refactor: Decompose suffix addition and removal

cmd/stbak/cmd/archive.go

@@ -309,32 +309,9 @@ func archive(
 			hdr.PAXRecords[pax.STFSRecordUncompressedSize] = strconv.Itoa(int(hdr.Size))
 			hdr.Size = int64(fileSizeCounter.BytesRead)
 
-			switch compressionFormat {
+			hdr.Name, err = addSuffix(hdr.Name, compressionFormat, encryptionFormat)
-			case compressionFormatGZipKey:
+			if err != nil {
-				fallthrough
+				return err
-			case compressionFormatParallelGZipKey:
-				hdr.Name += compressionFormatGZipSuffix
-			case compressionFormatLZ4Key:
-				hdr.Name += compressionFormatLZ4Suffix
-			case compressionFormatZStandardKey:
-				hdr.Name += compressionFormatZStandardSuffix
-			case compressionFormatBrotliKey:
-				hdr.Name += compressionFormatBrotliSuffix
-			case compressionFormatBzip2Key:
-				fallthrough
-			case compressionFormatBzip2ParallelKey:
-				hdr.Name += compressionFormatBzip2Suffix
-			case compressionFormatNoneKey:
-			default:
-				return errUnsupportedCompressionFormat
-			}
-
-			switch encryptionFormat {
-			case encryptionFormatAgeKey:
-				hdr.Name += encryptionFormatAgeSuffix
-			case compressionFormatNoneKey:
-			default:
-				return errUnsupportedEncryptionFormat
 			}
 		}
 
@@ -429,6 +406,38 @@ func checkCompressionLevel(compressionLevel string) error {
 	return nil
 }
 
+func addSuffix(name string, compressionFormat string, encryptionFormat string) (string, error) {
+	switch compressionFormat {
+	case compressionFormatGZipKey:
+		fallthrough
+	case compressionFormatParallelGZipKey:
+		name += compressionFormatGZipSuffix
+	case compressionFormatLZ4Key:
+		name += compressionFormatLZ4Suffix
+	case compressionFormatZStandardKey:
+		name += compressionFormatZStandardSuffix
+	case compressionFormatBrotliKey:
+		name += compressionFormatBrotliSuffix
+	case compressionFormatBzip2Key:
+		fallthrough
+	case compressionFormatBzip2ParallelKey:
+		name += compressionFormatBzip2Suffix
+	case compressionFormatNoneKey:
+	default:
+		return "", errUnsupportedCompressionFormat
+	}
+
+	switch encryptionFormat {
+	case encryptionFormatAgeKey:
+		name += encryptionFormatAgeSuffix
+	case compressionFormatNoneKey:
+	default:
+		return "", errUnsupportedEncryptionFormat
+	}
+
+	return name, nil
+}
+
 func encrypt(
 	dst io.Writer,
 	encryptionFormat string,

cmd/stbak/cmd/recovery_index.go

@@ -278,33 +278,11 @@ func indexHeader(
 	}
 
 	if hdr.FileInfo().Mode().IsRegular() {
-		switch encryptionFormat {
+		newName, err := removeSuffix(hdr.Name, compressionFormat, encryptionFormat)
-		case encryptionFormatAgeKey:
+		if err != nil {
-			hdr.Name = strings.TrimSuffix(hdr.Name, encryptionFormatAgeSuffix)
+			return err
-		case encryptionFormatNoneKey:
-		default:
-			return errUnsupportedEncryptionFormat
-		}
-
-		switch compressionFormat {
-		case compressionFormatGZipKey:
-			fallthrough
-		case compressionFormatParallelGZipKey:
-			hdr.Name = strings.TrimSuffix(hdr.Name, compressionFormatGZipSuffix)
-		case compressionFormatLZ4Key:
-			hdr.Name = strings.TrimSuffix(hdr.Name, compressionFormatLZ4Suffix)
-		case compressionFormatZStandardKey:
-			hdr.Name = strings.TrimSuffix(hdr.Name, compressionFormatZStandardSuffix)
-		case compressionFormatBrotliKey:
-			hdr.Name = strings.TrimSuffix(hdr.Name, compressionFormatBrotliSuffix)
-		case compressionFormatBzip2Key:
-			fallthrough
-		case compressionFormatBzip2ParallelKey:
-			hdr.Name = strings.TrimSuffix(hdr.Name, compressionFormatBzip2Suffix)
-		case compressionFormatNoneKey:
-		default:
-			return errUnsupportedCompressionFormat
 		}
+		hdr.Name = newName
 	}
 
 	if err := formatting.PrintCSV(formatting.GetTARHeaderAsCSV(record, block, hdr)); err != nil {
@@ -390,6 +368,38 @@ func indexHeader(
 	return nil
 }
 
+func removeSuffix(name string, compressionFormat string, encryptionFormat string) (string, error) {
+	switch encryptionFormat {
+	case encryptionFormatAgeKey:
+		name = strings.TrimSuffix(name, encryptionFormatAgeSuffix)
+	case encryptionFormatNoneKey:
+	default:
+		return "", errUnsupportedEncryptionFormat
+	}
+
+	switch compressionFormat {
+	case compressionFormatGZipKey:
+		fallthrough
+	case compressionFormatParallelGZipKey:
+		name = strings.TrimSuffix(name, compressionFormatGZipSuffix)
+	case compressionFormatLZ4Key:
+		name = strings.TrimSuffix(name, compressionFormatLZ4Suffix)
+	case compressionFormatZStandardKey:
+		name = strings.TrimSuffix(name, compressionFormatZStandardSuffix)
+	case compressionFormatBrotliKey:
+		name = strings.TrimSuffix(name, compressionFormatBrotliSuffix)
+	case compressionFormatBzip2Key:
+		fallthrough
+	case compressionFormatBzip2ParallelKey:
+		name = strings.TrimSuffix(name, compressionFormatBzip2Suffix)
+	case compressionFormatNoneKey:
+	default:
+		return "", errUnsupportedCompressionFormat
+	}
+
+	return name, nil
+}
+
 func openTapeReadOnly(tape string) (f *os.File, isRegular bool, err error) {
 	fileDescription, err := os.Stat(tape)
 	if err != nil {

cmd/stbak/cmd/update.go

@@ -205,32 +205,9 @@ func update(
 			hdr.PAXRecords[pax.STFSRecordUncompressedSize] = strconv.Itoa(int(hdr.Size))
 			hdr.Size = int64(fileSizeCounter.BytesRead)
 
-			switch compressionFormat {
+			hdr.Name, err = addSuffix(hdr.Name, compressionFormat, encryptionFormat)
-			case compressionFormatGZipKey:
+			if err != nil {
-				fallthrough
+				return err
-			case compressionFormatParallelGZipKey:
-				hdr.Name += compressionFormatGZipSuffix
-			case compressionFormatLZ4Key:
-				hdr.Name += compressionFormatLZ4Suffix
-			case compressionFormatZStandardKey:
-				hdr.Name += compressionFormatZStandardSuffix
-			case compressionFormatBrotliKey:
-				hdr.Name += compressionFormatBrotliSuffix
-			case compressionFormatBzip2Key:
-				fallthrough
-			case compressionFormatBzip2ParallelKey:
-				hdr.Name += compressionFormatBzip2Suffix
-			case compressionFormatNoneKey:
-			default:
-				return errUnsupportedCompressionFormat
-			}
-
-			switch encryptionFormat {
-			case encryptionFormatAgeKey:
-				hdr.Name += encryptionFormatAgeSuffix
-			case compressionFormatNoneKey:
-			default:
-				return errUnsupportedEncryptionFormat
 			}
 		}