Re-Write of the Writer to make it simpler

This commit is contained in:
Caleb Gardner
2021-01-08 05:09:38 -06:00
parent 35d22b4bd0
commit 3f71404a2a
+136 -149
View File
@@ -2,180 +2,167 @@ package squashfs
import (
"errors"
"io"
"log"
"os"
"path"
"strings"
"github.com/CalebQ42/squashfs/internal/inode"
)
//Writer is an interface to write a squashfs. Doesn't write until you call Write (TODO: maybe not do Write...).
//If AllowErrors is true, when errors are encountered, it just prints to the log instead of failing.
type fileHolder struct {
reader io.Reader
path string
name string
symLocation string
folder bool
symlink bool
}
//Writer is used to creaste squashfs archives. Currently unusable
//TODO: Make usable
type Writer struct {
files map[string][]*File
structure map[string][]*fileHolder
symlinkTable map[string]string //[oldpath]newpath
symTableTemp map[string]string
directories []string
compression int
ResolveSymlinks bool
AllowErrors bool
compressionType int
allowErrors bool //AllowErrors allows errors when adding folders and their children.
}
//NewWriter creates a new squashfs.Writer with the default settings (gzip compression, autoresolving symlinks, and allowErrors)
//NewWriter creates a new
func NewWriter() (*Writer, error) {
return NewWriterWithOptions(true, true, GzipCompression)
return NewWriterWithOptions(GzipCompression, true)
}
//NewWriterWithOptions creates a new squashfs.Writer with the given options.
//ResolveSymlinks tries to make sure symlinks aren't broken. It will either try to make the link's location work
func NewWriterWithOptions(resolveSymlinks, allowErrors bool, compressionType int) (*Writer, error) {
if compressionType < 0 || compressionType > 6 {
return nil, errors.New("Incorrect compression type")
}
if compressionType == 3 {
return nil, errors.New("Lzo compression is not currently supported")
}
out := Writer{
files: map[string][]*File{
"/": make([]*File, 0),
},
ResolveSymlinks: resolveSymlinks,
AllowErrors: allowErrors,
compression: compressionType,
}
if resolveSymlinks {
out.symlinkTable = make(map[string]string)
}
return &out, nil
func NewWriterWithOptions(compressionType int, allowErrors bool) (*Writer, error) {
}
type fileError struct {
err error
files []*File
//AddFile attempts to add an os.File to the archive at it's root.
func (w *Writer) AddFile(file *os.File) error {
return w.AddFileToFolder("/", file)
}
//convertFile converts the given os.File to a squashfs.File. Returns the errors and converted file to the channels.
func (w *Writer) convertFile(squashfsPath string, file *os.File, subDir bool, fileErrChan chan fileError) {
var out fileError
var fil File
fil.Reader = file
fil.path = squashfsPath
fil.name = path.Base(file.Name())
mode := fil.Mode()
//AddFileToFolder adds the given file to the squashfs archive, placing it inside the given folder.
func (w *Writer) AddFileToFolder(folder string, file *os.File) error {
name := path.Base(file.Name())
if !strings.HasSuffix(folder, "/") {
folder += "/"
}
return w.AddFileTo(folder+name, file)
}
if mode.IsRegular() {
fil.filType = inode.BasicFileType
goto successExit
} else if mode.IsDir() {
fil.filType = inode.BasicSymlinkType
subDirs, err := file.Readdirnames(-1)
//AddFileTo adds the given file to the squashfs archive at the given filepath.
func (w *Writer) AddFileTo(filepath string, file *os.File) error {
filepath = path.Clean(filepath)
if !strings.HasPrefix(filepath, "/") {
filepath = "/" + filepath
}
var holder fileHolder
holder.path, holder.name = path.Split(filepath)
holder.reader = file
stat, err := file.Stat()
if err != nil {
if w.AllowErrors && !subDir {
log.Println("Can't get sub-directories for", file.Name())
return err
}
holder.folder = stat.IsDir()
holder.symlink = (stat.Mode()&os.ModeSymlink == os.ModeSymlink)
if holder.symlink {
target, err := os.Readlink(file.Name())
if err != nil {
return err
}
holder.symLocation = target
} else if holder.folder {
subDirNames, err := file.Readdirnames(-1)
if err != nil {
return err
}
dirsAdded := make([]string, 0)
for _, subDir := range subDirNames {
fil, err := os.Open(file.Name() + subDir)
if err != nil {
return err
}
err = w.AddFileToFolder(holder.path+"/"+holder.name, fil)
if err != nil && !w.AllowErrors {
for _, dir := range dirsAdded {
w.Remove(dir)
}
return err
} else if err != nil {
log.Println("Error while adding", fil.Name())
log.Println(err)
}
if !w.AllowErrors {
dirsAdded = append(dirsAdded, holder.path+"/"+holder.name)
}
}
} else if !stat.Mode().IsRegular() {
return errors.New("Unsupported file type " + file.Name())
}
w.structure[holder.path] = append(w.structure[holder.path], &holder)
return nil
}
//AddReaderTo adds the data from the given reader to the archive as a file located at the given filepath.
