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Made most functions private.

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This will probably be the first version of the library.
This commit is contained in:
Caleb Gardner
2020-11-25 08:27:15 -06:00
parent 5d888eb761
commit afbc991f60
8 changed files with 53 additions and 87 deletions
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compression.go
+3 -3
View File
@@ -7,15 +7,15 @@ import (
)
//Decompressor is a squashfs decompressor interface. Allows for easy decompression no matter the type of compression.
type Decompressor interface {
type decompressor interface {
Decompress(io.Reader) ([]byte, error)
}
//ZlibDecompressor is a decompressor for gzip type compression
type ZlibDecompressor struct{}
type zlibDecompressor struct{}
//Decompress reads the entirety of the given reader and returns it uncompressed as a byte slice.
func (z *ZlibDecompressor) Decompress(r io.Reader) ([]byte, error) {
func (z *zlibDecompressor) Decompress(r io.Reader) ([]byte, error) {
rdr, err := zlib.NewReader(r)
if err != nil {
return nil, err
datareader.go
+14 -24
View File
@@ -3,7 +3,6 @@ package squashfs
import (
"bytes"
"errors"
"fmt"
"io"
"github.com/CalebQ42/GoSquashfs/internal/inode"
@@ -17,17 +16,17 @@ var (
)
//DataReader reads data from data blocks.
type DataReader struct {
type dataReader struct {
r *Reader
offset int64 //offset relative to the beginning of the squash file
blocks []DataBlock
blocks []dataBlock
curBlock int //Which block in sizes is currently cached
curData []byte
curReadOffset int //offset relative to the currently cached data
}
//DataBlock holds info about a given data block from it's size
type DataBlock struct {
type dataBlock struct {
begOffset int64 //The offset relative to the beginning of the squash file. Makes it easier to seek to it.
size uint32
compressed bool
@@ -35,7 +34,7 @@ type DataBlock struct {
}
//NewDataBlock creates a new squashfs.datablock from a given size.
func NewDataBlock(raw uint32) (dbs DataBlock) {
func newDataBlock(raw uint32) (dbs dataBlock) {
dbs.compressed = raw&(1<<24) != (1 << 24)
dbs.size = raw &^ (1 << 24)
if !dbs.compressed {
@@ -45,12 +44,12 @@ func NewDataBlock(raw uint32) (dbs DataBlock) {
}
//NewDataReader creates a new data reader at the given offset, with the blocks defined by sizes
func (r *Reader) NewDataReader(offset int64, sizes []uint32) (*DataReader, error) {
var dr DataReader
func (r *Reader) newDataReader(offset int64, sizes []uint32) (*dataReader, error) {
var dr dataReader
dr.r = r
dr.offset = offset
for _, size := range sizes {
dr.blocks = append(dr.blocks, NewDataBlock(size))
dr.blocks = append(dr.blocks, newDataBlock(size))
}
err := dr.readCurBlock()
if err != nil {
@@ -60,8 +59,8 @@ func (r *Reader) NewDataReader(offset int64, sizes []uint32) (*DataReader, error
}
//NewDataReaderFromInode creates a new DataReader from a given inode. Inode must be of BasicFile or ExtendedFile types
func (r *Reader) NewDataReaderFromInode(i *inode.Inode) (*DataReader, error) {
var rdr DataReader
func (r *Reader) newDataReaderFromInode(i *inode.Inode) (*dataReader, error) {
var rdr dataReader
rdr.r = r
switch i.Type {
case inode.BasicFileType:
@@ -71,7 +70,7 @@ func (r *Reader) NewDataReaderFromInode(i *inode.Inode) (*DataReader, error) {
}
rdr.offset = int64(fil.Init.BlockStart)
for _, sizes := range fil.BlockSizes {
rdr.blocks = append(rdr.blocks, NewDataBlock(sizes))
rdr.blocks = append(rdr.blocks, newDataBlock(sizes))
}
if fil.Fragmented {
rdr.blocks = rdr.blocks[:len(rdr.blocks)-1]
@@ -83,7 +82,7 @@ func (r *Reader) NewDataReaderFromInode(i *inode.Inode) (*DataReader, error) {
}
rdr.offset = int64(fil.Init.BlockStart)
for _, sizes := range fil.BlockSizes {
rdr.blocks = append(rdr.blocks, NewDataBlock(sizes))
rdr.blocks = append(rdr.blocks, newDataBlock(sizes))
}
if fil.Fragmented {
rdr.blocks = rdr.blocks[:len(rdr.blocks)-1]
@@ -98,7 +97,7 @@ func (r *Reader) NewDataReaderFromInode(i *inode.Inode) (*DataReader, error) {
return &rdr, nil
}
func (d *DataReader) readNextBlock() error {
func (d *dataReader) readNextBlock() error {
d.curBlock++
if d.curBlock >= len(d.blocks) {
d.curBlock--
@@ -108,15 +107,12 @@ func (d *DataReader) readNextBlock() error {
if err != nil {
d.curBlock--
d.readCurBlock()
fmt.Println("running back because of issues")
return err
}
fmt.Println("Read block success!")
