content: /*
   * Copyright (C) 2007 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.github.anrimian.musicplayer.data.utils.dev;
  
  import android.os.SystemClock;
  import android.util.Log;
  
  import java.util.ArrayList;
  
  /**
   * A utility class to help log timings splits throughout a method call.
   * Typical usage is:
   *
   * <pre>
   *     TimingLogger timings = new TimingLogger(TAG, "methodA");
   *     // ... do some work A ...
   *     timings.addSplit("work A");
   *     // ... do some work B ...
   *     timings.addSplit("work B");
   *     // ... do some work C ...
   *     timings.addSplit("work C");
   *     timings.dumpToLog();
   * </pre>
   *
   * <p>The dumpToLog call would add the following to the log:</p>
   *
   * <pre>
   *     D/TAG     ( 3459): methodA: begin
   *     D/TAG     ( 3459): methodA:      9 ms, work A
   *     D/TAG     ( 3459): methodA:      1 ms, work B
   *     D/TAG     ( 3459): methodA:      6 ms, work C
   *     D/TAG     ( 3459): methodA: end, 16 ms
   * </pre>
   */
  public class TimingLogger {
  
      /**
       * The Log tag to use for checking Log.isLoggable and for
       * logging the timings.
       */
      private String mTag;
  
      /** A label to be included in every log. */
      private String mLabel;
  
      /** Used to track whether Log.isLoggable was enabled at reset time. */
      private final boolean mDisabled = false;
  
      /** Stores the time of each split. */
      ArrayList<Long> mSplits;
  
      /** Stores the labels for each split. */
      ArrayList<String> mSplitLabels;
  
      /**
       * Create and initialize a TimingLogger object that will log using
       * the specific tag. If the Log.isLoggable is not enabled to at
       * least the Log.VERBOSE level for that tag at creation time then
       * the addSplit and dumpToLog call will do nothing.
       * @param tag the log tag to use while logging the timings
       * @param label a string to be displayed with each log
       */
      public TimingLogger(String tag, String label) {
          reset(tag, label);
      }
  
      public TimingLogger(String mLabel) {
          this("KEK", mLabel);
      }
  
      /**
       * Clear and initialize a TimingLogger object that will log using
       * the specific tag. If the Log.isLoggable is not enabled to at
       * least the Log.VERBOSE level for that tag at creation time then
       * the addSplit and dumpToLog call will do nothing.
       * @param tag the log tag to use while logging the timings
       * @param label a string to be displayed with each log
       */
      public void reset(String tag, String label) {
          mTag = tag;
          mLabel = label;
          reset();
      }
  
      /**
       * Clear and initialize a TimingLogger object that will log using
       * the tag and label that was specified previously, either via
       * the constructor or a call to reset(tag, label). If the
       * Log.isLoggable is not enabled to at least the Log.VERBOSE
       * level for that tag at creation time then the addSplit and
       * dumpToLog call will do nothing.
       */
      public void reset() {
          if (mDisabled) return;
          if (mSplits == null) {
              mSplits = new ArrayList<Long>();
              mSplitLabels = new ArrayList<String>();
          } else {
              mSplits.clear();
              mSplitLabels.clear();
          }
          addSplit(null);
      }
  
      /**
       * Add a split for the current time, labeled with splitLabel. If
       * Log.isLoggable was not enabled to at least the Log.VERBOSE for
       * the specified tag at construction or reset() time then this
       * call does nothing.
       * @param splitLabel a label to associate with this split.
       */
      public void addSplit(String splitLabel) {
          if (mDisabled) return;
          long now = SystemClock.elapsedRealtime();
          mSplits.add(now);
          mSplitLabels.add(splitLabel);
      }
  
      /**
       * Dumps the timings to the log using Log.d(). If Log.isLoggable was
       * not enabled to at least the Log.VERBOSE for the specified tag at
       * construction or reset() time then this call does nothing.
       */
      public void dumpToLog() {
          if (mDisabled) return;
          Log.d(mTag, mLabel + ": begin");
          final long first = mSplits.get(0);
          long now = first;
          for (int i = 1; i < mSplits.size(); i++) {
              now = mSplits.get(i);
              final String splitLabel = mSplitLabels.get(i);
              final long prev = mSplits.get(i - 1);
  
              Log.d(mTag, mLabel + ":      " + (now - prev) + " ms, " + splitLabel);
          }
          Log.d(mTag, mLabel + ": end, " + (now - first) + " ms");
      }
  }
  