Timber.java

package com.marshalchen.common.commonUtils.logUtils;

import android.util.Log;
import android.util.SparseBooleanArray;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/** Logging for lazy people. */
public final class Timber {
  /** Log a verbose message with optional format args. */
  public static void v(String message, Object... args) {
    TREE_OF_SOULS.v(message, args);
  }

  /** Log a verbose exception and a message with optional format args. */
  public static void v(Throwable t, String message, Object... args) {
    TREE_OF_SOULS.v(t, message, args);
  }

  /** Log a debug message with optional format args. */
  public static void d(String message, Object... args) {
    TREE_OF_SOULS.d(message, args);
  }

  /** Log a debug exception and a message with optional format args. */
  public static void d(Throwable t, String message, Object... args) {
    TREE_OF_SOULS.d(t, message, args);
  }

  /** Log an info message with optional format args. */
  public static void i(String message, Object... args) {
    TREE_OF_SOULS.i(message, args);
  }

  /** Log an info exception and a message with optional format args. */
  public static void i(Throwable t, String message, Object... args) {
    TREE_OF_SOULS.i(t, message, args);
  }

  /** Log a warning message with optional format args. */
  public static void w(String message, Object... args) {
    TREE_OF_SOULS.w(message, args);
  }

  /** Log a warning exception and a message with optional format args. */
  public static void w(Throwable t, String message, Object... args) {
    TREE_OF_SOULS.w(t, message, args);
  }

  /** Log an error message with optional format args. */
  public static void e(String message, Object... args) {
    TREE_OF_SOULS.e(message, args);
  }

  /** Log an error exception and a message with optional format args. */
  public static void e(Throwable t, String message, Object... args) {
    TREE_OF_SOULS.e(t, message, args);
  }

  /** Set a one-time tag for use on the next logging call. */
  public static Tree tag(String tag) {
    for (int index = 0, size = TAGGED_TREES.size(); index < size; index++) {
      ((TaggedTree) FOREST.get(TAGGED_TREES.keyAt(index))).tag(tag);
    }
    return TREE_OF_SOULS;
  }

  /** Add a new logging tree. */
  public static void plant(Tree tree) {
    if (tree instanceof TaggedTree) {
      TAGGED_TREES.append(FOREST.size(), true);
    }
    FOREST.add(tree);
  }

  /** Remove a planted tree. */
  public static void uproot(Tree tree) {
    for (int i = 0, size = FOREST.size(); i < size; i++) {
      if (FOREST.get(i) == tree) {
        TAGGED_TREES.delete(i);
        FOREST.remove(i);
        return;
      }
    }
    throw new IllegalArgumentException("Cannot uproot tree which is not planted: " + tree);
  }

  /** Remove all planted trees. */
  public static void uprootAll() {
    TAGGED_TREES.clear();
    FOREST.clear();
  }

  static final List<Tree> FOREST = new CopyOnWriteArrayList<Tree>();
  static final SparseBooleanArray TAGGED_TREES = new SparseBooleanArray();

  /** A {@link com.marshalchen.common.commonUtils.logUtils.Timber.Tree} that delegates to all planted trees in the {@link #FOREST forest}. */
  private static final Tree TREE_OF_SOULS = new Tree() {
    @Override public void v(String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.v(message, args);
      }
    }

    @Override public void v(Throwable t, String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.v(t, message, args);
      }
    }

    @Override public void d(String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.d(message, args);
      }
    }

    @Override public void d(Throwable t, String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.d(t, message, args);
      }
    }

    @Override public void i(String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.i(message, args);
      }
    }

    @Override public void i(Throwable t, String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.i(t, message, args);
      }
    }

    @Override public void w(String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.w(message, args);
      }
    }

    @Override public void w(Throwable t, String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.w(t, message, args);
      }
    }

    @Override public void e(String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.e(message, args);
      }
    }

    @Override public void e(Throwable t, String message, Object... args) {
      for (Tree tree : FOREST) {
        tree.e(t, message, args);
      }
    }
  };

  private Timber() {
  }

  /** A facade for handling logging calls. Install instances via {@link #plant}. */
  public interface Tree {
    /** Log a verbose message with optional format args. */
    void v(String message, Object... args);

    /** Log a verbose exception and a message with optional format args. */
    void v(Throwable t, String message, Object... args);

    /** Log a debug message with optional format args. */
    void d(String message, Object... args);

    /** Log a debug exception and a message with optional format args. */
    void d(Throwable t, String message, Object... args);

    /** Log an info message with optional format args. */
    void i(String message, Object... args);

    /** Log an info exception and a message with optional format args. */
    void i(Throwable t, String message, Object... args);