return nil
}
func (d *DataReader) readCurBlock() error {
fmt.Println("reading into block", d.curBlock, "out of", len(d.blocks))
func (d *dataReader) readCurBlock() error {
if d.curBlock >= len(d.blocks) {
return io.EOF
}
@@ -127,12 +123,9 @@ func (d *DataReader) readCurBlock() error {
return nil
}
sec := io.NewSectionReader(d.r.r, d.offset, int64(d.blocks[d.curBlock].size))
fmt.Println("block size", d.r.super.BlockSize)
fmt.Println("compressed size", int64(d.blocks[d.curBlock].size))
if d.blocks[d.curBlock].compressed {
btys, err := d.r.decompressor.Decompress(sec)
if err != nil {
fmt.Println("HERE!")
return err
}
d.blocks[d.curBlock].uncompressedSize = uint32(len(btys))
@@ -152,9 +145,8 @@ func (d *DataReader) readCurBlock() error {
return err
}
func (d *DataReader) Read(p []byte) (int, error) {
func (d *dataReader) Read(p []byte) (int, error) {
if d.curReadOffset+len(p) < len(d.curData) {
fmt.Println("Enough data in cache for direct read")
for i := 0; i < len(p); i++ {
p[i] = d.curData[d.curReadOffset+i]
}
@@ -164,7 +156,6 @@ func (d *DataReader) Read(p []byte) (int, error) {
read := 0
for read < len(p) {
if d.curReadOffset == len(d.curData) {
fmt.Println("reading new block...")
err := d.readNextBlock()
if err != nil {
return read, err
@@ -176,7 +167,6 @@ func (d *DataReader) Read(p []byte) (int, error) {
if d.curReadOffset < len(d.curData) {
p[read] = d.curData[d.curReadOffset]
} else {
fmt.Println("breaking out!")
break
}
}
filereader.go
+4 -9
View File
@@ -3,16 +3,15 @@ package squashfs
import (
"bytes"
"errors"
"fmt"
"io"
"github.com/CalebQ42/GoSquashfs/internal/inode"
)
//FileReader provides a io.Reader interface for files within
//FileReader provides a io.Reader interface for files within a squashfs archive
type FileReader struct {
r *Reader
data *DataReader
data *dataReader
fragmentData []byte
fragged bool
fragOnly bool
@@ -49,21 +48,19 @@ func (r *Reader) ReadFile(location string) (*FileReader, error) {
rdr.FileSize = int(fil.Init.Size)
}
if rdr.fragged {
rdr.fragmentData, err = r.GetFragmentDataFromInode(in)
rdr.fragmentData, err = r.getFragmentDataFromInode(in)
if err != nil {
return nil, err
}
}
if !rdr.fragOnly {
rdr.data, err = r.NewDataReaderFromInode(in)
rdr.data, err = r.newDataReaderFromInode(in)
}
return &rdr, nil
}
func (f *FileReader) Read(p []byte) (int, error) {
fmt.Println("reading!", len(p))
if f.fragOnly {
fmt.Println("HII")
n, err := bytes.NewBuffer(f.fragmentData[f.read:]).Read(p)
f.read += n
if err != nil {
@@ -75,7 +72,6 @@ func (f *FileReader) Read(p []byte) (int, error) {
n, err := f.data.Read(p)
read += n
if f.fragged && err == io.EOF {
fmt.Println("Trying to read fragment AFTER main data")
n, err = bytes.NewBuffer(f.fragmentData).Read(p[read:])
read += n
if err != nil {
@@ -84,6 +80,5 @@ func (f *FileReader) Read(p []byte) (int, error) {
} else if err != nil {
return read, err
}
fmt.Println("read", n)
return read, nil
}
fragment.go
+3 -5
View File
@@ -3,7 +3,6 @@ package squashfs
import (
"encoding/binary"
"errors"
"fmt"
"io"
"github.com/CalebQ42/GoSquashfs/internal/inode"
@@ -18,7 +17,7 @@ type FragmentEntry struct {
//GetFragmentDataFromInode returns the fragment data for a given inode.
