#region Copyright notice and license
// Copyright 2018 gRPC authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#endregion
using System;
using System.Reflection;
using System.Threading.Tasks;
using Grpc.Core.Internal;
namespace Grpc.Core.Interceptors
{
///
/// Serves as the base class for gRPC interceptors.
///
public abstract class Interceptor
{
///
/// Represents a continuation for intercepting simple blocking invocations.
/// A delegate of this type is passed to the BlockingUnaryCall method
/// when an outgoing invocation is being intercepted and calling the
/// delegate will invoke the next interceptor in the chain, or the underlying
/// call invoker if called from the last interceptor. The interceptor is
/// allowed to call it zero, one, or multiple times, passing it the appropriate
/// context and request values as it sees fit.
///
/// Request message type for this invocation.
/// Response message type for this invocation.
/// The request value to continue the invocation with.
///
/// The
/// instance to pass to the next step in the invocation process.
///
///
/// The response value of the invocation to return to the caller.
/// The interceptor can choose to return the return value of the
/// continuation delegate or an arbitrary value as it sees fit.
///
public delegate TResponse BlockingUnaryCallContinuation(TRequest request, ClientInterceptorContext context)
where TRequest : class
where TResponse : class;
///
/// Represents a continuation for intercepting simple asynchronous invocations.
/// A delegate of this type is passed to the AsyncUnaryCall method
/// when an outgoing invocation is being intercepted and calling the
/// delegate will invoke the next interceptor in the chain, or the underlying
/// call invoker if called from the last interceptor. The interceptor is
/// allowed to call it zero, one, or multiple times, passing it the appropriate
/// request value and context as it sees fit.
///
/// Request message type for this invocation.
/// Response message type for this invocation.
/// The request value to continue the invocation with.
///
/// The
/// instance to pass to the next step in the invocation process.
///
///
/// An instance of
/// representing an asynchronous invocation of a unary RPC.
/// The interceptor can choose to return the same object returned from
/// the continuation delegate or an arbitrarily constructed instance as it sees fit.
///
public delegate AsyncUnaryCall AsyncUnaryCallContinuation(TRequest request, ClientInterceptorContext context)
where TRequest : class
where TResponse : class;
///
/// Represents a continuation for intercepting asynchronous server-streaming invocations.
/// A delegate of this type is passed to the AsyncServerStreamingCall method
/// when an outgoing invocation is being intercepted and calling the
/// delegate will invoke the next interceptor in the chain, or the underlying
/// call invoker if called from the last interceptor. The interceptor is
/// allowed to call it zero, one, or multiple times, passing it the appropriate
/// request value and context as it sees fit.
///
/// Request message type for this invocation.
/// Response message type for this invocation.
/// The request value to continue the invocation with.
///
/// The
/// instance to pass to the next step in the invocation process.
///
///
/// An instance of
/// representing an asynchronous invocation of a server-streaming RPC.
/// The interceptor can choose to return the same object returned from
/// the continuation delegate or an arbitrarily constructed instance as it sees fit.
///
public delegate AsyncServerStreamingCall AsyncServerStreamingCallContinuation(TRequest request, ClientInterceptorContext context)
where TRequest : class
where TResponse : class;
///
/// Represents a continuation for intercepting asynchronous client-streaming invocations.
/// A delegate of this type is passed to the AsyncClientStreamingCall method
/// when an outgoing invocation is being intercepted and calling the
/// delegate will invoke the next interceptor in the chain, or the underlying
/// call invoker if called from the last interceptor. The interceptor is
/// allowed to call it zero, one, or multiple times, passing it the appropriate
/// request value and context as it sees fit.
///
/// Request message type for this invocation.
/// Response message type for this invocation.
///
/// The
/// instance to pass to the next step in the invocation process.
///
///
/// An instance of
/// representing an asynchronous invocation of a client-streaming RPC.
