157 lines
3.1 KiB
Go
157 lines
3.1 KiB
Go
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/*
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* MinIO Cloud Storage, (C) 2021 MinIO, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package cmd
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import (
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"archive/tar"
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"bufio"
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"bytes"
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"compress/bzip2"
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"fmt"
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"io"
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"os"
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"path"
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"github.com/klauspost/compress/s2"
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"github.com/klauspost/compress/zstd"
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gzip "github.com/klauspost/pgzip"
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"github.com/pierrec/lz4"
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)
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func detect(r *bufio.Reader) format {
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z, err := r.Peek(4)
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if err != nil {
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return formatUnknown
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}
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for _, f := range magicHeaders {
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if bytes.Equal(f.header, z[:len(f.header)]) {
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return f.f
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}
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}
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return formatUnknown
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}
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//go:generate stringer -type=format -trimprefix=format $GOFILE
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type format int
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const (
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formatUnknown format = iota
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formatGzip
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formatZstd
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formatLZ4
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formatS2
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formatBZ2
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)
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var magicHeaders = []struct {
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header []byte
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f format
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}{
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{
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header: []byte{0x1f, 0x8b, 8},
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f: formatGzip,
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},
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{
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// Zstd default header.
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header: []byte{0x28, 0xb5, 0x2f, 0xfd},
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f: formatZstd,
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},
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{
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// Zstd skippable frame header.
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header: []byte{0x2a, 0x4d, 0x18},
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f: formatZstd,
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},
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{
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// LZ4
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header: []byte{0x4, 0x22, 0x4d, 0x18},
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f: formatLZ4,
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},
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{
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// Snappy/S2 stream
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header: []byte{0xff, 0x06, 0x00, 0x00},
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f: formatS2,
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},
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{
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header: []byte{0x42, 0x5a, 'h'},
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f: formatBZ2,
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},
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}
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func untar(r io.Reader, putObject func(reader io.Reader, info os.FileInfo, name string)) error {
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bf := bufio.NewReader(r)
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switch f := detect(bf); f {
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case formatGzip:
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gz, err := gzip.NewReader(bf)
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if err != nil {
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return err
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}
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defer gz.Close()
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r = gz
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case formatS2:
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r = s2.NewReader(bf)
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case formatZstd:
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dec, err := zstd.NewReader(bf)
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if err != nil {
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return err
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}
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defer dec.Close()
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r = dec
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case formatBZ2:
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r = bzip2.NewReader(bf)
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case formatLZ4:
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r = lz4.NewReader(bf)
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case formatUnknown:
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r = bf
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default:
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return fmt.Errorf("Unsupported format %s", f)
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}
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tarReader := tar.NewReader(r)
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for {
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header, err := tarReader.Next()
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switch {
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// if no more files are found return
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case err == io.EOF:
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return nil
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// return any other error
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case err != nil:
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return err
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// if the header is nil, just skip it (not sure how this happens)
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case header == nil:
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continue
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}
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name := header.Name
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if name == slashSeparator {
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continue
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}
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switch header.Typeflag {
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case tar.TypeDir: // = directory
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putObject(tarReader, header.FileInfo(), trimLeadingSlash(pathJoin(name, slashSeparator)))
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case tar.TypeReg, tar.TypeChar, tar.TypeBlock, tar.TypeFifo, tar.TypeGNUSparse: // = regular
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putObject(tarReader, header.FileInfo(), trimLeadingSlash(path.Clean(name)))
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default:
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// ignore symlink'ed
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continue
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}
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}
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}
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