dubbo.apache.org/dubbo-go/v3@v3.1.1/xds/utils/balancerload/load.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 2019 gRPC authors.
    21   *
    22   */
    23  // Package balancerload defines APIs to parse server loads in trailers. The
    24  // parsed loads are sent to balancers in DoneInfo.
    25  package balancerload
    26  
    27  import (
    28  	"google.golang.org/grpc/metadata"
    29  )
    30  
    31  // Parser converts loads from metadata into a concrete type.
    32  type Parser interface {
    33  	// Parse parses loads from metadata.
    34  	Parse(md metadata.MD) interface{}
    35  }
    36  
    37  var parser Parser
    38  
    39  // SetParser sets the load parser.
    40  //
    41  // Not mutex-protected, should be called before any gRPC functions.
    42  func SetParser(lr Parser) {
    43  	parser = lr
    44  }
    45  
    46  // Parse calls parser.Read().
    47  func Parse(md metadata.MD) interface{} {
    48  	if parser == nil {
    49  		return nil
    50  	}
    51  	return parser.Parse(md)
    52  }