Modifier and Type	Class and Description
public static class	CacheLongKeyLIRS.Config The cache configuration.
pack-priv static class	CacheLongKeyLIRS.Entry< the value type V> A cache entry.
private static class	CacheLongKeyLIRS.Segment< the value type V> A cache segment

Modifier and Type	Field and Description
private long	maxMemory The maximum memory this cache should use.
private final int	nonResidentQueueSize
private final int	nonResidentQueueSizeHigh
private final int	segmentCount
private final int	segmentMask
private final CacheLongKeyLIRS.Segment<V>[]	segments
private final int	segmentShift
private final int	stackMoveDistance

Access	Constructor and Description
public	CacheLongKeyLIRS(CacheLongKeyLIRS.Config the configuration config) Create a new cache with the given memory size.

Method Summary

Modifier and Type	Method and Description
public void	clear() Remove all entries.
public boolean	Returns: true if there is a resident entry containsKey(long the key (may not be null) key) Check whether there is a resident entry for the given key.
public boolean	Returns: true if it is stored containsValue(V the value value) Check whether the given value is stored.
public synchronized Set<Map.Entry<Long, V>>	Returns: the entry set entrySet() Get the entry set for all resident entries.
private CacheLongKeyLIRS.Entry<V>	find(long key)
public V	Returns: the value, or null if there is no resident entry get(long the key (may not be null) key) Get the value for the given key if the entry is cached.
pack-priv static int	Returns: the hash code getHash(long the key key) Get the hash code for the given key.
public long	Returns: the cache hits getHits() Get the number of cache hits.
public Map<Long, V>	Returns: the map getMap() Convert this cache to a map.
public long	Returns: data items size limit getMaxItemSize() Determines max size of the data item size to fit into cache
public long	Returns: the maximum memory getMaxMemory() Get the maximum memory to use.
public long	Returns: the memory, or 0 if there is no resident entry getMemory(long the key (may not be null) key) Get the memory used for the given key.
public static int	Returns: the memory overhead per value getMemoryOverhead() Get the memory overhead per value.
public long	Returns: the cache misses getMisses() Get the number of cache misses.
private CacheLongKeyLIRS.Segment<V>	getSegment(int hash)
private int	getSegmentIndex(int hash)
public long	Returns: the used memory getUsedMemory() Get the currently used memory.
public boolean	Returns: true if it is empty isEmpty() Check whether the cache is empty.
public List<Long>	Returns: the key list keys(boolean if true, only keys for the cold entries are returned cold, boolean true for non-resident entries nonResident) Get the list of keys.
public Set<Long>	Returns: the set of keys keySet() Get the set of keys for resident entries.
public V	Returns: the value, or null if there is no resident entry peek(long the key (may not be null) key) Get the value for the given key if the entry is cached.
public V	Returns: the old value, or null if there was no resident entry put(long the key (may not be null) key, V the value (may not be null) value) Add an entry to the cache using the average memory size.
public V	Returns: the old value, or null if there was no resident entry put(long the key (may not be null) key, V the value (may not be null) value, long the memory used for the given entry memory) Add an entry to the cache.
public void	putAll(Map<Long, ? extends V> the map m) Add all elements of the map to this cache.
public V	Returns: the old value, or null if there was no resident entry remove(long the key (may not be null) key) Remove an entry.
private CacheLongKeyLIRS.Segment<V>	resizeIfNeeded(CacheLongKeyLIRS.Segment<V> s, int segmentIndex)
public void	setMaxMemory(long the maximum size (1 or larger) in bytes maxMemory) Set the maximum memory this cache should use.
public int	Returns: the number of entries size() Get the number of resident entries.
public int	Returns: the number of hot entries sizeHot() Get the number of hot entries in the cache.
public int	Returns: the size of the array sizeMapArray() Get the length of the internal map array.
public int	Returns: the number of non-resident entries sizeNonResident() Get the number of non-resident entries in the cache.
protected long	Returns: the size sizeOf(V the value value) Get the size of the given value.
public void	trimNonResidentQueue() Loop through segments, trimming the non resident queue.
public List<V>	Returns: the entry set values() Get the values for all resident entries.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

maxMemory	back to summary
private long maxMemory The maximum memory this cache should use.

