core/java/android/util/LocalLog.java

/*
 * Copyright (C) 2006 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 android.util;

import android.text.format.Time;

import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Iterator;
import java.util.LinkedList;

/**
 * @hide
 */
public final class LocalLog {

    private LinkedList<String> mLog;
    private int mMaxLines;
    private Time mNow;

    public LocalLog(int maxLines) {
        mLog = new LinkedList<String>();
        mMaxLines = maxLines;
        mNow = new Time();
    }

    public synchronized void log(String msg) {
        if (mMaxLines > 0) {
            mNow.setToNow();
            mLog.add(mNow.format("%H:%M:%S") + " - " + msg);
            while (mLog.size() > mMaxLines) mLog.remove();
        }
    }

    public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
        Iterator<String> itr = mLog.listIterator(0);
        while (itr.hasNext()) {
            pw.println(itr.next());
        }
    }
}