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Implemented the rest of the compression types

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Haven't implemented LZO due to limited libraries
This commit is contained in:
Caleb Gardner
2020-12-09 01:40:30 -06:00
parent 1da97137a5
commit 5c3bf8d528
7 changed files with 144 additions and 3 deletions
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README.md
+3 -1
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@@ -1,4 +1,6 @@
# squashfs [![PkgGoDev](https://pkg.go.dev/badge/github.com/CalebQ42/squashfs)](https://pkg.go.dev/github.com/CalebQ42/squashfs)
# squashfs
[![PkgGoDev](https://pkg.go.dev/badge/github.com/CalebQ42/squashfs)](https://pkg.go.dev/github.com/CalebQ42/squashfs) [![Go Report Card](https://goreportcard.com/badge/github.com/CalebQ42/squashfs)](https://goreportcard.com/report/github.com/CalebQ42/squashfs)
A PURE Go library to read and write squashfs.
go.mod
+2
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@@ -7,7 +7,9 @@ require (
github.com/adrg/xdg v0.2.3 // indirect
github.com/google/go-cmp v0.5.4 // indirect
github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 // indirect
github.com/klauspost/compress v1.11.3
github.com/kr/text v0.2.0 // indirect
github.com/pierrec/lz4/v4 v4.1.1
github.com/smartystreets/assertions v1.2.0 // indirect
github.com/ulikunitz/xz v0.5.8
golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
go.sum
+4
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@@ -18,6 +18,8 @@ github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 h1:l5lAOZEym3oK3
github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
github.com/klauspost/compress v1.11.3 h1:dB4Bn0tN3wdCzQxnS8r06kV74qN/TAfaIS0bVE8h3jc=
github.com/klauspost/compress v1.11.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
@@ -27,6 +29,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
github.com/pierrec/lz4/v4 v4.1.1 h1:cS6aGkNLJr4u+UwaA21yp+gbWN3WJWtKo1axmPDObMA=
github.com/pierrec/lz4/v4 v4.1.1/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
internal/compression/gzip.go
+27 -1
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@@ -3,11 +3,37 @@ package compression
import (
"bytes"
"compress/zlib"
"encoding/binary"
"io"
)
type gzipInit struct {
CompressionLevel int32
WindowSize int16
Strategies int16
}
//Gzip is a decompressor for gzip type compression. Uses zlib for compression and decompression
type Gzip struct{}
type Gzip struct {
CompressionLevel int32
HasCustomWindow bool
HasStrategies bool
}
//NewGzipCompressorWithOptions creates a new gzip compressor/decompressor with options read from the given reader.
func NewGzipCompressorWithOptions(r io.Reader) (*Gzip, error) {
var gzip Gzip
var init gzipInit
err := binary.Read(r, binary.LittleEndian, &init)
if err != nil {
return nil, err
}
gzip.CompressionLevel = init.CompressionLevel
//TODO: proper support for window size and strategies
gzip.HasCustomWindow = init.WindowSize != 15
gzip.HasStrategies = init.Strategies != 0 && init.Strategies != 1
return &gzip, nil
}
//Decompress reads the entirety of the given reader and returns it uncompressed as a byte slice.
func (g *Gzip) Decompress(r io.Reader) ([]byte, error) {
internal/compression/lz4.go
+37
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@@ -0,0 +1,37 @@
package compression
import (
"bytes"
"encoding/binary"
"io"
"github.com/pierrec/lz4/v4"
)
//Lz4 is a Lz4 Compressor/Decompressor
type Lz4 struct {
HC bool
}
//NewLz4CompressorWithOptions creates a new lz4 compressor/decompressor with options read from the given reader.