nonResidentQueueSize	back to summary
private final int nonResidentQueueSize

nonResidentQueueSizeHigh	back to summary
private final int nonResidentQueueSizeHigh

segmentCount	back to summary
private final int segmentCount

segmentMask	back to summary
private final int segmentMask

segments	back to summary
private final CacheLongKeyLIRS.Segment<V>[] segments

segmentShift	back to summary
private final int segmentShift

stackMoveDistance	back to summary
private final int stackMoveDistance

CacheLongKeyLIRS	back to summary
public CacheLongKeyLIRS(CacheLongKeyLIRS.Config config) Create a new cache with the given memory size. Parameters config:CacheLongKeyLIRS.Config the configuration Annotations @SuppressWarnings:unchecked

Method Detail

clear	back to summary
public void clear() Remove all entries.

containsKey	back to summary
public boolean containsKey(long key) Check whether there is a resident entry for the given key. This method does not adjust the internal state of the cache. Parameters key:long the key (may not be null) Returns:boolean true if there is a resident entry

containsKey

back to summary

public boolean containsKey(long key)

Check whether there is a resident entry for the given key. This method does not adjust the internal state of the cache.

Parameters

key:long: the key (may not be null)

Returns:boolean

true if there is a resident entry

containsValue	back to summary
public boolean containsValue(V value) Check whether the given value is stored. Parameters value:V the value Returns:boolean true if it is stored

containsValue

back to summary

public boolean containsValue(V value)

Check whether the given value is stored.

Parameters

value:V: the value

Returns:boolean

true if it is stored

entrySet	back to summary
public synchronized Set<Map.Entry<Long, V>> entrySet() Get the entry set for all resident entries. Returns:Set<Map.Entry<Long, V>> the entry set

entrySet

back to summary

public synchronized Set<Map.Entry<Long, V>> entrySet()

Get the entry set for all resident entries.

Returns:Set<Map.Entry<Long, V>>: the entry set

find	back to summary
private CacheLongKeyLIRS.Entry<V> find(long key)

get	back to summary
public V get(long key) Get the value for the given key if the entry is cached. This method adjusts the internal state of the cache sometimes, to ensure commonly used entries stay in the cache. Parameters key:long the key (may not be null) Returns:V the value, or null if there is no resident entry

get

back to summary

public V get(long key)

Get the value for the given key if the entry is cached. This method adjusts the internal state of the cache sometimes, to ensure commonly used entries stay in the cache.

Parameters

key:long: the key (may not be null)

Returns:V

the value, or null if there is no resident entry

getHash	back to summary
pack-priv static int getHash(long key) Get the hash code for the given key. The hash code is further enhanced to spread the values more evenly. Parameters key:long the key Returns:int the hash code

getHash

back to summary

pack-priv static int getHash(long key)

Get the hash code for the given key. The hash code is further enhanced to spread the values more evenly.

Parameters

key:long: the key

Returns:int

the hash code

getHits	back to summary
public long getHits() Get the number of cache hits. Returns:long the cache hits

getHits

back to summary

public long getHits()

Get the number of cache hits.

Returns:long: the cache hits

getMap	back to summary
public Map<Long, V> getMap() Convert this cache to a map. Returns:Map<Long, V> the map

getMap

back to summary

public Map<Long, V> getMap()

Convert this cache to a map.

Returns:Map<Long, V>: the map

getMaxItemSize	back to summary
public long getMaxItemSize() Determines max size of the data item size to fit into cache Returns:long data items size limit

getMaxItemSize

back to summary

public long getMaxItemSize()

Determines max size of the data item size to fit into cache

Returns:long: data items size limit

getMaxMemory	back to summary
public long getMaxMemory() Get the maximum memory to use. Returns:long the maximum memory

getMaxMemory

back to summary

public long getMaxMemory()

Get the maximum memory to use.

