I stuck at this error for a month I cannot find any solution via google. I build a chat app which need to work both online and offline, backend is NodeJS Below code is send any message that still in pending to target devices
async function _worker(socket) {
console.log('worker running...')
await connect.then(async (db) => {
// When user A sent message to user B but user B is offline so server need to sync this message to user B
Message.find({ isDeliver: 0 }).then(async (m) => {
if (m.length > 0) {
for (let i = 0; i < m.length; i++) {
let sender = m[i].sender;
let receiver = m[i].receiver;
let online = await checkUserOnline(socket, receiver);
if (online) {
let to_user_socket_id = getSocketIDfromMapForthisUser(`${receiver}`)
sendToConnectedSocket(socket, to_user_socket_id, "send_message_to_device", m[i]);
}
}
}
});
// When user A sent a message to user B and user B is offline but when user B is online and message delivered to user B and user A is offline server need to sync this message status to update for user A
Message.find({ isDeliver: 1 }).then(async (m) => {
if (m.length > 0) {
for (let i = 0; i < m.length; i++) {
let sender = m[i].sender;
let receiver = m[i].receiver;
let online = await checkUserOnline(socket, sender);
if (online) {
let to_user_socket_id = getSocketIDfromMapForthisUser(`${sender}`)
sendToConnectedSocket(socket, to_user_socket_id, "send_message_deliver", m[i]);
}
}
}
});
// When user A sent a message to user B and user B is offline but when user B is online and read the message and user A is offline server need to sync this message status to update for user A
Message.find({ isRead: 1 }).then(async (m) => {
if (m.length > 0) {
for (let i = 0; i < m.length; i++) {
let sender = m[i].sender;
let receiver = m[i].receiver;
let online = await checkUserOnline(socket, sender);
if (online) {
let to_user_socket_id = getSocketIDfromMapForthisUser(`${sender}`)
sendToConnectedSocket(socket, to_user_socket_id, "send_message_read", m[i]);
}
}
}
});
});
}
and below is a method to handle event from server:
Socket
setOnServerSendDeliver(Function onServerSendDeliver) {
_socket.on('send_message_deliver', (data) {
onServerSendDeliver(data);
});
}
setOnServerSendRead(Function onServerSendRead) {
_socket.on('send_message_read', (data) {
onServerSendRead(data);
});
}
setOnServerSendToDevice(Function onServerSendToDevice) {
_socket.on('send_message_to_device', (data) {
onServerSendToDevice(data);
});
}
Method
onServerSendDeliver(data) async {
MessageModel message = MessageModel.fromJson(jsonDecode(data));
await G.dbService.updateDeliver(message);
G.socketUtils.sendDeliveryDone(message, new UserModel(id: message.sender));
refreshMessage();
}
onServerSendRead(data) async {
MessageModel message = MessageModel.fromJson(jsonDecode(data));
await G.dbService.updateRead(message.chatId);
G.socketUtils.sendReadDone(message, new UserModel(id: message.sender));
refreshMessage();
}
onServerSendToDevice(data) async {
MessageModel message = MessageModel.fromJson(jsonDecode(data));
ChatModel chat = new ChatModel();
chat.id = message.chatId;
chat.fromId = message.sender;
chat.toId = message.receiver;
chat.message = message.content;
await G.dbService.chatOperation(chat);
await G.dbService.insertMessage(message);
await G.dbService.updateDeliver(message);
G.socketUtils.sendDelivery(message, new UserModel(id: message.sender));
refreshMessage();
}
in server I set
setInterval(_worker, 1500, socket);
to load check message and send to end devices
and my database function
Future<String> updateRead(String chatId) async {
Database db = await database;
try {
await db.transaction((txn) async {
return await txn.rawUpdate(
"UPDATE messages SET isRead = 1, isSend = 1, isDeliver = 1 WHERE chatId = ? AND status = 0",
[chatId]);
});
await db.transaction((txn) async {
return await txn.rawUpdate(
"UPDATE chats SET isRead = 1, isSend = 1, isDeliver = 1 WHERE id = ? AND status = 0",
[chatId]);
});
} catch (e) {
print(e.toString());
}
return chatId;
}
Future<String> updateDeliver(MessageModel message) async {
Database db = await database;
String id;
try {
id = message.id;
await db.transaction((txn) async {
return await txn.rawUpdate(
"UPDATE messages SET isDeliver = 1 WHERE id = ? AND status = 0",
[message.id]);
});
await db.transaction((txn) async {
return await txn.rawUpdate(
"UPDATE chats SET isDeliver = 1 WHERE id = ? AND status = 0",
[message.chatId]);
});
} catch (e) {
print(e.toString());
}
return id;
}
iOS is working fine but on android I always got this error and my app stuck:
flutter: Warning database has been locked for 0:00:10.000000. Make sure you always use the transaction object for database operations during a transaction
Any help would be appropriate
Update
I tried to modify the database function to:
Future<String> updateDeliver(MessageModel message) async {
Database db = await database;
String id;
try {
id = message.id;
await db.transaction((txn) async {
var batch = txn.batch();
batch.rawUpdate(
"UPDATE messages SET isDeliver = 1 WHERE id = ? AND status = 0",
[message.id]);
batch.rawUpdate(
"UPDATE chats SET isDeliver = 1 WHERE id = ? AND status = 0",
[message.chatId]);
batch.commit();
});
} catch (e) {
print(e.toString());
}
return id;
}
but I still faced the same issue
