Move changes from exp2 to main

This is largely a move to simplify a lot of the readers
Also further breaks out functions.

reader_inode.go

@@ -0,0 +1,134 @@
+package squashfs
+
+import (
+	"errors"
+	"io"
+
+	"github.com/CalebQ42/squashfs/internal/data"
+	"github.com/CalebQ42/squashfs/internal/directory"
+	"github.com/CalebQ42/squashfs/internal/inode"
+	"github.com/CalebQ42/squashfs/internal/metadata"
+	"github.com/CalebQ42/squashfs/internal/toreader"
+)
+
+func (r Reader) inodeFromRef(ref uint64) (i inode.Inode, err error) {
+	offset, meta := (ref>>16)+r.s.InodeTableStart, ref&0xFFFF
+	rdr, err := metadata.NewReader(toreader.NewReader(r.r, int64(offset)), r.d)
+	if err != nil {
+		return
+	}
+	_, err = rdr.Read(make([]byte, meta))
+	if err != nil {
+		return
+	}
+	return inode.Read(rdr, r.s.BlockSize)
+}
+
+func (r Reader) inodeFromDir(e directory.Entry) (i inode.Inode, err error) {
+	rdr, err := metadata.NewReader(toreader.NewReader(r.r, int64(uint64(e.BlockStart)+r.s.InodeTableStart)), r.d)
+	if err != nil {
+		return
+	}
+	_, err = rdr.Read(make([]byte, e.Offset))
+	if err != nil {
+		return
+	}
+	return inode.Read(rdr, r.s.BlockSize)
+}
+
+func (r Reader) getData(i inode.Inode) (io.Reader, error) {
+	var fragOffset uint64
+	var blockOffset uint32
+	var blockSizes []uint32
+	var fragInd uint32
+	if i.Type == inode.Fil {
+		fragOffset = uint64(i.Data.(inode.File).Offset)
+		blockOffset = i.Data.(inode.File).BlockStart
+		blockSizes = i.Data.(inode.File).BlockSizes
+		fragInd = i.Data.(inode.File).FragInd
+	} else if i.Type == inode.EFil {
+		fragOffset = uint64(i.Data.(inode.EFile).Offset)
+		blockOffset = i.Data.(inode.EFile).BlockStart
+		blockSizes = i.Data.(inode.EFile).BlockSizes
+		fragInd = i.Data.(inode.EFile).FragInd
+	} else {
+		return nil, errors.New("getData called on non-file type")
+	}
+	rdr, err := data.NewReader(toreader.NewReader(r.r, int64(blockOffset)), r.d, blockSizes, r.s.BlockSize)
+	if err != nil {
+		return nil, err
+	}
+	if fragInd != 0xFFFFFFFF {
+		var fragRdr io.Reader
+		fragRdr, err = r.fragReader(fragInd)
+		if err != nil {
+			return nil, err
+		}
+		_, err = fragRdr.Read(make([]byte, fragOffset))
+		if err != nil {
+			return nil, err
+		}
+		rdr.AddFragment(fragRdr)
+	}
+	return rdr, nil
+}
+
+func (r Reader) getFullReader(i inode.Inode) (rdr *data.FullReader, err error) {
+	var fragOffset uint64
+	var blockOffset uint32
+	var blockSizes []uint32
+	var fragInd uint32
+	if i.Type == inode.Fil {
+		fragOffset = uint64(i.Data.(inode.File).Offset)
+		blockOffset = i.Data.(inode.File).BlockStart
+		blockSizes = i.Data.(inode.File).BlockSizes
+		fragInd = i.Data.(inode.File).FragInd
+	} else if i.Type == inode.EFil {
+		fragOffset = uint64(i.Data.(inode.EFile).Offset)
+		blockOffset = i.Data.(inode.EFile).BlockStart
+		blockSizes = i.Data.(inode.EFile).BlockSizes
+		fragInd = i.Data.(inode.EFile).FragInd
+	} else {
+		return nil, errors.New("getData called on non-file type")
+	}
+	rdr = data.NewFullReader(r.r, uint64(blockOffset), r.d, blockSizes, r.s.BlockSize)
+	if fragInd != 0xFFFFFFFF {
+		var fragRdr io.Reader
+		fragRdr, err = r.fragReader(fragInd)
+		if err != nil {
+			return nil, err
+		}
+		_, err = fragRdr.Read(make([]byte, fragOffset))
+		if err != nil {
+			return nil, err
+		}
+		rdr.AddFragment(fragRdr)
+	}
+	return rdr, nil
+}
+
+func (r Reader) readDirectory(i inode.Inode) ([]directory.Entry, error) {
+	var offset uint64
+	var blockOffset uint16
+	var size uint32
+	if i.Type == inode.Dir {
+		offset = uint64(i.Data.(inode.Directory).BlockStart)
+		blockOffset = i.Data.(inode.Directory).Offset
+		size = uint32(i.Data.(inode.Directory).Size)
+	} else if i.Type == inode.EDir {
+		offset = uint64(i.Data.(inode.EDirectory).BlockStart)
+		blockOffset = i.Data.(inode.EDirectory).Offset
+		size = i.Data.(inode.EDirectory).Size
+	} else {
+		return nil, errors.New("readDirectory called on non-directory type")
+	}
+	rdr, err := metadata.NewReader(toreader.NewReader(r.r, int64(offset+r.s.DirTableStart)), r.d)
+	if err != nil {
+		return nil, err
+	}
+	_, err = rdr.Read(make([]byte, blockOffset))
+	if err != nil {
+		return nil, err
+	}
+	return directory.ReadEntries(rdr, size)
+}