func NewLz4CompressorWithOptions(r io.Reader) (*Lz4, error) {
var lz4 Lz4
var init struct {
Version int32
Flags int32
}
err := binary.Read(r, binary.LittleEndian, &init)
if err != nil {
return nil, err
}
lz4.HC = init.Flags == 1
return &lz4, nil
}
//Decompress decompresses all data from r and returns the uncompressed bytes
func (l *Lz4) Decompress(r io.Reader) ([]byte, error) {
rdr := lz4.NewReader(r)
var buf bytes.Buffer
_, err := io.Copy(&buf, rdr)
return buf.Bytes(), err
}
internal/compression/zstd.go
+36
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@@ -0,0 +1,36 @@
package compression
import (
"bytes"
"encoding/binary"
"io"
"github.com/klauspost/compress/zstd"
)
//Zstd is a zstd compressor/decompressor
type Zstd struct {
CompressionLevel int32
}
//NewZstdCompressorWithOptions creates a new Zstd with options read from the given reader
func NewZstdCompressorWithOptions(r io.Reader) (*Zstd, error) {
var zstd Zstd
err := binary.Read(r, binary.LittleEndian, &zstd)
if err != nil {
return nil, err
}
return &zstd, nil
}
//Decompress decompresses all data from the reader and returns the uncompressed data
func (z *Zstd) Decompress(r io.Reader) ([]byte, error) {
rdr, err := zstd.NewReader(r)
if err != nil {
return nil, err
}
defer rdr.Close()
var buf bytes.Buffer
_, err = io.Copy(&buf, rdr)
return buf.Bytes(), err
}
reader.go
+35 -1
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@@ -21,6 +21,8 @@ var (
errIncompatibleCompression = errors.New("Compression type unsupported")
//ErrCompressorOptions is returned if compressor options is present. It's not currently supported.
errCompressorOptions = errors.New("Compressor options is not currently supported")
//ErrOptions is returned when compression options that I haven't tested is set. When this is returned, the Reader is also returned.
ErrOptions = errors.New("Possibly incompatible compressor options")
)
//Reader processes and reads a squashfs archive.
@@ -35,6 +37,7 @@ type Reader struct {
//NewSquashfsReader returns a new squashfs.Reader from an io.ReaderAt
func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
hasUnsupportedOptions := false
var rdr Reader
rdr.r = r
err := binary.Read(io.NewSectionReader(rdr.r, 0, int64(binary.Size(rdr.super))), binary.LittleEndian, &rdr.super)
@@ -50,8 +53,17 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
rdr.flags = rdr.super.GetFlags()
if rdr.flags.CompressorOptions {
switch rdr.super.CompressionType {
case gzipCompression:
gzip, err := compression.NewGzipCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
if err != nil {
return nil, err
}
if gzip.HasCustomWindow || gzip.HasStrategies {
hasUnsupportedOptions = true
}
rdr.decompressor = gzip
case xzCompression:
xz, err := compression.NewXzCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 1000)) //1000 is technically too much, but it's just an easy way to do it.
xz, err := compression.NewXzCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
if err != nil {
return nil, err
}
@@ -59,6 +71,21 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
return nil, errors.New("XZ compression options has filters. These are not yet supported")
}
rdr.decompressor = xz
case lz4Compression:
lz4, err := compression.NewLz4CompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
if err != nil {
return nil, err
}
if lz4.HC {
hasUnsupportedOptions = true
}
rdr.decompressor = lz4
case zstdCompression:
zstd, err := compression.NewZstdCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 4))
if err != nil {
return nil, err
}
rdr.decompressor = zstd
default:
return nil, errCompressorOptions
}
@@ -70,6 +97,10 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
rdr.decompressor = &compression.Lzma{}
case xzCompression:
rdr.decompressor = &compression.Xz{}
case lz4Compression:
rdr.decompressor = &compression.Lz4{}
case zstdCompression:
rdr.decompressor = &compression.Zstd{}
default:
//TODO: all compression types.
return nil, errIncompatibleCompression
@@ -111,6 +142,9 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
}
unread -= read
}
if hasUnsupportedOptions {
return &rdr, ErrOptions
}
return &rdr, nil
}