DockerCLI/vendor/google.golang.org/grpc/tap/tap.go

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/*
*
* Copyright 2016 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.
*
*/
// Package tap defines the function handles which are executed on the transport
// layer of gRPC-Go and related information. Everything here is EXPERIMENTAL.
package tap
import (
"context"
)
// Info defines the relevant information needed by the handles.
type Info struct {
// FullMethodName is the string of grpc method (in the format of
// /package.service/method).
FullMethodName string
// TODO: More to be added.
}
// ServerInHandle defines the function which runs before a new stream is created
// on the server side. If it returns a non-nil error, the stream will not be
// created and a RST_STREAM will be sent back to the client with REFUSED_STREAM.
// The client will receive an RPC error "code = Unavailable, desc = stream
// terminated by RST_STREAM with error code: REFUSED_STREAM".
//
// It's intended to be used in situations where you don't want to waste the
// resources to accept the new stream (e.g. rate-limiting). And the content of
// the error will be ignored and won't be sent back to the client. For other
// general usages, please use interceptors.
//
// Note that it is executed in the per-connection I/O goroutine(s) instead of
// per-RPC goroutine. Therefore, users should NOT have any
// blocking/time-consuming work in this handle. Otherwise all the RPCs would
// slow down. Also, for the same reason, this handle won't be called
// concurrently by gRPC.
type ServerInHandle func(ctx context.Context, info *Info) (context.Context, error)