WIP unjank home screen

verify `description` isn't used elsewhere (notifications? conversation
view?)

Probably want to remove overzealous asserts for now, but would be good
to work towards leaving them enabled.

// FREEBIE

Signal/src/ViewControllers/HomeView/HomeViewCell.h

@@ -6,6 +6,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @class OWSContactsManager;
 @class TSThread;
+@class YapDatabaseReadTransaction;
 
 @interface HomeViewCell : UITableViewCell
 
@@ -15,7 +16,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)configureWithThread:(TSThread *)thread
             contactsManager:(OWSContactsManager *)contactsManager
-      blockedPhoneNumberSet:(NSSet<NSString *> *)blockedPhoneNumberSet;
+      blockedPhoneNumberSet:(NSSet<NSString *> *)blockedPhoneNumberSet
+                transaction:(YapDatabaseReadTransaction *)transaction;
 
 @end
 

Signal/src/ViewControllers/HomeView/HomeViewCell.m

@@ -146,11 +146,13 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)configureWithThread:(TSThread *)thread
               contactsManager:(OWSContactsManager *)contactsManager
         blockedPhoneNumberSet:(NSSet<NSString *> *)blockedPhoneNumberSet
+                transaction:(YapDatabaseReadTransaction *)transaction
 {
     OWSAssertIsOnMainThread();
     OWSAssert(thread);
     OWSAssert(contactsManager);
     OWSAssert(blockedPhoneNumberSet);
+    OWSAssert(transaction);
 
     self.thread = thread;
     self.contactsManager = contactsManager;
@@ -171,7 +173,9 @@ NS_ASSUME_NONNULL_BEGIN
     // changes to the dynamic type settings are reflected.
     self.snippetLabel.font = [self snippetFont];
     self.snippetLabel.attributedText =
-        [self attributedSnippetForThread:thread blockedPhoneNumberSet:blockedPhoneNumberSet];
+        [self attributedSnippetForThread:thread
+                   blockedPhoneNumberSet:blockedPhoneNumberSet
+                             transaction:transaction];
 
     self.dateTimeLabel.text = [self stringForDate:thread.lastMessageDate];
 
@@ -253,6 +257,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSAttributedString *)attributedSnippetForThread:(TSThread *)thread
                              blockedPhoneNumberSet:(NSSet<NSString *> *)blockedPhoneNumberSet
+                                       transaction:(YapDatabaseReadTransaction *)transaction
 {
     OWSAssert(thread);
 
@@ -285,7 +290,7 @@ NS_ASSUME_NONNULL_BEGIN
                                                                     : [UIColor lightGrayColor]),
                                                         }]];
         }
-        NSString *displayableText = thread.lastMessageLabel.filterStringForDisplay;
+        NSString *displayableText = [thread lastMessageLabelWithTransaction:transaction];
         if (displayableText) {
             [snippetText appendAttributedString:[[NSAttributedString alloc]
                                                     initWithString:displayableText

Signal/src/ViewControllers/HomeView/HomeViewController.m

@@ -395,7 +395,11 @@ typedef NS_ENUM(NSInteger, CellState) { kArchiveState, kInboxState };
 - (void)viewWillAppear:(BOOL)animated
 {
     [super viewWillAppear:animated];
-    if ([TSThread numberOfKeysInCollection] > 0) {
+    __block BOOL hasAnyMessages;
+    [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction * _Nonnull transaction) {
+        hasAnyMessages = [self hasAnyMessagesWithTransaction:transaction];
+    }];
+    if (hasAnyMessages) {
         [self.contactsManager requestSystemContactsOnceWithCompletion:^(NSError *_Nullable error) {
             dispatch_async(dispatch_get_main_queue(), ^{
                 [self updateReminderViews];
@@ -490,7 +494,11 @@ typedef NS_ENUM(NSInteger, CellState) { kArchiveState, kInboxState };
 
