/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.openjpa.kernel;
import java.io.PrintStream;
import java.io.Serializable;
import java.util.Collections;
import java.util.Date;
import java.util.Map;
import java.util.Set;
import org.apache.openjpa.lib.util.concurrent.SizedConcurrentHashMap;
/**
* Records query execution statistics.
*
* Statistics can be reset.
*
* Gathers both accumulated statistics since start as well as statistics since
* last reset.
*
* @since 1.3.0
*
* @author Pinaki Poddar
*
*/
public interface QueryStatistics<T> extends Serializable {
/**
* Gets all the identifier keys for the cached queries.
*/
public Set<T> keys();
/**
* Record that the given query has been executed.
*/
void recordExecution(T query);
/**
* Gets number of total query execution since last reset.
*/
public long getExecutionCount();
/**
* Gets number of total query execution since start.
*/
public long getTotalExecutionCount();
/**
* Gets number of executions for the given query since last reset.
*/
public long getExecutionCount(T query);
/**
* Gets number of executions for the given query since start.
*/
public long getTotalExecutionCount(T query);
/**
* Gets number of total query execution that are cached since last reset.
*/
public long getHitCount();
/**
* Gets number of total query execution that are cached since start.
*/
public long getTotalHitCount();
/**
* Gets number of executions for the given query that are cached since
* last reset.
*/
public long getHitCount(T query);
/**
* Gets number of executions for the given query that are cached since
* start.
*/
public long getTotalHitCount(T query);
/**
* Gets the time of last reset.
*/
public Date since();
/**
* Gets the time of start.
*/
public Date start();
/**
* Clears all statistics accumulated since last reset.
*/
public void reset();
/**
* Clears all statistics accumulated since start.
*/
public void clear();
/**
* Dumps on the given output stream.
*/
public void dump(PrintStream out);
/**
* A default implementation.
*
* Maintains statistics for only a fixed number of queries.
* Statistical counts are approximate and not exact (to keep thread synchorization overhead low).
*
*/
public static class Default<T> implements QueryStatistics<T> {
private static final int FIXED_SIZE = 1000;
private static final float LOAD_FACTOR = 0.75f;
private static final int CONCURRENCY = 16;
private static final int ARRAY_SIZE = 2;
private static final int READ = 0;
private static final int HIT = 1;
private long[] astat = new long[ARRAY_SIZE];
private long[] stat = new long[ARRAY_SIZE];
private Map<T, long[]> stats = new SizedConcurrentHashMap(FIXED_SIZE, LOAD_FACTOR, CONCURRENCY);
private Map<T, long[]> astats = new SizedConcurrentHashMap(FIXED_SIZE, LOAD_FACTOR, CONCURRENCY);
private Date start = new Date();
private Date since = start;
public Set<T> keys() {
return stats.keySet();
}
public long getExecutionCount() {
return stat[READ];
}
public long getTotalExecutionCount() {
return astat[READ];
}
public long getExecutionCount(T query) {
return getCount(stats, query, READ);
}
public long getTotalExecutionCount(T query) {
return getCount(astats, query, READ);
}
public long getHitCount() {
return stat[HIT];
}
public long getTotalHitCount() {
return astat[HIT];
}
public long getHitCount(T query) {
return getCount(stats, query, HIT);
}
public long getTotalHitCount(T query) {
return getCount(astats, query, HIT);
}
private long getCount(Map<T, long[]> target, T query, int i) {
long[] row = target.get(query);
return (row == null) ? 0 : row[i];
}
public Date since() {
return since;
}
public Date start() {
return start;
}
public synchronized void reset() {
stat = new long[ARRAY_SIZE];
stats.clear();
since = new Date();
}
public synchronized void clear() {
astat = new long[ARRAY_SIZE];
stat = new long[ARRAY_SIZE];
stats = new SizedConcurrentHashMap(FIXED_SIZE, LOAD_FACTOR, CONCURRENCY);
astats = new SizedConcurrentHashMap(FIXED_SIZE, LOAD_FACTOR, CONCURRENCY);
start = new Date();
since = start;
}
private void addSample(T query, int index) {
stat[index]++;
astat[index]++;
addSample(stats, query, index);
addSample(astats, query, index);
}
private void addSample(Map<T, long[]> target, T query, int i) {
long[] row = target.get(query);
if (row == null) {
row = new long[ARRAY_SIZE];
}
row[i]++;
target.put(query, row);
}
public void recordExecution(T query) {
if (query == null)
return;
boolean cached = astats.containsKey(query);
addSample(query, READ);
if (cached)
addSample(query, HIT);
}
public void dump(PrintStream out) {
String header = "Query Statistics starting from " + start;
out.print(header);
if (since == start) {
out.println();
out.println("Total Query Execution: " + toString(astat));
out.println("\tTotal \t\tQuery");
} else {
out.println(" last reset on " + since);
out.println("Total Query Execution since start " +
toString(astat) + " since reset " + toString(stat));
out.println("\tSince Start \tSince Reset \t\tQuery");
}
int i = 0;
for (T key : stats.keySet()) {
i++;
long[] arow = astats.get(key);
if (since == start) {
out.println(i + ". \t" + toString(arow) + " \t" + key);
} else {
long[] row = stats.get(key);
out.println(i + ". \t" + toString(arow) + " \t" + toString(row) + " \t\t" + key);
}
}
}
long pct(long per, long cent) {
if (cent <= 0)
return 0;
return (100*per)/cent;
}
String toString(long[] row) {
return row[READ] + ":" + row[HIT] + "(" + pct(row[HIT], row[READ]) + "%)";
}
}
/**
* A do-nothing implementation.
*
* @author Pinaki Poddar
*
* @param <T>
*/
public static class None<T> implements QueryStatistics<T> {
private Date start = new Date();
private Date since = start;
public void clear() {
}
public void dump(PrintStream out) {
}
public long getExecutionCount() {
return 0;
}
public long getExecutionCount(T query) {
return 0;
}
public long getHitCount() {
return 0;
}
public long getHitCount(T query) {
return 0;
}
public long getTotalExecutionCount() {
return 0;
}
public long getTotalExecutionCount(T query) {
return 0;
}
public long getTotalHitCount() {
return 0;
}
public long getTotalHitCount(T query) {
return 0;
}
public Set<T> keys() {
return Collections.emptySet();
}
public void recordExecution(T query) {
}
public void reset() {
start = new Date();
since = start;
}
public Date since() {
return since;
}
public Date start() {
return start;
}
}
}