load.go raw

   1  /*
   2   * Copyright 2019 gRPC authors.
   3   *
   4   * Licensed under the Apache License, Version 2.0 (the "License");
   5   * you may not use this file except in compliance with the License.
   6   * You may obtain a copy of the License at
   7   *
   8   *     http://www.apache.org/licenses/LICENSE-2.0
   9   *
  10   * Unless required by applicable law or agreed to in writing, software
  11   * distributed under the License is distributed on an "AS IS" BASIS,
  12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13   * See the License for the specific language governing permissions and
  14   * limitations under the License.
  15   */
  16  
  17  // Package balancerload defines APIs to parse server loads in trailers. The
  18  // parsed loads are sent to balancers in DoneInfo.
  19  package balancerload
  20  
  21  import (
  22  	"google.golang.org/grpc/metadata"
  23  )
  24  
  25  // Parser converts loads from metadata into a concrete type.
  26  type Parser interface {
  27  	// Parse parses loads from metadata.
  28  	Parse(md metadata.MD) any
  29  }
  30  
  31  var parser Parser
  32  
  33  // SetParser sets the load parser.
  34  //
  35  // Not mutex-protected, should be called before any gRPC functions.
  36  func SetParser(lr Parser) {
  37  	parser = lr
  38  }
  39  
  40  // Parse calls parser.Read().
  41  func Parse(md metadata.MD) any {
  42  	if parser == nil {
  43  		return nil
  44  	}
  45  	return parser.Parse(md)
  46  }
  47