Fixing WebServerIPhone example

Author: robbiehanson

Xcode/WebServerIPhone/Classes/MyHTTPConnection.h

@@ -4,5 +4,4 @@
 
 @interface MyHTTPConnection : HTTPConnection
 
-
 @end

Xcode/WebServerIPhone/Classes/MyHTTPConnection.m

@@ -13,6 +13,59 @@
 
 @implementation MyHTTPConnection
 
+static NSMutableSet *webSocketLoggers;
+
+/**
+ * The runtime sends initialize to each class in a program exactly one time just before the class,
+ * or any class that inherits from it, is sent its first message from within the program. (Thus the
+ * method may never be invoked if the class is not used.) The runtime sends the initialize message to
+ * classes in a thread-safe manner. Superclasses receive this message before their subclasses.
+ *
+ * This method may also be called directly (assumably by accident), hence the safety mechanism.
+**/
++ (void)initialize
+{
+	static dispatch_once_t onceToken;
+	dispatch_once(&onceToken, ^{
+		
+		// We need some place to store the webSocketLogger instances.
+		// So we'll store them here, in a class variable.
+		// 
+		// We'll also use a simple notification system to release them when they die.
+		
+		webSocketLoggers = [[NSMutableSet alloc] init];
+		
+		[[NSNotificationCenter defaultCenter] addObserver:self
+		                                         selector:@selector(webSocketLoggerDidDie:)
+		                                             name:WebSocketLoggerDidDieNotification
+		                                           object:nil];
+	});
+}
+
++ (void)addWebSocketLogger:(WebSocketLogger *)webSocketLogger
+{
+	@synchronized(webSocketLoggers)
+	{
+		[webSocketLoggers addObject:webSocketLogger];
+	}
+}
+
++ (void)webSocketLoggerDidDie:(NSNotification *)notification
+{
+	@synchronized(webSocketLoggers)
+	{
+		[webSocketLoggers removeObject:[notification object]];
+	}
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+#pragma mark Utilities
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Returns the logFileManager, which is a part of the DDFileLogger system.
+ * The DDLogFileManager is the subsystem which manages the location and creation of log files.
+**/
 - (id <DDLogFileManager>)logFileManager
 {
 	WebServerIPhoneAppDelegate *appDelegate;
@@ -21,6 +74,38 @@ @implementation MyHTTPConnection
 	return appDelegate.fileLogger.logFileManager;
 }
 
+/**
+ * Dynamic discovery of proper websocket href. 
+**/
+- (NSString *)wsLocation
+{
+	NSString *port = [NSString stringWithFormat:@"%hu", [asyncSocket localPort]];
+	
+	NSString *wsLocation;
+	NSString *wsHost = [request headerField:@"Host"];
+	
+	if (wsHost == nil)
+	{
+		wsLocation = [NSString stringWithFormat:@"ws://localhost:%@/livelog", port];
+	}
+	else
+	{
+		wsLocation = [NSString stringWithFormat:@"ws://%@/livelog", wsHost];
+	}
+	
+	return wsLocation;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+#pragma mark /logs.html
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Returns the response body for requests to "/logs/index.html".
+ * 
+ * The response is generated dynamically.
+ * It returns the list of log files currently on the system, along with their creation date and file size.
+**/
 - (NSData *)generateIndexData
 {
 	NSArray *sortedLogFileInfos = [[self logFileManager] sortedLogFileInfos];
@@ -83,40 +168,37 @@ - (NSData *)generateIndexData
 	return [response dataUsingEncoding:NSUTF8StringEncoding];
 }
 
-- (NSString *)filePathForURI:(NSString *)path
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+#pragma mark HTTPConnection
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Overrides method in HTTPConnection.
+ * 
+ * This method is invoked to retrieve the filePath for a given URI.
+ * We override it to provide proper mapping for log file paths.
+**/
+- (NSString *)filePathForURI:(NSString *)path allowDirectory:(BOOL)allowDirectory
 {
 	if ([path hasPrefix:@"/logs/"])
 	{
 		NSString *logsDir = [[self logFileManager] logsDirectory];
 		return [logsDir stringByAppendingPathComponent:[path lastPathComponent]];
 	}
 
-	return [super filePathForURI:path];
-}
-
-- (NSString *)wsLocation
-{
-	NSString *port = [NSString stringWithFormat:@"%hu", [asyncSocket localPort]];
-	
-	NSString *wsLocation;
-	NSString *wsHost = [request headerField:@"Host"];
-	
-	if (wsHost == nil)
-	{
-		wsLocation = [NSString stringWithFormat:@"ws://localhost:%@/livelog", port];
-	}
-	else
-	{
-		wsLocation = [NSString stringWithFormat:@"ws://%@/livelog", wsHost];
-	}
-	
-	return wsLocation;
+	// Fall through
+	return [super filePathForURI:path allowDirectory:allowDirectory];
 }
 
