Add a basic benchmark for android.text.format.Time

Add a benchmark to demonstrate performance tradeoffs between
alternatives for android.text.format.Time. This can be extended later
as needed for other Time usecases.

Executable with:
vogar --mode app_process --benchmark core/tests/benchmarks/src/android/text/format/AndroidTimeVsOthersBenchmark.java

Results from an aosp/master taimen:

    Experiment selection:
      Benchmark Methods:   [toMillis_androidIucUtil, toMillis_androidTime, toMillis_javaTime, toMillis_javaUtil]
      Instruments:   [runtime]
      User parameters:   {}
      Virtual machines:  [app_process]
      Selection type:    Full cartesian product
    This selection yields 4 experiments.
    Trial Report (1 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_androidIucUtil, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=6341.29, 1st qu.=6341.29, median=6341.29, mean=6341.29, 3rd qu.=6341.29, max=6341.29
    Trial Report (2 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_androidTime, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=12310.21, 1st qu.=12310.21, median=12310.21, mean=12310.21, 3rd qu.=12310.21, max=12310.21
    Trial Report (3 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_javaTime, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=1029.36, 1st qu.=1029.36, median=1029.36, mean=1029.36, 3rd qu.=1029.36, max=1029.36
    Trial Report (4 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_javaUtil, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=10142.66, 1st qu.=10142.66, median=10142.66, mean=10142.66, 3rd qu.=10142.66, max=10142.66
    Collected 4 measurements from:
      1 instrument(s)
      1 virtual machine(s)
      4 benchmark(s)

Note: When not cycling the time zone ID the results are different, but
java.time still comes out ahead.

    Trial Report (1 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_androidIucUtil, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=6583.57, 1st qu.=6583.57, median=6583.57, mean=6583.57, 3rd qu.=6583.57, max=6583.57
    Trial Report (2 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_androidTime, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=4653.01, 1st qu.=4653.01, median=4653.01, mean=4653.01, 3rd qu.=4653.01, max=4653.01
    Trial Report (3 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_javaTime, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=1095.20, 1st qu.=1095.20, median=1095.20, mean=1095.20, 3rd qu.=1095.20, max=1095.20
    Trial Report (4 of 4):
      Experiment {instrument=runtime, benchmarkMethod=toMillis_javaUtil, vm=app_process, parameters={}}
      Results:
        runtime(ns): min=2825.56, 1st qu.=2825.56, median=2825.56, mean=2825.56, 3rd qu.=2825.56, max=2825.56

Bug: 16550209
Test: see above
Change-Id: I8f1dffb083db00c2ea4cef40fd5cc2f4acab7a89
diff --git a/core/tests/benchmarks/src/android/text/format/AndroidTimeVsOthersBenchmark.java b/core/tests/benchmarks/src/android/text/format/AndroidTimeVsOthersBenchmark.java
new file mode 100644
index 0000000..ea24400
--- /dev/null
+++ b/core/tests/benchmarks/src/android/text/format/AndroidTimeVsOthersBenchmark.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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 android.text.format;
+
+import com.google.caliper.Benchmark;
+
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+
+public class AndroidTimeVsOthersBenchmark {
+
+    private static final String[] TIMEZONE_IDS = {
+            "Europe/London",
+            "America/Los_Angeles",
+            "Asia/Shanghai",
+    };
+
+    @Benchmark
+    public void toMillis_androidTime(int reps) {
+        long answer = 0;
+        for (int i = 0; i < reps; i++) {
+            String timezoneId = TIMEZONE_IDS[i % TIMEZONE_IDS.length];
+            Time time = new Time(timezoneId);
+            time.set(1, 2, 3, 4, 5, 2010);
+            answer = time.toMillis(false);
+        }
+        // System.out.println(answer);
+    }
+
+    @Benchmark
+    public void toMillis_javaTime(int reps) {
+        long answer = 0;
+        for (int i = 0; i < reps; i++) {
+            String timezoneId = TIMEZONE_IDS[i % TIMEZONE_IDS.length];
+            LocalDateTime time = LocalDateTime.of(2010, 5 + 1, 4, 3, 2, 1);
+            ZoneOffset offset = ZoneId.of(timezoneId).getRules().getOffset(time);
+            answer = time.toInstant(offset).toEpochMilli();
+        }
+        // System.out.println(answer);
+    }
+
+    @Benchmark
+    public void toMillis_javaUtil(int reps) {
+        long answer = 0;
+        for (int i = 0; i < reps; i++) {
+            String timezoneId = TIMEZONE_IDS[i % TIMEZONE_IDS.length];
+            java.util.TimeZone timeZone = java.util.TimeZone.getTimeZone(timezoneId);
+            java.util.Calendar calendar = new java.util.GregorianCalendar(timeZone);
+            calendar.set(2010, 5, 4, 3, 2, 1);
+            calendar.set(java.util.Calendar.MILLISECOND, 0);
+            answer = calendar.getTimeInMillis();
+        }
+        // System.out.println(answer);
+    }
+
+    @Benchmark
+    public void toMillis_androidIucUtil(int reps) {
+        long answer = 0;
+        for (int i = 0; i < reps; i++) {
+            String timezoneId = TIMEZONE_IDS[i % TIMEZONE_IDS.length];
+            android.icu.util.TimeZone timeZone =
+                    android.icu.util.TimeZone.getTimeZone(timezoneId);
+            android.icu.util.Calendar calendar = new android.icu.util.GregorianCalendar(timeZone);
+            calendar.set(2010, 5, 4, 3, 2, 1);
+            calendar.set(android.icu.util.Calendar.MILLISECOND, 0);
+            answer = calendar.getTimeInMillis();
+        }
+        // System.out.println(answer);
+    }
+}