Import atomix/{storage,utils}

[controller.git] / third-party / atomix / utils / src / main / java / io / atomix / utils / concurrent / Retries.java

diff --git a/third-party/atomix/utils/src/main/java/io/atomix/utils/concurrent/Retries.java b/third-party/atomix/utils/src/main/java/io/atomix/utils/concurrent/Retries.java
new file mode 100644 (file)
index 0000000..bd42a2b
--- /dev/null
+++ b/third-party/atomix/utils/src/main/java/io/atomix/utils/concurrent/Retries.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.atomix.utils.concurrent;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+/**
+ * Retry utilities.
+ */
+public final class Retries {
+
+  /**
+   * Returns a function that retries execution on failure.
+   * @param base base function
+   * @param exceptionClass type of exception for which to retry
+   * @param maxRetries max number of retries before giving up
+   * @param maxDelayBetweenRetries max delay between successive retries. The actual delay is randomly picked from
+   * the interval (0, maxDelayBetweenRetries]
+   * @return function
+   * @param <U> type of function input
+   * @param <V> type of function output
+   */
+  public static <U, V> Function<U, V> retryable(Function<U, V> base,
+                                                Class<? extends Throwable> exceptionClass,
+                                                int maxRetries,
+                                                int maxDelayBetweenRetries) {
+    return new RetryingFunction<>(base, exceptionClass, maxRetries, maxDelayBetweenRetries);
+  }
+
+  /**
+   * Returns a Supplier that retries execution on failure.
+   * @param base base supplier
+   * @param exceptionClass type of exception for which to retry
+   * @param maxRetries max number of retries before giving up
+   * @param maxDelayBetweenRetries max delay between successive retries. The actual delay is randomly picked from
+   * the interval (0, maxDelayBetweenRetries]
+   * @return supplier
+   * @param <V> type of supplied result
+   */
+  public static <V> Supplier<V> retryable(Supplier<V> base,
+                                          Class<? extends Throwable> exceptionClass,
+                                          int maxRetries,
+                                          int maxDelayBetweenRetries) {
+    return () -> new RetryingFunction<>(v -> base.get(),
+        exceptionClass,
+        maxRetries,
+        maxDelayBetweenRetries).apply(null);
+  }
+
+  /**
+   * Suspends the current thread for a random number of millis between 0 and
+   * the indicated limit.
+   *
+   * @param ms max number of millis
+   */
+  public static void randomDelay(int ms) {
+    try {
+      Thread.sleep(ThreadLocalRandom.current().nextInt(ms));
+    } catch (InterruptedException e) {
+      throw new RuntimeException("Interrupted", e);
+    }
+  }
+
+  /**
+   * Suspends the current thread for a specified number of millis and nanos.
+   *
+   * @param ms    number of millis
+   * @param nanos number of nanos
+   */
+  public static void delay(int ms, int nanos) {
+    try {
+      Thread.sleep(ms, nanos);
+    } catch (InterruptedException e) {
+      throw new RuntimeException("Interrupted", e);
+    }
+  }
+
+  private Retries() {
+  }
+
+}