com.stackify.api.common.log.LogAppender Maven / Gradle / Ivy

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/*
 * Copyright 2014 Stackify
 *
 * 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 com.stackify.api.common.log;

import java.io.Closeable;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import com.stackify.api.LogMsg;
import com.stackify.api.StackifyError;
import com.stackify.api.common.ApiConfiguration;
import com.stackify.api.common.AppIdentityService;
import com.stackify.api.common.error.ErrorGovernor;

/**
 * LogAppender
 * @author Eric Martin
 */
public class LogAppender implements Closeable {
		
	/**
	 * Logger project name
	 */
	private final String logger;
	
	/**
	 * Maps from specific log implementation events to our API
	 */
	private final EventAdapter eventAdapter;
	
	/**
	 * Collector for LogMsg objects that need to be sent to Stackify
	 */
	private LogCollector collector = null;
	
	/**
	 * Background thread for sending log events to Stackify
	 */
	private LogBackgroundService backgroundService = null;
	
	/**
	 * Client side error governor to suppress duplicate errors
	 */
	private final ErrorGovernor errorGovernor = new ErrorGovernor();

	/**
	 * Constructor
	 * @param logger Logger project name
	 */
	public LogAppender(final String logger, final EventAdapter eventAdapter) {
		Preconditions.checkNotNull(logger);
		Preconditions.checkArgument(!logger.isEmpty());
		Preconditions.checkNotNull(eventAdapter);
		this.logger = logger;
		this.eventAdapter = eventAdapter;
	}
	
	/**
	 * Activates the appender
	 * @param apiConfig API configuration
	 */
	public void activate(final ApiConfiguration apiConfig) {
		Preconditions.checkNotNull(apiConfig);
		Preconditions.checkNotNull(apiConfig.getApiUrl());
		Preconditions.checkArgument(!apiConfig.getApiUrl().isEmpty());
		Preconditions.checkNotNull(apiConfig.getApiKey());
		Preconditions.checkArgument(!apiConfig.getApiKey().isEmpty());
		
		// Single JSON object mapper for all services

		ObjectMapper objectMapper = new ObjectMapper();

		// build the app identity service

		AppIdentityService appIdentityService = new AppIdentityService(apiConfig, objectMapper);
		
		// build the services for collecting and sending log messages

		this.collector = new LogCollector(logger, apiConfig.getEnvDetail(), appIdentityService);
		
		LogSender sender = new LogSender(apiConfig, objectMapper);
		
		// build the background service to asynchronously post errors to Stackify
		// startup the background service
				
		this.backgroundService = new LogBackgroundService(collector, sender);
		
		try {
			backgroundService.startAsync().awaitRunning(5, TimeUnit.SECONDS);
		} catch (TimeoutException e) {
			Throwables.propagate(e);
		}
	}
	
	/**
	 * @see java.io.Closeable#close()
	 */
	@Override
	public void close() throws IOException {
		if (backgroundService != null) {
			try {
				backgroundService.stopAsync().awaitTerminated(5, TimeUnit.SECONDS);
			} catch (TimeoutException e) {
				Throwables.propagate(e);
			}
		}
	}
	
	/**
	 * Adds the log message to the collector
	 * @param logMsg 
	 */
	public void append(final T event) {

		// make sure we can append the log message
		
		if (backgroundService == null) {
			return;
		}
		
		if (!backgroundService.isRunning()) {
			return;
		}
		
		// build the log message and queue it to be sent to Stackify
		
		Optional exception = eventAdapter.getThrowable(event);
		
		Optional error = Optional.absent();
		
		if ((exception.isPresent()) || (eventAdapter.isErrorLevel(event))) {
			StackifyError e = eventAdapter.getStackifyError(event, exception.orNull());
			
			if (errorGovernor.errorShouldBeSent(e)) {
				error = Optional.of(e);
			}
		}
		
		LogMsg logMsg = eventAdapter.getLogMsg(event, error);
		
		collector.addLogMsg(logMsg);
	}
}