Move StopWatch class into common.
Bug: 6993891
Change-Id: I60e9a1f63ea09dc0eb3c5ede64e9d5a15272526d
diff --git a/src/com/android/contacts/common/util/StopWatch.java b/src/com/android/contacts/common/util/StopWatch.java
new file mode 100644
index 0000000..581d6ee
--- /dev/null
+++ b/src/com/android/contacts/common/util/StopWatch.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2012 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.android.contacts.common.util;
+
+import android.util.Log;
+
+import com.google.common.collect.Lists;
+
+import java.util.ArrayList;
+
+/**
+ * A {@link StopWatch} records start, laps and stop, and print them to logcat.
+ */
+public class StopWatch {
+
+ private final String mLabel;
+
+ private final ArrayList<Long> mTimes = Lists.newArrayList();
+ private final ArrayList<String> mLapLabels = Lists.newArrayList();
+
+ private StopWatch(String label) {
+ mLabel = label;
+ lap("");
+ }
+
+ /**
+ * Create a new instance and start it.
+ */
+ public static StopWatch start(String label) {
+ return new StopWatch(label);
+ }
+
+ /**
+ * Record a lap.
+ */
+ public void lap(String lapLabel) {
+ mTimes.add(System.currentTimeMillis());
+ mLapLabels.add(lapLabel);
+ }
+
+ /**
+ * Stop it and log the result, if the total time >= {@code timeThresholdToLog}.
+ */
+ public void stopAndLog(String TAG, int timeThresholdToLog) {
+
+ lap("");
+
+ final long start = mTimes.get(0);
+ final long stop = mTimes.get(mTimes.size() - 1);
+
+ final long total = stop - start;
+ if (total < timeThresholdToLog) return;
+
+ final StringBuilder sb = new StringBuilder();
+ sb.append(mLabel);
+ sb.append(",");
+ sb.append(total);
+ sb.append(": ");
+
+ long last = start;
+ for (int i = 1; i < mTimes.size(); i++) {
+ final long current = mTimes.get(i);
+ sb.append(mLapLabels.get(i));
+ sb.append(",");
+ sb.append((current - last));
+ sb.append(" ");
+ last = current;
+ }
+ Log.v(TAG, sb.toString());
+ }
+
+ /**
+ * Return a dummy instance that does no operations.
+ */
+ public static StopWatch getNullStopWatch() {
+ return NullStopWatch.INSTANCE;
+ }
+
+ private static class NullStopWatch extends StopWatch {
+ public static final NullStopWatch INSTANCE = new NullStopWatch();
+
+ public NullStopWatch() {
+ super(null);
+ }
+
+ @Override
+ public void lap(String lapLabel) {
+ // noop
+ }
+
+ @Override
+ public void stopAndLog(String TAG, int timeThresholdToLog) {
+ // noop
+ }
+ }
+}