/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 *
 */
package org.hibernate.stat;

/**
 * Query statistics (HQL and SQL)
 * <p/>
 * Note that for a cached query, the cache miss is equals to the db count
 *
 * @author Gavin King
 */
public class QueryStatisticsImpl extends CategorizedStatistics implements QueryStatistics {

	/*package*/
	long cacheHitCount;
	/*package*/
	long cacheMissCount;
	/*package*/
	long cachePutCount;
	private long executionCount;
	private long executionRowCount;
	private long executionAvgTime;
	private long executionMaxTime;
	private long executionMinTime = Long.MAX_VALUE;

	QueryStatisticsImpl(String query) {
		super(query);
	}

	/**
	 * queries executed to the DB
	 */
	public long getExecutionCount() {
		return executionCount;
	}

	/**
	 * Queries retrieved successfully from the cache
	 */
	public long getCacheHitCount() {
		return cacheHitCount;
	}

	public long getCachePutCount() {
		return cachePutCount;
	}

	public long getCacheMissCount() {
		return cacheMissCount;
	}

	/**
	 * Number of lines returned by all the executions of this query (from DB)
	 * For now, {@link org.hibernate.Query#iterate()}
	 * and {@link org.hibernate.Query#scroll()()} do not fill this statistic
	 *
	 * @return The number of rows cumulatively returned by the given query; iterate
	 *         and scroll queries do not effect this total as their number of returned rows
	 *         is not known at execution time.
	 */
	public long getExecutionRowCount() {
		return executionRowCount;
	}

	/**
	 * average time in ms taken by the execution of this query onto the DB
	 */
	public long getExecutionAvgTime() {
		return executionAvgTime;
	}

	/**
	 * max time in ms taken by the execution of this query onto the DB
	 */
	public long getExecutionMaxTime() {
		return executionMaxTime;
	}

	/**
	 * min time in ms taken by the execution of this query onto the DB
	 */
	public long getExecutionMinTime() {
		return executionMinTime;
	}

	/**
	 * add statistics report of a DB query
	 *
	 * @param rows rows count returned
	 * @param time time taken
	 */
	void executed(long rows, long time) {
		if (time < executionMinTime) executionMinTime = time;
		if (time > executionMaxTime) executionMaxTime = time;
		executionAvgTime = (executionAvgTime * executionCount + time) / (executionCount + 1);
		executionCount++;
		executionRowCount += rows;
	}

	public String toString() {
		return new StringBuilder()
				.append("QueryStatistics")
				.append("[cacheHitCount=").append(this.cacheHitCount)
				.append(",cacheMissCount=").append(this.cacheMissCount)
				.append(",cachePutCount=").append(this.cachePutCount)
				.append(",executionCount=").append(this.executionCount)
				.append(",executionRowCount=").append(this.executionRowCount)
				.append(",executionAvgTime=").append(this.executionAvgTime)
				.append(",executionMaxTime=").append(this.executionMaxTime)
				.append(",executionMinTime=").append(this.executionMinTime)
				.append(']')
				.toString();
	}

}
