1 files changed, 64 insertions, 0 deletions
diff --git a/src/main/java/com/code_intelligence/jazzer/mutation/support/RandomSupport.java b/src/main/java/com/code_intelligence/jazzer/mutation/support/RandomSupport.java
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+++ b/src/main/java/com/code_intelligence/jazzer/mutation/support/RandomSupport.java
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+/*
+ * Copyright 2023 Code Intelligence GmbH
+ *
+ * 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 com.code_intelligence.jazzer.mutation.support;
+
+import java.util.SplittableRandom;
+
+public final class RandomSupport {
+  private RandomSupport() {}
+
+  /**
+   * Polyfill for {@link SplittableRandom#nextBytes(byte[])}, which is not available in Java 8.
+   */
+  public static void nextBytes(SplittableRandom random, byte[] bytes) {
+    // Taken from the implementation contract
+    // https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/random/RandomGenerator.html#nextBytes(byte%5B%5D)
+    // for interoperability with the RandomGenerator interface available as of Java 17.
+    int i = 0;
+    int len = bytes.length;
+    for (int words = len >> 3; words-- > 0;) {
+      long rnd = random.nextLong();
+      for (int n = 8; n-- > 0; rnd >>>= Byte.SIZE) bytes[i++] = (byte) rnd;
+    }
+    if (i < len)
+      for (long rnd = random.nextLong(); i<len; rnd>>>= Byte.SIZE) bytes[i++] = (byte) rnd;
+  }
+
+  /**
+   * Clamp function for integers, which Java does not yet have
+   *
+   * @param value the value you want to clamp
+   * @param min the minimum allowable value (inclusive)
+   * @param max the maximum allowable value (inclusive)
+   * @return Closest number to {@code value} within the range {@code [min, max]}
+   */
+  public static int clamp(int value, int min, int max) {
+    return Math.min(Math.max(value, min), max);
+  }
+
+  /**
+   * Clamp function for longs, which Java does not yet have
+   *
+   * @param value the value you want to clamp
+   * @param min the minimum allowable value (inclusive)
+   * @param max the maximum allowable value (inclusive)
+   * @return Closest number to {@code value} within the range {@code [min, max]}
+   */
+  public static long clamp(long value, long min, long max) {
+    return Math.min(Math.max(value, min), max);
+  }
+}