/// The interceptor can choose to return the same object returned from
/// the continuation delegate or an arbitrarily constructed instance as it sees fit.
///
public delegate AsyncClientStreamingCall AsyncClientStreamingCallContinuation(ClientInterceptorContext context)
where TRequest : class
where TResponse : class;
///
/// Represents a continuation for intercepting asynchronous duplex invocations.
/// A delegate of this type is passed to the AsyncDuplexStreamingCall method
/// when an outgoing invocation is being intercepted and calling the
/// delegate will invoke the next interceptor in the chain, or the underlying
/// call invoker if called from the last interceptor. The interceptor is
/// allowed to call it zero, one, or multiple times, passing it the appropriate
/// request value and context as it sees fit.
///
///
/// The
/// instance to pass to the next step in the invocation process.
///
///
/// An instance of
/// representing an asynchronous invocation of a duplex-streaming RPC.
/// The interceptor can choose to return the same object returned from
/// the continuation delegate or an arbitrarily constructed instance as it sees fit.
///
public delegate AsyncDuplexStreamingCall AsyncDuplexStreamingCallContinuation(ClientInterceptorContext context)
where TRequest : class
where TResponse : class;
///
/// Intercepts a blocking invocation of a simple remote call.
///
/// The request message of the invocation.
///
/// The
/// associated with the current invocation.
///
///
/// The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// request value and context arguments, or substitute them as it sees fit.
///
///
/// The response message of the current invocation.
/// The interceptor can simply return the return value of the
/// continuation delegate passed to it intact, or an arbitrary
/// value as it sees fit.
///
public virtual TResponse BlockingUnaryCall(TRequest request, ClientInterceptorContext context, BlockingUnaryCallContinuation continuation)
where TRequest : class
where TResponse : class
{
return continuation(request, context);
}
///
/// Intercepts an asynchronous invocation of a simple remote call.
///
/// The request message of the invocation.
///
/// The
/// associated with the current invocation.
///
///
/// The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// request value and context arguments, or substitute them as it sees fit.
///
///
/// An instance of
/// representing an asynchronous unary invocation.
/// The interceptor can simply return the return value of the
/// continuation delegate passed to it intact, or construct its
/// own substitute as it sees fit.
///
public virtual AsyncUnaryCall AsyncUnaryCall(TRequest request, ClientInterceptorContext context, AsyncUnaryCallContinuation continuation)
where TRequest : class
where TResponse : class
{
return continuation(request, context);
}
///
/// Intercepts an asynchronous invocation of a streaming remote call.
///
/// The request message of the invocation.
///
/// The
/// associated with the current invocation.
///
///
/// The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// request value and context arguments, or substitute them as it sees fit.
///
///
/// An instance of
/// representing an asynchronous server-streaming invocation.
/// The interceptor can simply return the return value of the
/// continuation delegate passed to it intact, or construct its
/// own substitute as it sees fit.
///
public virtual AsyncServerStreamingCall AsyncServerStreamingCall(TRequest request, ClientInterceptorContext context, AsyncServerStreamingCallContinuation continuation)
where TRequest : class
where TResponse : class
{
return continuation(request, context);
}
///
/// Intercepts an asynchronous invocation of a client streaming call.
///
///
/// The
/// associated with the current invocation.
///
///
/// The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// context argument, or substitute as it sees fit.
///
///
/// An instance of
/// representing an asynchronous client-streaming invocation.
/// The interceptor can simply return the return value of the
/// continuation delegate passed to it intact, or construct its
/// own substitute as it sees fit.
///
public virtual AsyncClientStreamingCall AsyncClientStreamingCall(ClientInterceptorContext context, AsyncClientStreamingCallContinuation continuation)
where TRequest : class
where TResponse : class
{
return continuation(context);
}
///
/// Intercepts an asynchronous invocation of a duplex streaming call.
///
///
/// The
/// associated with the current invocation.
///
///
/// The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// context argument, or substitute as it sees fit.
