Fixing thread safety issue and potential memory leak in DDLogMessage.…

… Fixes issue #21

Lumberjack/DDLog.h

@@ -425,14 +425,6 @@ NSString *DDExtractFileNameWithoutExtension(const char *filePath, BOOL copy);
     char *queueLabel;
 	NSString *threadName;
 	id tag; // For 3rd party extensions to the framework, where flags and contexts aren't enough.
-
-// The private variables below are only calculated if needed.
-// You should use the public methods to access this information.
-
-@private
-	NSString *threadID;
-	NSString *fileName;
-	NSString *methodName;
 }
 
 /**
@@ -457,18 +449,18 @@ NSString *DDExtractFileNameWithoutExtension(const char *filePath, BOOL copy);
  * Returns the threadID as it appears in NSLog.
  * That is, it is a hexadecimal value which is calculated from the machThreadID.
 **/
-@property (nonatomic, readonly) NSString *threadID;
+- (NSString *)threadID;
 
 /**
  * Convenience property to get just the file name, as the file variable is generally the full file path.
  * This method does not include the file extension, which is generally unwanted for logging purposes.
 **/
-@property (nonatomic, readonly) NSString *fileName;
+- (NSString *)fileName;
 
 /**
  * Returns the function variable in NSString form.
 **/
-@property (nonatomic, readonly) NSString *methodName;
+- (NSString *)methodName;
 
 @end
 

Lumberjack/DDLog.m

@@ -806,32 +806,20 @@ - (id)initWithLogMsg:(NSString *)msg
 
 - (NSString *)threadID
 {
-	if (threadID == nil)
-	{
-		threadID = [[NSString alloc] initWithFormat:@"%x", machThreadID];
-	}
-
-	return threadID;
+	return [[NSString alloc] initWithFormat:@"%x", machThreadID];
 }
 
 - (NSString *)fileName
 {
-	if (fileName == nil && file != NULL)
-	{
-		fileName = DDExtractFileNameWithoutExtension(file, NO);
-	}
-
-	return fileName;
+	return DDExtractFileNameWithoutExtension(file, NO);
 }
 
 - (NSString *)methodName
 {
-	if (methodName == nil && function != NULL)
-	{
-		methodName = [[NSString alloc] initWithUTF8String:function];
-	}
-
-	return methodName;
+	if (function == NULL)
+		return nil;
+	else
+		return [[NSString alloc] initWithUTF8String:function];
 }
 
 - (void)dealloc