Trying to figure out the best way to convert files

writer.go

@@ -5,7 +5,6 @@ import (
 	"log"
 	"os"
 	"path"
-	"sort"
 	"strings"
 
 	"github.com/CalebQ42/squashfs/internal/inode"
@@ -17,10 +16,10 @@ type Writer struct {
 	files           map[string][]*File
 	directories     []string
 	symlinkTable    map[string]string //symlinkTable holds info about symlink'd to files that had to be moved from their original position. [originalpath]newpath
+	symTableTemp    map[string]string
 	ResolveSymlinks bool
 	AllowErrors     bool
 	compression     int
-	temp            []*File
 }
 
 //NewWriter creates a new squashfs.Writer with the default settings (gzip compression, autoresolving symlinks, and allowErrors)
@@ -51,87 +50,102 @@ func NewWriterWithOptions(resolveSymlinks, allowErrors bool, compressionType int
 	return &out, nil
 }
 
-//convertFile converts the given os.File to a squashfs.File and then adds it to the Writer's temp File slice.
-func (w *Writer) convertFile(squashfsPath string, file *os.File, errChan chan error) {
+type fileError struct {
+	files []*File
+	err   error
+}
+
+//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.name = path.Base(file.Name())
 	fil.path = squashfsPath
-	stat, err := file.Stat()
-	if err != nil {
-		if w.AllowErrors {
-			log.Println("Error while getting FileInfo for", file.Name()+":")
-			log.Println(err)
-			err = nil
-		}
-		errChan <- err
-		return
-	}
-	if stat.IsDir() {
-		fil.filType = inode.BasicDirectoryType
-		dirs, err := file.Readdirnames(-1)
+	fil.name = path.Base(file.Name())
+	mode := fil.Mode()
+
+	if mode.IsRegular() {
+		fil.filType = inode.BasicFileType
+		goto successExit
+	} else if mode.IsDir() {
+		fil.filType = inode.BasicSymlinkType
+		subDirs, err := file.Readdirnames(-1)
 		if err != nil {
-			if w.AllowErrors {
-				log.Println("Error when getting directory names for", file.Name()+":")
+			if w.AllowErrors && !subDir {
+				log.Println("Can't get sub-directories for", file.Name())
 				log.Println(err)
-				err = nil
+			} else {
+				out.err = err
 			}
-			errChan <- err
-			return
+			goto failExit
 		}
-		subDirErrChan := make(chan error)
-		for _, dir := range dirs {
-			go func(newFilename string, errChan chan error) {
-				subFil, err := os.Open(file.Name() + newFilename)
+		subDirChan := make(chan fileError)
+		for _, filName := range subDirs {
+			go func(filename string, returnChan chan fileError) {
+				subFil, err := os.Open(filename)
 				if err != nil {
-					if w.AllowErrors {
-						log.Println("Error when opening sub-directory", subFil.Name()+":")
-						log.Println(err)
-						err = nil
+					out.err = err
+					returnChan <- fileError{
+						err: err,
 					}
-					errChan <- err
 					return
 				}
-				subDirErrChan := make(chan error)
-				w.convertFile(fil.Path(), subFil, subDirErrChan)
-				errChan <- <-subDirErrChan
-				return
-			}(dir, subDirErrChan)
+				w.convertFile(fil.Path(), subFil, true, subDirChan)
+			}(file.Name()+filName, subDirChan)
 		}
-		for range dirs {
-			err = <-subDirErrChan
-			if err != nil {
-				errChan <- err
-				return
+		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...)
 		}
-		w.temp = append(w.temp, &fil)
-		errChan <- nil
-		return
-	} else if stat.Mode().IsRegular() {
-		fil.filType = inode.BasicFileType
-		w.temp = append(w.temp, &fil)
-		errChan <- nil
-		return
-	} else if stat.Mode()&os.ModeSymlink == os.ModeSymlink {
-		linkLocation, err := os.Readlink(file.Name())
+		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 {
-				log.Println("Error when reading symlink's target", file.Name()+":")
+			if w.AllowErrors && !subDir {
+				log.Println("Error while getting symlink's information for", file.Name())
 				log.Println(err)
-				err = nil
+			} else {
+				out.err = err
 			}
-			errChan <- err
-			return
+			goto failExit
 		}
 		if w.ResolveSymlinks {
-			if w.symlinkTable[linkLocation] != "" {
-				linkLocation = w.symlinkTable[linkLocation]
+			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: finish symlink support
+		//TODO: store the symLocation inside the File somehow....
 	}
-	errChan <- errors.New("Unsupported file type")
+	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
 }
 
@@ -145,33 +159,10 @@ func (w *Writer) AddFilesToPath(squashfsPath string, files ...*os.File) error {
 	if squashfsPath == "." {
 		squashfsPath = "/"
 	}
-	errChan := make(chan error)
+	fileErrChan := make(chan fileError)
 	for _, fil := range files {
-		go w.convertFile(squashfsPath, fil, errChan)
+		go w.convertFile(squashfsPath, fil, false, fileErrChan)
 	}
-	var firstError error
-	for range files {
-		err := <-errChan
-		if firstError != nil && err != nil {
-			firstError = err
-		}
-	}
-	if firstError != nil {
-		w.temp = nil
-		return firstError
-	}
-	for _, tempFil := range w.temp {
-		if tempFil.path != "/" {
-			ind := sort.SearchStrings(w.directories, tempFil.path)
-			if ind == len(w.directories) {
-				w.directories = append(w.directories, tempFil.path)
-				sort.Strings(w.directories)
-			}
-		}
-		w.files[tempFil.path] = append(w.files[tempFil.path], tempFil)
-	}
-	w.temp = nil
-	return nil
 }
 
 //AddFiles adds all files given to the root directory