62 lines
1.3 KiB
Go
62 lines
1.3 KiB
Go
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package archiver
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import (
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"compress/gzip"
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"fmt"
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"io"
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"path/filepath"
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)
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// Gz facilitates gzip compression.
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type Gz struct {
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CompressionLevel int
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}
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// Compress reads in, compresses it, and writes it to out.
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func (gz *Gz) Compress(in io.Reader, out io.Writer) error {
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w, err := gzip.NewWriterLevel(out, gz.CompressionLevel)
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if err != nil {
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return err
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}
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defer w.Close()
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_, err = io.Copy(w, in)
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return err
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}
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// Decompress reads in, decompresses it, and writes it to out.
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func (gz *Gz) Decompress(in io.Reader, out io.Writer) error {
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r, err := gzip.NewReader(in)
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if err != nil {
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return err
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}
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defer r.Close()
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_, err = io.Copy(out, r)
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return err
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}
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// CheckExt ensures the file extension matches the format.
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func (gz *Gz) CheckExt(filename string) error {
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if filepath.Ext(filename) != ".gz" {
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return fmt.Errorf("filename must have a .gz extension")
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}
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return nil
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}
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func (gz *Gz) String() string { return "gz" }
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// NewGz returns a new, default instance ready to be customized and used.
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func NewGz() *Gz {
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return &Gz{
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CompressionLevel: gzip.DefaultCompression,
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}
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}
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// Compile-time checks to ensure type implements desired interfaces.
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var (
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_ = Compressor(new(Gz))
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_ = Decompressor(new(Gz))
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)
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// DefaultGz is a default instance that is conveniently ready to use.
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var DefaultGz = NewGz()
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