     // If the user hasn't already granted contact access
     // we don't want to request until they receive a message.
-    if ([TSThread numberOfKeysInCollection] > 0) {
+    __block BOOL hasAnyMessages;
+    [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction * _Nonnull transaction) {
+        hasAnyMessages = [self hasAnyMessagesWithTransaction:transaction];
+    }];
+    if (hasAnyMessages) {
         [self.contactsManager requestSystemContactsOnce];
     }
 }
@@ -506,11 +514,21 @@ typedef NS_ENUM(NSInteger, CellState) { kArchiveState, kInboxState };
     self.isAppInBackground = YES;
 }
 
+- (BOOL)hasAnyMessagesWithTransaction:(YapDatabaseReadTransaction *)transaction
+{
+    return [TSThread numberOfKeysInCollectionWithTransaction:transaction] > 0;
+}
+
 - (void)applicationDidBecomeActive:(NSNotification *)notification
 {
     // It's possible a thread was created while we where in the background. But since we don't honor contact
     // requests unless the app is in the foregrond, we must check again here upon becoming active.
-    if ([TSThread numberOfKeysInCollection] > 0) {
+    __block BOOL hasAnyMessages;
+    [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction * _Nonnull transaction) {
+        hasAnyMessages = [self hasAnyMessagesWithTransaction:transaction];
+    }];
+    
+    if (hasAnyMessages) {
         [self.contactsManager requestSystemContactsOnceWithCompletion:^(NSError *_Nullable error) {
             dispatch_async(dispatch_get_main_queue(), ^{
                 [self updateReminderViews];
@@ -584,9 +602,12 @@ typedef NS_ENUM(NSInteger, CellState) { kArchiveState, kInboxState };
 
     TSThread *thread = [self threadForIndexPath:indexPath];
 
-    [cell configureWithThread:thread
-              contactsManager:self.contactsManager
-        blockedPhoneNumberSet:self.blockedPhoneNumberSet];
+    [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction * _Nonnull transaction) {
+        [cell configureWithThread:thread
+                  contactsManager:self.contactsManager
+            blockedPhoneNumberSet:self.blockedPhoneNumberSet
+                      transaction:transaction];
+    }];
 
     if ((unsigned long)indexPath.row == [self.threadMappings numberOfItemsInSection:0] - 1) {
         cell.separatorInset = UIEdgeInsetsMake(0.f, cell.bounds.size.width, 0.f, 0.f);

SignalServiceKit/src/Contacts/TSThread.h

@@ -90,7 +90,7 @@ NS_ASSUME_NONNULL_BEGIN
  *
  *  @return Thread preview string.
  */
-- (NSString *)lastMessageLabel;
+- (NSString *)lastMessageLabelWithTransaction:(YapDatabaseReadTransaction *)transaction;
 
 /**
  *  Updates the thread's caches of the latest interaction.

SignalServiceKit/src/Contacts/TSThread.m

@@ -4,6 +4,7 @@
 
 #import "TSThread.h"
 #import "NSDate+OWS.h"
+#import "NSString+SSK.h"
 #import "OWSPrimaryStorage.h"
 #import "OWSReadTracking.h"
 #import "TSDatabaseView.h"
@@ -246,26 +247,24 @@ NS_ASSUME_NONNULL_BEGIN
     return last;
 }
 
-- (TSInteraction *)lastInteractionForInbox
+- (TSInteraction *)lastInteractionForInboxWithTransaction:(YapDatabaseReadTransaction *)transaction
 {
     __block TSInteraction *last = nil;
-    [OWSPrimaryStorage.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
-        [[transaction ext:TSMessageDatabaseViewExtensionName]
-            enumerateRowsInGroup:self.uniqueId
-                     withOptions:NSEnumerationReverse
-                      usingBlock:^(
-                          NSString *collection, NSString *key, id object, id metadata, NSUInteger index, BOOL *stop) {
-
-                          OWSAssert([object isKindOfClass:[TSInteraction class]]);
-
-                          TSInteraction *interaction = (TSInteraction *)object;
-
-                          if ([TSThread shouldInteractionAppearInInbox:interaction]) {
-                              last = interaction;
-                              *stop = YES;
-                          }
-                      }];
-    }];
+    [[transaction ext:TSMessageDatabaseViewExtensionName]
+     enumerateRowsInGroup:self.uniqueId
+     withOptions:NSEnumerationReverse
+     usingBlock:^(
+                  NSString *collection, NSString *key, id object, id metadata, NSUInteger index, BOOL *stop) {
+         
+         OWSAssert([object isKindOfClass:[TSInteraction class]]);
+         
+         TSInteraction *interaction = (TSInteraction *)object;
+         
+         if ([TSThread shouldInteractionAppearInInbox:interaction]) {
+             last = interaction;
+             *stop = YES;
+         }
+     }];
     return last;
 }
 