//If the inode does not have a fragment, harmlessly returns an empty slice without an error.
func (r *Reader) GetFragmentDataFromInode(in *inode.Inode) ([]byte, error) {
func (r *Reader) getFragmentDataFromInode(in *inode.Inode) ([]byte, error) {
var size uint32
var fragIndex uint32
var fragOffset uint32
@@ -50,7 +49,7 @@ func (r *Reader) GetFragmentDataFromInode(in *inode.Inode) ([]byte, error) {
return nil, errors.New("Inode type not supported")
}
//reading the fragment entry first
fragEntryRdr, err := r.NewMetadataReader(int64(r.fragOffsets[int(fragIndex/512)]))
fragEntryRdr, err := r.newMetadataReader(int64(r.fragOffsets[int(fragIndex/512)]))
if err != nil {
return nil, err
}
@@ -64,7 +63,7 @@ func (r *Reader) GetFragmentDataFromInode(in *inode.Inode) ([]byte, error) {
return nil, err
}
//now reading the actual fragment
dr, err := r.NewDataReader(int64(entry.Start), []uint32{entry.Size})
dr, err := r.newDataReader(int64(entry.Start), []uint32{entry.Size})
if err != nil {
return nil, err
}
@@ -77,6 +76,5 @@ func (r *Reader) GetFragmentDataFromInode(in *inode.Inode) ([]byte, error) {
if err != nil {
return nil, err
}
fmt.Println("read fragment with size", len(tmp))
return tmp, nil
}
metadatareader.go
+9 -9
View File
@@ -14,7 +14,7 @@ type metadata struct {
}
//MetadataReader is a block reader for metadata. It will automatically read the next block, when it reaches the end of a block.
type MetadataReader struct {
type metadataReader struct {
s *Reader
offset int64
headers []*metadata
@@ -23,8 +23,8 @@ type MetadataReader struct {
}
//NewMetadataReader creates a new MetadataReader, beginning to read at the given offset. It will automatically cache the first block at the location.
func (s *Reader) NewMetadataReader(offset int64) (*MetadataReader, error) {
var br MetadataReader
func (s *Reader) newMetadataReader(offset int64) (*metadataReader, error) {
var br metadataReader
br.s = s
br.offset = offset
err := br.parseMetadata()
@@ -39,9 +39,9 @@ func (s *Reader) NewMetadataReader(offset int64) (*MetadataReader, error) {
}
//NewMetadataReaderFromInodeRef creates a new MetadataReader with the offsets set by the given inode reference.
func (s *Reader) NewMetadataReaderFromInodeRef(ref uint64) (*MetadataReader, error) {
func (s *Reader) newMetadataReaderFromInodeRef(ref uint64) (*metadataReader, error) {
offset, metaOffset := processInodeRef(ref)
br, err := s.NewMetadataReader(int64(s.super.InodeTableStart + offset))
br, err := s.newMetadataReader(int64(s.super.InodeTableStart + offset))
if err != nil {
return nil, err
}
@@ -52,7 +52,7 @@ func (s *Reader) NewMetadataReaderFromInodeRef(ref uint64) (*MetadataReader, err
return br, nil
}
func (br *MetadataReader) parseMetadata() error {
func (br *metadataReader) parseMetadata() error {
var raw uint16
err := binary.Read(io.NewSectionReader(br.s.r, br.offset, 2), binary.LittleEndian, &raw)
if err != nil {
@@ -69,7 +69,7 @@ func (br *MetadataReader) parseMetadata() error {
return nil
}
func (br *MetadataReader) readNextDataBlock() error {
func (br *metadataReader) readNextDataBlock() error {
meta := br.headers[len(br.headers)-1]
r := io.NewSectionReader(br.s.r, br.offset, int64(meta.size))
if meta.compressed {
@@ -92,7 +92,7 @@ func (br *MetadataReader) readNextDataBlock() error {
}
//Read reads bytes into the given byte slice. Returns the amount of data read.
