github.com/hxx258456/ccgo@v0.0.5-0.20230213014102-48b35f46f66f/grpc/internal/grpcutil/metadata.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 grpcutil
    20  
    21  import (
    22  	"context"
    23  
    24  	"github.com/hxx258456/ccgo/grpc/metadata"
    25  )
    26  
    27  type mdExtraKey struct{}
    28  
    29  // WithExtraMetadata creates a new context with incoming md attached.
    30  func WithExtraMetadata(ctx context.Context, md metadata.MD) context.Context {
    31  	return context.WithValue(ctx, mdExtraKey{}, md)
    32  }
    33  
    34  // ExtraMetadata returns the incoming metadata in ctx if it exists.  The
    35  // returned MD should not be modified. Writing to it may cause races.
    36  // Modification should be made to copies of the returned MD.
    37  func ExtraMetadata(ctx context.Context) (md metadata.MD, ok bool) {
    38  	md, ok = ctx.Value(mdExtraKey{}).(metadata.MD)
    39  	return
    40  }