+/**
+ * Overrides method in HTTPConnection.
+**/
 - (NSObject<HTTPResponse> *)httpResponseForMethod:(NSString *)method URI:(NSString *)path
 {
 	if ([path isEqualToString:@"/logs.html"])
 	{
+		// Dynamically generate html response with list of available log files
+		
 		NSData *indexData = [self generateIndexData];
 		return [[HTTPDataResponse alloc] initWithData:indexData];
 	}
@@ -139,30 +221,26 @@ - (NSString *)wsLocation
 		                                                separator:@"%%"
 		                                    replacementDictionary:replacementDict];
 	}
-	else
-	{
-		return [super httpResponseForMethod:method URI:path];
-	}
+	
+	// Fall through
+	return [super httpResponseForMethod:method URI:path];
 }
 
+/**
+ * Overrides method in HTTPConnection.
+**/
 - (WebSocket *)webSocketForURI:(NSString *)path
 {
 	if ([path isEqualToString:@"/livelog"])
 	{
 		// Create the WebSocket
-		WebSocket *ws = [[WebSocket alloc] initWithRequest:request socket:asyncSocket];
+		WebSocket *webSocket = [[WebSocket alloc] initWithRequest:request socket:asyncSocket];
 
 		// Create the WebSocketLogger
-		WebSocketLogger *wsLogger = [[WebSocketLogger alloc] initWithWebSocket:ws];
-		
-		// Todo - Broken under ARC. Needs a fix. Commens below from pre-arc.
-		// 
-		// Memory management:
-		// The WebSocket will be retained by the HTTPServer and the WebSocketLogger.
-		// The WebSocketLogger will be retained by the logging framework,
-		// as it adds itself to the list of active loggers from within its init method.
+		WebSocketLogger *webSocketLogger = [[WebSocketLogger alloc] initWithWebSocket:webSocket];
 
-		return ws;
+		[[self class] addWebSocketLogger:webSocketLogger];
+		return webSocket;
 	}
 
 	return [super webSocketForURI:path];

Xcode/WebServerIPhone/Classes/WebSocketLogger.h

@@ -3,6 +3,8 @@
 #import "WebSocket.h"
 
 
+#define WebSocketLoggerDidDieNotification  @"WebSocketLoggerDidDie"
+
 @interface WebSocketLogger : DDAbstractLogger <DDLogger>
 {
 	WebSocket *websocket;

Xcode/WebServerIPhone/Classes/WebSocketLogger.m

@@ -12,21 +12,13 @@ - (id)initWithWebSocket:(WebSocket *)ws
 		websocket.delegate = self;
 
 		formatter = [[WebSocketFormatter alloc] init];
-		
-		// Add our logger
-		// 
-		// We do this here (as opposed to in webSocketDidOpen:) so the logging framework will retain us.
-		// This is important as nothing else is retaining us.
-		// It may be a bit hackish, but it's also the simplest solution.
-		[DDLog addLogger:self];
 	}
 	return self;
 }
 
 - (void)dealloc
 {
 	[websocket setDelegate:nil];
-	
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -38,6 +30,9 @@ - (void)webSocketDidOpen:(WebSocket *)ws
 	// This method is invoked on the websocketQueue
 
 	isWebSocketOpen = YES;
+	
+	// Add our logger
+	[DDLog addLogger:self];
 }
 
 - (void)webSocketDidClose:(WebSocket *)ws
@@ -48,6 +43,9 @@ - (void)webSocketDidClose:(WebSocket *)ws
 
 	// Remove our logger
 	[DDLog removeLogger:self];
+	
+	// Post notification
+	[[NSNotificationCenter defaultCenter] postNotificationName:WebSocketLoggerDidDieNotification object:self];
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -73,17 +71,14 @@ - (void)logMessage:(DDLogMessage *)logMessage
 
 	if (logMsg)
 	{
-		dispatch_async(websocket.websocketQueue, ^{
+		dispatch_async(websocket.websocketQueue, ^{ @autoreleasepool {
 
 			if (isWebSocketOpen)
 			{
-				@autoreleasepool {
-				
-					[websocket sendMessage:logMsg];
+				[websocket sendMessage:logMsg];
 
-				}
 			}
-		});
+		}});
 	}
 }