1 files changed, 109 insertions, 0 deletions
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/RelativeDateFormatter.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/RelativeDateFormatter.java
new file mode 100644
index 0000000000..3298a06ca8
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+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/RelativeDateFormatter.java
@@ -0,0 +1,109 @@
+// Copyright (C) 2013 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 com.google.gerrit.client;
+
+import com.google.gerrit.client.changes.Util;
+
+import java.util.Date;
+
+/**
+ * Formatter to format timestamps relative to the current time using time units
+ * in the format defined by {@code git log --relative-date}.
+ */
+public class RelativeDateFormatter {
+  final static long SECOND_IN_MILLIS = 1000;
+
+  final static long MINUTE_IN_MILLIS = 60 * SECOND_IN_MILLIS;
+
+  final static long HOUR_IN_MILLIS = 60 * MINUTE_IN_MILLIS;
+
+  final static long DAY_IN_MILLIS = 24 * HOUR_IN_MILLIS;
+
+  final static long WEEK_IN_MILLIS = 7 * DAY_IN_MILLIS;
+
+  final static long MONTH_IN_MILLIS = 30 * DAY_IN_MILLIS;
+
+  final static long YEAR_IN_MILLIS = 365 * DAY_IN_MILLIS;
+
+  /**
+   * @param when {@link Date} to format
+   * @return age of given {@link Date} compared to now formatted in the same
+   *         relative format as returned by {@code git log --relative-date}
+   */
+  @SuppressWarnings("boxing")
+  public static String format(Date when) {
+    long ageMillis = (new Date()).getTime() - when.getTime();
+
+    // shouldn't happen in a perfect world
+    if (ageMillis < 0) return Util.C.inTheFuture();
+
+    // seconds
+    if (ageMillis < upperLimit(MINUTE_IN_MILLIS)) {
+      return Util.M.secondsAgo(round(ageMillis, SECOND_IN_MILLIS));
+    }
+
+    // minutes
+    if (ageMillis < upperLimit(HOUR_IN_MILLIS)) {
+      return Util.M.minutesAgo(round(ageMillis, MINUTE_IN_MILLIS));
+    }
+
+    // hours
+    if (ageMillis < upperLimit(DAY_IN_MILLIS)) {
+      return Util.M.hoursAgo(round(ageMillis, HOUR_IN_MILLIS));
+    }
+
+    // up to 14 days use days
+    if (ageMillis < 14 * DAY_IN_MILLIS) {
+      return Util.M.daysAgo(round(ageMillis, DAY_IN_MILLIS));
+    }
+
+    // up to 10 weeks use weeks
+    if (ageMillis < 10 * WEEK_IN_MILLIS) {
+      return Util.M.weeksAgo(round(ageMillis, WEEK_IN_MILLIS));
+    }
+
+    // months
+    if (ageMillis < YEAR_IN_MILLIS) {
+      return Util.M.monthsAgo(round(ageMillis, MONTH_IN_MILLIS));
+    }
+
+    // up to 5 years use "year, months" rounded to months
+    if (ageMillis < 5 * YEAR_IN_MILLIS) {
+      long years = ageMillis / YEAR_IN_MILLIS;
+      String yearLabel = (years > 1) ? Util.C.years() : Util.C.year();
+      long months = round(ageMillis % YEAR_IN_MILLIS, MONTH_IN_MILLIS);
+      String monthLabel =
+          (months > 1) ? Util.C.months() : (months == 1 ? Util.C.month() : "");
+      if (months == 0) {
+        return Util.M.years0MonthsAgo(years, yearLabel);
+      } else {
+        return Util.M.yearsMonthsAgo(years, yearLabel, months, monthLabel);
+      }
+    }
+
+    // years
+    return Util.M.yearsAgo(round(ageMillis, YEAR_IN_MILLIS));
+  }
+
+  private static long upperLimit(long unit) {
+    long limit = unit + unit / 2;
+    return limit;
+  }
+
+  private static long round(long n, long unit) {
+    long rounded = (n + unit / 2) / unit;
+    return rounded;
+  }
+}