WIP - implemented basic functionality of downloader - need to support…

… resume and writing to disk.

.gitignore

@@ -15,4 +15,7 @@
 xcuserdata
 profile
 *.moved-aside
-DerivedData
+DerivedData
+
+# Custom
+Sample/build

AFAcceleratedDownloadRequestOperation.h

@@ -23,4 +23,14 @@
 
 @interface AFAcceleratedDownloadRequestOperation : AFHTTPRequestOperation
 
+/** Defines the maximum size of single chunks for downloading a file */
+@property (nonatomic, assign) NSUInteger maximumChunkSize;
+
+/** Designated Initializer to create a download operation with resume support
+ * @param urlRequest request to the resource being downloaded
+ * @param shouldResume should the download request be resumed from a prior attempt or start over
+ * @return instance of class AFAcceleratedDownloadRequestOperation
+ */
+- (id)initWithRequest:(NSURLRequest *)urlRequest shouldResume:(BOOL)shouldResume;
+
 @end

AFAcceleratedDownloadRequestOperation.m

@@ -19,12 +19,234 @@
 //  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 //
 
+#import <tgmath.h>
 #import "AFAcceleratedDownloadRequestOperation.h"
 
+#if !__has_feature(objc_arc)
+#error "AFAcceleratedDownloadRequestOperation requires compiling with ARC."
+#endif
+
+NSString * const kAFInternalCachedURLFolderPrefix = @"af_";
+NSString * const kAFInternalCachedFolderName = @"Incomplete";
+NSString * const kAFInternalDownloadInformation = @"af_download.plist";
+static const NSUInteger kAFInternalDefaultMaximumChunkSize = 4;
+
 @interface AFAcceleratedDownloadRequestOperation ()
 
+@property (nonatomic, strong) NSData *responseData;
+@property (nonatomic, assign, getter = shouldResume) BOOL resume;
+@property (nonatomic, strong) NSOperationQueue *innerQueue;
+
+@property (nonatomic, strong) NSMutableArray *downloadedData;
+
++ (NSString *)downloadCacheFolder;
++ (NSURL *)downloadCacheURLForURL:(NSURL *)url;
+
+- (NSOperation *)HEADOperationForURL:(NSURL *)url;
+- (NSSet *)operationsForURL:(NSURL *)url contentSize:(NSUInteger)contentSize chunks:(NSUInteger)chunks;
+
 @end
 
