Caleb Gardner
56 lines
1.1 KiB
Go
56 lines
1.1 KiB
Go
package compression
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import (
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"bytes"
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"encoding/binary"
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"io"
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"github.com/ulikunitz/xz"
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)
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type xzInit struct {
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DictionarySize int32
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Filters int32
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}
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//Xz is a Xz decompressor.
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type Xz struct {
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DictionarySize int32
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HasFilters bool
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}
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//NewXzCompressorWithOptions creates a new Xz compressor/decompressor that reads the compressor options from the given reader.
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func NewXzCompressorWithOptions(rdr io.Reader) (*Xz, error) {
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var x Xz
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var init xzInit
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err := binary.Read(rdr, binary.LittleEndian, &init)
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if err != nil {
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return nil, err
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}
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x.DictionarySize = init.DictionarySize
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//TODO: When I can do filters, parse the filters
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if init.Filters != 0 {
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x.HasFilters = true
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}
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return &x, nil
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}
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//Decompress decompresses all the data from the rdr and returns the uncompressed bytes.
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func (x *Xz) Decompress(rdr io.Reader) ([]byte, error) {
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r, err := xz.NewReader(rdr)
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if err != nil {
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return nil, err
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}
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r.DictCap = int(x.DictionarySize)
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err = r.Verify()
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if err != nil {
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return nil, err
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}
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var buf bytes.Buffer
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_, err = io.Copy(&buf, r)
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if err != nil {
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return nil, err
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}
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return buf.Bytes(), nil
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}
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