Use ICU for relative time formatting

Rewrite the DateUtils' relative time formatting APIs
(getRelativeTimeSpanString, getRelativeDateTimeString) to use ICU ones.
Two APIs that take withPreposition parameter are not changed. Because
(a) ICU doesn't provide functionality to format preposition; (b) They
are not really computing relative time but instead calling
formatDateRange() to get the absolute time/date string.

Benchmark results on aosp_hammerhead-userdebug:

before:
                                     benchmark    us linear runtime
           DateUtils_getRelativeDateTimeString 127.1 ==========================
    DateUtils_getRelativeDateTimeString_ABBREV 145.0 ==============================
           DateUtils_getRelativeTimeSpanString  28.0 =====
    DateUtils_getRelativeTimeSpanString_ABBREV  27.9 =====

now:
                                                     benchmark    us linear runtime
           RelativeDateTimeFormatter_getRelativeDateTimeString 119.2 ==========================
    RelativeDateTimeFormatter_getRelativeDateTimeString_ABBREV 133.8 ==============================
           RelativeDateTimeFormatter_getRelativeTimeSpanString  24.6 =====
    RelativeDateTimeFormatter_getRelativeTimeSpanString_ABBREV  24.7 =====

Bug: 19146457
Bug: 5252772
Change-Id: Ief74608354964a17e42191d7b1a58964f3a9acfd

1 files changed, 68 insertions, 0 deletions

diff --git a/benchmarks/src/benchmarks/regression/RelativeDateTimeFormatterBenchmark.java b/benchmarks/src/benchmarks/regression/RelativeDateTimeFormatterBenchmark.java
new file mode 100644
index 0000000..30670b4
--- /dev/null
+++ b/benchmarks/src/benchmarks/regression/RelativeDateTimeFormatterBenchmark.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2015 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 benchmarks.regression;
+
+import com.google.caliper.SimpleBenchmark;
+
+import java.util.Locale;
+import java.util.TimeZone;
+
+import static libcore.icu.RelativeDateTimeFormatter.getRelativeDateTimeString;
+import static libcore.icu.RelativeDateTimeFormatter.getRelativeTimeSpanString;
+import static libcore.icu.RelativeDateTimeFormatter.FORMAT_ABBREV_RELATIVE;
+
+public class RelativeDateTimeFormatterBenchmark extends SimpleBenchmark {
+  public void timeRelativeDateTimeFormatter_getRelativeTimeSpanString(int reps) throws Exception {
+    Locale l = Locale.US;
+    TimeZone utc = TimeZone.getTimeZone("Europe/London");
+    int flags = 0;
+
+    for (int rep = 0; rep < reps; ++rep) {
+      getRelativeTimeSpanString(l, utc, 0L, 0L, 0L, flags);
+    }
+  }
+
+  public void timeRelativeDateTimeFormatter_getRelativeTimeSpanString_ABBREV(int reps) throws Exception {
+    Locale l = Locale.US;
+    TimeZone utc = TimeZone.getTimeZone("UTC");
+    int flags = FORMAT_ABBREV_RELATIVE;
+
+    for (int rep = 0; rep < reps; ++rep) {
+      getRelativeTimeSpanString(l, utc, 0L, 0L, 0L, flags);
+    }
+  }
+
+  public void timeRelativeDateTimeFormatter_getRelativeDateTimeString(int reps) throws Exception {
+    Locale l = Locale.US;
+    TimeZone utc = TimeZone.getTimeZone("UTC");
+    int flags = 0;
+
+    for (int rep = 0; rep < reps; ++rep) {
+      getRelativeDateTimeString(l, utc, 0L, 0L, 0L, 0L, flags);
+    }
+  }
+
+  public void timeRelativeDateTimeFormatter_getRelativeDateTimeString_ABBREV(int reps) throws Exception {
+    Locale l = Locale.US;
+    TimeZone utc = TimeZone.getTimeZone("America/Los_Angeles");
+    int flags = FORMAT_ABBREV_RELATIVE;
+
+    for (int rep = 0; rep < reps; ++rep) {
+      getRelativeDateTimeString(l, utc, 0L, 0L, 0L, 0L, flags);
+    }
+  }
+}