content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.util.logging;
  
  import org.slf4j.Logger;
  import org.slf4j.Marker;
  
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * A logger which limits log message frequency to prevent spamming the logs.
   *
   * After the logger logs a message, it enters a configurable cooldown period where it will ignore
   * repeated logging requests with the same message. Messages are compared by message template, not
   * message arguments.
   */
  public class SamplingLogger implements Logger {
    private final Logger mDelegate;
    private final long mCooldownMs;
    private final Map<String, AtomicLong> mCooldowns = new ConcurrentHashMap<>();
  
    /**
     * @param delegate the logger to log to
     * @param cooldownMs the cooldown period between log messages
     */
    public SamplingLogger(Logger delegate, long cooldownMs) {
      mDelegate = delegate;
      mCooldownMs = cooldownMs;
    }
  
    private boolean acquireLogPermission(String msg) {
      AtomicLong cooldown = mCooldowns.computeIfAbsent(msg, m -> new AtomicLong(0));
      long allowed = cooldown.get();
      long now = System.currentTimeMillis();
      return now >= allowed && cooldown.compareAndSet(allowed, now + mCooldownMs);
    }
  
    @Override
    public void trace(String msg) {
      if (isTraceEnabled() && acquireLogPermission(msg)) {
        mDelegate.trace(msg);
      }
    }
  
    @Override
    public void trace(String format, Object arg) {
      if (isTraceEnabled() && acquireLogPermission(format)) {
        mDelegate.trace(format, arg);
      }
    }
  
    @Override
    public void trace(String format, Object arg1, Object arg2) {
      if (isTraceEnabled() && acquireLogPermission(format)) {
        mDelegate.trace(format, arg1, arg2);
      }
    }
  
    @Override
    public void trace(String format, Object... arguments) {
      if (isTraceEnabled() && acquireLogPermission(format)) {
        mDelegate.trace(format, arguments);
      }
    }
  
    @Override
    public void trace(String msg, Throwable t) {
      if (isTraceEnabled() && acquireLogPermission(msg)) {
        mDelegate.trace(msg, t);
      }
    }
  
    @Override
    public void trace(Marker marker, String msg) {
      if (isTraceEnabled() && acquireLogPermission(msg)) {
        mDelegate.trace(marker, msg);
      }
    }
  
    @Override
    public void trace(Marker marker, String format, Object arg) {
      if (isTraceEnabled() && acquireLogPermission(format)) {
        mDelegate.trace(marker, format, arg);
      }
    }
  
    @Override
    public void trace(Marker marker, String format, Object arg1, Object arg2) {
      if (isTraceEnabled() && acquireLogPermission(format)) {
        mDelegate.trace(marker, format, arg1, arg2);
      }
    }
  
    @Override
    public void trace(Marker marker, String format, Object... argArray) {
      if (isTraceEnabled() && acquireLogPermission(format)) {
        mDelegate.trace(marker, format, argArray);
      }
    }
  
    @Override
    public void trace(Marker marker, String msg, Throwable t) {
      if (isTraceEnabled() && acquireLogPermission(msg)) {
        mDelegate.trace(marker, msg, t);
      }
    }
  
    @Override
    public void debug(String msg) {
      if (isDebugEnabled() && acquireLogPermission(msg)) {
        mDelegate.debug(msg);
      }
    }
  
    @Override
    public void debug(String format, Object arg) {
      if (isDebugEnabled() && acquireLogPermission(format)) {
        mDelegate.debug(format, arg);
      }
    }
  
    @Override
    public void debug(String format, Object arg1, Object arg2) {
      if (isDebugEnabled() && acquireLogPermission(format)) {
        mDelegate.debug(format, arg1, arg2);
      }
    }
  
    @Override
    public void debug(String format, Object... arguments) {
      if (isDebugEnabled() && acquireLogPermission(format)) {
        mDelegate.debug(format, arguments);
      }
    }
  
    @Override
    public void debug(String msg, Throwable t) {
      if (isDebugEnabled() && acquireLogPermission(msg)) {
        mDelegate.debug(msg, t);
      }
    }
  
