Execute networking and parsing code on a background thread

Fixes 0xced#147

CHANGELOG.md

@@ -1,3 +1,7 @@
+#### Version 2.2.0
+
+* Networking and parsing code is executed on a background thread for better performance. The `XCDYouTubeVideoOperation` class has changed from an asynchronous to a synchronous operation and must not be started on the main thread. (#147)
+
 #### Version 2.1.3
 
 * Adaptation to YouTube API change. (#144)

XCDYouTubeKit Tests/Cassettes/XCDYouTubeVideoOperationTestCase/testIsAsynchronous.json

@@ -0,0 +1 @@
+[]

XCDYouTubeKit Tests/Cassettes/XCDYouTubeVideoOperationTestCase/testIsConcurrent.json

@@ -0,0 +1 @@
+[]

XCDYouTubeKit Tests/Cassettes/XCDYouTubeVideoOperationTestCase/testStartingOnMainThread.json

@@ -0,0 +1 @@
+[]

XCDYouTubeKit Tests/Cassettes/XCDYouTubeVideoOperationTestCase/testWrongInitializer.json

@@ -0,0 +1 @@
+[]

XCDYouTubeKit Tests/XCDYouTubeVideoOperationTestCase.m

@@ -2,11 +2,11 @@
 //  Copyright (c) 2013-2015 Cédric Luthi. All rights reserved.
 //
 
-#import <XCTest/XCTest.h>
+#import "XCDYouTubeKitTestCase.h"
 
 #import <XCDYouTubeKit/XCDYouTubeVideoOperation.h>
 
-@interface XCDYouTubeVideoOperationTestCase : XCTestCase
+@interface XCDYouTubeVideoOperationTestCase : XCDYouTubeKitTestCase
 @end
 
 @implementation XCDYouTubeVideoOperationTestCase
@@ -16,10 +16,40 @@ - (void) testWrongInitializer
 	XCTAssertThrowsSpecificNamed([[XCDYouTubeVideoOperation alloc] init], NSException, NSGenericException);
 }
 
+- (void) testIsAsynchronous
+{
+	XCDYouTubeVideoOperation *operation = [[XCDYouTubeVideoOperation alloc] initWithVideoIdentifier:nil languageIdentifier:nil];
+	XCTAssertFalse(operation.isAsynchronous);
+}
+
 - (void) testIsConcurrent
 {
 	XCDYouTubeVideoOperation *operation = [[XCDYouTubeVideoOperation alloc] initWithVideoIdentifier:nil languageIdentifier:nil];
-	XCTAssertTrue(operation.isConcurrent);
+	XCTAssertFalse(operation.isConcurrent);
+}
+
+- (void) testStartingOnMainThread
+{
+	XCDYouTubeVideoOperation *operation = [[XCDYouTubeVideoOperation alloc] initWithVideoIdentifier:nil languageIdentifier:nil];
+	XCTAssertTrue([NSThread isMainThread]);
+	XCTAssertThrowsSpecificNamed([operation start], NSException, NSGenericException);
+}
+
+- (void) testStartingOnBackgroundThread
+{
+	XCDYouTubeVideoOperation *operation = [[XCDYouTubeVideoOperation alloc] initWithVideoIdentifier:nil languageIdentifier:nil];
+	[self keyValueObservingExpectationForObject:operation keyPath:@"isFinished" handler:^BOOL(id observedObject, NSDictionary *change)
+	{
+		XCTAssertNil([observedObject video]);
+		XCTAssertNotNil([observedObject error]);
+		return YES;
+	}];
+
+	dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+		XCTAssertFalse([NSThread isMainThread]);
+		[operation start];
+	});
+	[self waitForExpectationsWithTimeout:5 handler:nil];
 }
 
 @end

XCDYouTubeKit/XCDYouTubeVideoOperation.h

@@ -10,7 +10,9 @@
 /**
  *  XCDYouTubeVideoOperation is a subclass of `NSOperation` that connects to the YouTube API and parse the response.
  *
- *  Use this class only if you are very familiar with `NSOperation` and need to manage dependencies between operations. Else you should use the higher level class `XCDYouTubeClient`.
+ *  You should probably use the higher level class `XCDYouTubeClient`. Use this class only if you are very familiar with `NSOperation` and need to manage dependencies between operations.
+ *
+ *  Since version 2.2.0 this operation is synchronous and must not be started on the main thread. Starting the operation on the main thread throws an exception.
  */
 @interface XCDYouTubeVideoOperation : NSOperation <XCDYouTubeOperation>
 

XCDYouTubeKit/XCDYouTubeVideoOperation.m

@@ -31,8 +31,7 @@ @interface XCDYouTubeVideoOperation () <NSURLConnectionDataDelegate, NSURLConnec
 @property (atomic, strong) NSMutableData *connectionData;
 @property (atomic, strong) NSMutableArray *eventLabels;
 
-@property (atomic, assign) BOOL isExecuting;
-@property (atomic, assign) BOOL isFinished;
+@property (atomic, assign) BOOL keepRunning;
 
 @property (atomic, strong) XCDYouTubeVideoWebpage *webpage;
 @property (atomic, strong) XCDYouTubeVideoWebpage *embedWebpage;
@@ -111,7 +110,7 @@ - (void) startRequestWithURL:(NSURL *)url type:(XCDYouTubeRequestType)requestTyp
 
 	NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO];
 	objc_setAssociatedObject(connection, XCDYouTubeRequestTypeKey, @(requestType), OBJC_ASSOCIATION_RETAIN);
-	[connection scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
+	[connection scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
 	[connection start];
 	self.connection = connection;
 }
@@ -216,28 +215,19 @@ - (void) finishWithError
 
 #pragma mark - NSOperation
 
-+ (BOOL) automaticallyNotifiesObserversForKey:(NSString *)key
+- (void) main
 {
-	SEL selector = NSSelectorFromString(key);
-	return selector == @selector(isExecuting) || selector == @selector(isFinished) || [super automaticallyNotifiesObserversForKey:key];
-}
-
-- (BOOL) isConcurrent
-{
-	return YES;
-}
-
-- (void) start
-{
-	if ([self isCancelled])
-		return;
+	if ([NSThread isMainThread])
+		@throw [NSException exceptionWithName:NSGenericException reason:@"XCDYouTubeVideoOperation must not be executed on the main thread." userInfo:nil];
 
 	XCDYouTubeLogInfo(@"Starting video operation: %@", self);
 
-	self.isExecuting = YES;
-
 	self.eventLabels = [[NSMutableArray alloc] initWithArray:@[ @"embedded", @"detailpage" ]];
 	[self startNextRequest];
+
+	self.keepRunning = YES;
+	while (self.keepRunning)
+		[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
 }
 
 - (void) cancel
@@ -253,8 +243,7 @@ - (void) cancel
 
 - (void) finish
 {
-	self.isExecuting = NO;
-	self.isFinished = YES;
+	self.keepRunning = NO;
 }
 
 #pragma mark - NSURLConnectionDataDelegate / NSURLConnectionDelegate