func (br *MetadataReader) Read(p []byte) (int, error) {
func (br *metadataReader) Read(p []byte) (int, error) {
if br.readOffset+len(p) < len(br.data) {
for i := 0; i < len(p); i++ {
p[i] = br.data[br.readOffset+i]
@@ -130,7 +130,7 @@ func (br *MetadataReader) Read(p []byte) (int, error) {
//Seek will seek to the specified location (if possible). Seeking is relative to the uncompressed data.
//When io.SeekCurrent or io.SeekStart is set, if seeking would put the offset beyond the current cached data, it will try to read the next data blocks to accomodate. On a failure it will seek to the end of the data.
//When io.SeekEnd is set, it wil seek reletive to the currently cached data.
func (br *MetadataReader) Seek(offset int64, whence int) (int64, error) {
func (br *metadataReader) Seek(offset int64, whence int) (int64, error) {
switch whence {
case io.SeekCurrent:
br.readOffset += int(offset)
reader.go
+8 -25
View File
@@ -3,7 +3,6 @@ package squashfs
import (
"encoding/binary"
"errors"
"fmt"
"io"
"math"
@@ -30,9 +29,9 @@ var (
//TODO: Give a way to actually read files :P
type Reader struct {
r io.ReaderAt
super Superblock
flags SuperblockFlags
decompressor Decompressor
super superblock
flags superblockFlags
decompressor decompressor
fragOffsets []uint64
}
@@ -50,7 +49,7 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
rdr.flags = rdr.super.GetFlags()
switch rdr.super.CompressionType {
case gzipCompression:
rdr.decompressor = &ZlibDecompressor{}
rdr.decompressor = &zlibDecompressor{}
default:
return nil, ErrIncompatibleCompression
}
@@ -65,7 +64,6 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
tmp := make([]byte, 8)
_, err = r.ReadAt(tmp, offset)
if err != nil {
fmt.Println("Error while reading fragment block offsets")
return nil, err
}
rdr.fragOffsets = append(rdr.fragOffsets, binary.LittleEndian.Uint64(tmp))
@@ -76,9 +74,9 @@ func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
}
//GetFilesList returns a list of ALL files in the squashfs, going down every folder.
//Paths that terminate in a folder end with /
//Folders end in /
func (r *Reader) GetFilesList() ([]string, error) {
inoderdr, err := r.NewMetadataReaderFromInodeRef(r.super.RootInodeRef)
inoderdr, err := r.newMetadataReaderFromInodeRef(r.super.RootInodeRef)
if err != nil {
return nil, err
}
@@ -95,20 +93,14 @@ func (r *Reader) GetFilesList() ([]string, error) {
//readDir returns a list of all decendents of a given inode. Inode given MUST be a directory type.
func (r *Reader) readDir(i *inode.Inode) (paths []string, err error) {
dir, err := r.ReadDirFromInode(i)
dir, err := r.readDirFromInode(i)
if err != nil {
return
}
for _, entry := range dir.Entries {
if entry.Init.Type == inode.BasicFileType {
in, _ := r.GetInodeFromEntry(&entry)
fil := in.Info.(inode.BasicFile)
fmt.Println("name:", entry.Name)
fmt.Println("frag index:", fil.Init.FragmentIndex, "frag offset:", fil.Init.FragmentOffset)
}
if entry.Init.Type == inode.BasicDirectoryType {
paths = append(paths)
i, err = r.GetInodeFromEntry(&entry)
i, err = r.getInodeFromEntry(&entry)
if err != nil {
return
}
@@ -128,12 +120,3 @@ func (r *Reader) readDir(i *inode.Inode) (paths []string, err error) {
}
return
}
//GetFileStructure returns ALL folders and files contained in the squashfs. Folders end with a "/".
