Add failure methods to thumbnail service.

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m

@@ -859,8 +859,12 @@ NS_ASSUME_NONNULL_BEGIN
         stillImageView.image = [strongSelf
             tryToLoadCellMedia:^{
                 OWSCAssert([strongSelf.attachmentStream isImage]);
-                return [strongSelf.attachmentStream thumbnailImageMediumWithCompletion:^(UIImage *image) {
+                return [strongSelf.attachmentStream
+                    thumbnailImageMediumWithSuccess:^(UIImage *image) {
                         weakImageView.image = image;
+                    }
+                    failure:^{
+                        DDLogError(@"Could not load thumbnail.");
                     }];
             }
                      mediaView:stillImageView

Signal/src/ViewControllers/MediaGalleryViewController.swift

@@ -35,7 +35,7 @@ public struct MediaGalleryItem: Equatable, Hashable {
 
     public typealias AsyncThumbnailBlock = (UIImage) -> Void
     func thumbnailImage(async:@escaping AsyncThumbnailBlock) -> UIImage? {
-        return attachmentStream.thumbnailImageSmall(completion: async)
+        return attachmentStream.thumbnailImageSmall(success: async, failure: {})
     }
 
     var fullSizedImage: UIImage {

Signal/src/util/OWSOrphanDataCleaner.m

@@ -323,10 +323,8 @@ typedef void (^OrphanDataBlock)(OWSOrphanData *);
                                              OWSFail(@"%@ attachment has no file path.", self.logTag);
                                          }
 
-                                         NSString *_Nullable thumbnailPath = [attachmentStream legacyThumbnailPath];
+                                         [allAttachmentFilePaths
-                                         if (thumbnailPath.length > 0) {
+                                             addObjectsFromArray:attachmentStream.allThumbnailPaths];
-                                             [allAttachmentFilePaths addObject:thumbnailPath];
-                                         }
                                      }];
 
         if (shouldAbort) {

SignalMessaging/ViewModels/OWSQuotedReplyModel.m

@@ -227,7 +227,7 @@ NS_ASSUME_NONNULL_BEGIN
                                   authorId:authorId
                                       body:quotedText
                                 bodySource:TSQuotedMessageContentSourceLocal
-                            thumbnailImage:quotedAttachment.legacyThumbnailImage
+                            thumbnailImage:quotedAttachment.thumbnailImageSmallSync
                                contentType:quotedAttachment.contentType
                             sourceFilename:quotedAttachment.sourceFilename
                           attachmentStream:quotedAttachment

SignalServiceKit/src/Messages/Attachments/OWSThumbnailService.swift

@@ -4,8 +4,33 @@
 
 import Foundation
 
+@objc public class OWSLoadedThumbnail: NSObject {
+    public typealias DataSourceBlock = () throws -> Data
+
+    @objc public let image: UIImage
+    let dataSourceBlock: DataSourceBlock
+
+    @objc public init(image: UIImage, filePath: String) {
+        self.image = image
+        self.dataSourceBlock = {
+            return try Data(contentsOf: URL(fileURLWithPath: filePath))
+        }
+    }
+
+    @objc public init(image: UIImage, data: Data) {
+        self.image = image
+        self.dataSourceBlock = {
+            return data
+        }
+    }
+
+    @objc public func data() throws -> Data {
+        return try dataSourceBlock()
+    }
+}
+
 private struct OWSThumbnailRequest {
-    public typealias SuccessBlock = (UIImage) -> Void
+    public typealias SuccessBlock = (OWSLoadedThumbnail) -> Void
     public typealias FailureBlock = () -> Void
 
     let attachmentId: String
@@ -28,7 +53,7 @@ private struct OWSThumbnailRequest {
     @objc(shared)
     public static let shared = OWSThumbnailService()
 
-    public typealias SuccessBlock = (UIImage) -> Void
+    public typealias SuccessBlock = (OWSLoadedThumbnail) -> Void
     public typealias FailureBlock = () -> Void
 
     private let serialQueue = DispatchQueue(label: "OWSThumbnailService")
@@ -97,9 +122,9 @@ private struct OWSThumbnailRequest {
         }
         let thumbnailRequest = thumbnailRequestStack.removeLast()
 
-        if let image = process(thumbnailRequest: thumbnailRequest) {
+        if let loadedThumbnail = process(thumbnailRequest: thumbnailRequest) {
             DispatchQueue.main.async {
-                thumbnailRequest.success(image)
+                thumbnailRequest.success(loadedThumbnail)
             }
         } else {
             DispatchQueue.main.async {
@@ -109,7 +134,7 @@ private struct OWSThumbnailRequest {
     }
 