 @implementation AFAcceleratedDownloadRequestOperation
 
+#pragma mark - Class methods
+
++ (NSString *)downloadCacheFolder
+{
+	static dispatch_once_t downloadFolder_onceToken;
+	static NSString *af_internal_acceleratedDownloadRequestCacheFolder = nil;
+
+	dispatch_once(&downloadFolder_onceToken, ^{
+		af_internal_acceleratedDownloadRequestCacheFolder = [NSTemporaryDirectory() stringByAppendingString:kAFInternalCachedFolderName];
+
+		NSError *folderError;
+		[[NSFileManager defaultManager] createDirectoryAtPath:af_internal_acceleratedDownloadRequestCacheFolder
+								  withIntermediateDirectories:YES
+												   attributes:nil
+														error:&folderError];
+
+		if (folderError) {
+			NSLog(@"Failed to create cache folder for download: %@", af_internal_acceleratedDownloadRequestCacheFolder);
+		}
+	});
+
+	return af_internal_acceleratedDownloadRequestCacheFolder;
+}
+
++ (NSURL *)downloadCacheURLForURL:(NSURL *)url
+{
+	NSURL *folderURL = [NSURL fileURLWithPath:[self downloadCacheFolder] isDirectory:YES];
+	NSString *folderName = [NSString stringWithFormat:@"%@%u", kAFInternalCachedURLFolderPrefix, url.absoluteString.hash];
+
+	NSURL *urlCacheFolderURL = [folderURL URLByAppendingPathComponent:folderName isDirectory:YES];
+
+	static dispatch_once_t urlFolder_onceToken;
+	dispatch_once(&urlFolder_onceToken, ^{
+		NSError *folderError;
+		[[NSFileManager defaultManager] createDirectoryAtURL:urlCacheFolderURL
+								 withIntermediateDirectories:YES
+												  attributes:nil
+													   error:&folderError];
+		if (folderError) {
+			NSLog(@"Failed to create cache folder: %@ for URL: %@", [urlCacheFolderURL absoluteString], url);
+		}
+
+	});
+
+	return urlCacheFolderURL;
+}
+
+#pragma mark - Life cycle
+
+- (id)initWithRequest:(NSURLRequest *)urlRequest shouldResume:(BOOL)shouldResume
+{
+	if (self = [super initWithRequest:urlRequest]) {
+		_innerQueue = [[NSOperationQueue alloc] init];
+		[_innerQueue setMaxConcurrentOperationCount:NSOperationQueueDefaultMaxConcurrentOperationCount];
+		_resume = shouldResume;
+		_maximumChunkSize = kAFInternalDefaultMaximumChunkSize;
+		_downloadedData = [NSMutableArray array];
+	}
+	return self;
+}
+
+- (id)initWithRequest:(NSURLRequest *)urlRequest
+{
+	return [self initWithRequest:urlRequest shouldResume:YES];
+}
+
+#pragma mark - AFHTTPRequestOperation overrides
+
+- (void)start
+{
+	// Build Info Dictionary
+	// TODO: Setup for resuming
+
+	// Start HEAD request to begin downloading process
+	NSOperation *headOperation = [self HEADOperationForURL:[self.request URL]];
+	[self.innerQueue addOperation:headOperation];
+}
+
+#pragma mark - Properties
+
+- (void)setCompletionBlockWithSuccess:(void (^)(AFHTTPRequestOperation *, id))success failure:(void (^)(AFHTTPRequestOperation *, NSError *))failure
+{
+	__block typeof(self) weak_self = self;
+	[self setCompletionBlock:^{
+		if (success) {
+			success(weak_self, weak_self.responseData);
+		}
+	}];
+}
+
+#pragma mark - Helpers
+
+- (NSSet *)operationsForURL:(NSURL *)url contentSize:(NSUInteger)contentSize chunks:(NSUInteger)chunks
+{
+	NSMutableSet *operationSet = [NSMutableSet set];
+
+	NSInteger chunkSize = contentSize / chunks;
+	NSInteger chunkRemainder = fmod(contentSize, chunks);
+	NSInteger chunkPosition = 0;
+	NSUInteger downloadNumber = 0;
+
+	[self.downloadedData removeAllObjects];
+	self.downloadedData = [NSMutableArray array];
+
+	__weak typeof(self) weak_self = self;
+
+	for (NSInteger i = 0; i < chunks; i++) {
+		NSInteger divisonBuffer = 0;
+		if (i == (chunks - 1)) {
