github.com/hxx258456/ccgo@v0.0.5-0.20230213014102-48b35f46f66f/grpc/internal/balancer/stub/stub.go (about)

     1  /*
     2   *
     3   * Copyright 2020 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  // Package stub implements a balancer for testing purposes.
    20  package stub
    21  
    22  import "github.com/hxx258456/ccgo/grpc/balancer"
    23  
    24  // BalancerFuncs contains all balancer.Balancer functions with a preceding
    25  // *BalancerData parameter for passing additional instance information.  Any
    26  // nil functions will never be called.
    27  type BalancerFuncs struct {
    28  	// Init is called after ClientConn and BuildOptions are set in
    29  	// BalancerData.  It may be used to initialize BalancerData.Data.
    30  	Init func(*BalancerData)
    31  
    32  	UpdateClientConnState func(*BalancerData, balancer.ClientConnState) error
    33  	ResolverError         func(*BalancerData, error)
    34  	UpdateSubConnState    func(*BalancerData, balancer.SubConn, balancer.SubConnState)
    35  	Close                 func(*BalancerData)
    36  	ExitIdle              func(*BalancerData)
    37  }
    38  
    39  // BalancerData contains data relevant to a stub balancer.
    40  type BalancerData struct {
    41  	// ClientConn is set by the builder.
    42  	ClientConn balancer.ClientConn
    43  	// BuildOptions is set by the builder.
    44  	BuildOptions balancer.BuildOptions
    45  	// Data may be used to store arbitrary user data.
    46  	Data interface{}
    47  }
    48  
    49  type bal struct {
    50  	bf BalancerFuncs
    51  	bd *BalancerData
    52  }
    53  
    54  func (b *bal) UpdateClientConnState(c balancer.ClientConnState) error {
    55  	if b.bf.UpdateClientConnState != nil {
    56  		return b.bf.UpdateClientConnState(b.bd, c)
    57  	}
    58  	return nil
    59  }
    60  
    61  func (b *bal) ResolverError(e error) {
    62  	if b.bf.ResolverError != nil {
    63  		b.bf.ResolverError(b.bd, e)
    64  	}
    65  }
    66  
    67  func (b *bal) UpdateSubConnState(sc balancer.SubConn, scs balancer.SubConnState) {
    68  	if b.bf.UpdateSubConnState != nil {
    69  		b.bf.UpdateSubConnState(b.bd, sc, scs)
    70  	}
    71  }
    72  
    73  func (b *bal) Close() {
    74  	if b.bf.Close != nil {
    75  		b.bf.Close(b.bd)
    76  	}
    77  }
    78  
    79  func (b *bal) ExitIdle() {
    80  	if b.bf.ExitIdle != nil {
    81  		b.bf.ExitIdle(b.bd)
    82  	}
    83  }
    84  
    85  type bb struct {
    86  	name string
    87  	bf   BalancerFuncs
    88  }
    89  
    90  func (bb bb) Build(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer {
    91  	b := &bal{bf: bb.bf, bd: &BalancerData{ClientConn: cc, BuildOptions: opts}}
    92  	if b.bf.Init != nil {
    93  		b.bf.Init(b.bd)
    94  	}
    95  	return b
    96  }
    97  
    98  func (bb bb) Name() string { return bb.name }
    99  
   100  // Register registers a stub balancer builder which will call the provided
   101  // functions.  The name used should be unique.
   102  func Register(name string, bf BalancerFuncs) {
   103  	balancer.Register(bb{name: name, bf: bf})
   104  }