package org.apache.logging.log4j.core.filter;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;
import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.Marker;
import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.Logger;
import org.apache.logging.log4j.core.config.Node;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
import org.apache.logging.log4j.message.Message;
@Plugin(name = "BurstFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE, printObject = true)
public final class BurstFilter extends AbstractFilter {
private static final long NANOS_IN_SECONDS = 1000000000;
private static final int DEFAULT_RATE = 10;
private static final int DEFAULT_RATE_MULTIPLE = 100;
private static final int HASH_SHIFT = 32;
private final Level level;
private final long burstInterval;
private final DelayQueue<LogDelay> history = new DelayQueue<>();
private final Queue<LogDelay> available = new ConcurrentLinkedQueue<>();
static LogDelay createLogDelay(final long expireTime) {
return new LogDelay(expireTime);
}
private BurstFilter(final Level level, final float rate, final long maxBurst, final Result onMatch,
final Result onMismatch) {
super(onMatch, onMismatch);
this.level = level;
this.burstInterval = (long) (NANOS_IN_SECONDS * (maxBurst / rate));
for (int i = 0; i < maxBurst; ++i) {
available.add(createLogDelay(0));
}
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object... params) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg,
final Throwable t) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
final Throwable t) {
return filter(level);
}
@Override
public Result filter(final LogEvent event) {
return filter(event.getLevel());
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2, final Object p3) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2, final Object p3,
final Object p4) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2, final Object p3,
final Object p4, final Object p5) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2, final Object p3,
final Object p4, final Object p5, final Object p6) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2, final Object p3,
final Object p4, final Object p5, final Object p6,
final Object p7) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2, final Object p3,
final Object p4, final Object p5, final Object p6,
final Object p7, final Object p8) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object p0, final Object p1, final Object p2, final Object p3,
final Object p4, final Object p5, final Object p6,
final Object p7, final Object p8, final Object p9) {
return filter(level);
}
private Result filter(final Level level) {
if (this.level.isMoreSpecificThan(level)) {
LogDelay delay = history.poll();
while (delay != null) {
available.add(delay);
delay = history.poll();
}
delay = available.poll();
if (delay != null) {
delay.setDelay(burstInterval);
history.add(delay);
return onMatch;
}
return onMismatch;
}
return onMatch;
}
public int getAvailable() {
return available.size();
}
public void clear() {
for (final LogDelay delay : history) {
history.remove(delay);
available.add(delay);
}
}
@Override
public String toString() {
return "level=" + level.toString() + ", interval=" + burstInterval + ", max=" + history.size();
}
private static class LogDelay implements Delayed {
LogDelay(final long expireTime) {
this.expireTime = expireTime;
}
private long expireTime;
public void setDelay(final long delay) {
this.expireTime = delay + System.nanoTime();
}
@Override
public long getDelay(final TimeUnit timeUnit) {
return timeUnit.convert(expireTime - System.nanoTime(), TimeUnit.NANOSECONDS);
}
@Override
public int compareTo(final Delayed delayed) {
final long diff = this.expireTime - ((LogDelay) delayed).expireTime;
return Long.signum(diff);
}
@Override
public boolean equals(final Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
final LogDelay logDelay = (LogDelay) o;
if (expireTime != logDelay.expireTime) {
return false;
}
return true;
}
@Override
public int hashCode() {
return (int) (expireTime ^ (expireTime >>> HASH_SHIFT));
}
}
@PluginBuilderFactory
public static Builder newBuilder() {
return new Builder();
}
public static class Builder extends AbstractFilterBuilder<Builder> implements org.apache.logging.log4j.core.util.Builder<BurstFilter> {
@PluginBuilderAttribute
private Level level = Level.WARN;
@PluginBuilderAttribute
private float rate = DEFAULT_RATE;
@PluginBuilderAttribute
private long maxBurst;
public Builder setLevel(final Level level) {
this.level = level;
return this;
}
public Builder setRate(final float rate) {
this.rate = rate;
return this;
}
public Builder setMaxBurst(final long maxBurst) {
this.maxBurst = maxBurst;
return this;
}
@Override
public BurstFilter build() {
if (this.rate <= 0) {
this.rate = DEFAULT_RATE;
}
if (this.maxBurst <= 0) {
this.maxBurst = (long) (this.rate * DEFAULT_RATE_MULTIPLE);
}
return new BurstFilter(this.level, this.rate, this.maxBurst, this.getOnMatch(), this.getOnMismatch());
}
}
}