Adding ability to specify whitespace keep-alive character

Author: robbiehanson

Core/XMPPStream.h

@@ -75,6 +75,7 @@ typedef enum XMPPStreamErrorCode XMPPStreamErrorCode;
 	NSTimeInterval keepAliveInterval;
 	dispatch_source_t keepAliveTimer;
 	NSTimeInterval lastSendReceiveTime;
+	NSData *keepAliveData;
 
 	DDList *registeredModules;
 	NSMutableDictionary *autoDelegateDict;
@@ -211,6 +212,17 @@ typedef enum XMPPStreamErrorCode XMPPStreamErrorCode;
 **/
 @property (readwrite, assign) NSTimeInterval keepAliveInterval;
 
+/**
+ * The keep-alive mechanism sends whitespace which is ignored by the xmpp protocol.
+ * The default whitespace character is a space (' ').
+ * 
+ * This can be changed, for whatever reason, to another whitespace character.
+ * Valid whitespace characters are space(' '), tab('\t') and newline('\n').
+ * 
+ * If you attempt to set the character to any non-whitespace character, the attempt is ignored.
+**/
+@property (readwrite, assign) char keepAliveWhitespaceCharacter;
+
 /**
  * Represents the last sent presence element concerning the presence of myJID on the server.
  * In other words, it represents the presence as others see us.

Core/XMPPStream.m

@@ -115,6 +115,7 @@ - (void)commonInit
 
 	hostPort = 5222;
 	keepAliveInterval = DEFAULT_KEEPALIVE_INTERVAL;
+	keepAliveData = [@" " dataUsingEncoding:NSUTF8StringEncoding];
 
 	registeredModules = [[DDList alloc] init];
 	autoDelegateDict = [[NSMutableDictionary alloc] init];
@@ -403,20 +404,18 @@ - (XMPPPresence *)myPresence
 
 - (NSTimeInterval)keepAliveInterval
 {
+	__block NSTimeInterval result = 0.0;
+	
+	dispatch_block_t block = ^{
+		result = keepAliveInterval;
+	};
+	
 	if (dispatch_get_current_queue() == xmppQueue)
-	{
-		return keepAliveInterval;
-	}
+		block();
 	else
-	{
-		__block NSTimeInterval result;
-		
-		dispatch_sync(xmppQueue, ^{
-			result = keepAliveInterval;
-		});
-		
-		return result;
-	}
+		dispatch_sync(xmppQueue, block);
+	
+	return result;
 }
 
 - (void)setKeepAliveInterval:(NSTimeInterval)interval
@@ -440,6 +439,43 @@ - (void)setKeepAliveInterval:(NSTimeInterval)interval
 		dispatch_async(xmppQueue, block);
 }
 
+- (char)keepAliveWhitespaceCharacter
+{
+	__block char keepAliveChar = ' ';
+	
+	dispatch_block_t block = ^{
+		
+		NSString *keepAliveString = [[NSString alloc] initWithData:keepAliveData encoding:NSUTF8StringEncoding];
+		if ([keepAliveString length] > 0)
+		{
+			keepAliveChar = (char)[keepAliveString characterAtIndex:0];
+		}
+	};
+	
+	if (dispatch_get_current_queue() == xmppQueue)
+		block();
+	else
+		dispatch_sync(xmppQueue, block);
+	
+	return keepAliveChar;
+}
+
+- (void)setKeepAliveWhitespaceCharacter:(char)keepAliveChar
+{
+	dispatch_block_t block = ^{
+		
+		if (keepAliveChar == ' ' || keepAliveChar == '\n' || keepAliveChar == '\t')
+		{
+			keepAliveData = [[NSString stringWithFormat:@"%c", keepAliveChar] dataUsingEncoding:NSUTF8StringEncoding];
+		}
+	};
+	
+	if (dispatch_get_current_queue() == xmppQueue)
+		block();
+	else
+		dispatch_async(xmppQueue, block);
+}
+
 - (UInt64)numberOfBytesSent
 {
 	if (dispatch_get_current_queue() == xmppQueue)
@@ -3349,11 +3385,9 @@ - (void)keepAlive
 
 		if (elapsed < 0 || elapsed >= keepAliveInterval)
 		{
-			NSData *outgoingData = [@" " dataUsingEncoding:NSUTF8StringEncoding];
+			numberOfBytesSent += [keepAliveData length];
 
-			numberOfBytesSent += [outgoingData length];
-			
-			[asyncSocket writeData:outgoingData
+			[asyncSocket writeData:keepAliveData
 			           withTimeout:TIMEOUT_XMPP_WRITE
 			                   tag:TAG_XMPP_WRITE_STREAM];