Returns:long: the maximum memory

getMemory	back to summary
public long getMemory(long key) Get the memory used for the given key. Parameters key:long the key (may not be null) Returns:long the memory, or 0 if there is no resident entry

getMemory

back to summary

public long getMemory(long key)

Get the memory used for the given key.

Parameters

key:long: the key (may not be null)

Returns:long

the memory, or 0 if there is no resident entry

getMemoryOverhead	back to summary
public static int getMemoryOverhead() Get the memory overhead per value. Returns:int the memory overhead per value

getMemoryOverhead

back to summary

public static int getMemoryOverhead()

Get the memory overhead per value.

Returns:int: the memory overhead per value

getMisses	back to summary
public long getMisses() Get the number of cache misses. Returns:long the cache misses

getMisses

back to summary

public long getMisses()

Get the number of cache misses.

Returns:long: the cache misses

getSegment	back to summary
private CacheLongKeyLIRS.Segment<V> getSegment(int hash)

getSegmentIndex	back to summary
private int getSegmentIndex(int hash)

getUsedMemory	back to summary
public long getUsedMemory() Get the currently used memory. Returns:long the used memory

getUsedMemory

back to summary

public long getUsedMemory()

Get the currently used memory.

Returns:long: the used memory

isEmpty	back to summary
public boolean isEmpty() Check whether the cache is empty. Returns:boolean true if it is empty

isEmpty

back to summary

public boolean isEmpty()

Check whether the cache is empty.

Returns:boolean: true if it is empty

keys	back to summary
public List<Long> keys(boolean cold, boolean nonResident) Get the list of keys. This method allows to read the internal state of the cache. Parameters cold:boolean if true, only keys for the cold entries are returned nonResident:boolean true for non-resident entries Returns:List<Long> the key list

keys

back to summary

public List<Long> keys(boolean cold, boolean nonResident)

Get the list of keys. This method allows to read the internal state of the cache.

Parameters

cold:boolean: if true, only keys for the cold entries are returned
nonResident:boolean: true for non-resident entries

Returns:List<Long>

the key list

keySet	back to summary
public Set<Long> keySet() Get the set of keys for resident entries. Returns:Set<Long> the set of keys

keySet

back to summary

public Set<Long> keySet()

Get the set of keys for resident entries.

Returns:Set<Long>: the set of keys

peek	back to summary
public V peek(long key) Get the value for the given key if the entry is cached. This method does not modify the internal state. Parameters key:long the key (may not be null) Returns:V the value, or null if there is no resident entry

peek

back to summary

public V peek(long key)

Get the value for the given key if the entry is cached. This method does not modify the internal state.

Parameters

key:long: the key (may not be null)

Returns:V

the value, or null if there is no resident entry

put	back to summary
public V put(long key, V value) Add an entry to the cache using the average memory size. Parameters key:long the key (may not be null) value:V the value (may not be null) Returns:V the old value, or null if there was no resident entry

put

back to summary

public V put(long key, V value)

Add an entry to the cache using the average memory size.

Parameters

key:long: the key (may not be null)
value:V: the value (may not be null)

Returns:V

the old value, or null if there was no resident entry

put	back to summary
public V put(long key, V value, long memory) Add an entry to the cache. The entry may or may not exist in the cache yet. This method will usually mark unknown entries as cold and known entries as hot. Parameters key:long the key (may not be null) value:V the value (may not be null) memory:long the memory used for the given entry Returns:V the old value, or null if there was no resident entry

put

back to summary

public V put(long key, V value, long memory)

Add an entry to the cache. The entry may or may not exist in the cache yet. This method will usually mark unknown entries as cold and known entries as hot.

Parameters

key:long: the key (may not be null)
value:V: the value (may not be null)
memory:long: the memory used for the given entry

Returns:V

the old value, or null if there was no resident entry

putAll	back to summary
public void putAll(Map<Long, ? extends V> m) Add all elements of the map to this cache. Parameters m:Map<Long, ? extends V> the map

putAll

back to summary

public void putAll(Map<Long, ? extends V> m)

Add all elements of the map to this cache.