+			divisonBuffer = -chunkRemainder;
+		}
+
+		NSOutputStream *stream = [NSOutputStream outputStreamToMemory];
+
+		NSNumber *requestSizeEnd = @(chunkPosition + chunkSize + divisonBuffer);
+		NSString *rangeString = [NSString stringWithFormat:@"bytes=%i-%@/%i", chunkPosition, requestSizeEnd, contentSize];
+		NSLog(@"range string: %@", rangeString);
+
+		NSMutableURLRequest *downloadRequest = [NSMutableURLRequest requestWithURL:url];
+		[downloadRequest setValue:@"bytes" forHTTPHeaderField:@"If-Ranges"];
+		[downloadRequest setValue:rangeString forHTTPHeaderField:@"Range"];
+
+		AFHTTPRequestOperation *downloadOperation = [[AFHTTPRequestOperation alloc] initWithRequest:downloadRequest];
+//		[downloadOperation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
+//			float percentDone = ((float)((int)totalBytesRead) / (float)((int)totalBytesExpectedToRead)) * 100;
+//			NSLog(@"download number %i %f%%: %u %llu %llu %@", downloadNumber, percentDone, bytesRead, totalBytesRead, totalBytesExpectedToRead, requestSize);
+//		}];
+
+		[downloadOperation setOutputStream:stream];
+		[weak_self.downloadedData addObject:stream];
+
+		[downloadOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
+			NSOutputStream *stream = [weak_self.downloadedData objectAtIndex:downloadNumber];
+			[stream close];
+			//			NSLog(@"download number %i finished", downloadNumber);
+		} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
+			NSLog(@"download error: %@", [error localizedDescription]);
+		}];
+
+		[operationSet addObject:downloadOperation];
+		chunkPosition += chunkSize + 1;
+
+		downloadNumber++;
+	}
+
+	return operationSet;
+}
+
+- (NSOperation *)HEADOperationForURL:(NSURL *)url
+{
+	NSParameterAssert(url);
+
+	NSMutableURLRequest *headRequest = [NSMutableURLRequest requestWithURL:self.request.URL];
+	[headRequest setHTTPMethod:@"HEAD"];
+	[headRequest setValue:@"bytes" forHTTPHeaderField:@"If-Ranges"];
+	[headRequest setValue:@"bytes=0-1/1" forHTTPHeaderField:@"Range"];
+
+	__weak typeof(self) weak_self = self;
+
+	AFHTTPRequestOperation *headOperation = [[AFHTTPRequestOperation alloc] initWithRequest:headRequest];
+	[headOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
+//		NSInteger statusCode = operation.response.statusCode;
+//		NSLog(@"%i", statusCode);
+
+		NSString *contentLengthString = [operation.response.allHeaderFields objectForKey:@"Content-Range"];
+		contentLengthString = [contentLengthString stringByReplacingOccurrencesOfString:@"bytes 0-1/" withString:@""];
+		NSInteger contentLength = [contentLengthString integerValue];
+
+		// TODO: If 200, only create one request since it should be 206 when supported
+
+		NSSet *operations = [weak_self operationsForURL:operation.request.URL contentSize:contentLength chunks:weak_self.maximumChunkSize];
+		NSOperation *finishOperation = [NSBlockOperation blockOperationWithBlock:^{
+
+			NSMutableData *compiledData = [NSMutableData data];
+			for (id partialData in weak_self.downloadedData) {
+				[compiledData appendData:[partialData propertyForKey:NSStreamDataWrittenToMemoryStreamKey]];
+			}
+
+			weak_self.responseData = compiledData;
+
+			if (weak_self.completionBlock) {
+				weak_self.completionBlock();
+			}
+		}];
+
+		for (NSOperation *operation in operations) {
+			[finishOperation addDependency:operation];
+			[weak_self.innerQueue addOperation:operation];
+		}
+
+		[weak_self.innerQueue addOperation:finishOperation];
+	} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
+
+		// handle HEAD error
+
+	}];
+
+	return headOperation;
+}
+
 @end

