OrphanDataCleaner shouldn't delete active thumbnails

// FREEBIE

Signal/src/ViewControllers/MediaGalleryViewController.swift

@@ -26,7 +26,7 @@ public struct MediaGalleryItem: Equatable {
     }
 
     var thumbnailImage: UIImage {
-        guard let image = attachmentStream.thumbnailImage else {
+        guard let image = attachmentStream.thumbnailImage() else {
             owsFail("\(logTag) in \(#function) unexpectedly unable to build attachment thumbnail")
             return UIImage()
         }

Signal/src/ViewControllers/MediaTileViewController.swift

@@ -268,8 +268,8 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryCe
     // MARK: Lazy Loading
 
     // This should be substantially larger than one screen size so we don't have to call it
-    // multiple times in a rapid succession.
-    let kMediaTileViewLoadBatchSize: UInt = 200
+    // multiple times in a rapid succession, but not so large that loading more get's chopping
+    let kMediaTileViewLoadBatchSize: UInt = 80
     var oldestLoadedItem: MediaGalleryItem? {
         guard let oldestDate = galleryDates.first else {
             return nil

SignalServiceKit/src/Messages/Attachments/TSAttachmentStream.h

@@ -29,11 +29,6 @@ NS_ASSUME_NONNULL_BEGIN
 // messages received from other clients
 @property (nullable, nonatomic) NSData *digest;
 
-// A serialized image which lives in the db, accessible without additional disk access.
-// This is useful for the gallery view which allows us to fetch potentially many
-// attachments in a single read.
-@property (nullable, readonly) UIImage *thumbnailImage;
-
 // This only applies for attachments being uploaded.
 @property (atomic) BOOL isUploaded;
 
@@ -51,6 +46,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (nullable NSURL *)mediaURL;
 
 - (nullable NSString *)filePath;
+- (nullable NSString *)thumbnailPath;
 
 - (nullable NSData *)readDataFromFileWithError:(NSError **)error;
 - (BOOL)writeData:(NSData *)data error:(NSError **)error;

SignalServiceKit/src/Storage/OWSOrphanedDataCleaner.m

@@ -73,6 +73,11 @@ NS_ASSUME_NONNULL_BEGIN
                                                   NSString *_Nullable filePath = [attachmentStream filePath];
                                                   OWSAssert(filePath);
                                                   [attachmentFilePaths addObject:filePath];
+
+                                                  NSString *_Nullable thumbnailPath = [attachmentStream thumbnailPath];
+                                                  if (thumbnailPath.length > 0) {
+                                                      [attachmentFilePaths addObject:thumbnailPath];
+                                                  }
                                               }];
     }];