acquireLock method

@override Future acquireLock(String? correlationId, String key, int ttl, int timeout)

Makes multiple attempts to acquire a lock by its key within give time interval.

• correlationId (optional) transaction id to trace execution through call chain.
• key a unique lock key to acquire.
• ttl a lock timeout (time to live) in milliseconds.
• timeout a lock acquisition timeout. Return Future that receives null for success. Throw error

Implementation

@override
Future acquireLock(
    String? correlationId, String key, int ttl, int timeout) async {
  var retryTime = DateTime.now()
      .toUtc()
      .add(Duration(milliseconds: timeout))
      .millisecondsSinceEpoch;

  // Try to get lock first
  var result = await tryAcquireLock(correlationId, key, ttl);
  if (result) {
    return null;
  }
  // Start retrying
  var now = DateTime.now().toUtc().millisecondsSinceEpoch;
  for (; now <= retryTime;) {
    await Future.delayed(Duration(milliseconds: _retryTimeout));
    result = await tryAcquireLock(correlationId, key, ttl);
    if (result) {
      return;
    }
    now = DateTime.now().toUtc().millisecondsSinceEpoch;
  }
  // When timeout expires throw exception
  throw ConflictException(correlationId, 'LOCK_TIMEOUT',
          'Acquiring lock ' + key + ' failed on timeout')
      .withDetails('key', key);
}