github.com/sagernet/gvisor@v0.0.0-20240428053021-e691de28565f/pkg/usermem/marshal.go (about)

     1  // Copyright 2021 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 usermem
    16  
    17  import (
    18  	"github.com/sagernet/gvisor/pkg/context"
    19  	"github.com/sagernet/gvisor/pkg/hostarch"
    20  )
    21  
    22  // IOCopyContext wraps an object implementing hostarch.IO to implement
    23  // marshal.CopyContext.
    24  type IOCopyContext struct {
    25  	Ctx  context.Context
    26  	IO   IO
    27  	Opts IOOpts
    28  }
    29  
    30  // CopyScratchBuffer implements marshal.CopyContext.CopyScratchBuffer.
    31  func (i *IOCopyContext) CopyScratchBuffer(size int) []byte {
    32  	return make([]byte, size)
    33  }
    34  
    35  // CopyOutBytes implements marshal.CopyContext.CopyOutBytes.
    36  func (i *IOCopyContext) CopyOutBytes(addr hostarch.Addr, b []byte) (int, error) {
    37  	return i.IO.CopyOut(i.Ctx, addr, b, i.Opts)
    38  }
    39  
    40  // CopyInBytes implements marshal.CopyContext.CopyInBytes.
    41  func (i *IOCopyContext) CopyInBytes(addr hostarch.Addr, b []byte) (int, error) {
    42  	return i.IO.CopyIn(i.Ctx, addr, b, i.Opts)
    43  }