dubbo.apache.org/dubbo-go/v3@v3.1.1/xds/balancer/priority/ignore_resolve_now.go (about)

     1  /*
     2   * Licensed to the Apache Software Foundation (ASF) under one or more
     3   * contributor license agreements.  See the NOTICE file distributed with
     4   * this work for additional information regarding copyright ownership.
     5   * The ASF licenses this file to You under the Apache License, Version 2.0
     6   * (the "License"); you may not use this file except in compliance with
     7   * the License.  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   *
    20   * Copyright 2021 gRPC authors.
    21   *
    22   */
    23  
    24  package priority
    25  
    26  import (
    27  	"sync/atomic"
    28  )
    29  
    30  import (
    31  	"google.golang.org/grpc/balancer"
    32  
    33  	"google.golang.org/grpc/resolver"
    34  )
    35  
    36  type ignoreResolveNowBalancerBuilder struct {
    37  	balancer.Builder
    38  	ignoreResolveNow *uint32
    39  }
    40  
    41  // If `ignore` is true, all `ResolveNow()` from the balancer built from this
    42  // builder will be ignored.
    43  //
    44  // `ignore` can be updated later by `updateIgnoreResolveNow`, and the update
    45  // will be propagated to all the old and new balancers built with this.
    46  func newIgnoreResolveNowBalancerBuilder(bb balancer.Builder, ignore bool) *ignoreResolveNowBalancerBuilder {
    47  	ret := &ignoreResolveNowBalancerBuilder{
    48  		Builder:          bb,
    49  		ignoreResolveNow: new(uint32),
    50  	}
    51  	ret.updateIgnoreResolveNow(ignore)
    52  	return ret
    53  }
    54  
    55  func (irnbb *ignoreResolveNowBalancerBuilder) updateIgnoreResolveNow(b bool) {
    56  	if b {
    57  		atomic.StoreUint32(irnbb.ignoreResolveNow, 1)
    58  		return
    59  	}
    60  	atomic.StoreUint32(irnbb.ignoreResolveNow, 0)
    61  
    62  }
    63  
    64  func (irnbb *ignoreResolveNowBalancerBuilder) Build(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer {
    65  	return irnbb.Builder.Build(&ignoreResolveNowClientConn{
    66  		ClientConn:       cc,
    67  		ignoreResolveNow: irnbb.ignoreResolveNow,
    68  	}, opts)
    69  }
    70  
    71  type ignoreResolveNowClientConn struct {
    72  	balancer.ClientConn
    73  	ignoreResolveNow *uint32
    74  }
    75  
    76  func (i ignoreResolveNowClientConn) ResolveNow(o resolver.ResolveNowOptions) {
    77  	if atomic.LoadUint32(i.ignoreResolveNow) != 0 {
    78  		return
    79  	}
    80  	i.ClientConn.ResolveNow(o)
    81  }