51 lines
1.1 KiB
Go
51 lines
1.1 KiB
Go
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package exif
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import (
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"io"
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"github.com/dsoprea/go-logging"
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"github.com/dsoprea/go-utility/v2/filesystem"
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)
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type ExifBlobSeeker interface {
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GetReadSeeker(initialOffset int64) (rs io.ReadSeeker, err error)
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}
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// ExifReadSeeker knows how to retrieve data from the EXIF blob relative to the
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// beginning of the blob (so, absolute position (0) is the first byte of the
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// EXIF data).
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type ExifReadSeeker struct {
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rs io.ReadSeeker
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}
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func NewExifReadSeeker(rs io.ReadSeeker) *ExifReadSeeker {
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return &ExifReadSeeker{
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rs: rs,
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}
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}
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func NewExifReadSeekerWithBytes(exifData []byte) *ExifReadSeeker {
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sb := rifs.NewSeekableBufferWithBytes(exifData)
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edbs := NewExifReadSeeker(sb)
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return edbs
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}
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// Fork creates a new ReadSeeker instead that wraps a BouncebackReader to
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// maintain its own position in the stream.
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func (edbs *ExifReadSeeker) GetReadSeeker(initialOffset int64) (rs io.ReadSeeker, err error) {
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defer func() {
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if state := recover(); state != nil {
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err = log.Wrap(state.(error))
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}
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}()
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br, err := rifs.NewBouncebackReader(edbs.rs)
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log.PanicIf(err)
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_, err = br.Seek(initialOffset, io.SeekStart)
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log.PanicIf(err)
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return br, nil
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}
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