added some functions to remove messages

before a certain timestamp

Author: Velin92

MatrixSDK/Data/Store/MXMemoryStore/MXMemoryRoomStore.h

@@ -48,6 +48,16 @@
  */
 - (void)replaceEvent:(MXEvent*)event;
 
+/**
+ Remove all the messages sent before a specific timestamp in a room.
+ The state events are not removed during this operation. We keep them in the timeline.
+ 
+ @param limitTs the timestamp from which the messages are kept.
+ 
+ @return YES if at least one event has been removed.
+ */
+- (BOOL)removeAllMessagesSentBefore:(uint64_t)limitTs;
+
 /**
  Get an event from this room.
 

MatrixSDK/Data/Store/MXMemoryStore/MXMemoryRoomStore.m

@@ -197,4 +197,31 @@ - (NSString *)description
     return [NSString stringWithFormat:@"%tu messages - paginationToken: %@ - hasReachedHomeServerPaginationEnd: %@ - hasLoadedAllRoomMembersForRoom: %@", messages.count, _paginationToken, @(_hasReachedHomeServerPaginationEnd), @(_hasLoadedAllRoomMembersForRoom)];
 }
 
+- (BOOL)removeAllMessagesSentBefore:(uint64_t)limitTs
+{
+    NSUInteger index = 0;
+    BOOL didChange = NO;
+    while (index < messages.count)
+    {
+        MXEvent *anEvent = [messages objectAtIndex:index];
+        if (anEvent.isState)
+        {
+            // Keep state event
+            index ++;
+        }
+        else if (anEvent.originServerTs < limitTs)
+        {
+            [messages removeObjectAtIndex:index];
+            [messagesByEventIds removeObjectForKey:anEvent.eventId];
+            didChange = YES;
+        }
+        else
+        {
+            // Break the loop, we've reached the first non-state event in the timeline which is not expired
+            break;
+        }
+    }
+    return didChange;
+}
+
 @end

MatrixSDK/Data/Store/MXMemoryStore/MXMemoryStore.m

@@ -83,6 +83,12 @@ - (void)replaceEvent:(MXEvent *)event inRoom:(NSString *)roomId
     [roomStore replaceEvent:event];
 }
 
+- (BOOL)removeAllMessagesSentBefore:(uint64_t)limitTs inRoom:(nonnull NSString *)roomId
+{
+    MXMemoryRoomStore *roomStore = [self getOrCreateRoomStore:roomId];
+    return [roomStore removeAllMessagesSentBefore:limitTs];
+}
+
 - (BOOL)eventExistsWithEventId:(NSString *)eventId inRoom:(NSString *)roomId
 {
     return (nil != [self eventWithEventId:eventId inRoom:roomId]);

MatrixSDK/Data/Store/MXNoStore/MXNoStore.m

@@ -124,6 +124,17 @@ - (BOOL)eventExistsWithEventId:(NSString *)eventId inRoom:(NSString *)roomId
     return NO;
 }
 
+- (BOOL)removeAllMessagesSentBefore:(uint64_t)limitTs inRoom:(nonnull NSString *)roomId
+{
+    // Only the last message is stored
+    MXEvent *lastMessage = lastMessages[roomId];
+    if (!lastMessage.isState && lastMessage.originServerTs < limitTs) {
+        lastMessages[roomId] = nil;
+        return YES;
+    }
+    return NO;
+}
+
 - (MXEvent *)eventWithEventId:(NSString *)eventId inRoom:(NSString *)roomId
 {
     // Events are not stored. So, we cannot find it.

MatrixSDK/Data/Store/MXStore.h

@@ -593,5 +593,17 @@
                   success:(nonnull void (^)(NSString * _Nullable filterId))success
                   failure:(nullable void (^)(NSError * _Nullable error))failure;
 
+/**
+ Remove all the messages sent before a specific timestamp in a room.
+ The state events are not removed during this operation. We keep them in the timeline.
+ This operation doesn't change the pagination token, and the flag indicating that the SDK has reached the end of pagination.
+ 
+ @param limitTs the timestamp from which the messages are kept.
+ @param roomId the id of the room.
+ 
+ @return YES if at least one event has been removed.
+ */
+- (BOOL)removeAllMessagesSentBefore:(uint64_t)limitTs inRoom:(nonnull NSString *)roomId;
+
 
 @end