func (r *Reader) GetFileStructure() ([]string, error) {
in, err := r.GetInodeFromPath("")
if err != nil {
return nil, err
}
return r.readDir(in)
}
superblock.go
+4 -4
View File
@@ -10,7 +10,7 @@ const (
)
//Superblock contains important information about a squashfs file. Located at the very front of the archive.
type Superblock struct {
type superblock struct {
Magic uint32
InodeCount uint32
CreationTime uint32
@@ -33,7 +33,7 @@ type Superblock struct {
}
//SuperblockFlags is the parsed version of Superblock.Flags
type SuperblockFlags struct {
type superblockFlags struct {
UncompressedInodes bool
UncompressedData bool
Check bool
@@ -49,8 +49,8 @@ type SuperblockFlags struct {
}
//GetFlags returns a SuperblockFlags for a given superblock.
func (s *Superblock) GetFlags() SuperblockFlags {
return SuperblockFlags{
func (s *superblock) GetFlags() superblockFlags {
return superblockFlags{
UncompressedInodes: s.Flags&0x1 == 0x1,
UncompressedData: s.Flags&0x2 == 0x2,
Check: s.Flags&0x4 == 0x4,
utils.go
+8 -8
View File
@@ -27,7 +27,7 @@ func processInodeRef(inodeRef uint64) (tableOffset uint64, metaOffset uint64) {
//ReadDirFromInode returns a fully populated directory.Directory from a given inode.Inode.
//If the given inode is not a directory it returns an error.
func (r *Reader) ReadDirFromInode(i *inode.Inode) (*directory.Directory, error) {
func (r *Reader) readDirFromInode(i *inode.Inode) (*directory.Directory, error) {
var offset uint32
var metaOffset uint16
var size uint16
@@ -43,7 +43,7 @@ func (r *Reader) ReadDirFromInode(i *inode.Inode) (*directory.Directory, error)
default:
return nil, errors.New("Not a directory inode")
}
br, err := r.NewMetadataReader(int64(r.super.DirTableStart + uint64(offset)))
br, err := r.newMetadataReader(int64(r.super.DirTableStart + uint64(offset)))
if err != nil {
return nil, err
}
@@ -59,8 +59,8 @@ func (r *Reader) ReadDirFromInode(i *inode.Inode) (*directory.Directory, error)
}
//GetInodeFromEntry returns the inode associated with a given directory.Entry
func (r *Reader) GetInodeFromEntry(en *directory.Entry) (*inode.Inode, error) {
br, err := r.NewMetadataReader(int64(r.super.InodeTableStart + uint64(en.Header.InodeOffset)))
func (r *Reader) getInodeFromEntry(en *directory.Entry) (*inode.Inode, error) {
br, err := r.newMetadataReader(int64(r.super.InodeTableStart + uint64(en.Header.InodeOffset)))
if err != nil {
return nil, err
}
@@ -80,7 +80,7 @@ func (r *Reader) GetInodeFromEntry(en *directory.Entry) (*inode.Inode, error) {
func (r *Reader) GetInodeFromPath(path string) (*inode.Inode, error) {
path = strings.TrimSuffix(strings.TrimPrefix(path, "/"), "/")
pathDirs := strings.Split(path, "/")
rdr, err := r.NewMetadataReaderFromInodeRef(r.super.RootInodeRef)
rdr, err := r.newMetadataReaderFromInodeRef(r.super.RootInodeRef)
if err != nil {
return nil, err
}
@@ -95,20 +95,20 @@ func (r *Reader) GetInodeFromPath(path string) (*inode.Inode, error) {
if curInodeDir.Type != inode.BasicDirectoryType && curInodeDir.Type != inode.ExtDirType {
return nil, ErrNotFound
}
dir, err := r.ReadDirFromInode(curInodeDir)
dir, err := r.readDirFromInode(curInodeDir)
if err != nil {
return nil, err
}
for _, entry := range dir.Entries {
if entry.Name == pathDirs[depth] {
if depth == len(pathDirs)-1 {
in, err := r.GetInodeFromEntry(&entry)
in, err := r.getInodeFromEntry(&entry)
if err != nil {
return nil, err
}
return in, nil
}
curInodeDir, err = r.GetInodeFromEntry(&entry)
curInodeDir, err = r.getInodeFromEntry(&entry)
if err != nil {
return nil, err
}