    /** Log a warning message with optional format args. */
    void w(String message, Object... args);

    /** Log a warning exception and a message with optional format args. */
    void w(Throwable t, String message, Object... args);

    /** Log an error message with optional format args. */
    void e(String message, Object... args);

    /** Log an error exception and a message with optional format args. */
    void e(Throwable t, String message, Object... args);
  }

  /** A facade for attaching tags to logging calls. Install instances via {@link #plant} */
  public interface TaggedTree extends Tree {
    /** Set a one-time tag for use on the next logging call. */
    void tag(String tag);
  }

  /** A {@link com.marshalchen.common.commonUtils.logUtils.Timber.Tree} for debug builds. Automatically infers the tag from the calling class. */
  public static class DebugTree implements TaggedTree {
    private static final Pattern ANONYMOUS_CLASS = Pattern.compile("\\$\\d+$");
    private static final ThreadLocal<String> NEXT_TAG = new ThreadLocal<String>();

    private static String createTag() {
      String tag = NEXT_TAG.get();
      if (tag != null) {
        NEXT_TAG.remove();
        return tag;
      }

      StackTraceElement[] stackTrace = new Throwable().getStackTrace();
      if (stackTrace.length < 6) {
        throw new IllegalStateException(
            "Synthetic stacktrace didn't have enough elements: are you using proguard?");
      }
      tag = stackTrace[5].getClassName();
      Matcher m = ANONYMOUS_CLASS.matcher(tag);
      if (m.find()) {
        tag = m.replaceAll("");
      }
      return tag.substring(tag.lastIndexOf('.') + 1);
    }

    static String formatString(String message, Object... args) {
      // If no varargs are supplied, treat it as a request to log the string without formatting.
      return args.length == 0 ? message : String.format(message, args);
    }

    @Override public void v(String message, Object... args) {
      throwShade(Log.VERBOSE, formatString(message, args), null);
    }

    @Override public void v(Throwable t, String message, Object... args) {
      throwShade(Log.VERBOSE, formatString(message, args), t);
    }

    @Override public void d(String message, Object... args) {
      throwShade(Log.DEBUG, formatString(message, args), null);
    }

    @Override public void d(Throwable t, String message, Object... args) {
      throwShade(Log.DEBUG, formatString(message, args), t);
    }

    @Override public void i(String message, Object... args) {
      throwShade(Log.INFO, formatString(message, args), null);
    }

    @Override public void i(Throwable t, String message, Object... args) {
      throwShade(Log.INFO, formatString(message, args), t);
    }

    @Override public void w(String message, Object... args) {
      throwShade(Log.WARN, formatString(message, args), null);
    }

    @Override public void w(Throwable t, String message, Object... args) {
      throwShade(Log.WARN, formatString(message, args), t);
    }

    @Override public void e(String message, Object... args) {
      throwShade(Log.ERROR, formatString(message, args), null);
    }

    @Override public void e(Throwable t, String message, Object... args) {
      throwShade(Log.ERROR, formatString(message, args), t);
    }

    private void throwShade(int priority, String message, Throwable t) {
      if (message == null || message.length() == 0) {
        if (t != null) {
          message = Log.getStackTraceString(t);
        } else {
          // Swallow message if it's null and there's no throwable.
          return;
        }
      } else if (t != null) {
        message += "\n" + Log.getStackTraceString(t);
      }

      String tag = createTag();
      if (message.length() < 4000) {
        Log.println(priority, tag, message);
      } else {
        // It's rare that the message will be this large, so we're ok with the perf hit of splitting
        // and calling Log.println N times.  It's possible but unlikely that a single line will be
        // longer than 4000 characters: we're explicitly ignoring this case here.
        String[] lines = message.split("\n");
        for (String line : lines) {
          Log.println(priority, tag, line);
        }
      }
    }

    @Override public void tag(String tag) {
      NEXT_TAG.set(tag);
    }
  }

  /** A {@link com.marshalchen.common.commonUtils.logUtils.Timber.Tree} which does nothing. Useful for extending. */
  public static class HollowTree implements Tree {
    @Override public void v(String message, Object... args) {
    }

    @Override public void v(Throwable t, String message, Object... args) {
    }

    @Override public void d(String message, Object... args) {
    }

    @Override public void d(Throwable t, String message, Object... args) {
    }

    @Override public void i(String message, Object... args) {
    }

    @Override public void i(Throwable t, String message, Object... args) {
    }

    @Override public void w(String message, Object... args) {
    }

    @Override public void w(Throwable t, String message, Object... args) {
    }

    @Override public void e(String message, Object... args) {
    }

    @Override public void e(Throwable t, String message, Object... args) {
    }
  }
}