mirror of
https://github.com/ebean-orm/ebean.git
synced 2024-04-21 10:51:47 +00:00
#919 - io.ebean package initial
This commit is contained in:
Rob Bygrave
@@ -0,0 +1,403 @@
|
||||
package io.ebeaninternal.server.cache;
|
||||
|
||||
import io.ebean.BackgroundExecutor;
|
||||
import io.ebean.cache.ServerCache;
|
||||
import io.ebean.cache.ServerCacheOptions;
|
||||
import io.ebean.cache.ServerCacheStatistics;
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
|
||||
import java.io.Serializable;
|
||||
import java.util.ArrayList;
|
||||
import java.util.Collections;
|
||||
import java.util.Comparator;
|
||||
import java.util.Iterator;
|
||||
import java.util.Map;
|
||||
import java.util.concurrent.ConcurrentHashMap;
|
||||
import java.util.concurrent.TimeUnit;
|
||||
import java.util.concurrent.atomic.LongAdder;
|
||||
|
||||
/**
|
||||
* The default cache implementation.
|
||||
* <p>
|
||||
* It is base on ConcurrentHashMap with periodic trimming using a TimerTask.
|
||||
* The periodic trimming means that an LRU list does not have to be maintained.
|
||||
* </p>
|
||||
*/
|
||||
public class DefaultServerCache implements ServerCache {
|
||||
|
||||
protected static final Logger logger = LoggerFactory.getLogger(DefaultServerCache.class);
|
||||
|
||||
/**
|
||||
* Compare by last access time (for LRU eviction).
|
||||
*/
|
||||
public static final CompareByLastAccess BY_LAST_ACCESS = new CompareByLastAccess();
|
||||
|
||||
/**
|
||||
* The underlying map (ConcurrentHashMap or similar)
|
||||
*/
|
||||
protected final Map<Object, CacheEntry> map;
|
||||
|
||||
protected final LongAdder missCount = new LongAdder();
|
||||
protected final LongAdder hitCount = new LongAdder();
|
||||
protected final LongAdder insertCount = new LongAdder();
|
||||
protected final LongAdder updateCount = new LongAdder();
|
||||
protected final LongAdder removeCount = new LongAdder();
|
||||
protected final LongAdder clearCount = new LongAdder();
|
||||
|
||||
protected final LongAdder evictByIdle = new LongAdder();
|
||||
protected final LongAdder evictByTTL = new LongAdder();
|
||||
protected final LongAdder evictByLRU = new LongAdder();
|
||||
protected final LongAdder evictCount = new LongAdder();
|
||||
protected final LongAdder evictMicros = new LongAdder();
|
||||
|
||||
protected final Object monitor = new Object();
|
||||
|
||||
protected final String name;
|
||||
|
||||
protected int maxSize;
|
||||
|
||||
protected final int trimFrequency;
|
||||
|
||||
protected int maxIdleSecs;
|
||||
|
||||
protected int maxSecsToLive;
|
||||
|
||||
/**
|
||||
* Construct using a ConcurrentHashMap and cache options.
|
||||
*/
|
||||
public DefaultServerCache(String name, ServerCacheOptions options) {
|
||||
this(name, new ConcurrentHashMap<>(), options);
|
||||
}
|
||||
|
||||
/**
|
||||
* Construct passing in name, map and base eviction controls as ServerCacheOptions.
|
||||
*/
|
||||
public DefaultServerCache(String name, Map<Object, CacheEntry> map, ServerCacheOptions options) {
|
||||
this(name, map, options.getMaxSize(), options.getMaxIdleSecs(), options.getMaxSecsToLive(), options.getTrimFrequency());
|
||||
}
|
||||
|
||||
/**
|
||||
* Construct passing in name, map and base eviction controls.
|
||||
*/
|
||||
public DefaultServerCache(String name, Map<Object, CacheEntry> map, int maxSize, int maxIdleSecs, int maxSecsToLive, int trimFrequency) {
|
||||
this.name = name;
|
||||
this.map = map;
|
||||
this.maxSize = maxSize;
|
||||
this.maxIdleSecs = maxIdleSecs;
|
||||
this.maxSecsToLive = maxSecsToLive;
|
||||
this.trimFrequency = determineTrim(maxIdleSecs, maxSecsToLive, trimFrequency);
|
||||
}
|
||||
|
||||
/**
|
||||
* Determine a good trimFrequency as half of maxIdleSecs (or maxSecsToLive).
