53 lines
977 B
Go
53 lines
977 B
Go
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package fs
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import (
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"errors"
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"os"
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)
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// A FileDisk is an implementation of a BlockDevice that uses a
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// *os.File as its backing store.
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type FileDisk struct {
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f *os.File
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size int64
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}
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// NewFileDisk creates a new FileDisk from the given *os.File. The
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// file must already be created and set the to the proper size.
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func NewFileDisk(f *os.File) (*FileDisk, error) {
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fi, err := f.Stat()
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if err != nil {
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return nil, err
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}
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if fi.IsDir() {
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return nil, errors.New("file is a directory")
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}
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return &FileDisk{
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f: f,
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size: fi.Size(),
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}, nil
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}
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func (f *FileDisk) Close() error {
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return f.f.Close()
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}
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func (f *FileDisk) Len() int64 {
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return f.size
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}
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func (f *FileDisk) ReadAt(p []byte, off int64) (int, error) {
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return f.f.ReadAt(p, off)
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}
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func (f *FileDisk) SectorSize() int {
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// Hardcoded for now, one day we may want to make this customizable
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return 512
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}
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func (f *FileDisk) WriteAt(p []byte, off int64) (int, error) {
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return f.f.WriteAt(p, off)
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}
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