     // This should only be called on the serialQueue.
-    private func process(thumbnailRequest: OWSThumbnailRequest) -> UIImage? {
+    private func process(thumbnailRequest: OWSThumbnailRequest) -> OWSLoadedThumbnail? {
         var possibleAttachment: TSAttachmentStream?
         self.dbConnection.read({ (transaction) in
             possibleAttachment = TSAttachmentStream.fetch(uniqueId: thumbnailRequest.attachmentId, transaction: transaction)
@@ -133,7 +158,7 @@ private struct OWSThumbnailRequest {
                         owsFail("Could not load thumbnail.")
                         return nil
                     }
-                    return image
+                    return OWSLoadedThumbnail(image: image, filePath: filePath)
                 }
             }
         }
@@ -200,6 +225,6 @@ private struct OWSThumbnailRequest {
                               size: thumbnailSize,
                               transaction: transaction)
         })
-        return thumbnailImage
+        return OWSLoadedThumbnail(image: thumbnailImage, data: thumbnailData)
     }
 }

SignalServiceKit/src/Messages/Attachments/TSAttachmentStream.h

@@ -17,7 +17,8 @@ NS_ASSUME_NONNULL_BEGIN
 @class TSAttachmentPointer;
 @class YapDatabaseReadWriteTransaction;
 
-typedef void (^OWSThumbnailCompletion)(UIImage *image);
+typedef void (^OWSThumbnailSuccess)(UIImage *image);
+typedef void (^OWSThumbnailFailure)(void);
 
 @interface TSAttachmentThumbnail : MTLModel
 
@@ -66,10 +67,7 @@ typedef void (^OWSThumbnailCompletion)(UIImage *image);
 - (nullable NSString *)originalFilePath;
 - (nullable NSURL *)originalMediaURL;
 
-// TODO: Rename to legacy...
+- (NSArray<NSString *> *)allThumbnailPaths;
-- (nullable UIImage *)legacyThumbnailImage;
-//- (nullable NSData *)legacyThumbnailData;
-- (nullable NSString *)legacyThumbnailPath;
 
 + (BOOL)hasThumbnailForMimeType:(NSString *)contentType;
 
@@ -96,16 +94,18 @@ typedef void (^OWSThumbnailCompletion)(UIImage *image);
 // Non-nil for attachments which need "lazy backup restore."
 - (nullable OWSBackupFragment *)lazyRestoreFragment;
 
-
 #pragma mark - Thumbnails
 
 // On cache hit, the thumbnail will be returned synchronously and completion will never be invoked.
 // On cache miss, nil will be returned and the completion will be invoked async on main if
 // thumbnail can be generated.
-- (nullable UIImage *)thumbnailImageWithSizeHint:(CGSize)sizeHint completion:(OWSThumbnailCompletion)completion;
+- (nullable UIImage *)thumbnailImageWithSizeHint:(CGSize)sizeHint
-- (nullable UIImage *)thumbnailImageSmallWithCompletion:(OWSThumbnailCompletion)completion;
+                                      completion:(OWSThumbnailSuccess)success
-- (nullable UIImage *)thumbnailImageMediumWithCompletion:(OWSThumbnailCompletion)completion;
+                                         failure:(OWSThumbnailFailure)failure;
-- (nullable UIImage *)thumbnailImageLargeWithCompletion:(OWSThumbnailCompletion)completion;
+- (nullable UIImage *)thumbnailImageSmallWithSuccess:(OWSThumbnailSuccess)success failure:(OWSThumbnailFailure)failure;
+- (nullable UIImage *)thumbnailImageMediumWithSuccess:(OWSThumbnailSuccess)success failure:(OWSThumbnailFailure)failure;
+- (nullable UIImage *)thumbnailImageLargeWithSuccess:(OWSThumbnailSuccess)success failure:(OWSThumbnailFailure)failure;
+- (nullable UIImage *)thumbnailImageSmallSync;
 
 // This method should only be invoked by OWSThumbnailService.
 - (nullable NSString *)pathForThumbnail:(TSAttachmentThumbnail *)thumbnail;

SignalServiceKit/src/Messages/Attachments/TSAttachmentStream.m

@@ -24,6 +24,8 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
     return MAX(screenSizePoints.width, screenSizePoints.height);
 }
 
+typedef void (^OWSLoadedThumbnailSuccess)(OWSLoadedThumbnail *loadedThumbnail);
+
 @implementation TSAttachmentThumbnail
 
 - (instancetype)initWithFilename:(NSString *)filename
@@ -128,18 +130,9 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
         _creationTimestamp = [NSDate new];
     }
 
