github.com/pingcap/ticdc@v0.0.0-20220526033649-485a10ef2652/cdc/kv/grpc_pool.go (about)

     1  // Copyright 2021 PingCAP, Inc.
     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  //     http://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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package kv
    15  
    16  import (
    17  	"context"
    18  
    19  	"google.golang.org/grpc"
    20  )
    21  
    22  type sharedConn struct {
    23  	*grpc.ClientConn
    24  	active int64
    25  }
    26  
    27  // GrpcPool defines an interface that can serve as a gPRC connection pool.
    28  // It provides API to get a shared connection from pool and API to decrease usage
    29  // reference of the shared connection
    30  type GrpcPool interface {
    31  	// GetConn returns an available gRPC ClientConn
    32  	GetConn(target string) (*sharedConn, error)
    33  
    34  	// ReleaseConn is called when a gRPC stream is released
    35  	ReleaseConn(sc *sharedConn, target string)
    36  
    37  	// Recycle recycles idle connections periodically
    38  	RecycleConn(ctx context.Context)
    39  
    40  	// Close tears down all ClientConns maintained in pool
    41  	Close()
    42  }