[BUG] Excessive number of read operations from Firestore. #65
Description
Describe the bug
When using the FirestorePagination widget with isLive: true, the app performs an excessive number of read operations from Firestore, causing potential performance issues.
Package version: 4.0.1
Platform: ios and android
My Code
Expanded(
child: FirestorePagination(
query: FirebaseFirestore.instance
.collection('Chat')
.doc(controller.newMessage!.threadId)
.collection('Messages')
.orderBy('createdAt', descending: true),
limit: 20,
isLive: true,
shrinkWrap: true,
reverse: true,
controller: controller.scrollController,
itemBuilder: (context, snapshot, index) {
print('snapstot==================================');
print(snapshot.length);
final messageData =
snapshot[index].data() as Map<String, dynamic>;
final messageModel = MessageModel.fromMap(messageData);
bool showDateHeader = false;
bool showUnreadDivider = false;
if (index == snapshot.length - 1) {
showDateHeader = true;
} else if (!ConstantFunction().isSameDay(
messageModel.createdAt!.toDate(),
(snapshot[index + 1].data()
as Map<String, dynamic>)['createdAt']
.toDate())) {
showDateHeader = true;
}
if (index ==
controller.newMessage!.unreadMessages! - 1 &&
controller.newMessage!.receiverId ==
StaticData.userModel!.userId &&
controller.newMessage!.unreadMessages! >= 1) {
showUnreadDivider = true;
}
if (index == 0 &&
messageModel.receiverId ==
StaticData.userModel!.userId &&
messageModel.unreadMessages! >= 1) {
FirebaseChatService().resetMessageCountBadge(
messageModel: controller.newMessage!,
);
controller.newMessage!.unreadMessages = 0;
}
return Column(
crossAxisAlignment: messageModel.senderId ==
StaticData.userModel!.userId
? CrossAxisAlignment.end
: CrossAxisAlignment.start,
children: [
if (showDateHeader)
Padding(
padding:
const EdgeInsets.only(top: 10, bottom: 10),
child: Center(
child: Text(
ConstantFunction().formatDateHeader(
messageModel.createdAt!.toDate(),
),
style: TextStyle(
color: Colors.grey, fontSize: 14),
),
),
),
MessageBubble(
messageModel: messageModel,
index: index,
),
],
);
},
onEmpty: Center(
child: Text("No chat yet"),
),
),
)
Expected behavior
The FirestorePagination widget should efficiently load and display paginated messages without causing excessive read operations when isLive: true is enabled.
Actual behavior
When isLive: true is enabled, the widget performs an excessive number of Firestore reads, which can negatively impact app performance and incur higher Firestore read costs.
Screenshots/Code Snippets
In just one hour after implementation of this package.
Additional context
This issue is observed on both iOS and Android platforms.