//Data from the reader is not read until the squashfs archive is writen.
//If the given reader implements io.Closer, it will be closed after it is fully read.
func (w *Writer) AddReaderTo(filepath string, reader io.Reader) error {
filepath = path.Clean(filepath)
if !strings.HasPrefix(filepath, "/") {
filepath = "/" + filepath
}
var holder fileHolder
holder.path, holder.name = path.Split(filepath)
holder.reader = reader
w.structure[holder.path] = append(w.structure[holder.path], &holder)
return nil
}
//Remove tries to remove the file(s) at the given filepath. If wildcards are used, it will remove all files that match.
//Returns true if one or more files are removed.
func (w *Writer) Remove(filepath string) bool {
var matchFound bool
filepath = path.Clean(filepath)
if !strings.HasPrefix(filepath, "/") {
filepath = "/" + filepath
}
dir, name := path.Split(filepath)
for structDir, files := range w.structure {
if match, _ := path.Match(dir, structDir); match {
for i, fil := range files {
if match, _ = path.Match(name, fil.name); match {
matchFound = true
if i != len(files)-1 {
w.structure[structDir] = append(w.structure[structDir][:i], w.structure[structDir][i+1:]...)
} else {
out.err = err
w.structure[structDir] = w.structure[structDir][:i]
}
goto failExit
}
subDirChan := make(chan fileError)
for _, filName := range subDirs {
go func(filename string, returnChan chan fileError) {
subFil, err := os.Open(filename)
}
}
}
return matchFound
}
//FixSymlinks will scan through the squashfs archive and try to find broken symlinks and fix them.
//This done by replacing the symlink with the target file and then pointing other symlinks to that file.
//
//If this is not run before writing, you may end up with broken symlinks.
func (w *Writer) FixSymlinks() error {
return errors.New("DON'T")
}
//WriteToFilename creates the squashfs archive with the given filepath.
func (w *Writer) WriteToFilename(filepath string) error {
newFil, err := os.Create(filepath)
if err != nil {
out.err = err
returnChan <- fileError{
err: err,
return err
}
return
}
w.convertFile(fil.Path(), subFil, true, subDirChan)
}(file.Name()+filName, subDirChan)
}
for range subDirs {
filErr := <-subDirChan
if filErr.err != nil {
if w.AllowErrors && !subDir {
log.Println("Error while adding subdirectory of", file.Name())
log.Println(filErr.err)
} else if subDir {
if out.err == nil {
out.err = filErr.err
}
} else {
out.err = err
goto failExit
}
continue
}
out.files = append(out.files, filErr.files...)
}
goto successExit
} else if mode&os.ModeSymlink == os.ModeSymlink {
fil.filType = inode.BasicSymlinkType
symLocation, err := os.Readlink(file.Name())
if err != nil {
if w.AllowErrors && !subDir {
log.Println("Error while getting symlink's information for", file.Name())
log.Println(err)
} else {
out.err = err
}
goto failExit
}
if w.ResolveSymlinks {
if val, ok := w.symlinkTable[symLocation]; ok {
symLocation = val
} else if val, ok := w.symTableTemp[symLocation]; ok {
symLocation = val
} else {
//TODO: either add the file, or place the file in this location. Maybe defer this until after all the other files are added?
}
}
//TODO: store the symLocation inside the File somehow....
}
if w.AllowErrors && !subDir {
log.Println("Unsupported file type for", file.Name())
} else {
out.err = errors.New("Unsupported file type")
}
failExit: //before this is used, make sure to log or set the error.
fileErrChan <- out
return
successExit:
out.files = []*File{&fil}
fileErrChan <- out
return
_, err = w.WriteTo(newFil)
return err
}
//AddFilesToPath adds the give os.Files to the given path within the squashfs archive.
//If AllowErrors is true, this will ALWAYS return nil
func (w *Writer) AddFilesToPath(squashfsPath string, files ...*os.File) error {
squashfsPath = path.Clean(squashfsPath)
if strings.HasPrefix(squashfsPath, "/") {
squashfsPath = strings.TrimPrefix(squashfsPath, "/")
}
if squashfsPath == "." {
squashfsPath = "/"
}
fileErrChan := make(chan fileError)
for _, fil := range files {
go w.convertFile(squashfsPath, fil, false, fileErrChan)
}
return errors.New("Not yet ready")
}
//AddFiles adds all files given to the root directory
//If AllowErrors is true, this will ALWAYS return nil
func (w *Writer) AddFiles(files ...*os.File) error {
return w.AddFilesToPath("/", files...)
}
//RemoveFileAt removes the file at filepath from the Writer.
//If multiple files match the given filepath (such as if there are wildcards), all matching files are removed.
//If one or more files are removed, returns true.
func (w *Writer) RemoveFileAt(filepath string) bool {
//TODO
return false
//WriteTo attempts to write the archive to the given io.Writer.
func (w *Writer) WriteTo(write io.Writer) (int64, error) {
return 0, errors.New("I SAID DON'T")
}