github.com/hxx258456/ccgo@v0.0.5-0.20230213014102-48b35f46f66f/grpc/balancer/grpclb/state/state.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 state declares grpclb types to be set by resolvers wishing to pass
    20  // information to grpclb via resolver.State Attributes.
    21  package state
    22  
    23  import (
    24  	"github.com/hxx258456/ccgo/grpc/resolver"
    25  )
    26  
    27  // keyType is the key to use for storing State in Attributes.
    28  type keyType string
    29  
    30  const key = keyType("grpc.grpclb.state")
    31  
    32  // State contains gRPCLB-relevant data passed from the name resolver.
    33  type State struct {
    34  	// BalancerAddresses contains the remote load balancer address(es).  If
    35  	// set, overrides any resolver-provided addresses with Type of GRPCLB.
    36  	BalancerAddresses []resolver.Address
    37  }
    38  
    39  // Set returns a copy of the provided state with attributes containing s.  s's
    40  // data should not be mutated after calling Set.
    41  func Set(state resolver.State, s *State) resolver.State {
    42  	state.Attributes = state.Attributes.WithValue(key, s)
    43  	return state
    44  }
    45  
    46  // Get returns the grpclb State in the resolver.State, or nil if not present.
    47  // The returned data should not be mutated.
    48  func Get(state resolver.State) *State {
    49  	s, _ := state.Attributes.Value(key).(*State)
    50  	return s
    51  }