|
||||
*/
|
||||
int determineTrim(int maxIdleSecs, int maxSecsToLive, int trimFrequency) {
|
||||
if (trimFrequency > 0) {
|
||||
return trimFrequency;
|
||||
}
|
||||
if (maxIdleSecs > 0) {
|
||||
return maxIdleSecs / 2 - 1;
|
||||
}
|
||||
if (maxSecsToLive > 0) {
|
||||
return maxSecsToLive / 2 - 1;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
public void periodicTrim(BackgroundExecutor executor) {
|
||||
|
||||
EvictionRunnable trim = new EvictionRunnable();
|
||||
|
||||
// default to trimming the cache every 60 seconds
|
||||
long trimFreqSecs = (trimFrequency == 0) ? 60 : trimFrequency;
|
||||
executor.executePeriodically(trim, trimFreqSecs, TimeUnit.SECONDS);
|
||||
}
|
||||
|
||||
@Override
|
||||
public ServerCacheStatistics getStatistics(boolean reset) {
|
||||
|
||||
ServerCacheStatistics cacheStats = new ServerCacheStatistics();
|
||||
cacheStats.setCacheName(name);
|
||||
cacheStats.setMaxSize(maxSize);
|
||||
|
||||
// these counters won't necessarily be consistent with
|
||||
// respect to each other as activity can occur while
|
||||
// they are being calculated here but they should be good enough
|
||||
// and we don't want to reduce concurrent use to make them consistent
|
||||
long clear = reset ? clearCount.sumThenReset() : clearCount.sum();
|
||||
long remove = reset ? removeCount.sumThenReset() : removeCount.sum();
|
||||
long update = reset ? updateCount.sumThenReset() : updateCount.sum();
|
||||
long insert = reset ? insertCount.sumThenReset() : insertCount.sum();
|
||||
long miss = reset ? missCount.sumThenReset() : missCount.sum();
|
||||
long hit = reset ? hitCount.sumThenReset() : hitCount.sum();
|
||||
|
||||
long evict = reset ? evictCount.sumThenReset() : evictCount.sum();
|
||||
long evictTime = reset ? evictMicros.sumThenReset() : evictMicros.sum();
|
||||
long evictIdle = reset ? evictByIdle.sumThenReset() : evictByIdle.sum();
|
||||
long evictTTL = reset ? evictByTTL.sumThenReset() : evictByTTL.sum();
|
||||
long evictLRU = reset ? evictByLRU.sumThenReset() : evictByLRU.sum();
|
||||
|
||||
int size = size();
|
||||
|
||||
cacheStats.setSize(size);
|
||||
cacheStats.setHitCount(hit);
|
||||
cacheStats.setMissCount(miss);
|
||||
cacheStats.setInsertCount(insert);
|
||||
cacheStats.setUpdateCount(update);
|
||||
cacheStats.setRemoveCount(remove);
|
||||
cacheStats.setClearCount(clear);
|
||||
|
||||
cacheStats.setEvictionRunCount(evict);
|
||||
cacheStats.setEvictionRunMicros(evictTime);
|
||||
cacheStats.setEvictByIdle(evictIdle);
|
||||
cacheStats.setEvictByTTL(evictTTL);
|
||||
cacheStats.setEvictByLRU(evictLRU);
|
||||
|
||||
return cacheStats;
|
||||
}
|
||||
|
||||
@Override
|
||||
public int getHitRatio() {
|
||||
|
||||
long mc = missCount.sum();
|
||||
long hc = hitCount.sum();
|
||||
|
||||
long totalCount = hc + mc;
|
||||
if (totalCount == 0) {
|
||||
return 0;
|
||||
} else {
|
||||
return (int) (hc * 100 / totalCount);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the name of the cache.
|
||||
*/
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
/**
|
||||
* Clear the cache.
|
||||
*/
|
||||
@Override
|
||||
public void clear() {
|
||||
clearCount.increment();
|
||||
map.clear();
|
||||
}
|
||||
|
||||
/**
|
||||
* Return a value from the cache.
|
||||
*/
|
||||
@Override
|
||||
public Object get(Object key) {
|
||||
|
||||
CacheEntry entry = map.get(key);
|
||||
if (entry == null) {
|
||||
missCount.increment();
|
||||
return null;
|
||||
|
||||
} else {
|
||||
// Important that hitCount.increment() MUST be low latency under concurrent
|
||||
// use hence must use LongAdder or better here
|
||||
hitCount.increment();
|
||||
return entry.getValue();
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Put a value into the cache.
|
||||
*/
|
||||
@Override
|
||||
public Object put(Object key, Object value) {
|
||||
CacheEntry entry = map.put(key, new CacheEntry(key, value));
|
||||
if (entry == null) {
|
||||
insertCount.increment();
|
||||
return null;
|
||||
} else {
|
||||
updateCount.increment();
|
||||
return entry.getValue();
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Remove an entry from the cache.
|
||||
*/
|
||||
@Override
|
||||
public Object remove(Object key) {
|
||||
CacheEntry entry = map.remove(key);
|
||||
if (entry == null) {
|
||||
return null;
|
||||
} else {
|
||||
removeCount.increment();
|
||||
return entry.getValue();
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the number of elements in the cache.
|
||||
*/
|
||||
@Override
|
||||
public int size() {
|
||||
return map.size();
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the size to trim to based on the max size.
|
||||
* <p>
|
||||
* This returns 90% of the max size.
|
||||
* </p>
|
||||
*/
|
||||
protected int getTrimSize() {
|
||||
return (maxSize * 90 / 100);
|
||||
}
|
||||
|
||||
/**
|
||||
* Run the eviction based on Idle time, Time to live and LRU last access.