@@ -277,12 +276,14 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
-- (NSString *)lastMessageLabel {
-    TSInteraction *interaction = self.lastInteractionForInbox;
-    if (interaction == nil) {
-        return @"";
+- (NSString *)lastMessageLabelWithTransaction:(YapDatabaseReadTransaction *)transaction
+{
+    TSInteraction *interaction = [self lastInteractionForInboxWithTransaction:transaction];
+    if ([interaction conformsToProtocol:@protocol(OWSPreviewText)]) {
+        id<OWSPreviewText> previewable = (id<OWSPreviewText>)interaction;
+        return [previewable previewTextWithTransaction:transaction].filterStringForDisplay;
     } else {
-        return interaction.description;
+        return @"";
     }
 }
 

SignalServiceKit/src/Messages/Interactions/OWSDisappearingConfigurationUpdateInfoMessage.m

@@ -56,7 +56,7 @@ NS_ASSUME_NONNULL_BEGIN
     return NO;
 }
 
-- (NSString *)description
+-(NSString *)previewTextWithTransaction:(YapDatabaseReadTransaction *)transaction
 {
     if (self.createdByRemoteName) {
         if (self.configurationIsEnabled && self.configurationDurationSeconds > 0) {

SignalServiceKit/src/Messages/Interactions/TSErrorMessage.m

@@ -97,7 +97,8 @@ NSUInteger TSErrorMessageSchemaVersion = 1;
     return OWSInteractionType_Error;
 }
 
-- (NSString *)description {
+- (NSString *)previewTextWithTransaction:(YapDatabaseReadTransaction *)transaction
+{
     switch (_errorType) {
         case TSErrorMessageNoSession:
             return NSLocalizedString(@"ERROR_MESSAGE_NO_SESSION", @"");

SignalServiceKit/src/Messages/Interactions/TSInfoMessage.m

@@ -91,7 +91,8 @@ NSUInteger TSInfoMessageSchemaVersion = 1;
     return OWSInteractionType_Info;
 }
 
-- (NSString *)description {
+- (NSString *)previewTextWithTransaction:(YapDatabaseReadTransaction *)transaction
+{
     switch (_messageType) {
         case TSInfoMessageTypeSessionDidEnd:
             return NSLocalizedString(@"SECURE_SESSION_RESET", nil);

SignalServiceKit/src/Messages/Interactions/TSInteraction.h

@@ -19,6 +19,12 @@ typedef NS_ENUM(NSInteger, OWSInteractionType) {
     OWSInteractionType_Offer,
 };
 
+@protocol OWSPreviewText
+
+- (NSString *)previewTextWithTransaction:(YapDatabaseReadTransaction *)transaction;
+
+@end
+
 @interface TSInteraction : TSYapDatabaseObject
 
 - (instancetype)initInteractionWithTimestamp:(uint64_t)timestamp inThread:(TSThread *)thread;

SignalServiceKit/src/Messages/Interactions/TSInteraction.m

@@ -128,6 +128,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (NSString *)description {
+    OWSFail(@"Abstract Method");
     return @"Interaction description";
 }
 

SignalServiceKit/src/Messages/Interactions/TSMessage.h

@@ -15,7 +15,7 @@ NS_ASSUME_NONNULL_BEGIN
 @class TSQuotedMessage;
 @class YapDatabaseReadWriteTransaction;
 
