Added data.FullReader and moved to low level library

Added ability to get readers from Base

internal/data/fullreader.go

@@ -1,5 +0,0 @@
-package data
-
-type FullReader struct{
-	
-}

internal/data/reader.go

@@ -1,81 +0,0 @@
-package data
-
-import (
-	"encoding/binary"
-	"io"
-
-	"github.com/CalebQ42/squashfs/internal/decompress"
-)
-
-type Reader struct {
-	r         io.Reader
-	d         decompress.Decompressor
-	frag      *Reader
-	sizes     []uint32
-	dat       []byte
-	curOffset uint16
-	curIndex  uint64
-}
-
-func NewReader(r io.Reader, d decompress.Decompressor, sizes []uint32) *Reader {
-	return &Reader{
-		r:     r,
-		d:     d,
-		sizes: sizes,
-	}
-}
-
-func (r *Reader) AddFrag(fragRdr *Reader) {
-	r.frag = fragRdr
-}
-
-func (r *Reader) advance() error {
-	r.curOffset = 0
-	defer func() { r.curIndex++ }()
-	var err error
-	if r.curIndex == uint64(len(r.sizes))-1 && r.frag != nil {
-		r.dat, err = io.ReadAll(r.frag)
-		return err
-	} else if r.curIndex >= uint64(len(r.sizes))-1 {
-		return io.EOF
-	}
-	realSize := r.sizes[r.curIndex] &^ 0x8000
-	r.dat = make([]byte, realSize)
-	err = binary.Read(r.r, binary.LittleEndian, &r.dat)
-	if err != nil {
-		return err
-	}
-	if r.sizes[r.curIndex] != realSize {
-		return nil
-	}
-	r.dat, err = r.d.Decompress(r.dat)
-	return err
-}
-
-func (r *Reader) Read(b []byte) (int, error) {
-	curRead := 0
-	var toRead int
-	for curRead < len(b) {
-		if r.curOffset >= uint16(len(r.dat)) {
-			if err := r.advance(); err != nil {
-				return curRead, err
-			}
-		}
-		toRead = len(b) - curRead
-		if toRead > len(r.dat)-int(r.curOffset) {
-			toRead = len(r.dat) - int(r.curOffset)
-		}
-		copy(b[curRead:], r.dat[r.curOffset:int(r.curOffset)+toRead])
-		r.curOffset += uint16(toRead)
-		curRead += toRead
-	}
-	return curRead, nil
-}
-
-func (r *Reader) Close() error {
-	if r.frag != nil {
-		return r.frag.Close()
-	}
-	r.dat = nil
-	return nil
-}