Package org.apache.solr.util
Class ConcurrentLRUCache<K,V>
- java.lang.Object
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- org.apache.solr.util.ConcurrentLRUCache<K,V>
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- All Implemented Interfaces:
org.apache.lucene.util.Accountable
,org.apache.solr.common.util.Cache<K,V>
public class ConcurrentLRUCache<K,V> extends Object implements org.apache.solr.common.util.Cache<K,V>, org.apache.lucene.util.Accountable
A LRU cache implementation based upon ConcurrentHashMap and other techniques to reduce contention and synchronization overhead to utilize multiple CPU cores more effectively.Note that the implementation does not follow a true LRU (least-recently-used) eviction strategy. Instead it strives to remove least recently used items but when the initial cleanup does not remove enough items to reach the 'acceptableWaterMark' limit, it can remove more items forcefully regardless of access order.
- Since:
- solr 1.4
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ConcurrentLRUCache.CacheEntry<K,V>
static interface
ConcurrentLRUCache.EvictionListener<K,V>
static class
ConcurrentLRUCache.Stats
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Constructor Summary
Constructors Constructor Description ConcurrentLRUCache(int size, int lowerWaterMark)
ConcurrentLRUCache(int upperWaterMark, int lowerWaterMark, int acceptableWaterMark, int initialSize, boolean runCleanupThread, boolean runNewThreadForCleanup, ConcurrentLRUCache.EvictionListener<K,V> evictionListener)
ConcurrentLRUCache(int upperWaterMark, int lowerWaterMark, int acceptableWaterMark, int initialSize, boolean runCleanupThread, boolean runNewThreadForCleanup, ConcurrentLRUCache.EvictionListener<K,V> evictionListener, int maxIdleTimeSec)
ConcurrentLRUCache(long ramLowerWatermark, long ramUpperWatermark, boolean runCleanupThread, ConcurrentLRUCache.EvictionListener<K,V> evictionListener)
ConcurrentLRUCache(long ramLowerWatermark, long ramUpperWatermark, boolean runCleanupThread, ConcurrentLRUCache.EvictionListener<K,V> evictionListener, int maxIdleTimeSec)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clear()
V
computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction)
void
destroy()
V
get(K key)
Collection<org.apache.lucene.util.Accountable>
getChildResources()
Map<K,V>
getLatestAccessedItems(int n)
Map<Object,ConcurrentLRUCache.CacheEntry<K,V>>
getMap()
Map<K,V>
getOldestAccessedItems(int n)
Returns 'n' number of oldest accessed entries present in this cache.ConcurrentLRUCache.Stats
getStats()
void
markAndSweep()
Removes items from the cache to bring the size down to an acceptable value.V
put(K key, V val)
V
putCacheEntry(ConcurrentLRUCache.CacheEntry<K,V> e)
Visible for testing to create synthetic cache entries.long
ramBytesUsed()
V
remove(K key)
void
setAcceptableWaterMark(int acceptableWaterMark)
void
setAlive(boolean live)
void
setLowerWaterMark(int lowerWaterMark)
void
setMaxIdleTime(int maxIdleTime)
void
setRamLowerWatermark(long ramLowerWatermark)
void
setRamUpperWatermark(long ramUpperWatermark)
void
setRunCleanupThread(boolean runCleanupThread)
void
setUpperWaterMark(int upperWaterMark)
int
size()
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Constructor Detail
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ConcurrentLRUCache
public ConcurrentLRUCache(long ramLowerWatermark, long ramUpperWatermark, boolean runCleanupThread, ConcurrentLRUCache.EvictionListener<K,V> evictionListener)
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ConcurrentLRUCache
public ConcurrentLRUCache(long ramLowerWatermark, long ramUpperWatermark, boolean runCleanupThread, ConcurrentLRUCache.EvictionListener<K,V> evictionListener, int maxIdleTimeSec)
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ConcurrentLRUCache
public ConcurrentLRUCache(int upperWaterMark, int lowerWaterMark, int acceptableWaterMark, int initialSize, boolean runCleanupThread, boolean runNewThreadForCleanup, ConcurrentLRUCache.EvictionListener<K,V> evictionListener)
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ConcurrentLRUCache
public ConcurrentLRUCache(int upperWaterMark, int lowerWaterMark, int acceptableWaterMark, int initialSize, boolean runCleanupThread, boolean runNewThreadForCleanup, ConcurrentLRUCache.EvictionListener<K,V> evictionListener, int maxIdleTimeSec)
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ConcurrentLRUCache
public ConcurrentLRUCache(int size, int lowerWaterMark)
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Method Detail
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setAlive
public void setAlive(boolean live)
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setUpperWaterMark
public void setUpperWaterMark(int upperWaterMark)
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setLowerWaterMark
public void setLowerWaterMark(int lowerWaterMark)
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setAcceptableWaterMark
public void setAcceptableWaterMark(int acceptableWaterMark)
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setRamUpperWatermark
public void setRamUpperWatermark(long ramUpperWatermark)
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setRamLowerWatermark
public void setRamLowerWatermark(long ramLowerWatermark)
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setMaxIdleTime
public void setMaxIdleTime(int maxIdleTime)
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setRunCleanupThread
public void setRunCleanupThread(boolean runCleanupThread)
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putCacheEntry
public V putCacheEntry(ConcurrentLRUCache.CacheEntry<K,V> e)
Visible for testing to create synthetic cache entries.- NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
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markAndSweep
public void markAndSweep()
Removes items from the cache to bring the size down to an acceptable value.Visible for unit testing.
- NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
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getOldestAccessedItems
public Map<K,V> getOldestAccessedItems(int n)
Returns 'n' number of oldest accessed entries present in this cache.This uses a TreeSet to collect the 'n' oldest items ordered by ascending last access time and returns a LinkedHashMap containing 'n' or less than 'n' entries.
- Parameters:
n
- the number of oldest items needed- Returns:
- a LinkedHashMap containing 'n' or less than 'n' entries
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size
public int size()
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getMap
public Map<Object,ConcurrentLRUCache.CacheEntry<K,V>> getMap()
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destroy
public void destroy()
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getStats
public ConcurrentLRUCache.Stats getStats()
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ramBytesUsed
public long ramBytesUsed()
- Specified by:
ramBytesUsed
in interfaceorg.apache.lucene.util.Accountable
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getChildResources
public Collection<org.apache.lucene.util.Accountable> getChildResources()
- Specified by:
getChildResources
in interfaceorg.apache.lucene.util.Accountable
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