Sample/AFAcceleratedDownloadRequestOperation-Sample.xcodeproj/project.pbxproj

@@ -26,6 +26,8 @@
 		A45E0B3A1616BA9E00E23C6D /* AFURLConnectionOperation.m in Sources */ = {isa = PBXBuildFile; fileRef = A45E0B2F1616BA9E00E23C6D /* AFURLConnectionOperation.m */; };
 		A45E0B3B1616BA9E00E23C6D /* AFXMLRequestOperation.m in Sources */ = {isa = PBXBuildFile; fileRef = A45E0B311616BA9E00E23C6D /* AFXMLRequestOperation.m */; };
 		A45E0B3C1616BA9E00E23C6D /* UIImageView+AFNetworking.m in Sources */ = {isa = PBXBuildFile; fileRef = A45E0B331616BA9E00E23C6D /* UIImageView+AFNetworking.m */; };
+		A45E0B3F1617EEDE00E23C6D /* JJViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = A45E0B3E1617EEDE00E23C6D /* JJViewController.m */; };
+		A477FE88164635A200407DFE /* JJViewController.xib in Resources */ = {isa = PBXBuildFile; fileRef = A477FE87164635A200407DFE /* JJViewController.xib */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -63,6 +65,9 @@
 		A45E0B311616BA9E00E23C6D /* AFXMLRequestOperation.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = AFXMLRequestOperation.m; path = Libraries/AFNetworking/AFNetworking/AFXMLRequestOperation.m; sourceTree = "<group>"; };
 		A45E0B321616BA9E00E23C6D /* UIImageView+AFNetworking.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = "UIImageView+AFNetworking.h"; path = "Libraries/AFNetworking/AFNetworking/UIImageView+AFNetworking.h"; sourceTree = "<group>"; };
 		A45E0B331616BA9E00E23C6D /* UIImageView+AFNetworking.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = "UIImageView+AFNetworking.m"; path = "Libraries/AFNetworking/AFNetworking/UIImageView+AFNetworking.m"; sourceTree = "<group>"; };
+		A45E0B3D1617EEDE00E23C6D /* JJViewController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = JJViewController.h; sourceTree = "<group>"; };
+		A45E0B3E1617EEDE00E23C6D /* JJViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = JJViewController.m; sourceTree = "<group>"; };
+		A477FE87164635A200407DFE /* JJViewController.xib */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = file.xib; path = JJViewController.xib; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -113,6 +118,9 @@
 			children = (
 				A45E0AE71616B6F200E23C6D /* JJAppDelegate.h */,
 				A45E0AE81616B6F200E23C6D /* JJAppDelegate.m */,
+				A45E0B3D1617EEDE00E23C6D /* JJViewController.h */,
+				A45E0B3E1617EEDE00E23C6D /* JJViewController.m */,
+				A477FE87164635A200407DFE /* JJViewController.xib */,
 				A45E0ADF1616B6F200E23C6D /* Supporting Files */,
 			);
 			path = "AFAcceleratedDownloadRequestOperation-Sample";
@@ -231,6 +239,7 @@
 				A45E0AEB1616B6F200E23C6D /* Default.png in Resources */,
 				A45E0AED1616B6F200E23C6D /* Default@2x.png in Resources */,
 				A45E0AEF1616B6F200E23C6D /* Default-568h@2x.png in Resources */,
+				A477FE88164635A200407DFE /* JJViewController.xib in Resources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -253,6 +262,7 @@
 				A45E0B3A1616BA9E00E23C6D /* AFURLConnectionOperation.m in Sources */,
 				A45E0B3B1616BA9E00E23C6D /* AFXMLRequestOperation.m in Sources */,
 				A45E0B3C1616BA9E00E23C6D /* UIImageView+AFNetworking.m in Sources */,
+				A45E0B3F1617EEDE00E23C6D /* JJViewController.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Sample/AFAcceleratedDownloadRequestOperation-Sample/JJAppDelegate.m

@@ -7,45 +7,16 @@
 //
 
 #import "JJAppDelegate.h"
-
-#import "AFNetworking.h"
+#import "JJViewController.h"
 
 @implementation JJAppDelegate
 
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
 {
-    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
-    // Override point for customization after application launch.
+	self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
+	[self.window setRootViewController:[[JJViewController alloc] initWithNibName:nil bundle:nil]];
     self.window.backgroundColor = [UIColor whiteColor];
     [self.window makeKeyAndVisible];
     return YES;
 }
-
-- (void)applicationWillResignActive:(UIApplication *)application
-{
-	// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
-	// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
-}
-
-- (void)applicationDidEnterBackground:(UIApplication *)application
-{
-	// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. 
-	// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
-}
-
-- (void)applicationWillEnterForeground:(UIApplication *)application
-{
-	// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
-}
-
-- (void)applicationDidBecomeActive:(UIApplication *)application
-{
-	// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
-}
-
-- (void)applicationWillTerminate:(UIApplication *)application
-{
-	// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
-}
-
 @end

Sample/AFAcceleratedDownloadRequestOperation-Sample/JJViewController.h

@@ -0,0 +1,13 @@
+//
+//  JJViewController.h
+//  AFAcceleratedDownloadRequestOperation-Sample
+//
+//  Created by Josh Johnson on 9/29/12.
+//  Copyright (c) 2012 jnjosh.com. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+
+@interface JJViewController : UIViewController
+
+@end