Fixup storage.go

Add file writer and file size functions to posix backend

internal/storage/storage.go

@@ -16,15 +16,17 @@ import (
 
 // Backend defines methods to be implemented by PosixBackend and S3Backend
 type Backend interface {
-	ReadFile(filePath string) io.Reader
-	WriteFile(filePath string, f io.Reader)
-	GetSize(filepath string) int64
+	GetFileSize(filePath string) (int64, error)
+	ReadFile(filePath string) (io.Reader, error)
+	WriteFile(filePath string) (io.Writer, error)
 }
 
 // PosixBackend encapsulates an io.Reader instance
 type PosixBackend struct {
 	FileReader io.Reader
+	FileWriter io.Writer
 	Location   string
+	Size       int64
 }
 
 // PosixConf stores information about the POSIX storage backend
@@ -42,26 +44,36 @@ func NewPosixBackend(c PosixConf) *PosixBackend {
 }
 
 // ReadFile returns an io.Reader instance
-func (pb *PosixBackend) ReadFile(filePath string) io.Reader {
-	f := filepath.Join(filepath.Clean(pb.Location), filePath)
-	file, err := os.Open(f)
+func (pb *PosixBackend) ReadFile(filePath string) (io.Reader, error) {
+	file, err := os.Open(filepath.Join(filepath.Clean(pb.Location), filePath))
 	if err != nil {
 		log.Error(err)
+		return nil, err
 	}
-	pb.FileReader = file
 
-	return pb.FileReader
+	return file, nil
 }
 
-// WriteFile writes an io.Reader to a specific location
-func (pb *PosixBackend) WriteFile(filePath string, f io.Reader) {
-	// TODO
+// WriteFile returns an io.Writer instance
+func (pb *PosixBackend) WriteFile(filePath string) (io.Writer, error) {
+	file, err := os.OpenFile(filepath.Join(filepath.Clean(pb.Location), filePath), os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0640)
+	if err != nil {
+		log.Error(err)
+		return nil, err
+	}
+
+	return file, nil
 }
 
-// GetSize returns the size of a specific file
-func (pb *PosixBackend) GetSize(filePath string) int64 {
-	// TODO
-	return 0
+// GetFileSize returns the size of the file
+func (pb *PosixBackend) GetFileSize(filePath string) (int64, error) {
+	stat, err := os.Stat(filepath.Join(filepath.Clean(pb.Location), filePath))
+	if err != nil {
+		log.Error(err)
+		return 0, err
+	}
+
+	return stat.Size(), nil
 }
 
 // S3Backend encapsulates a S3 client instance
@@ -99,42 +111,46 @@ func NewS3Backend(c S3Conf, trConf http.RoundTripper) *S3Backend {
 }
 
 // ReadFile returns an io.Reader instance
-func (sb *S3Backend) ReadFile(filePath string) io.Reader {
+func (sb *S3Backend) ReadFile(filePath string) (io.Reader, error) {
 	r, err := sb.Client.GetObject(&s3.GetObjectInput{
 		Bucket: aws.String(sb.Bucket),
 		Key:    aws.String(filePath)})
 
 	if err != nil {
 		log.Println(err)
+		return nil, err
 	}
 
-	return r.Body
+	return r.Body, nil
 }
 
 // WriteFile uploads the contents of an io.Reader to a S3 bucket
-func (sb *S3Backend) WriteFile(filePath string, f io.Reader) {
-	result, err := sb.Uploader.Upload(&s3manager.UploadInput{
-		Bucket: aws.String(sb.Bucket),
-		Key:    aws.String(filePath),
-		Body:   f,
-	})
-
-	if err != nil {
-		log.Println("failed to upload file", err)
-	} else {
-		log.Println("File uploaded to", result.Location)
-	}
+func (sb *S3Backend) WriteFile(filePath string) (io.Writer, error) {
+	// result, err := sb.Uploader.Upload(&s3manager.UploadInput{
+	// 	Bucket: aws.String(sb.Bucket),
+	// 	Key:    aws.String(filePath),
+	// 	Body:   bytes.NewReader(buffer),
+	// })
+
+	// if err != nil {
+	// 	log.Println("failed to upload file", err)
+	// } else {
+	// 	log.Println("File uploaded to", result.Location)
+	// }
+
+	return nil, nil
 }
 
-// GetSize returns the size of a specific object
-func (sb *S3Backend) GetSize(filePath string) int64 {
+// GetFileSize returns the size of a specific object
+func (sb *S3Backend) GetFileSize(filePath string) (int64, error) {
 	r, err := sb.Client.HeadObject(&s3.HeadObjectInput{
 		Bucket: aws.String(sb.Bucket),
 		Key:    aws.String(filePath)})
 
 	if err != nil {
 		log.Println(err)
+		return 0, err
 	}
 
-	return *r.ContentLength
+	return *r.ContentLength, nil
 }