-    // This is going to be slow the first time it runs.
-    [self ensureLegacyThumbnail];
-
     return self;
 }
 
-- (void)saveWithTransaction:(YapDatabaseReadWriteTransaction *)transaction
-{
-    [super saveWithTransaction:transaction];
-    [self ensureLegacyThumbnail];
-}
-
 - (void)upgradeFromAttachmentSchemaVersion:(NSUInteger)attachmentSchemaVersion
 {
     [super upgradeFromAttachmentSchemaVersion:attachmentSchemaVersion];
@@ -429,24 +422,6 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
         [MIMETypeUtil isAnimated:contentType]);
 }
 
-- (nullable NSData *)legacyThumbnailData
-{
-    NSString *thumbnailPath = self.legacyThumbnailPath;
-    if (!thumbnailPath) {
-        OWSAssert(!self.isImage && !self.isVideo && !self.isAnimated);
-
-        return nil;
-    }
-
-    if (![[NSFileManager defaultManager] fileExistsAtPath:thumbnailPath]) {
-        OWSFail(@"%@ missing thumbnail for attachmentId: %@", self.logTag, self.uniqueId);
-
-        return nil;
-    }
-
-    return [NSData dataWithContentsOfFile:thumbnailPath];
-}
-
 - (void)ensureLegacyThumbnail
 {
     NSString *thumbnailPath = self.legacyThumbnailPath;
@@ -764,7 +739,9 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
 
 #pragma mark - Thumbnails
 
-- (nullable UIImage *)thumbnailImageWithSizeHint:(CGSize)sizeHint completion:(OWSThumbnailCompletion)completion
+- (nullable UIImage *)thumbnailImageWithSizeHint:(CGSize)sizeHint
+                                         success:(OWSThumbnailSuccess)success
+                                         failure:(OWSThumbnailFailure)failure
 {
     CGFloat maxDimensionHint = MAX(sizeHint.width, sizeHint.height);
     NSUInteger thumbnailDimensionPoints;
@@ -776,26 +753,46 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
         thumbnailDimensionPoints = ThumbnailDimensionPointsLarge();
     }
 
-    return [self thumbnailImageWithThumbnailDimensionPoints:thumbnailDimensionPoints completion:completion];
+    return [self thumbnailImageWithThumbnailDimensionPoints:thumbnailDimensionPoints success:success failure:failure];
 }
 
-- (nullable UIImage *)thumbnailImageSmallWithCompletion:(OWSThumbnailCompletion)completion
+- (nullable UIImage *)thumbnailImageSmallWithSuccess:(OWSThumbnailSuccess)success failure:(OWSThumbnailFailure)failure
 {
-    return [self thumbnailImageWithThumbnailDimensionPoints:kThumbnailDimensionPointsSmall completion:completion];
+    return [self thumbnailImageWithThumbnailDimensionPoints:kThumbnailDimensionPointsSmall
+                                                    success:success
+                                                    failure:failure];
 }
 
-- (nullable UIImage *)thumbnailImageMediumWithCompletion:(OWSThumbnailCompletion)completion
+- (nullable UIImage *)thumbnailImageMediumWithSuccess:(OWSThumbnailSuccess)success failure:(OWSThumbnailFailure)failure
 {
-    return [self thumbnailImageWithThumbnailDimensionPoints:kThumbnailDimensionPointsMedium completion:completion];
+    return [self thumbnailImageWithThumbnailDimensionPoints:kThumbnailDimensionPointsMedium
+                                                    success:success
+                                                    failure:failure];
 }
 
-- (nullable UIImage *)thumbnailImageLargeWithCompletion:(OWSThumbnailCompletion)completion
+- (nullable UIImage *)thumbnailImageLargeWithSuccess:(OWSThumbnailSuccess)success failure:(OWSThumbnailFailure)failure
 {
-    return [self thumbnailImageWithThumbnailDimensionPoints:ThumbnailDimensionPointsLarge() completion:completion];
+    return [self thumbnailImageWithThumbnailDimensionPoints:ThumbnailDimensionPointsLarge()
+                                                    success:success
+                                                    failure:failure];
 }
 
