Class AbstractOffHeapClockCache<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.terracotta.offheapstore.OffHeapHashMap<K,V>

org.terracotta.offheapstore.AbstractLockedOffHeapHashMap<K,V>

org.terracotta.offheapstore.AbstractOffHeapClockCache<K,V>

Type Parameters:

K - the type of keys maintained by this map

V - the type of mapped values

All Implemented Interfaces:

ConcurrentMap<K,V>, ReadWriteLock, Map<K,V>, HashingMap<K,V>, MapInternals, PinnableCache<K,V>, PinnableSegment<K,V>, Segment<K,V>, StorageEngine.Owner

Direct Known Subclasses:

AbstractPersistentOffHeapCache, ReadWriteLockedOffHeapClockCache, WriteLockedOffHeapClockCache

public abstract class AbstractOffHeapClockCache<K,V>
extends AbstractLockedOffHeapHashMap<K,V>
implements PinnableCache<K,V>, PinnableSegment<K,V>

An abstract off-heap cache implementation.

Subclasses must implement the two getEvictionIndex(...) methods to instruct the cache regarding which mappings to remove.

Nested Class Summary

Nested classes/interfaces inherited from class AbstractLockedOffHeapHashMap

AbstractLockedOffHeapHashMap.LockedEntryIterator, AbstractLockedOffHeapHashMap.LockedEntrySet, AbstractLockedOffHeapHashMap.LockedKeyIterator, AbstractLockedOffHeapHashMap.LockedKeySet

Nested classes/interfaces inherited from class OffHeapHashMap

OffHeapHashMap.DirectEntry, OffHeapHashMap.EncodingIterator, OffHeapHashMap.EncodingSet, OffHeapHashMap.EntryIterator, OffHeapHashMap.EntrySet, OffHeapHashMap.HashIterator<T>, OffHeapHashMap.KeyIterator, OffHeapHashMap.KeySet, OffHeapHashMap.PendingPage

Nested classes/interfaces inherited from class AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface Map

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
private int	clockHand
private static final org.slf4j.Logger	LOGGER
private static final int	PRESENT_CLOCK
private final Random	rndm

Fields inherited from class OffHeapHashMap

ENCODING, ENTRY_BIT_SHIFT, ENTRY_SIZE, hashtable, hashTablePage, KEY_HASHCODE, modCount, removedSlots, reprobeLimit, RESERVED_STATUS_BITS, size, STATUS, STATUS_REMOVED, STATUS_USED, storageEngine, tableSource

Constructor Summary

Constructors

Constructor	Description
AbstractOffHeapClockCache(PageSource source, boolean tableAllocationsSteal, StorageEngine<? super K, ? super V> storageEngine)
AbstractOffHeapClockCache(PageSource source, boolean tableAllocationsSteal, StorageEngine<? super K, ? super V> storageEngine, int tableSize)
AbstractOffHeapClockCache(PageSource source, StorageEngine<? super K, ? super V> storageEngine)
AbstractOffHeapClockCache(PageSource source, StorageEngine<? super K, ? super V> storageEngine, boolean bootstrap)
AbstractOffHeapClockCache(PageSource source, StorageEngine<? super K, ? super V> storageEngine, int tableSize)
AbstractOffHeapClockCache(PageSource source, StorageEngine<? super K, ? super V> storageEngine, int tableSize, boolean bootstrap)

Method Summary

Modifier and Type	Method	Description
boolean	evict(int index, boolean shrink)
protected boolean	evictable(int status)
V	getAndPin(K key)
int	getEvictionIndex()	Return the table offset of the to be evicted mapping.
private int	getEvictionIndex(int start, int length)	Return the table offset of the to be evicted mapping within the given probe sequence.
protected void	hit(int position, IntBuffer entry)
boolean	isPinned(Object key)
V	putPinned(K key, V value)
void	setPinning(K key, boolean pinned)
protected void	storageEngineFailure(Object failure)
protected void	tableExpansionFailure(int start, int length)

Methods inherited from class AbstractLockedOffHeapHashMap

clear, computeIfAbsentWithMetadata, computeIfPresentWithMetadata, computeWithMetadata, containsKey, createEntrySet, createKeySet, destroy, fill, fill, get, getAndSetMetadata, getEncodingForHashAndBinary, getMetadata, getValueAndSetMetadata, installMappingForHashAndEncoding, put, put, putIfAbsent, readLock, remove, remove, removeAllWithHash, removeMapping, removeNoReturn, replace, replace, shrink, size, writeLock