Parameters

m:Map<Long, ? extends V>: the map

remove	back to summary
public V remove(long key) Remove an entry. Both resident and non-resident entries can be removed. Parameters key:long the key (may not be null) Returns:V the old value, or null if there was no resident entry

remove

back to summary

public V remove(long key)

Remove an entry. Both resident and non-resident entries can be removed.

Parameters

key:long: the key (may not be null)

Returns:V

the old value, or null if there was no resident entry

resizeIfNeeded	back to summary
private CacheLongKeyLIRS.Segment<V> resizeIfNeeded(CacheLongKeyLIRS.Segment<V> s, int segmentIndex)

setMaxMemory	back to summary
public void setMaxMemory(long maxMemory) Set the maximum memory this cache should use. This will not immediately cause entries to get removed however; it will only change the limit. To resize the internal array, call the clear method. Parameters maxMemory:long the maximum size (1 or larger) in bytes

setMaxMemory

back to summary

public void setMaxMemory(long maxMemory)

Set the maximum memory this cache should use. This will not immediately cause entries to get removed however; it will only change the limit. To resize the internal array, call the clear method.

Parameters

maxMemory:long: the maximum size (1 or larger) in bytes

size	back to summary
public int size() Get the number of resident entries. Returns:int the number of entries

size

back to summary

public int size()

Get the number of resident entries.

Returns:int: the number of entries

sizeHot	back to summary
public int sizeHot() Get the number of hot entries in the cache. Returns:int the number of hot entries

sizeHot

back to summary

public int sizeHot()

Get the number of hot entries in the cache.

Returns:int: the number of hot entries

sizeMapArray	back to summary
public int sizeMapArray() Get the length of the internal map array. Returns:int the size of the array

sizeMapArray

back to summary

public int sizeMapArray()

Get the length of the internal map array.

Returns:int: the size of the array

sizeNonResident	back to summary
public int sizeNonResident() Get the number of non-resident entries in the cache. Returns:int the number of non-resident entries

sizeNonResident

back to summary

public int sizeNonResident()

Get the number of non-resident entries in the cache.

Returns:int: the number of non-resident entries

sizeOf	back to summary
protected long sizeOf(V value) Get the size of the given value. The default implementation returns 16. Parameters value:V the value Returns:long the size Annotations @SuppressWarnings:unused

sizeOf

back to summary

protected long sizeOf(V value)

Get the size of the given value. The default implementation returns 16.

Parameters

value:V: the value

Returns:long

the size

Annotations

@SuppressWarnings:unused

trimNonResidentQueue	back to summary
public void trimNonResidentQueue() Loop through segments, trimming the non resident queue.

values	back to summary
public List<V> values() Get the values for all resident entries. Returns:List<V> the entry set

values

back to summary

public List<V> values()

Get the values for all resident entries.

Returns:List<V>: the entry set

org.h2.mvstore.cache back to summary

public Class CacheLongKeyLIRS.Config

Class Inheritance

extends Object

java.lang.Object
org.h2.mvstore.cache.CacheLongKeyLIRS.Config

The cache configuration.

Field Summary

Modifier and Type	Field and Description
public long	maxMemory The maximum memory to use (1 or larger).
public final int	nonResidentQueueSize Low water mark for the number of entries in the non-resident queue, as a factor of the number of all other entries in the map.
public final int	nonResidentQueueSizeHigh High watermark for the number of entries in the non-resident queue, as a factor of the number of all other entries in the map
public int	segmentCount The number of cache segments (must be a power of 2).
public int	stackMoveDistance How many other item are to be moved to the top of the stack before the current item is moved.

Constructor Summary

Access	Constructor and Description
public	Config()

Method Summary

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

maxMemory	back to summary
public long maxMemory The maximum memory to use (1 or larger).

nonResidentQueueSize	back to summary
public final int nonResidentQueueSize Low water mark for the number of entries in the non-resident queue, as a factor of the number of all other entries in the map.

nonResidentQueueSizeHigh	back to summary
public final int nonResidentQueueSizeHigh High watermark for the number of entries in the non-resident queue, as a factor of the number of all other entries in the map

segmentCount	back to summary
public int segmentCount The number of cache segments (must be a power of 2).

stackMoveDistance	back to summary
public int stackMoveDistance How many other item are to be moved to the top of the stack before the current item is moved.

