test & benchmark clean-up

Added tests to verify that big strings are not cached

Author: dougqh

dd-trace-core/src/jmh/java/datadog/trace/common/writer/ddagent/Utf8Benchmark.java

@@ -7,9 +7,6 @@
 import org.openjdk.jmh.annotations.Mode;
 import org.openjdk.jmh.infra.Blackhole;
 
-import datadog.trace.common.writer.ddagent.GenerationalUtf8Cache;
-import datadog.trace.common.writer.ddagent.SimpleUtf8CacheTest;
-
 /**
  * This benchmark isn't really intended to used to measure throughput, but rather to be used with
  * "-prof gc" to check bytes / op.

dd-trace-core/src/test/java/datadog/trace/common/writer/ddagent/GenerationalUtf8CacheTest.java

@@ -1,9 +1,10 @@
 package datadog.trace.common.writer.ddagent;
 
 import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertSame;
-import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 import java.nio.charset.StandardCharsets;
 import java.util.Random;
@@ -110,6 +111,33 @@ public void fuzz() {
     assertNotEquals(0, promotedHits);
   }
 
+  @Test
+  public void bigString_dont_cache() {
+    String lorem = "Lorem ipsum dolor sit amet";
+    while (lorem.length() < 500) {
+      lorem += lorem;
+    }
+    byte[] expected = lorem.getBytes(StandardCharsets.UTF_8);
+
+    GenerationalUtf8Cache cache = new GenerationalUtf8Cache();
+    byte[] first = cache.getUtf8(lorem);
+    assertArrayEquals(expected, first);
+
+    byte[] second = cache.getUtf8(lorem);
+    assertArrayEquals(expected, second);
+    assertNotSame(first, second);
+
+    for (int i = 0; i < 10; ++i) {
+      byte[] result = cache.getUtf8(lorem);
+      assertArrayEquals(expected, result);
+
+      assertNotSame(first, result);
+      assertNotSame(second, result);
+    }
+    assertEquals(0, cache.edenHits);
+    assertEquals(0, cache.tenuredHits);
+  }
+
   static final String[] TAGS = {"foo", "bar", "baz"};
 
   static final String[] BASE_STRINGS = {"Hello", "world", "foo", "bar", "baz", "quux"};

dd-trace-core/src/test/java/datadog/trace/common/writer/ddagent/SimpleUtf8CacheTest.java

@@ -1,9 +1,10 @@
 package datadog.trace.common.writer.ddagent;
 
 import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertSame;
-import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 import java.nio.charset.StandardCharsets;
 import java.util.Random;
@@ -75,6 +76,32 @@ public void fuzz() {
     assertNotEquals(0, hits);
   }
 
+  @Test
+  public void bigString_dont_cache() {
+    String lorem = "Lorem ipsum dolor sit amet";
+    while (lorem.length() < 100) {
+      lorem += lorem;
+    }
+    byte[] expected = lorem.getBytes(StandardCharsets.UTF_8);
+
+    SimpleUtf8Cache cache = new SimpleUtf8Cache();
+    byte[] first = cache.getUtf8(lorem);
+    assertArrayEquals(expected, first);
+
+    byte[] second = cache.getUtf8(lorem);
+    assertArrayEquals(expected, second);
+    assertNotSame(first, second);
+
+    for (int i = 0; i < 10; ++i) {
+      byte[] result = cache.getUtf8(lorem);
+      assertArrayEquals(expected, result);
+
+      assertNotSame(first, result);
+      assertNotSame(second, result);
+    }
+    assertEquals(0, cache.hits);
+  }
+
   static final String[] TAGS = {"foo", "bar", "baz"};
 
   static final String[] BASE_STRINGS = {"Hello", "world", "foo", "bar", "baz", "quux"};