 - (nullable UIImage *)thumbnailImageWithThumbnailDimensionPoints:(NSUInteger)thumbnailDimensionPoints
-                                                      completion:(OWSThumbnailCompletion)completion
+                                                         success:(OWSThumbnailSuccess)success
+                                                         failure:(OWSThumbnailFailure)failure
+{
+    OWSLoadedThumbnail *_Nullable loadedThumbnail;
+    loadedThumbnail = [self loadedThumbnailWithThumbnailDimensionPoints:thumbnailDimensionPoints
+                                                                success:^(OWSLoadedThumbnail *loadedThumbnail) {
+                                                                    success(loadedThumbnail.image);
+                                                                }
+                                                                failure:failure];
+    return loadedThumbnail.image;
+}
+
+- (nullable OWSLoadedThumbnail *)loadedThumbnailWithThumbnailDimensionPoints:(NSUInteger)thumbnailDimensionPoints
+                                                                     success:(OWSLoadedThumbnailSuccess)success
+                                                                     failure:(OWSThumbnailFailure)failure
 {
     CGSize originalSize = self.imageSize;
     if (originalSize.width < 1 || originalSize.height < 1) {
@@ -804,7 +801,7 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
     if (originalSize.width <= thumbnailDimensionPoints || originalSize.height <= thumbnailDimensionPoints) {
         // There's no point in generating a thumbnail if the original is smaller than the
         // thumbnail size.
-        return self.originalImage;
+        return [[OWSLoadedThumbnail alloc] initWithImage:self.originalImage filePath:self.originalFilePath];
     }
 
     for (TSAttachmentThumbnail *thumbnail in self.thumbnails) {
@@ -817,15 +814,77 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
             continue;
         }
         UIImage *_Nullable image = [UIImage imageWithContentsOfFile:thumbnailPath];
-        return image;
+        if (!image) {
+            OWSFail(@"couldn't load image.");
+            continue;
+        }
+        return [[OWSLoadedThumbnail alloc] initWithImage:image filePath:thumbnailPath];
     }
 
     [OWSThumbnailService.shared ensureThumbnailForAttachmentIdWithAttachmentId:self.uniqueId
                                                       thumbnailDimensionPoints:thumbnailDimensionPoints
-                                                                    completion:completion];
+                                                                       success:success
+                                                                       failure:failure];
     return nil;
 }
 
+- (nullable OWSLoadedThumbnail *)loadedThumbnailSmallSync
+{
+    __block dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
+
+    __block OWSLoadedThumbnail *_Nullable loadedThumbnail = nil;
+    loadedThumbnail = [self loadedThumbnailWithThumbnailDimensionPoints:kThumbnailDimensionPointsSmall
+        success:^(OWSLoadedThumbnail *asyncLoadedThumbnail) {
+            @synchronized(self) {
+                loadedThumbnail = asyncLoadedThumbnail;
+            }
+            dispatch_semaphore_signal(semaphore);
+        }
+        failure:^{
+            dispatch_semaphore_signal(semaphore);
+        }];
+    // Wait up to five seconds.
+    dispatch_semaphore_wait(semaphore, dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)));
+    @synchronized(self) {
+        return loadedThumbnail;
+    }
+}
+
+- (nullable UIImage *)thumbnailImageSmallSync
+{
+    return [self loadedThumbnailSmallSync].image;
+}
+
+- (nullable NSData *)thumbnailDataSmallSync
+{
+    NSError *error;
+    NSData *_Nullable data = [[self loadedThumbnailSmallSync] dataAndReturnError:&error];
+    if (error || !data) {
+        OWSFail(@"Couldn't load thumbnail data: %@", error);
+        return nil;
+    }
+    return data;
+}
+
+- (NSArray<NSString *> *)allThumbnailPaths
+{
+    NSMutableArray<NSString *> *result = [NSMutableArray new];
+    for (TSAttachmentThumbnail *thumbnail in self.thumbnails) {
+        NSString *_Nullable thumbnailPath = [self pathForThumbnail:thumbnail];
+        if (!thumbnailPath) {
+            OWSFail(@"Missing thumbnail path.");
+            continue;
+        }
+        [result addObject:thumbnailPath];
+    }
+    NSString *_Nullable legacyThumbnailPath = self.legacyThumbnailPath;
+    if (legacyThumbnailPath && [[NSFileManager defaultManager] fileExistsAtPath:legacyThumbnailPath]) {
+        [result addObject:legacyThumbnailPath];
+    }
+
+    return result;
+}
+
 #pragma mark - Update With... Methods
 
 - (void)markForLazyRestoreWithFragment:(OWSBackupFragment *)lazyRestoreFragment
@@ -858,7 +917,7 @@ const NSUInteger ThumbnailDimensionPointsLarge() {
 
 - (nullable TSAttachmentStream *)cloneAsThumbnail
 {
-    NSData *thumbnailData = self.legacyThumbnailData;
+    NSData *_Nullable thumbnailData = self.thumbnailDataSmallSync;
     //  Only some media types have thumbnails
     if (!thumbnailData) {
         return nil;