Constructor Detail

Config	back to summary
public Config()

org.h2.mvstore.cache back to summary

pack-priv Class CacheLongKeyLIRS.Entry<V>

Class Inheritance

extends Object

java.lang.Object
org.h2.mvstore.cache.CacheLongKeyLIRS.Entry

Type Parameters

<V>: the value type

A cache entry. Each entry is either hot (low inter-reference recency; LIR), cold (high inter-reference recency; HIR), or non-resident-cold. Hot entries are in the stack only. Cold entries are in the queue, and may be in the stack. Non-resident-cold entries have their value set to null and are in the stack and in the non-resident queue.

Field Summary

Modifier and Type	Field and Description
pack-priv final long	key The key.
pack-priv CacheLongKeyLIRS.Entry<V>	mapNext The next entry in the map (the chained entry).
pack-priv final long	memory The estimated memory used.
pack-priv CacheLongKeyLIRS.Entry<V>	queueNext The next entry in the queue (either the resident queue or the non-resident queue).
pack-priv CacheLongKeyLIRS.Entry<V>	queuePrev The previous entry in the queue.
pack-priv WeakReference<V>	reference Weak reference to the value.
pack-priv CacheLongKeyLIRS.Entry<V>	stackNext The next entry in the stack.
pack-priv CacheLongKeyLIRS.Entry<V>	stackPrev The previous entry in the stack.
pack-priv int	topMove When the item was last moved to the top of the stack.
pack-priv static final int	TOTAL_MEMORY_OVERHEAD
pack-priv V	value The value.

Constructor Summary

Access	Constructor and Description
pack-priv	Entry()
pack-priv	Entry(long key, V value, long memory)
pack-priv	Entry(CacheLongKeyLIRS.Entry<V> old)

Method Summary

Modifier and Type	Method and Description
pack-priv long	getMemory()
pack-priv V	getValue()
pack-priv boolean	Returns: whether the entry is hot isHot() Whether this entry is hot.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

key	back to summary
pack-priv final long key The key.

mapNext	back to summary
pack-priv CacheLongKeyLIRS.Entry<V> mapNext The next entry in the map (the chained entry).

memory	back to summary
pack-priv final long memory The estimated memory used.

queueNext	back to summary
pack-priv CacheLongKeyLIRS.Entry<V> queueNext The next entry in the queue (either the resident queue or the non-resident queue).

queuePrev	back to summary
pack-priv CacheLongKeyLIRS.Entry<V> queuePrev The previous entry in the queue.

reference	back to summary
pack-priv WeakReference<V> reference Weak reference to the value. Set to null for resident entries.

stackNext	back to summary
pack-priv CacheLongKeyLIRS.Entry<V> stackNext The next entry in the stack.

stackPrev	back to summary
pack-priv CacheLongKeyLIRS.Entry<V> stackPrev The previous entry in the stack.

topMove	back to summary
pack-priv int topMove When the item was last moved to the top of the stack.

TOTAL_MEMORY_OVERHEAD	back to summary
pack-priv static final int TOTAL_MEMORY_OVERHEAD

value	back to summary
pack-priv V value The value. Set to null for non-resident-cold entries.

Constructor Detail

Entry	back to summary
pack-priv Entry()

Entry	back to summary
pack-priv Entry(long key, V value, long memory)

Entry	back to summary
pack-priv Entry(CacheLongKeyLIRS.Entry<V> old)

Method Detail

getMemory	back to summary
pack-priv long getMemory()

getValue	back to summary
pack-priv V getValue()

isHot

back to summary

pack-priv boolean isHot()

Whether this entry is hot. Cold entries are in one of the two queues.

