The metadata sent by the client
    """

class GenericRpcHandler(abc.ABC):
    """An implementation of arbitrarily many RPC methods."""
    
    def service(self, handler_call_details: HandlerCallDetails):
        """
        Returns the handler for servicing the RPC.

        Parameters:
        - handler_call_details: HandlerCallDetails describing the RPC

        Returns:
        RpcMethodHandler or None: Handler if this implementation services the RPC
        """

class ServiceRpcHandler(GenericRpcHandler):
    """
    An implementation of RPC methods belonging to a service.
    Handles RPCs with structured names: '/Service.Name/Service.Method'
    """
    
    def service_name(self) -> str:
        """Returns this service's name."""