Generalized image decoding and resizing logic

Summary:
public

Standardises the image decoding logic for all image sources, meaning we get the benefits of efficient downscaling of images from all sources, not just ALAssets.

Reviewed By: javache

Differential Revision: D2647083

fb-gh-sync-id: e41456f838e4c6ab709b1c1523f651a86ff6e623

RCTAssetsLibraryRequestHandler.h

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import "RCTBridge.h"
+#import "RCTURLRequestHandler.h"
+
+@class ALAssetsLibrary;
+
+@interface RCTAssetsLibraryRequestHandler : NSObject <RCTURLRequestHandler>
+
+@end
+
+@interface RCTBridge (RCTAssetsLibraryImageLoader)
+
+/**
+ * The shared asset library instance.
+ */
+@property (nonatomic, readonly) ALAssetsLibrary *assetsLibrary;
+
+@end

RCTAssetsLibraryRequestHandler.m

@@ -0,0 +1,114 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import "RCTAssetsLibraryRequestHandler.h"
+
+#import <AssetsLibrary/AssetsLibrary.h>
+#import <libkern/OSAtomic.h>
+
+#import "RCTBridge.h"
+#import "RCTUtils.h"
+
+@implementation RCTAssetsLibraryRequestHandler
+{
+  ALAssetsLibrary *_assetsLibrary;
+}
+
+RCT_EXPORT_MODULE()
+
+@synthesize bridge = _bridge;
+
+- (ALAssetsLibrary *)assetsLibrary
+{
+  return _assetsLibrary ?: (_assetsLibrary = [ALAssetsLibrary new]);
+}
+
+#pragma mark - RCTURLRequestHandler
+
+- (BOOL)canHandleRequest:(NSURLRequest *)request
+{
+  return [request.URL.scheme caseInsensitiveCompare:@"assets-library"] == NSOrderedSame;
+}
+
+- (id)sendRequest:(NSURLRequest *)request
+     withDelegate:(id<RCTURLRequestDelegate>)delegate
+{
+  __block volatile uint32_t cancelled = 0;
+  void (^cancellationBlock)(void) = ^{
+    OSAtomicOr32Barrier(1, &cancelled);
+  };
+
+  [[self assetsLibrary] assetForURL:request.URL resultBlock:^(ALAsset *asset) {
+    if (cancelled) {
+      return;
+    }
+
+    if (asset) {
+
+      ALAssetRepresentation *representation = [asset defaultRepresentation];
+      NSInteger length = (NSInteger)representation.size;
+
+      NSURLResponse *response =
+      [[NSURLResponse alloc] initWithURL:request.URL
+                                MIMEType:representation.UTI
+                   expectedContentLength:length
+                        textEncodingName:nil];
+
+      [delegate URLRequest:cancellationBlock didReceiveResponse:response];
+
+      NSError *error = nil;
+      uint8_t *buffer = (uint8_t *)malloc((size_t)length);
+      if ([representation getBytes:buffer
+                        fromOffset:0
+                            length:length
+                             error:&error]) {
+
+        NSData *data = [[NSData alloc] initWithBytesNoCopy:buffer
+                                                    length:length
+                                              freeWhenDone:YES];
+
+        [delegate URLRequest:cancellationBlock didReceiveData:data];
+        [delegate URLRequest:cancellationBlock didCompleteWithError:nil];
+
+      } else {
+        free(buffer);
+        [delegate URLRequest:cancellationBlock didCompleteWithError:error];
+      }
+
+    } else {
+      NSString *errorMessage = [NSString stringWithFormat:@"Failed to load asset"
+                                " at URL %@ with no error message.", request.URL];
+      NSError *error = RCTErrorWithMessage(errorMessage);
+      [delegate URLRequest:cancellationBlock didCompleteWithError:error];
+    }
+  } failureBlock:^(NSError *loadError) {
+    if (cancelled) {
+      return;
+    }
+    [delegate URLRequest:cancellationBlock didCompleteWithError:loadError];
+  }];
+
+  return cancellationBlock;
+}
+
+- (void)cancelRequest:(id)requestToken
+{
+  ((void (^)(void))requestToken)();
+}
+
+@end
+
+@implementation RCTBridge (RCTAssetsLibraryImageLoader)
+
+- (ALAssetsLibrary *)assetsLibrary
+{
+  return [[self moduleForClass:[RCTAssetsLibraryRequestHandler class]] assetsLibrary];
+}
+
+@end