Returns:boolean: whether the entry is hot

org.h2.mvstore.cache back to summary

private Class CacheLongKeyLIRS.Segment<V>

Class Inheritance

extends Object

java.lang.Object
org.h2.mvstore.cache.CacheLongKeyLIRS.Segment

Type Parameters

<V>: the value type

A cache segment

Field Summary

Modifier and Type	Field and Description
pack-priv final CacheLongKeyLIRS.Entry<V>[]	entries The map array.
pack-priv long	hits The number of cache hits.
pack-priv int	mapSize The number of (hot, cold, and non-resident) entries in the map.
private final int	mask The bit mask that is applied to the key hash code to get the index in the map array.
private long	maxMemory The maximum memory this cache should use in bytes.
pack-priv long	misses The number of cache misses.
private final int	nonResidentQueueSize Low watermark for the number of entries in the non-resident queue, as a factor of the number of entries in the map.
private final int	nonResidentQueueSizeHigh High watermark for the number of entries in the non-resident queue, as a factor of the number of entries in the map.
private final CacheLongKeyLIRS.Entry<V>	queue The queue of resident cold entries.
private final CacheLongKeyLIRS.Entry<V>	queue2 The queue of non-resident cold entries.
pack-priv int	queue2Size The size of the LIRS queue for non-resident cold entries.
pack-priv int	queueSize The size of the LIRS queue for resident cold entries.
private final CacheLongKeyLIRS.Entry<V>	stack The stack of recently referenced elements.
private int	stackMoveCounter The number of times any item was moved to the top of the stack.
private final int	stackMoveDistance How many other item are to be moved to the top of the stack before the current item is moved.
private int	stackSize The number of entries in the stack.
pack-priv long	usedMemory The currently used memory.

Constructor Summary

Access

Constructor and Description

pack-priv

Segment(long

the maximum memory to use

maxMemory, int

the number of other entries to be moved to the top of the stack before moving an entry to the top

stackMoveDistance, int

the number of hash table buckets (must be a power of 2)

len, int

the non-resident queue size low watermark factor

nonResidentQueueSize, int

the non-resident queue size high watermark factor

nonResidentQueueSizeHigh)

Create a new cache segment.

pack-priv

Segment(CacheLongKeyLIRS.Segment<V>

the old segment

old, int

the number of hash table buckets (must be a power of 2)

len)

Create a new cache segment from an existing one.

Method Summary

Modifier and Type	Method and Description
private void	access(CacheLongKeyLIRS.Entry<V> entry to record access for e) Access an item, moving the entry to the top of the stack or front of the queue if found.
private void	addToMap(CacheLongKeyLIRS.Entry<V> e)
private void	addToQueue(CacheLongKeyLIRS.Entry<V> q, CacheLongKeyLIRS.Entry<V> e)
private void	addToStack(CacheLongKeyLIRS.Entry<V> e)
private void	addToStackBottom(CacheLongKeyLIRS.Entry<V> e)
private void	convertOldestHotToCold()
private void	evict() Evict cold entries (resident and non-resident) until the memory limit is reached.
private void	evictBlock()
pack-priv CacheLongKeyLIRS.Entry<V>	Returns: the entry (might be a non-resident) find(long the key key, int the hash hash) Try to find an entry in the map.
pack-priv synchronized V	Returns: the value, or null if there is no resident entry get(CacheLongKeyLIRS.Entry<V> the entry e) Get the value from the given entry.
pack-priv int	Returns: 0 if no resizing is needed, or the new length getNewMapLen() Calculate the new number of hash table buckets if the internal map should be re-sized.
pack-priv synchronized List<Long>	Returns: the key list keys(boolean if true, only keys for the cold entries are returned cold, boolean true for non-resident entries nonResident) Get the list of keys.
pack-priv synchronized Set<Long>	Returns: the set of keys keySet() Get the set of keys for resident entries.
private void	pruneStack() Ensure the last entry of the stack is cold.
pack-priv synchronized V	Returns: the old value, or null if there was no resident entry put(long the key (may not be null) key, int the hash hash, V the value (may not be null) value, long the memory used for the given entry memory) Add an entry to the cache.
pack-priv synchronized V	Returns: the old value, or null if there was no resident entry remove(long the key (may not be null) key, int the hash hash) Remove an entry.
private void	removeFromQueue(CacheLongKeyLIRS.Entry<V> e)
private void	removeFromStack(CacheLongKeyLIRS.Entry<V> the entry e) Remove the entry from the stack.
pack-priv void	setMaxMemory(long the maximum size (1 or larger) in bytes maxMemory) Set the maximum memory this cache should use.
pack-priv void	trimNonResidentQueue()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

entries	back to summary
pack-priv final CacheLongKeyLIRS.Entry<V>[] entries The map array. The size is always a power of 2.

