first commit

siro_rider/packages/get/lib/get_utils/src/queue/get_queue.dart

@@ -0,0 +1,57 @@
+import 'dart:async';
+
+class GetMicrotask {
+  int _version = 0;
+  int _microtask = 0;
+
+  int get microtask => _microtask;
+  int get version => _version;
+
+  void exec(Function callback) {
+    if (_microtask == _version) {
+      _microtask++;
+      scheduleMicrotask(() {
+        _version++;
+        _microtask = _version;
+        callback();
+      });
+    }
+  }
+}
+
+class GetQueue {
+  final List<_Item> _queue = [];
+  bool _active = false;
+
+  Future<T> add<T>(Function job) {
+    var completer = Completer<T>();
+    _queue.add(_Item(completer, job));
+    _check();
+    return completer.future;
+  }
+
+  void cancelAllJobs() {
+    _queue.clear();
+  }
+
+  void _check() async {
+    if (!_active && _queue.isNotEmpty) {
+      _active = true;
+      var item = _queue.removeAt(0);
+      try {
+        item.completer.complete(await item.job());
+      } on Exception catch (e) {
+        item.completer.completeError(e);
+      }
+      _active = false;
+      _check();
+    }
+  }
+}
+
+class _Item {
+  final dynamic completer;
+  final dynamic job;
+
+  _Item(this.completer, this.job);
+}