Refactors downloading and fixes download start time.

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## master
 * Add your own contributions to the next release on the line below this with your name.
+- [fixed] Fixed bytes per second on download tasks (which could affect if an image is progressively rendered) [#360](https://github.com/pinterest/PINRemoteImage/pull/360) [garrettmoon](https://github.com/garrettmoon)
 - [new] Added request configuration handler to allow customizing HTTP headers per request [#355](https://github.com/pinterest/PINRemoteImage/pull/355) [zachwaugh](https://github.com/zachwaugh)
 - [fixed] Moved storage of resume data to disk from memory. [garrettmoon](https://github.com/garrettmoon)
 - [fixed] Hopefully fixes crashes occuring in PINURLSessionManager on iOS 9. [garrettmoon](https://github.com/garrettmoon)

PINRemoteImage.xcodeproj/project.pbxproj

@@ -7,6 +7,8 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		680B83CF1ECFABD400210A55 /* NSURLSessionTask+Timing.h in Headers */ = {isa = PBXBuildFile; fileRef = 680B83CD1ECFABD400210A55 /* NSURLSessionTask+Timing.h */; };
+		680B83D01ECFABD400210A55 /* NSURLSessionTask+Timing.m in Sources */ = {isa = PBXBuildFile; fileRef = 680B83CE1ECFABD400210A55 /* NSURLSessionTask+Timing.m */; };
 		6818C1551E551B5A00875DB7 /* PINCache.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 6818C1541E551B5A00875DB7 /* PINCache.framework */; };
 		6818C1661E551CC600875DB7 /* decode.h in Headers */ = {isa = PBXBuildFile; fileRef = 6818C15E1E551CC600875DB7 /* decode.h */; };
 		6818C1671E551CC600875DB7 /* demux.h in Headers */ = {isa = PBXBuildFile; fileRef = 6818C15F1E551CC600875DB7 /* demux.h */; };
@@ -155,6 +157,7 @@
 		6818C2851E551DA800875DB7 /* utils.h in Headers */ = {isa = PBXBuildFile; fileRef = 6818C26B1E551DA800875DB7 /* utils.h */; };
 		6858C0751C9CC5BA00E420EB /* PINRemoteLock.h in Headers */ = {isa = PBXBuildFile; fileRef = 6858C0731C9CC5BA00E420EB /* PINRemoteLock.h */; };
 		6858C0761C9CC5BA00E420EB /* PINRemoteLock.m in Sources */ = {isa = PBXBuildFile; fileRef = 6858C0741C9CC5BA00E420EB /* PINRemoteLock.m */; };
+		686D48D01ED38FC0003DB4C2 /* PINRemoteImageTask+Subclassing.h in Headers */ = {isa = PBXBuildFile; fileRef = 686D48CE1ED38FC0003DB4C2 /* PINRemoteImageTask+Subclassing.h */; };
 		687D3FC91E5650790027B131 /* PINOperation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 687D3FC81E5650790027B131 /* PINOperation.framework */; };
 		68A0FC1C1E523434000B552D /* PINRemoteImageTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 68A0FC1B1E523434000B552D /* PINRemoteImageTests.m */; };
 		68A0FC1E1E523434000B552D /* PINRemoteImage.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = F1B918D11BCF239200710963 /* PINRemoteImage.framework */; };
@@ -292,6 +295,9 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		680B83C71ECE5F9D00210A55 /* PINRemoteImageManager+Private.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; name = "PINRemoteImageManager+Private.h"; path = "../PINRemoteImageManager+Private.h"; sourceTree = "<group>"; };
+		680B83CD1ECFABD400210A55 /* NSURLSessionTask+Timing.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "NSURLSessionTask+Timing.h"; sourceTree = "<group>"; };
+		680B83CE1ECFABD400210A55 /* NSURLSessionTask+Timing.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSURLSessionTask+Timing.m"; sourceTree = "<group>"; };
 		6818C1541E551B5A00875DB7 /* PINCache.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = PINCache.framework; path = "Carthage/Checkouts/PINCache/build/Debug-iphoneos/PINCache.framework"; sourceTree = "<group>"; };
