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

     1  /*
     2   *
     3   * Copyright 2021 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 ringhash
    20  
    21  import "context"
    22  
    23  type clusterKey struct{}
    24  
    25  func getRequestHash(ctx context.Context) uint64 {
    26  	requestHash, _ := ctx.Value(clusterKey{}).(uint64)
    27  	return requestHash
    28  }
    29  
    30  // GetRequestHashForTesting returns the request hash in the context; to be used
    31  // for testing only.
    32  func GetRequestHashForTesting(ctx context.Context) uint64 {
    33  	return getRequestHash(ctx)
    34  }
    35  
    36  // SetRequestHash adds the request hash to the context for use in Ring Hash Load
    37  // Balancing.
    38  func SetRequestHash(ctx context.Context, requestHash uint64) context.Context {
    39  	return context.WithValue(ctx, clusterKey{}, requestHash)
    40  }