Methods inherited from class OffHeapHashMap

added, createEncodingSet, encodingSet, entrySet, fill, freePendingTables, getAllocatedMemory, getAtTableOffset, getDataAllocatedMemory, getDataOccupiedMemory, getDataSize, getDataVitalMemory, getEntryAtTableOffset, getOccupiedMemory, getRemovedSlotCount, getReprobeLength, getSize, getSlotForHashAndEncoding, getStorageEngine, getTableCapacity, getUsedSlotCount, getVitalMemory, indexFor, indexFor, isAvailable, isPresent, isRemoved, isRemoved, isTerminating, isTerminating, isThiefForTableAllocations, keySet, readLong, readLong, removeAtTableOffset, removed, shrinkTable, spread, tryIncreaseReprobe, updated, updateEncoding

Methods inherited from class AbstractMap

clone, containsValue, equals, hashCode, isEmpty, putAll, toString, values

Methods inherited from class Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface ConcurrentMap

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Methods inherited from interface HashingMap

removeAllWithHash

Methods inherited from interface Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from interface MapInternals

getAllocatedMemory, getDataAllocatedMemory, getDataOccupiedMemory, getDataSize, getDataVitalMemory, getOccupiedMemory, getRemovedSlotCount, getReprobeLength, getSize, getTableCapacity, getUsedSlotCount, getVitalMemory

Methods inherited from interface ReadWriteLock

readLock, writeLock

Methods inherited from interface Segment

computeIfAbsentWithMetadata, computeIfPresentWithMetadata, computeWithMetadata, destroy, fill, fill, getAndSetMetadata, getLock, getMetadata, getValueAndSetMetadata, put, removeNoReturn, shrink

Field Details

LOGGER

private static final org.slf4j.Logger LOGGER

PRESENT_CLOCK

private static final int PRESENT_CLOCK

See Also:

• Constant Field Values

rndm

private final Random rndm

clockHand

private int clockHand

Constructor Details

AbstractOffHeapClockCache

public AbstractOffHeapClockCache(PageSource source,
 StorageEngine<? super K, ? super V> storageEngine)

AbstractOffHeapClockCache

public AbstractOffHeapClockCache(PageSource source,
 boolean tableAllocationsSteal,
 StorageEngine<? super K, ? super V> storageEngine)

AbstractOffHeapClockCache

public AbstractOffHeapClockCache(PageSource source,
 StorageEngine<? super K, ? super V> storageEngine,
 boolean bootstrap)

AbstractOffHeapClockCache

public AbstractOffHeapClockCache(PageSource source,
 StorageEngine<? super K, ? super V> storageEngine,
 int tableSize)

AbstractOffHeapClockCache

public AbstractOffHeapClockCache(PageSource source,
 boolean tableAllocationsSteal,
 StorageEngine<? super K, ? super V> storageEngine,
 int tableSize)

AbstractOffHeapClockCache

public AbstractOffHeapClockCache(PageSource source,
 StorageEngine<? super K, ? super V> storageEngine,
 int tableSize,
 boolean bootstrap)

Method Details

storageEngineFailure

protected void storageEngineFailure(Object failure)

Overrides:

storageEngineFailure in class OffHeapHashMap<K,V>

tableExpansionFailure

protected void tableExpansionFailure(int start,
 int length)

Overrides:

tableExpansionFailure in class OffHeapHashMap<K,V>

hit

protected void hit(int position,
 IntBuffer entry)

Overrides:

hit in class OffHeapHashMap<K,V>

getEvictionIndex

public int getEvictionIndex()

Return the table offset of the to be evicted mapping.

The mapping to be evicted can occur anywhere in this cache's table.

Returns:

table offset of the mapping to be evicted

getEvictionIndex

private int getEvictionIndex(int start,
 int length)

Return the table offset of the to be evicted mapping within the given probe sequence.

The mapping to be evicted must occur within the given probe sequence.

Parameters:

start - initial slot in probe sequence

length - number of slots in probe sequence

Returns:

table offset of the mapping to be evicted

evictable

protected boolean evictable(int status)

evict

public boolean evict(int index,
 boolean shrink)

Specified by:

evict in interface StorageEngine.Owner

Overrides:

evict in class AbstractLockedOffHeapHashMap<K,V>

isPinned

public boolean isPinned(Object key)

Specified by:

isPinned in interface PinnableCache<K,V>

setPinning

public void setPinning(K key,
 boolean pinned)

Specified by:

setPinning in interface PinnableCache<K,V>

putPinned

public V putPinned(K key,
 V value)

Specified by:

putPinned in interface PinnableCache<K,V>

getAndPin

public V getAndPin(K key)

Specified by:

getAndPin in interface PinnableCache<K,V>