gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/devutil/context.go (about)

     1  // Copyright 2023 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package devutil
    16  
    17  import "context"
    18  
    19  // contextID is this package's type for context.Context.Value keys.
    20  type contextID int
    21  
    22  const (
    23  	// CtxDevGoferClient is a Context.Value key for a /dev gofer client.
    24  	CtxDevGoferClient contextID = iota
    25  
    26  	// CtxDevGoferClientProvider is a Context.Value key for GoferClientProvider.
    27  	CtxDevGoferClientProvider
    28  )
    29  
    30  // GoferClientFromContext returns the device gofer client used by ctx.
    31  func GoferClientFromContext(ctx context.Context) *GoferClient {
    32  	if v := ctx.Value(CtxDevGoferClient); v != nil {
    33  		return v.(*GoferClient)
    34  	}
    35  	return nil
    36  }
    37  
    38  // GoferClientProviderFromContext returns the GoferClientProvider used by ctx.
    39  func GoferClientProviderFromContext(ctx context.Context) GoferClientProvider {
    40  	if v := ctx.Value(CtxDevGoferClientProvider); v != nil {
    41  		return v.(GoferClientProvider)
    42  	}
    43  	return nil
    44  }