 		6818C1561E551BAB00875DB7 /* PINOperation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = PINOperation.framework; path = "Carthage/Checkouts/PINOperation/build/Debug-iphoneos/PINOperation.framework"; sourceTree = "<group>"; };
 		6818C15E1E551CC600875DB7 /* decode.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = decode.h; sourceTree = "<group>"; };
@@ -442,6 +448,7 @@
 		6818C2AE1E564FF900875DB7 /* PINCache.xcodeproj */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.pb-project"; name = PINCache.xcodeproj; path = Carthage/Checkouts/PINCache/PINCache.xcodeproj; sourceTree = "<group>"; };
 		6858C0731C9CC5BA00E420EB /* PINRemoteLock.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = PINRemoteLock.h; sourceTree = "<group>"; };
 		6858C0741C9CC5BA00E420EB /* PINRemoteLock.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = PINRemoteLock.m; sourceTree = "<group>"; };
+		686D48CE1ED38FC0003DB4C2 /* PINRemoteImageTask+Subclassing.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "PINRemoteImageTask+Subclassing.h"; sourceTree = "<group>"; };
 		687D3FC81E5650790027B131 /* PINOperation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = PINOperation.framework; path = "Carthage/Checkouts/PINCache/Carthage/Checkouts/PINOperation/build/Debug-iphoneos/PINOperation.framework"; sourceTree = "<group>"; };
 		68A0FC191E523434000B552D /* PINRemoteImageTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = PINRemoteImageTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		68A0FC1B1E523434000B552D /* PINRemoteImageTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = PINRemoteImageTests.m; sourceTree = "<group>"; };
@@ -894,12 +901,16 @@
 		F1B918DD1BCF23C800710963 /* Categories */ = {
 			isa = PBXGroup;
 			children = (
+				680B83C71ECE5F9D00210A55 /* PINRemoteImageManager+Private.h */,
 				68A6B1D91E5248BF003A92D1 /* PINImage+ScaledImage.m */,
 				68A6B1DA1E5248BF003A92D1 /* PINImage+ScaledImage.h */,
 				9DD47FA01C699FDC00F12CA0 /* PINImage+DecodedImage.h */,
 				9DD47FA11C699FDC00F12CA0 /* PINImage+DecodedImage.m */,
 				9DD47FA21C699FDC00F12CA0 /* PINImage+WebP.h */,
 				9DD47FA31C699FDC00F12CA0 /* PINImage+WebP.m */,
+				680B83CD1ECFABD400210A55 /* NSURLSessionTask+Timing.h */,
+				680B83CE1ECFABD400210A55 /* NSURLSessionTask+Timing.m */,
+				686D48CE1ED38FC0003DB4C2 /* PINRemoteImageTask+Subclassing.h */,
 			);
 			path = Categories;
 			sourceTree = "<group>";
@@ -972,12 +983,14 @@
 				6818C1661E551CC600875DB7 /* decode.h in Headers */,
 				6818C1FE1E551D1D00875DB7 /* neon.h in Headers */,
 				6818C1691E551CC600875DB7 /* extras.h in Headers */,
+				686D48D01ED38FC0003DB4C2 /* PINRemoteImageTask+Subclassing.h in Headers */,
 				6818C1671E551CC600875DB7 /* demux.h in Headers */,
 				F1B919001BCF23C900710963 /* NSData+ImageDetectors.h in Headers */,
 				F1B9191E1BCF23C900710963 /* PINURLSessionManager.h in Headers */,
 				6818C2791E551DA800875DB7 /* huffman.h in Headers */,
 				6818C2771E551DA800875DB7 /* huffman_encode.h in Headers */,
 				6818C2301E551D7500875DB7 /* cost.h in Headers */,
+				680B83CF1ECFABD400210A55 /* NSURLSessionTask+Timing.h in Headers */,
 				F1B919061BCF23C900710963 /* FLAnimatedImageView+PINRemoteImage.h in Headers */,
 				6818C16D1E551CC600875DB7 /* types.h in Headers */,
 				F1B919111BCF23C900710963 /* PINRemoteImageCallbacks.h in Headers */,
@@ -1231,6 +1244,7 @@
 				6818C22B1E551D7500875DB7 /* analysis.c in Sources */,
 				6818C1E51E551D1D00875DB7 /* dec.c in Sources */,
 				6818C1DD1E551D1D00875DB7 /* cpu.c in Sources */,
+				680B83D01ECFABD400210A55 /* NSURLSessionTask+Timing.m in Sources */,
 				6818C20A1E551D1E00875DB7 /* yuv_sse2.c in Sources */,
 				6818C2451E551D7500875DB7 /* webpenc.c in Sources */,
 				6818C2311E551D7500875DB7 /* delta_palettization.c in Sources */,

