moving filenameStringWithCString to its own method

Author: Coeur

SSZipArchive/SSZipArchive.m

@@ -339,39 +339,7 @@ + (BOOL)unzipFileAtPath:(NSString *)path
 
  BOOL fileIsSymbolicLink = _fileIsSymbolicLink(&fileInfo);
 
- NSString * strPath = @(filename);
- if (!strPath) {
- // if filename is non-unicode, detect and transform Encoding
- NSData *data = [NSData dataWithBytes:(const void *)filename length:sizeof(unsigned char) * fileInfo.size_filename];
-#ifdef __MAC_10_13
- // Xcode 9+
- if (@available(macOS 10.10, iOS 8.0, watchOS 2.0, tvOS 9.0, *)) {
- // supported encodings are in [NSString availableStringEncodings]
- [NSString stringEncodingForData:data encodingOptions:nil convertedString:&strPath usedLossyConversion:nil];
- }
-#else
- // Xcode 8-
- if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber10_9_2) {
- // supported encodings are in [NSString availableStringEncodings]
- [NSString stringEncodingForData:data encodingOptions:nil convertedString:&strPath usedLossyConversion:nil];
- }
-#endif
- else {
- // fallback to a simple manual detect for macOS 10.9 or older
- NSArray<NSNumber *> *encodings = @[@(kCFStringEncodingGB_18030_2000), @(kCFStringEncodingShiftJIS)];
- for (NSNumber *encoding in encodings) {
- strPath = [NSString stringWithCString:filename encoding:(NSStringEncoding)CFStringConvertEncodingToNSStringEncoding(encoding.unsignedIntValue)];
- if (strPath) {
- break;
- }
- }
- }
- if (!strPath) {
- // if filename encoding is non-detected, we default to something based on data
- // _hexString is more readable than _base64RFC4648 for debugging unknown encodings
- strPath = [data _hexString];
- }
- }
+ NSString * strPath = [SSZipArchive _filenameStringWithCString:filename size:fileInfo.size_filename];
  if (!strPath.length) {
  // if filename data is unsalvageable, we default to currentFileNumber
  strPath = @(currentFileNumber).stringValue;
@@ -929,6 +897,45 @@ - (BOOL)close
 
 #pragma mark - Private
 
++ (NSString *)_filenameStringWithCString:(const char *)filename size:(uint16_t)size_filename
+{
+ NSString * strPath = @(filename);
+ if (strPath) {
+ return strPath;
+ }
+ // if filename is non-unicode, detect and transform Encoding
+ NSData *data = [NSData dataWithBytes:(const void *)filename length:sizeof(unsigned char) * size_filename];
+#ifdef __MAC_10_13
+ // Xcode 9+
+ if (@available(macOS 10.10, iOS 8.0, watchOS 2.0, tvOS 9.0, *)) {
+ // supported encodings are in [NSString availableStringEncodings]
+ [NSString stringEncodingForData:data encodingOptions:nil convertedString:&strPath usedLossyConversion:nil];
+ }
+#else
+ // Xcode 8-
+ if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber10_9_2) {
+ // supported encodings are in [NSString availableStringEncodings]
+ [NSString stringEncodingForData:data encodingOptions:nil convertedString:&strPath usedLossyConversion:nil];
+ }
+#endif
+ else {
+ // fallback to a simple manual detect for macOS 10.9 or older
+ NSArray<NSNumber *> *encodings = @[@(kCFStringEncodingGB_18030_2000), @(kCFStringEncodingShiftJIS)];
+ for (NSNumber *encoding in encodings) {
+ strPath = [NSString stringWithCString:filename encoding:(NSStringEncoding)CFStringConvertEncodingToNSStringEncoding(encoding.unsignedIntValue)];
+ if (strPath) {
+ break;
+ }
+ }
+ }
+ if (!strPath) {
+ // if filename encoding is non-detected, we default to something based on data
+ // _hexString is more readable than _base64RFC4648 for debugging unknown encodings
+ strPath = [data _hexString];
+ }
+ return strPath;
+}
+
 + (NSString *)_temporaryPathForDiscardableFile
 {
  static NSString *discardableFileName = @".DS_Store";