github.com/tickoalcantara12/micro/v3@v3.0.0-20221007104245-9d75b9bcbab9/service/client/grpc/stream.go (about)

     1  // Copyright 2020 Asim Aslam
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     https://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  // Original source: github.com/micro/go-micro/v3/client/grpc/stream.go
    16  
    17  package grpc
    18  
    19  import (
    20  	"context"
    21  	"io"
    22  	"sync"
    23  
    24  	"github.com/tickoalcantara12/micro/v3/service/client"
    25  	"google.golang.org/grpc"
    26  )
    27  
    28  // Implements the streamer interface
    29  type grpcStream struct {
    30  	// embed so we can access if need be
    31  	grpc.ClientStream
    32  
    33  	sync.RWMutex
    34  	closed   bool
    35  	err      error
    36  	conn     *poolConn
    37  	request  client.Request
    38  	response client.Response
    39  	context  context.Context
    40  	close    func(err error)
    41  }
    42  
    43  func (g *grpcStream) Context() context.Context {
    44  	return g.context
    45  }
    46  
    47  func (g *grpcStream) Request() client.Request {
    48  	return g.request
    49  }
    50  
    51  func (g *grpcStream) Response() client.Response {
    52  	return g.response
    53  }
    54  
    55  func (g *grpcStream) Send(msg interface{}) error {
    56  	if err := g.ClientStream.SendMsg(msg); err != nil {
    57  		g.setError(err)
    58  		return err
    59  	}
    60  	return nil
    61  }
    62  
    63  func (g *grpcStream) Recv(msg interface{}) (err error) {
    64  	defer g.setError(err)
    65  
    66  	if err = g.ClientStream.RecvMsg(msg); err != nil {
    67  		// #202 - inconsistent gRPC stream behavior
    68  		// the only way to tell if the stream is done is when we get a EOF on the Recv
    69  		// here we should close the underlying gRPC ClientConn
    70  		closeErr := g.Close()
    71  		if err == io.EOF && closeErr != nil {
    72  			err = closeErr
    73  		}
    74  
    75  		return err
    76  	}
    77  
    78  	return
    79  }
    80  
    81  func (g *grpcStream) Error() error {
    82  	g.RLock()
    83  	defer g.RUnlock()
    84  	return g.err
    85  }
    86  
    87  func (g *grpcStream) setError(e error) {
    88  	g.Lock()
    89  	g.err = e
    90  	g.Unlock()
    91  }
    92  
    93  // Close the gRPC send stream
    94  // #202 - inconsistent gRPC stream behavior
    95  // The underlying gRPC stream should not be closed here since the
    96  // stream should still be able to receive after this function call
    97  // TODO: should the conn be closed in another way?
    98  func (g *grpcStream) Close() error {
    99  	g.Lock()
   100  	defer g.Unlock()
   101  
   102  	if g.closed {
   103  		return nil
   104  	}
   105  
   106  	// close the connection
   107  	g.closed = true
   108  	g.close(g.err)
   109  	return g.ClientStream.CloseSend()
   110  }