Source/Classes/Categories/NSURLSessionTask+Timing.h

@@ -0,0 +1,17 @@
+//
+//  NSURLSessionTask+Timing.h
+//  PINRemoteImage
+//
+//  Created by Garrett Moon on 5/19/17.
+//  Copyright © 2017 Pinterest. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface NSURLSessionTask (Timing)
+
+- (void)PIN_setupSessionTaskObserver;
+- (CFTimeInterval)PIN_startTime;
+- (CFTimeInterval)PIN_endTime;
+
+@end

Source/Classes/Categories/NSURLSessionTask+Timing.m

@@ -0,0 +1,111 @@
+//
+//  NSURLSessionTask+Timing.m
+//  PINRemoteImage
+//
+//  Created by Garrett Moon on 5/19/17.
+//  Copyright © 2017 Pinterest. All rights reserved.
+//
+
+#import "NSURLSessionTask+Timing.h"
+
+#import <objc/runtime.h>
+#import <QuartzCore/QuartzCore.h>
+
+@interface PINURLSessionTaskObserver : NSObject
+
+@property (atomic, assign) CFTimeInterval startTime;
+@property (atomic, assign) CFTimeInterval endTime;
+
+- (instancetype)init NS_UNAVAILABLE;
+- (instancetype)initWithTask:(NSURLSessionTask *)task NS_DESIGNATED_INITIALIZER;
+
+@end
+
+@implementation PINURLSessionTaskObserver
+
+- (instancetype)initWithTask:(NSURLSessionTask *)task
+{
+    if (self = [super init]) {
+        _startTime = 0;
+        _endTime = 0;
+        [task addObserver:self forKeyPath:@"state" options:0 context:nil];
+    }
+    return self;
+}
+
+- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context
+{
+    NSURLSessionTask *task = (NSURLSessionTask *)object;
+    switch (task.state) {
+        case NSURLSessionTaskStateRunning:
+            if (self.startTime == 0) {
+                self.startTime = CACurrentMediaTime();
+            }
+            break;
+
+        case NSURLSessionTaskStateCompleted:
+            NSAssert(self.startTime != 0, @"Expect that task was started before it's completed.");
+            if (self.endTime == 0) {
+                self.endTime = CACurrentMediaTime();
+            }
+            break;
+
+        default:
+            break;
+    }
+}
+
+@end
+
+@implementation NSURLSessionTask (Additions)
+
+- (void)PIN_setupSessionTaskObserver
+{
+    // It's necessary to swizzle dealloc here to remove the observer :(
+    // I wasn't able to figure out another way; kvo assertion about observed objects being observed occurs
+    // *before* associated objects are dealloc'd
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        SEL deallocSelector = NSSelectorFromString(@"dealloc");
+        Method deallocMethod = class_getInstanceMethod([NSURLSessionTask class], deallocSelector);
+        IMP originalImplementation = method_getImplementation(deallocMethod);
+        IMP newImplementation = imp_implementationWithBlock(^(void *obj){
+            @autoreleasepool {
+                //remove state observer
+                PINURLSessionTaskObserver *observer = objc_getAssociatedObject((__bridge id)obj, @selector(PIN_setupSessionTaskObserver));
+                if (observer) {
+                    [(__bridge id)obj removeObserver:observer forKeyPath:@"state"];
+                }
+            }
+
+            //casting original implementation is necessary to ensure ARC doesn't attempt to retain during dealloc
+            ((void (*)(void *, SEL))originalImplementation)(obj, deallocSelector);
+        });
+        class_replaceMethod([NSURLSessionTask class], deallocSelector, newImplementation, method_getTypeEncoding(deallocMethod));
+    });
+
+    PINURLSessionTaskObserver *observer = [[PINURLSessionTaskObserver alloc] initWithTask:self];
+    objc_setAssociatedObject(self, @selector(PIN_setupSessionTaskObserver), observer, OBJC_ASSOCIATION_RETAIN);
+}
+
+- (CFTimeInterval)PIN_startTime
+{
+    PINURLSessionTaskObserver *observer = objc_getAssociatedObject(self, @selector(PIN_setupSessionTaskObserver));
+    NSAssert(observer != nil, @"setupSessionTaskObserver should have been called before.");
+    if (observer == nil) {
+        return 0;
+    }
+    return observer.startTime;
+}
+
+- (CFTimeInterval)PIN_endTime
+{
+    PINURLSessionTaskObserver *observer = objc_getAssociatedObject(self, @selector(PIN_setupSessionTaskObserver));
+    NSAssert(observer != nil, @"setupSessionTaskObserver should have been called before.");
+    if (observer == nil) {
+        return 0;
+    }
+    return observer.endTime;
+}
+
+@end

Source/Classes/Categories/PINRemoteImageTask+Subclassing.h

@@ -0,0 +1,20 @@
+//
+//  PINRemoteImageTask+Subclassing.h
+//  PINRemoteImage
+//
+//  Created by Garrett Moon on 5/22/17.
+//  Copyright © 2017 Pinterest. All rights reserved.
+//
+
+#import "PINRemoteImageTask.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface PINRemoteImageTask (Subclassing)
+
+- (NSMutableDictionary *)l_callbackBlocks;
+- (BOOL)l_cancelWithUUID:(NSUUID *)UUID resume:(PINResume * _Nullable * _Nullable)resume;
+
+@end
+
+NS_ASSUME_NONNULL_END

Source/Classes/PINProgressiveImage.h

@@ -16,12 +16,19 @@
 
 #import "PINRemoteImageMacros.h"
 
+@class PINRemoteImageDownloadTask;
+
 /** An object which store the data of a downloading image and vends progressive scans **/
 @interface PINProgressiveImage : NSObject
 
 @property (atomic, copy, nonnull) NSArray *progressThresholds;
 @property (atomic, assign) CFTimeInterval estimatedRemainingTimeThreshold;
-@property (atomic, assign) CFTimeInterval startTime;
+@property (nonatomic, strong, readonly, nonnull) NSURLSessionDataTask * dataTask;
+@property (nonatomic, readonly) float bytesPerSecond;
+@property (nonatomic, readonly) CFTimeInterval estimatedRemainingTime;
+
+- (nonnull instancetype)init NS_UNAVAILABLE;
+- (nonnull instancetype)initWithDataTask:(nonnull NSURLSessionDataTask *)dataTask;
 
 - (void)updateProgressiveImageWithData:(nonnull NSData *)data expectedNumberOfBytes:(int64_t)expectedNumberOfBytes isResume:(BOOL)isResume;