66 lines
1.8 KiB
Go
66 lines
1.8 KiB
Go
// Copyright 2019 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package ext
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import (
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"io"
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)
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// inlineFile is a type of regular file. All the data here is stored in the
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// inode.Data() array.
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type inlineFile struct {
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regFile regularFile
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}
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// Compiles only if inlineFile implements fileReader.
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var _ fileReader = (*inlineFile)(nil)
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// getFileReader implements fileReader.getFileReader.
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func (f *inlineFile) getFileReader(_ io.ReadSeeker, _ uint64, offset uint64) io.Reader {
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diskInode := f.regFile.inode.diskInode
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return &inlineReader{offset: offset, data: diskInode.Data()[:diskInode.Size()]}
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}
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// newInlineFile is the inlineFile constructor.
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func newInlineFile(regFile regularFile) *inlineFile {
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file := &inlineFile{regFile: regFile}
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file.regFile.impl = file
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return file
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}
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// inlineReader implements io.Reader which can read the underlying data.
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type inlineReader struct {
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offset uint64
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data []byte
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}
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// Compiles only if inlineReader implements io.Reader.
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var _ io.Reader = (*inlineReader)(nil)
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// Read implements io.Reader.Read.
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func (r *inlineReader) Read(dst []byte) (int, error) {
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if len(dst) == 0 {
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return 0, nil
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}
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if int(r.offset) >= len(r.data) {
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return 0, io.EOF
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}
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n := copy(dst, r.data[r.offset:])
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r.offset += uint64(n)
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return n, nil
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}
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