60 lines
1.2 KiB
Go
60 lines
1.2 KiB
Go
// Copyright (C) 2019 Storj Labs, Inc.
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// See LICENSE for copying information.
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package filestore
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import (
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"errors"
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"io"
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"os"
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)
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// blobBodyReader implements reader that is offset by blob header size
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type blobBodyReader struct {
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file *os.File
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}
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func newBlobBodyReader(file *os.File) (blobBodyReader, error) {
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_, err := file.Seek(headerSize, io.SeekStart)
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return blobBodyReader{file}, err
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}
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func (r blobBodyReader) Read(p []byte) (n int, err error) {
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return r.file.Read(p)
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}
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func (r blobBodyReader) Close() error {
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return r.file.Close()
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}
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func (r blobBodyReader) ReadAt(p []byte, off int64) (n int, err error) {
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if off < 0 {
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return 0, errors.New("invalid offset")
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}
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return r.file.ReadAt(p, off+headerSize)
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}
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func (r blobBodyReader) Seek(offset int64, whence int) (int64, error) {
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var pos int64
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var err error
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if whence == io.SeekStart {
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pos, err = r.file.Seek(offset+headerSize, io.SeekStart)
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} else {
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pos, err = r.file.Seek(offset, whence)
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}
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pos -= headerSize
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if err != nil {
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return -1, err
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}
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if pos < 0 {
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return -1, errors.New("invalid offset")
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}
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return pos, err
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}
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func (r blobBodyReader) Size() (n int64) {
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stat, _ := r.file.Stat()
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return stat.Size() - headerSize
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}
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