icu4c DateIntervalFormat objects are expensive enough that we need to cache them.

It takes ~1ms to create a DateIntervalFormat on a z620, and around 8ms on a
current mobile device (Nexus 4). Add a small cache of recently-used formatters,
using a big lock rather than per-thread caches since this typically only
happens on the UI thread anyway, and because all the other frameworks date/time
formatting is behind a single lock too.

Bug: 10696944
Change-Id: I8ccbe0b31b722a95a08fbc5a119173b7a0f44807

1 files changed, 56 insertions, 0 deletions

diff --git a/benchmarks/src/benchmarks/regression/DateIntervalFormatBenchmark.java b/benchmarks/src/benchmarks/regression/DateIntervalFormatBenchmark.java
new file mode 100644
index 0000000..02d8f97
--- /dev/null
+++ b/benchmarks/src/benchmarks/regression/DateIntervalFormatBenchmark.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2013 Google Inc.
+ *
+ * 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 benchmarks.regression;
+
+import com.google.caliper.SimpleBenchmark;
+
+import java.util.Locale;
+import java.util.TimeZone;
+
+import static libcore.icu.DateIntervalFormat.*;
+
+public class DateIntervalFormatBenchmark extends SimpleBenchmark {
+  public void timeDateIntervalFormat_formatDateRange_DATE(int reps) throws Exception {
+    Locale l = Locale.US;
+    TimeZone utc = TimeZone.getTimeZone("UTC");
+    int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_WEEKDAY;
+
+    for (int rep = 0; rep < reps; ++rep) {
+      formatDateRange(l, utc, 0L, 0L, flags);
+    }
+  }
+
+  public void timeDateIntervalFormat_formatDateRange_TIME(int reps) throws Exception {
+    Locale l = Locale.US;
+    TimeZone utc = TimeZone.getTimeZone("UTC");
+    int flags = FORMAT_SHOW_TIME | FORMAT_24HOUR;
+
+    for (int rep = 0; rep < reps; ++rep) {
+      formatDateRange(l, utc, 0L, 0L, flags);
+    }
+  }
+
+  public void timeDateIntervalFormat_formatDateRange_DATE_TIME(int reps) throws Exception {
+    Locale l = Locale.US;
+    TimeZone utc = TimeZone.getTimeZone("UTC");
+    int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_WEEKDAY | FORMAT_SHOW_TIME | FORMAT_24HOUR;
+
+    for (int rep = 0; rep < reps; ++rep) {
+      formatDateRange(l, utc, 0L, 0L, flags);
+    }
+  }
+}