    @Override
    public void debug(Marker marker, String msg) {
      if (isDebugEnabled() && acquireLogPermission(msg)) {
        mDelegate.debug(marker, msg);
      }
    }
  
    @Override
    public void debug(Marker marker, String format, Object arg) {
      if (isDebugEnabled() && acquireLogPermission(format)) {
        mDelegate.debug(marker, format, arg);
      }
    }
  
    @Override
    public void debug(Marker marker, String format, Object arg1, Object arg2) {
      if (isDebugEnabled() && acquireLogPermission(format)) {
        mDelegate.debug(marker, format, arg1, arg2);
      }
    }
  
    @Override
    public void debug(Marker marker, String format, Object... arguments) {
      if (isDebugEnabled() && acquireLogPermission(format)) {
        mDelegate.debug(marker, format, arguments);
      }
    }
  
    @Override
    public void debug(Marker marker, String msg, Throwable t) {
      if (isDebugEnabled() && acquireLogPermission(msg)) {
        mDelegate.debug(marker, msg, t);
      }
    }
  
    @Override
    public void info(String msg) {
      if (isInfoEnabled() && acquireLogPermission(msg)) {
        mDelegate.info(msg);
      }
    }
  
    @Override
    public void info(String format, Object arg) {
      if (isInfoEnabled() && acquireLogPermission(format)) {
        mDelegate.info(format, arg);
      }
    }
  
    @Override
    public void info(String format, Object arg1, Object arg2) {
      if (isInfoEnabled() && acquireLogPermission(format)) {
        mDelegate.info(format, arg1, arg2);
      }
    }
  
    @Override
    public void info(String format, Object... arguments) {
      if (isInfoEnabled() && acquireLogPermission(format)) {
        mDelegate.info(format, arguments);
      }
    }
  
    @Override
    public void info(String msg, Throwable t) {
      if (isInfoEnabled() && acquireLogPermission(msg)) {
        mDelegate.info(msg, t);
      }
    }
  
    @Override
    public void info(Marker marker, String msg) {
      if (isInfoEnabled() && acquireLogPermission(msg)) {
        mDelegate.info(marker, msg);
      }
    }
  
    @Override
    public void info(Marker marker, String format, Object arg) {
      if (isInfoEnabled() && acquireLogPermission(format)) {
        mDelegate.info(marker, format, arg);
      }
    }
  
    @Override
    public void info(Marker marker, String format, Object arg1, Object arg2) {
      if (isInfoEnabled() && acquireLogPermission(format)) {
        mDelegate.info(marker, format, arg1, arg2);
      }
    }
  
    @Override
    public void info(Marker marker, String format, Object... arguments) {
      if (isInfoEnabled() && acquireLogPermission(format)) {
        mDelegate.info(marker, format, arguments);
      }
    }
  
    @Override
    public void info(Marker marker, String msg, Throwable t) {
      if (isInfoEnabled() && acquireLogPermission(msg)) {
        mDelegate.info(marker, msg, t);
      }
    }
  
    @Override
    public void warn(String msg) {
      if (isWarnEnabled() && acquireLogPermission(msg)) {
        mDelegate.warn(msg);
      }
    }
  
    @Override
    public void warn(String format, Object arg) {
      if (isWarnEnabled() && acquireLogPermission(format)) {
        mDelegate.warn(format, arg);
      }
    }
  
    @Override
    public void warn(String format, Object... arguments) {
      if (isWarnEnabled() && acquireLogPermission(format)) {
        mDelegate.warn(format, arguments);
      }
    }
  
    @Override
    public void warn(String format, Object arg1, Object arg2) {
      if (isWarnEnabled() && acquireLogPermission(format)) {
        mDelegate.warn(format, arg1, arg2);
      }
    }
  
    @Override
    public void warn(String msg, Throwable t) {
      if (isWarnEnabled() && acquireLogPermission(msg)) {
        mDelegate.warn(msg, t);
      }
    }
  
    @Override
    public void warn(Marker marker, String msg) {
      if (isWarnEnabled() && acquireLogPermission(msg)) {
        mDelegate.warn(marker, msg);
      }
    }
  
