feat(http): add new middleware feature

2022-06-24 15:58:48 +02:00
parent 14cb3485e4
commit 81367e5f3a
42 changed files with 1021 additions and 2146 deletions
@@ -0,0 +1,36 @@
+// Copyright (C) 2022 WYATT GROUP
+// Please see the AUTHORS file for details.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+import 'dart:core';
+import 'dart:math';
+
+abstract class Delay {
+  static Duration getRetryDelay(int attempt) {
+    assert(attempt >= 0, 'attempt cannot be negative');
+    if (attempt <= 0) {
+      return Duration.zero;
+    }
+    final rand = Random();
+    final Duration delayFactor = const Duration(milliseconds: 200);
+    final double randomizationFactor = 0.25;
+    final Duration maxDelay = const Duration(seconds: 30);
+
+    final rf = randomizationFactor * (rand.nextDouble() * 2 - 1) + 1;
+    final exp = min(attempt, 31); // prevent overflows.
+    final delay = delayFactor * pow(2.0, exp) * rf;
+    return delay < maxDelay ? delay : maxDelay;
+  }
+}