Fall back on basic StringCodec if FastStringCodec isn't available

Also adds a method which can be used to tell if this behavior actually applied,
for more performance-sensitive users.

PiperOrigin-RevId: 172512011

2 files changed, 38 insertions, 1 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/serialization/strings/FastStringCodecTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/serialization/strings/FastStringCodecTest.java
index b472f54b49..30b9a1ded2 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/serialization/strings/FastStringCodecTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/serialization/strings/FastStringCodecTest.java
@@ -26,7 +26,8 @@ public class FastStringCodecTest extends AbstractObjectCodecTest<String> {
 
   public FastStringCodecTest() {
     super(
-        new FastStringCodec(),
+        // TODO(michajlo): Don't bother running this test if FastStringCodec isn't available.
+        FastStringCodec.isAvailable() ? new FastStringCodec() : new StringCodec(),
         "ow now brown cow. ow now brown cow",
         "（╯°□°）╯︵┻━┻ string with utf8/ascii",
         "string with ascii/utf8 （╯°□°）╯︵┻━┻",
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/serialization/strings/StringCodecsTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/serialization/strings/StringCodecsTest.java
new file mode 100644
index 0000000000..52c50fc8ab
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/serialization/strings/StringCodecsTest.java
@@ -0,0 +1,36 @@
+// Copyright 2017 The Bazel Authors. All rights reserved.
+//
+// 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.google.devtools.build.lib.skyframe.serialization.strings;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** {@link StringCodecs} tests */
+@RunWith(JUnit4.class)
+public class StringCodecsTest {
+
+  @Test
+  public void testUsesFastStringCodecIfAvailable() {
+    if (FastStringCodec.isAvailable()) {
+      assertThat(StringCodecs.asciiOptimized()).isInstanceOf(FastStringCodec.class);
+    } else {
+      assertThat(StringCodecs.asciiOptimized()).isSameAs(StringCodecs.simple());
+    }
+  }
+
+}