    @Override
    public void warn(Marker marker, String format, Object arg) {
      if (isWarnEnabled() && acquireLogPermission(format)) {
        mDelegate.warn(marker, format, arg);
      }
    }
  
    @Override
    public void warn(Marker marker, String format, Object arg1, Object arg2) {
      if (isWarnEnabled() && acquireLogPermission(format)) {
        mDelegate.warn(marker, format, arg1, arg2);
      }
    }
  
    @Override
    public void warn(Marker marker, String format, Object... arguments) {
      if (isWarnEnabled() && acquireLogPermission(format)) {
        mDelegate.warn(marker, format, arguments);
      }
    }
  
    @Override
    public void warn(Marker marker, String msg, Throwable t) {
      if (isWarnEnabled() && acquireLogPermission(msg)) {
        mDelegate.warn(marker, msg, t);
      }
    }
  
    @Override
    public void error(String msg) {
      if (isErrorEnabled() && acquireLogPermission(msg)) {
        mDelegate.error(msg);
      }
    }
  
    @Override
    public void error(String format, Object arg) {
      if (isErrorEnabled() && acquireLogPermission(format)) {
        mDelegate.error(format, arg);
      }
    }
  
    @Override
    public void error(String format, Object arg1, Object arg2) {
      if (isErrorEnabled() && acquireLogPermission(format)) {
        mDelegate.error(format, arg1, arg2);
      }
    }
  
    @Override
    public void error(String format, Object... arguments) {
      if (isErrorEnabled() && acquireLogPermission(format)) {
        mDelegate.error(format, arguments);
      }
    }
  
    @Override
    public void error(String msg, Throwable t) {
      if (isErrorEnabled() && acquireLogPermission(msg)) {
        mDelegate.error(msg, t);
      }
    }
  
    @Override
    public void error(Marker marker, String msg) {
      if (isErrorEnabled() && acquireLogPermission(msg)) {
        mDelegate.error(marker, msg);
      }
    }
  
    @Override
    public void error(Marker marker, String format, Object arg) {
      if (isErrorEnabled() && acquireLogPermission(format)) {
        mDelegate.error(marker, format, arg);
      }
    }
  
    @Override
    public void error(Marker marker, String format, Object arg1, Object arg2) {
      if (isErrorEnabled() && acquireLogPermission(format)) {
        mDelegate.error(marker, format, arg1, arg2);
      }
    }
  
    @Override
    public void error(Marker marker, String format, Object... arguments) {
      if (isErrorEnabled() && acquireLogPermission(format)) {
        mDelegate.error(marker, format, arguments);
      }
    }
  
    @Override
    public void error(Marker marker, String msg, Throwable t) {
      if (isErrorEnabled() && acquireLogPermission(msg)) {
        mDelegate.error(marker, msg, t);
      }
    }
  
    @Override
    public String getName() {
      return mDelegate.getName();
    }
  
    @Override
    public boolean isTraceEnabled() {
      return mDelegate.isTraceEnabled();
    }
  
    @Override
    public boolean isTraceEnabled(Marker marker) {
      return mDelegate.isTraceEnabled(marker);
    }
  
    @Override
    public boolean isDebugEnabled() {
      return mDelegate.isDebugEnabled();
    }
  
    @Override
    public boolean isDebugEnabled(Marker marker) {
      return mDelegate.isDebugEnabled(marker);
    }
  
    @Override
    public boolean isInfoEnabled() {
      return mDelegate.isInfoEnabled();
    }
  
    @Override
    public boolean isInfoEnabled(Marker marker) {
      return mDelegate.isInfoEnabled(marker);
    }
  
    @Override
    public boolean isWarnEnabled() {
      return mDelegate.isWarnEnabled();
    }
  
    @Override
    public boolean isWarnEnabled(Marker marker) {
      return mDelegate.isWarnEnabled(marker);
    }
  
    @Override
    public boolean isErrorEnabled() {
      return mDelegate.isErrorEnabled();
    }
  
    @Override
    public boolean isErrorEnabled(Marker marker) {
      return mDelegate.isErrorEnabled(marker);
    }
  }
  