Lazy restore attachments.

Signal/src/util/OWSBackupAPI.swift

@@ -12,9 +12,6 @@ import CloudKit
 // Note that all of our CloudKit records are immutable.
 // "Persistent" records are only uploaded once.
 // "Ephemeral" records are always uploaded to a new record name.
-//
-// TODO: We could store known encryption ids locally to
-// facilitate "resume" of failed backup exports.
 @objc public class OWSBackupAPI: NSObject {
 
     // If we change the record types, we need to ensure indices

Signal/src/util/OWSBackupImportJob.m

@@ -219,7 +219,7 @@ NSString *const kOWSBackup_ImportDatabaseKeySpec = @"kOWSBackup_ImportDatabaseKe
                                             @"Indicates that the backup import data is being downloaded.")
                                progress:@(progress)];
 
-    // Use a predictable file path so that multiple "import backup" attempts
+    // TODO: Use a predictable file path so that multiple "import backup" attempts
     // will leverage successful file downloads from previous attempts.
     //
     // TODO: This will also require imports using a predictable jobTempDirPath.
@@ -287,7 +287,7 @@ NSString *const kOWSBackup_ImportDatabaseKeySpec = @"kOWSBackup_ImportDatabaseKe
                 // Attachment-related errors are recoverable and can be ignored.
                 continue;
             }
-            [attachment updateWithLazyRestoreFragment:item transaction:transaction];
+            [attachment markForLazyRestoreWithFragment:item transaction:transaction];
             count++;
             [self updateProgressWithDescription:NSLocalizedString(@"BACKUP_IMPORT_PHASE_RESTORING_FILES",
                                                     @"Indicates that the backup import data is being restored.")

SignalServiceKit/src/Messages/Attachments/TSAttachmentStream.h

@@ -69,8 +69,8 @@ NS_ASSUME_NONNULL_BEGIN
 #pragma mark - Update With... Methods
 
 // Marks attachment as needing "lazy backup restore."
-- (void)updateWithLazyRestoreFragment:(OWSBackupFragment *)lazyRestoreFragment
+- (void)markForLazyRestoreWithFragment:(OWSBackupFragment *)lazyRestoreFragment
-                          transaction:(YapDatabaseReadWriteTransaction *)transaction;
+                           transaction:(YapDatabaseReadWriteTransaction *)transaction;
 // Marks attachment as having completed "lazy backup restore."
 - (void)updateWithLazyRestoreComplete;
 

SignalServiceKit/src/Messages/Attachments/TSAttachmentStream.m

@@ -623,8 +623,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - Update With... Methods
 
-- (void)updateWithLazyRestoreFragment:(OWSBackupFragment *)lazyRestoreFragment
+- (void)markForLazyRestoreWithFragment:(OWSBackupFragment *)lazyRestoreFragment
-                          transaction:(YapDatabaseReadWriteTransaction *)transaction
+                           transaction:(YapDatabaseReadWriteTransaction *)transaction
 {
     OWSAssert(lazyRestoreFragment);
     OWSAssert(transaction);