-@interface TSMessage : TSInteraction
+@interface TSMessage : TSInteraction <OWSPreviewText>
 
 @property (nonatomic, readonly) NSMutableArray<NSString *> *attachmentIds;
 @property (nonatomic, readonly, nullable) NSString *body;
@@ -39,7 +39,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (BOOL)hasAttachments;
 - (nullable TSAttachment *)attachmentWithTransaction:(YapDatabaseReadTransaction *)transaction;
-- (NSString *)previewTextWithTransaction:(YapDatabaseReadTransaction *)transaction;
 - (void)setQuotedMessageThumbnailAttachmentStream:(TSAttachmentStream *)attachmentStream;
 
 - (BOOL)shouldStartExpireTimer;

SignalServiceKit/src/Messages/Interactions/TSMessage.m

@@ -265,14 +265,11 @@ static const NSUInteger OWSMessageSchemaVersion = 4;
     }
 }
 
-// TODO deprecate this and implement something like previewTextWithTransaction: for all TSInteractions
 - (NSString *)description
 {
-    __block NSString *result;
-    [self.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
-        result = [self previewTextWithTransaction:transaction];
-    }];
-    return result;
+    // TODO verify this isn't exposed in the UI
+    OWSFail(@"%@ in %s verify this isn't being used anywhere except logging.", self.logTag, __PRETTY_FUNCTION__);
+    return [super description];
 }
 
 - (void)removeWithTransaction:(YapDatabaseReadWriteTransaction *)transaction

SignalServiceKit/src/Messages/TSCall.m

@@ -67,7 +67,13 @@ NSUInteger TSCallCurrentSchemaVersion = 1;
     return OWSInteractionType_Call;
 }
 
-- (NSString *)description {
+- (NSString *)previewTextWithTransaction:(YapDatabaseReadTransaction *)transaction
+{
+    return [self previewText];
+}
+
+- (NSString *)previewText
+{
     switch (_callType) {
         case RPRecentCallTypeIncoming:
             return NSLocalizedString(@"INCOMING_CALL", @"");
@@ -83,10 +89,16 @@ NSUInteger TSCallCurrentSchemaVersion = 1;
             return NSLocalizedString(@"INFO_MESSAGE_MISSED_CALL_DUE_TO_CHANGED_IDENITY", @"info message text shown in conversation view");
         case RPRecentCallTypeIncomingDeclined:
             return NSLocalizedString(@"INCOMING_DECLINED_CALL",
-                @"info message recorded in conversation history when local user declined a call");
+                                     @"info message recorded in conversation history when local user declined a call");
     }
 }
 
+- (NSString *)description
+{
+    OWSFail(@"%@ in %s verify this isnt exposed in the UI", self.logTag, __PRETTY_FUNCTION__);
+    return [self previewText];
+}
+
 #pragma mark - OWSReadTracking
 
 - (uint64_t)expireStartedAt

SignalServiceKit/src/Storage/TSYapDatabaseObject.m

@@ -109,17 +109,20 @@ NS_ASSUME_NONNULL_BEGIN
 
 + (YapDatabaseConnection *)dbReadConnection
 {
+    OWSAssert(![NSThread isMainThread]);
+    
     // We use TSYapDatabaseObject's dbReadWriteConnection (not OWSPrimaryStorage's
     // dbReadConnection) for consistency, since we tend to [TSYapDatabaseObject
     // save] and want to write to the same connection we read from.  To get true
     // consistency, we'd want to update entities by reading & writing from within
     // the same transaction, but that'll be a big refactor.
-
     return self.dbReadWriteConnection;
 }
 
 + (YapDatabaseConnection *)dbReadWriteConnection
 {
+    OWSAssert(![NSThread isMainThread]);
+
     // Use a dedicated connection for model reads & writes.
     static YapDatabaseConnection *dbReadWriteConnection = nil;
     static dispatch_once_t onceToken;