1 files changed, 75 insertions, 0 deletions
diff --git a/impl/src/test/java/io/perfmark/impl/PerfMarkImplTest.java b/impl/src/test/java/io/perfmark/impl/PerfMarkImplTest.java
new file mode 100644
index 0000000..9a9259d
--- /dev/null
+++ b/impl/src/test/java/io/perfmark/impl/PerfMarkImplTest.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * 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.perfmark.impl;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class PerfMarkImplTest {
+
+  @Test
+  public void nextGeneration_enable() {
+    var gen = SecretPerfMarkImpl.PerfMarkImpl.nextGeneration(0, 3*1024);
+    assertEquals((3L<<10) + (1<<8), gen);
+  }
+
+  @Test
+  public void nextGeneration_disable() {
+    var gen = SecretPerfMarkImpl.PerfMarkImpl.nextGeneration(1 << Generator.GEN_OFFSET, 3*1024);
+    assertEquals((3L<<10), gen);
+  }
+
+  @Test
+  public void nextGeneration_newStampEnabled() {
+    var gen = SecretPerfMarkImpl.PerfMarkImpl.nextGeneration(
+        (3<< (Generator.GEN_OFFSET + 2))
+            + (1 << Generator.GEN_OFFSET),
+        3*1024);
+    assertEquals((3L<<10), gen);
+  }
+
+  @Test
+  public void nextGeneration_newStampDisabled() {
+    var gen = SecretPerfMarkImpl.PerfMarkImpl.nextGeneration(
+        (3<< (Generator.GEN_OFFSET + 2)),
+        3*1024);
+    assertEquals((4L<<10) + (1<<Generator.GEN_OFFSET), gen);
+  }
+
+  @Test
+  public void nextGeneration_maxNanos() {
+    var gen = SecretPerfMarkImpl.PerfMarkImpl.nextGeneration(1 << Generator.GEN_OFFSET, -1);
+    assertNotEquals(Generator.FAILURE, gen);
+  }
+
+  @Test
+  public void nextGeneration_noOverflowOnDisable() {
+    var gen = SecretPerfMarkImpl.PerfMarkImpl.nextGeneration(0xFFFF_FFFF_FFFF_FD00L, -1);
+    assertNotEquals(Generator.FAILURE, gen);
+  }
+
+  @Test
+  public void nextGeneration_overflowOnEnable() {
+    var gen = SecretPerfMarkImpl.PerfMarkImpl.nextGeneration(0xFFFF_FFFF_FFFF_FC00L, -1);
+    assertEquals(Generator.FAILURE, gen);
+  }
+}