Documentation!

Though may functions/structs will be made private, I still want things documented.

compression.go

@@ -6,12 +6,15 @@ import (
 	"io"
 )
 
+//Decompressor is a squashfs decompressor interface. Allows for easy decompression no matter the type of compression.
 type Decompressor interface {
 	Decompress(io.Reader) ([]byte, error)
 }
 
+//ZlibDecompressor is a decompressor for gzip type compression
 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) {
 	rdr, err := zlib.NewReader(r)
 	if err != nil {

datareader.go

@@ -106,6 +106,8 @@ func (d *DataReader) readCurBlock() error {
 		d.curData = make([]byte, d.r.super.BlockSize)
 		d.blocks[d.curBlock].uncompressedSize = d.r.super.BlockSize
 		d.blocks[d.curBlock].begOffset = d.offset
+		fmt.Println("dat red")
+		fmt.Println(len(d.curData))
 		return nil
 	}
 	sec := io.NewSectionReader(d.r.r, d.offset, int64(d.blocks[d.curBlock].size))
@@ -118,6 +120,8 @@ func (d *DataReader) readCurBlock() error {
 		d.curData = btys
 		d.blocks[d.curBlock].begOffset = d.offset
 		d.offset += int64(d.blocks[d.curBlock].size)
+		fmt.Println("dat red")
+		fmt.Println(len(d.curData))
 		return nil
 	}
 	var buf bytes.Buffer

metadatareader.go

@@ -13,6 +13,7 @@ type metadata struct {
 	compressed bool
 }
 
+//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 {
 	s          *Reader
 	offset     int64
@@ -21,6 +22,7 @@ type MetadataReader struct {
 	readOffset int
 }
 
+//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
 	br.s = s
@@ -36,6 +38,7 @@ func (s *Reader) NewMetadataReader(offset int64) (*MetadataReader, error) {
 	return &br, nil
 }
 
+//NewMetadataReaderFromInodeRef creates a new MetadataReader with the offsets set by the given inode reference.
 func (s *Reader) NewMetadataReaderFromInodeRef(ref uint64) (*MetadataReader, error) {
 	offset, metaOffset := processInodeRef(ref)
 	br, err := s.NewMetadataReader(int64(s.super.InodeTableStart + offset))
@@ -88,6 +91,7 @@ func (br *MetadataReader) readNextDataBlock() error {
 	return nil
 }
 
+//Read reads bytes into the given byte slice. Returns the amount of data read.
 func (br *MetadataReader) Read(p []byte) (int, error) {
 	if br.readOffset+len(p) < len(br.data) {
 		for i := 0; i < len(p); i++ {
@@ -123,7 +127,7 @@ func (br *MetadataReader) Read(p []byte) (int, error) {
 	return read, nil
 }
 
-//Seek will seek to the specified location (if possible).
+//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) {

reader.go

@@ -129,6 +129,7 @@ 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 {

superblock.go

@@ -9,6 +9,7 @@ const (
 	zstdCompression
 )
 
+//Superblock contains important information about a squashfs file. Located at the very front of the archive.
 type Superblock struct {
 	Magic            uint32
 	InodeCount       uint32
@@ -31,6 +32,7 @@ type Superblock struct {
 	ExportTableStart uint64
 }
 
+//SuperblockFlags is the parsed version of Superblock.Flags
 type SuperblockFlags struct {
 	UncompressedInodes    bool
 	UncompressedData      bool
@@ -46,6 +48,7 @@ type SuperblockFlags struct {
 	UncompressedIDs       bool
 }
 
+//GetFlags returns a SuperblockFlags for a given superblock.
 func (s *Superblock) GetFlags() SuperblockFlags {
 	return SuperblockFlags{
 		UncompressedInodes:    s.Flags&0x1 == 0x1,