///
///
/// An instance of
/// representing an asynchronous duplex-streaming invocation.
/// The interceptor can simply return the return value of the
/// continuation delegate passed to it intact, or construct its
/// own substitute as it sees fit.
///
public virtual AsyncDuplexStreamingCall AsyncDuplexStreamingCall(ClientInterceptorContext context, AsyncDuplexStreamingCallContinuation continuation)
where TRequest : class
where TResponse : class
{
return continuation(context);
}
///
/// Server-side handler for intercepting and incoming unary call.
///
/// Request message type for this method.
/// Response message type for this method.
/// The request value of the incoming invocation.
///
/// An instance of representing
/// the context of the invocation.
///
///
/// A delegate that asynchronously proceeds with the invocation, calling
/// the next interceptor in the chain, or the service request handler,
/// in case of the last interceptor and return the response value of
/// the RPC. The interceptor can choose to call it zero or more times
/// at its discretion.
///
///
/// A future representing the response value of the RPC. The interceptor
/// can simply return the return value from the continuation intact,
/// or an arbitrary response value as it sees fit.
///
public virtual Task UnaryServerHandler(TRequest request, ServerCallContext context, UnaryServerMethod continuation)
where TRequest : class
where TResponse : class
{
return continuation(request, context);
}
///
/// Server-side handler for intercepting client streaming call.
///
/// Request message type for this method.
/// Response message type for this method.
/// The request stream of the incoming invocation.
///
/// An instance of representing
/// the context of the invocation.
///
///
/// A delegate that asynchronously proceeds with the invocation, calling
/// the next interceptor in the chain, or the service request handler,
/// in case of the last interceptor and return the response value of
/// the RPC. The interceptor can choose to call it zero or more times
/// at its discretion.
///
///
/// A future representing the response value of the RPC. The interceptor
/// can simply return the return value from the continuation intact,
/// or an arbitrary response value as it sees fit. The interceptor has
/// the ability to wrap or substitute the request stream when calling
/// the continuation.
///
public virtual Task ClientStreamingServerHandler(IAsyncStreamReader requestStream, ServerCallContext context, ClientStreamingServerMethod continuation)
where TRequest : class
where TResponse : class
{
return continuation(requestStream, context);
}
///
/// Server-side handler for intercepting server streaming call.
///
/// Request message type for this method.
/// Response message type for this method.
/// The request value of the incoming invocation.
/// The response stream of the incoming invocation.
///
/// An instance of representing
/// the context of the invocation.
///
///
/// A delegate that asynchronously proceeds with the invocation, calling
/// the next interceptor in the chain, or the service request handler,
/// in case of the last interceptor and the interceptor can choose to
/// call it zero or more times at its discretion. The interceptor has
/// the ability to wrap or substitute the request value and the response stream
/// when calling the continuation.
///
public virtual Task ServerStreamingServerHandler(TRequest request, IServerStreamWriter responseStream, ServerCallContext context, ServerStreamingServerMethod continuation)
where TRequest : class
where TResponse : class
{
return continuation(request, responseStream, context);
}
///
/// Server-side handler for intercepting bidirectional streaming calls.
///
/// Request message type for this method.
/// Response message type for this method.
/// The request stream of the incoming invocation.
/// The response stream of the incoming invocation.
///
/// An instance of representing
/// the context of the invocation.
///
///
/// A delegate that asynchronously proceeds with the invocation, calling
/// the next interceptor in the chain, or the service request handler,
/// in case of the last interceptor and the interceptor can choose to
/// call it zero or more times at its discretion. The interceptor has
/// the ability to wrap or substitute the request and response streams
/// when calling the continuation.
///
public virtual Task DuplexStreamingServerHandler(IAsyncStreamReader requestStream, IServerStreamWriter responseStream, ServerCallContext context, DuplexStreamingServerMethod continuation)
where TRequest : class
where TResponse : class
{
return continuation(requestStream, responseStream, context);
}
}
}