RCTCameraRoll.xcodeproj/project.pbxproj

@@ -9,7 +9,7 @@
 /* Begin PBXBuildFile section */
 		137620351B31C53500677FF0 /* RCTImagePickerManager.m in Sources */ = {isa = PBXBuildFile; fileRef = 137620341B31C53500677FF0 /* RCTImagePickerManager.m */; };
 		143879351AAD238D00F088A5 /* RCTCameraRollManager.m in Sources */ = {isa = PBXBuildFile; fileRef = 143879341AAD238D00F088A5 /* RCTCameraRollManager.m */; };
-		8312EAEE1B85EB7C001867A2 /* RCTAssetsLibraryImageLoader.m in Sources */ = {isa = PBXBuildFile; fileRef = 8312EAED1B85EB7C001867A2 /* RCTAssetsLibraryImageLoader.m */; };
+		8312EAEE1B85EB7C001867A2 /* RCTAssetsLibraryRequestHandler.m in Sources */ = {isa = PBXBuildFile; fileRef = 8312EAED1B85EB7C001867A2 /* RCTAssetsLibraryRequestHandler.m */; };
 		8312EAF11B85F071001867A2 /* RCTPhotoLibraryImageLoader.m in Sources */ = {isa = PBXBuildFile; fileRef = 8312EAF01B85F071001867A2 /* RCTPhotoLibraryImageLoader.m */; };
 /* End PBXBuildFile section */
 
@@ -31,8 +31,8 @@
 		143879331AAD238D00F088A5 /* RCTCameraRollManager.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RCTCameraRollManager.h; sourceTree = "<group>"; };
 		143879341AAD238D00F088A5 /* RCTCameraRollManager.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RCTCameraRollManager.m; sourceTree = "<group>"; };
 		58B5115D1A9E6B3D00147676 /* libRCTCameraRoll.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = libRCTCameraRoll.a; sourceTree = BUILT_PRODUCTS_DIR; };
-		8312EAEC1B85EB7C001867A2 /* RCTAssetsLibraryImageLoader.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RCTAssetsLibraryImageLoader.h; sourceTree = "<group>"; };
-		8312EAED1B85EB7C001867A2 /* RCTAssetsLibraryImageLoader.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RCTAssetsLibraryImageLoader.m; sourceTree = "<group>"; };
+		8312EAEC1B85EB7C001867A2 /* RCTAssetsLibraryRequestHandler.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RCTAssetsLibraryRequestHandler.h; sourceTree = "<group>"; };
+		8312EAED1B85EB7C001867A2 /* RCTAssetsLibraryRequestHandler.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RCTAssetsLibraryRequestHandler.m; sourceTree = "<group>"; };
 		8312EAEF1B85F071001867A2 /* RCTPhotoLibraryImageLoader.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RCTPhotoLibraryImageLoader.h; sourceTree = "<group>"; };
 		8312EAF01B85F071001867A2 /* RCTPhotoLibraryImageLoader.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RCTPhotoLibraryImageLoader.m; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -51,8 +51,8 @@
 		58B511541A9E6B3D00147676 = {
 			isa = PBXGroup;
 			children = (
-				8312EAEC1B85EB7C001867A2 /* RCTAssetsLibraryImageLoader.h */,
-				8312EAED1B85EB7C001867A2 /* RCTAssetsLibraryImageLoader.m */,
+				8312EAEC1B85EB7C001867A2 /* RCTAssetsLibraryRequestHandler.h */,
+				8312EAED1B85EB7C001867A2 /* RCTAssetsLibraryRequestHandler.m */,
 				143879331AAD238D00F088A5 /* RCTCameraRollManager.h */,
 				143879341AAD238D00F088A5 /* RCTCameraRollManager.m */,
 				137620331B31C53500677FF0 /* RCTImagePickerManager.h */,
@@ -129,7 +129,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				8312EAEE1B85EB7C001867A2 /* RCTAssetsLibraryImageLoader.m in Sources */,
+				8312EAEE1B85EB7C001867A2 /* RCTAssetsLibraryRequestHandler.m in Sources */,
 				8312EAF11B85F071001867A2 /* RCTPhotoLibraryImageLoader.m in Sources */,
 				137620351B31C53500677FF0 /* RCTImagePickerManager.m in Sources */,
 				143879351AAD238D00F088A5 /* RCTCameraRollManager.m in Sources */,

RCTCameraRollManager.m

@@ -13,7 +13,7 @@
 #import <Foundation/Foundation.h>
 #import <UIKit/UIKit.h>
 
-#import "RCTAssetsLibraryImageLoader.h"
+#import "RCTAssetsLibraryRequestHandler.h"
 #import "RCTBridge.h"
 #import "RCTConvert.h"
 #import "RCTImageLoader.h"