synchronized void putIfAbsent(Query query, LeafReaderContext context, DocIdSet set) {
// under a lock to make sure that mostRecentlyUsedQueries and cache remain sync'ed
// we don't want to have user-provided queries as keys in our cache since queries are mutable
assert query instanceof BoostQuery == false;
assert query instanceof ConstantScoreQuery == false;
Query singleton = uniqueQueries.putIfAbsent(query, query);
if (singleton == null) {
onQueryCache(singleton, LINKED_HASHTABLE_RAM_BYTES_PER_ENTRY + ramBytesUsed(query));
} else {
query = singleton;
}
final Object key = context.reader().getCoreCacheKey();
LeafCache leafCache = cache.get(key);
if (leafCache == null) {
leafCache = new LeafCache(key);
final LeafCache previous = cache.put(context.reader().getCoreCacheKey(), leafCache);
ramBytesUsed += HASHTABLE_RAM_BYTES_PER_ENTRY;
assert previous == null;
// we just created a new leaf cache, need to register a close listener
context
.reader()
.addCoreClosedListener(
new CoreClosedListener() {
@Override
public void onClose(Object ownerCoreCacheKey) {
clearCoreCacheKey(ownerCoreCacheKey);
}
});
}
leafCache.putIfAbsent(query, set);
evictIfNecessary();
}
synchronized DocIdSet get(Query key, LeafReaderContext context) {
assert key instanceof BoostQuery == false;
assert key instanceof ConstantScoreQuery == false;
final Object readerKey = context.reader().getCoreCacheKey();
final LeafCache leafCache = cache.get(readerKey);
if (leafCache == null) {
onMiss(readerKey, key);
return null;
}
// this get call moves the query to the most-recently-used position
final Query singleton = uniqueQueries.get(key);
if (singleton == null) {
onMiss(readerKey, key);
return null;
}
final DocIdSet cached = leafCache.get(singleton);
if (cached == null) {
onMiss(readerKey, singleton);
} else {
onHit(readerKey, singleton);
}
return cached;
}
private void onEviction(Query singleton) {
onQueryEviction(singleton, LINKED_HASHTABLE_RAM_BYTES_PER_ENTRY + ramBytesUsed(singleton));
for (LeafCache leafCache : cache.values()) {
leafCache.remove(singleton);
}
}