|
||||
*/
|
||||
public void runEviction() {
|
||||
|
||||
long trimForMaxSize;
|
||||
if (maxSize == 0) {
|
||||
trimForMaxSize = 0;
|
||||
} else {
|
||||
trimForMaxSize = size() - maxSize;
|
||||
}
|
||||
|
||||
if (maxIdleSecs == 0 && maxSecsToLive == 0 && trimForMaxSize < 0) {
|
||||
// nothing to trim on this cache
|
||||
return;
|
||||
}
|
||||
|
||||
long startNanos = System.nanoTime();
|
||||
|
||||
long trimmedByIdle = 0;
|
||||
long trimmedByTTL = 0;
|
||||
long trimmedByLRU = 0;
|
||||
|
||||
ArrayList<CacheEntry> activeList = new ArrayList<>();
|
||||
|
||||
long idleExpire = System.currentTimeMillis() - (maxIdleSecs * 1000);
|
||||
long ttlExpire = System.currentTimeMillis() - (maxSecsToLive * 1000);
|
||||
|
||||
Iterator<CacheEntry> it = map.values().iterator();
|
||||
while (it.hasNext()) {
|
||||
CacheEntry cacheEntry = it.next();
|
||||
if (maxIdleSecs > 0 && idleExpire > cacheEntry.getLastAccessTime()) {
|
||||
it.remove();
|
||||
trimmedByIdle++;
|
||||
|
||||
} else if (maxSecsToLive > 0 && ttlExpire > cacheEntry.getCreateTime()) {
|
||||
it.remove();
|
||||
trimmedByTTL++;
|
||||
|
||||
} else if (trimForMaxSize > 0) {
|
||||
activeList.add(cacheEntry);
|
||||
}
|
||||
}
|
||||
|
||||
if (trimForMaxSize > 0) {
|
||||
trimmedByLRU = activeList.size() - maxSize;
|
||||
if (trimmedByLRU > 0) {
|
||||
// sort into last access time ascending
|
||||
Collections.sort(activeList, BY_LAST_ACCESS);
|
||||
int trimSize = getTrimSize();
|
||||
for (int i = trimSize; i < activeList.size(); i++) {
|
||||
// remove if still in the cache
|
||||
map.remove(activeList.get(i).getKey());
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
long exeNanos = System.nanoTime() - startNanos;
|
||||
long exeMicros = TimeUnit.MICROSECONDS.convert(exeNanos, TimeUnit.NANOSECONDS);
|
||||
|
||||
// increment the eviction statistics
|
||||
evictMicros.add(exeMicros);
|
||||
evictCount.increment();
|
||||
evictByIdle.add(trimmedByIdle);
|
||||
evictByTTL.add(trimmedByTTL);
|
||||
evictByLRU.add(trimmedByLRU);
|
||||
|
||||
if (logger.isTraceEnabled()) {
|
||||
logger.trace("Executed trim of cache {} in [{}]millis idle[{}] timeToLive[{}] accessTime[{}]"
|
||||
, name, exeMicros, trimmedByIdle, trimmedByTTL, trimmedByLRU);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Runnable that calls the eviction routine.
|
||||
*/
|
||||
public class EvictionRunnable implements Runnable {
|
||||
|
||||
@Override
|
||||
public void run() {
|
||||
runEviction();
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Comparator for sorting by last access time.
|
||||
*/
|
||||
public static class CompareByLastAccess implements Comparator<CacheEntry>, Serializable {
|
||||
|
||||
private static final long serialVersionUID = 1L;
|
||||
|
||||
public int compare(CacheEntry entry1, CacheEntry entry2) {
|
||||
long x = entry1.getLastAccessTime();
|
||||
long y = entry2.getLastAccessTime();
|
||||
return (x < y) ? -1 : ((x == y) ? 0 : 1);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Wraps the value to additionally hold createTime and lastAccessTime and hit counter.
|
||||
*/
|
||||
public static class CacheEntry {
|
||||
|
||||
private final Object key;
|
||||
private final Object value;
|
||||
private final long createTime;
|
||||
private long lastAccessTime;
|
||||
|
||||
public CacheEntry(Object key, Object value) {
|
||||
this.key = key;
|
||||
this.value = value;
|
||||
this.createTime = System.currentTimeMillis();
|
||||
this.lastAccessTime = createTime;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the entry key.
|
||||
*/
|
||||
public Object getKey() {
|
||||
return key;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the entry value.
|
||||
*/
|
||||
public Object getValue() {
|
||||
// long assignment should be atomic these days (Ref Cliff Click)
|
||||
lastAccessTime = System.currentTimeMillis();
|
||||
return value;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the time the entry was created.
|
||||
*/
|
||||
public long getCreateTime() {
|
||||
return createTime;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return the time the entry was last accessed.
|
||||
*/
|
||||
public long getLastAccessTime() {
|
||||
return lastAccessTime;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
}
|
||||
Reference in New Issue
Block a user