org.snapscript.agent.log.ProcessLogger Maven / Gradle / Ivy
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Dynamic scripting for the JVM
package org.snapscript.agent.log;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import org.snapscript.common.thread.ThreadBuilder;
public class ProcessLogger {
private static final String TIME_FORMAT = "HH:mm:ss";
private static final int EVENT_LIMIT = 10000;
private final LogDispatcher dispatcher;
private final DateFormatter formatter;
private final ProcessLog logger;
private final LogLevel level;
public ProcessLogger(ProcessLog logger) {
this(logger, null);
}
public ProcessLogger(ProcessLog logger, String level) {
this.dispatcher = new LogDispatcher(EVENT_LIMIT);
this.formatter = new DateFormatter(TIME_FORMAT);
this.level = LogLevel.resolveLevel(level);
this.logger = logger;
}
public String getLevel() {
return level.name();
}
public boolean isTrace() {
return level.isTrace();
}
public boolean isDebug() {
return level.isDebug();
}
public void trace(String message) {
if(level.isTrace()) {
log(message);
}
}
public void trace(String message, Throwable cause) {
if(level.isTrace()) {
log(message, cause);
}
}
public void debug(String message) {
if(level.isDebug()) {
log(message);
}
}
public void debug(String message, Throwable cause) {
if(level.isDebug()) {
log(message, cause);
}
}
public void info(String message) {
if(level.isInfo()) {
log(message);
}
}
public void info(String message, Throwable cause) {
if(level.isInfo()) {
log(message, cause);
}
}
private void log(String message) {
LogEvent event = new LogEvent(message, null);
dispatcher.log(event);
}
private void log(String message, Throwable cause) {
LogEvent event = new LogEvent(message, cause);
dispatcher.log(event);
}
private class DateFormatter extends ThreadLocal {
private final String format;
public DateFormatter(String format) {
this.format = format;
}
@Override
public DateFormat initialValue(){
return new SimpleDateFormat(format);
}
}
private enum LogLevel {
TRACE(0),
DEBUG(1),
INFO(2);
private final int level;
private LogLevel(int level){
this.level = level;
}
public boolean isTrace(){
return level <= TRACE.level;
}
public boolean isDebug(){
return level <= DEBUG.level;
}
public boolean isInfo(){
return level <= INFO.level;
}
public static LogLevel resolveLevel(String token){
if(token != null) {
String match = token.trim();
LogLevel[] levels = values();
for(LogLevel level : levels){
String name = level.name();
if(name.equalsIgnoreCase(match)) {
return level;
}
}
}
return LogLevel.INFO;
}
}
private class LogDispatcher implements Runnable {
private final BlockingQueue queue;
private final ThreadFactory factory;
private final AtomicBoolean active;
public LogDispatcher(int capacity) {
this.factory = new ThreadBuilder();
this.queue = new ArrayBlockingQueue(capacity);
this.active = new AtomicBoolean(false);
}
public void log(LogEvent event) {
try {
if(active.compareAndSet(false, true)) {
Thread thread = factory.newThread(this);
thread.start();
}
queue.offer(event, 10000, TimeUnit.MILLISECONDS);
}catch(Exception e) {
throw new IllegalStateException("Could not log event", e);
}
}
@Override
public void run() {
try {
while(active.get()) {
try {
LogEvent event = queue.poll(1000, TimeUnit.MILLISECONDS);
if(event != null) {
event.run();
}
} catch(Exception e) {
throw new IllegalStateException("Could not poll queue", e);
}
}
} finally {
active.set(false);
}
}
}
private class LogEvent implements Runnable {
private final Throwable cause;
private final String message;
private final Thread thread;
private final long time;
public LogEvent(String message, Throwable cause) {
this.time = System.currentTimeMillis();
this.thread = Thread.currentThread();
this.message = message;
this.cause = cause;
}
@Override
public void run() {
String name = thread.getName();
DateFormat format = formatter.get();
String date = format.format(time);
if(message != null) {
StringBuilder builder = new StringBuilder();
builder.append(date);
builder.append(" [");
builder.append(name);
builder.append("] ");
builder.append(message);
if(cause != null) {
if(level.isTrace()) {
logger.log(builder, cause);
} else {
builder.append(": ");
builder.append(cause);
logger.log(builder);
}
} else {
logger.log(builder);
}
}
}
}
}