hits	back to summary
pack-priv long hits The number of cache hits.

mapSize	back to summary
pack-priv int mapSize The number of (hot, cold, and non-resident) entries in the map.

mask	back to summary
private final int mask The bit mask that is applied to the key hash code to get the index in the map array. The mask is the length of the array minus one.

maxMemory	back to summary
private long maxMemory The maximum memory this cache should use in bytes.

misses	back to summary
pack-priv long misses The number of cache misses.

nonResidentQueueSize	back to summary
private final int nonResidentQueueSize Low watermark for the number of entries in the non-resident queue, as a factor of the number of entries in the map.

nonResidentQueueSizeHigh	back to summary
private final int nonResidentQueueSizeHigh High watermark for the number of entries in the non-resident queue, as a factor of the number of entries in the map.

queue

back to summary

private final CacheLongKeyLIRS.Entry<V> queue

The queue of resident cold entries.

There is always at least one entry: the head entry.

queue2

back to summary

private final CacheLongKeyLIRS.Entry<V> queue2

The queue of non-resident cold entries.

There is always at least one entry: the head entry.

queue2Size	back to summary
pack-priv int queue2Size The size of the LIRS queue for non-resident cold entries.

queueSize	back to summary
pack-priv int queueSize The size of the LIRS queue for resident cold entries.

stack

back to summary

private final CacheLongKeyLIRS.Entry<V> stack

The stack of recently referenced elements. This includes all hot entries, and the recently referenced cold entries. Resident cold entries that were not recently referenced, as well as non-resident cold entries, are not in the stack.

There is always at least one entry: the head entry.

stackMoveCounter	back to summary
private int stackMoveCounter The number of times any item was moved to the top of the stack.

stackMoveDistance	back to summary
private final int stackMoveDistance How many other item are to be moved to the top of the stack before the current item is moved.

stackSize	back to summary
private int stackSize The number of entries in the stack.

usedMemory	back to summary
pack-priv long usedMemory The currently used memory.

Constructor Detail

Segment

back to summary

pack-priv Segment(long maxMemory, int stackMoveDistance, int len, int nonResidentQueueSize, int nonResidentQueueSizeHigh)

Create a new cache segment.

Parameters

maxMemory:long: the maximum memory to use
stackMoveDistance:int: the number of other entries to be moved to the top of the stack before moving an entry to the top
len:int: the number of hash table buckets (must be a power of 2)
nonResidentQueueSize:int: the non-resident queue size low watermark factor
nonResidentQueueSizeHigh:int: the non-resident queue size high watermark factor

Segment

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pack-priv Segment(CacheLongKeyLIRS.Segment<V> old, int len)

Create a new cache segment from an existing one. The caller must synchronize on the old segment, to avoid concurrent modifications.

Parameters

old:CacheLongKeyLIRS.Segment<V>: the old segment
len:int: the number of hash table buckets (must be a power of 2)

Method Detail

access

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private void access(CacheLongKeyLIRS.Entry<V> e)

Access an item, moving the entry to the top of the stack or front of the queue if found.

Parameters

e:CacheLongKeyLIRS.Entry<V>: entry to record access for

addToMap	back to summary
private void addToMap(CacheLongKeyLIRS.Entry<V> e)

addToQueue	back to summary
private void addToQueue(CacheLongKeyLIRS.Entry<V> q, CacheLongKeyLIRS.Entry<V> e)

addToStack	back to summary
private void addToStack(CacheLongKeyLIRS.Entry<V> e)

addToStackBottom	back to summary
private void addToStackBottom(CacheLongKeyLIRS.Entry<V> e)

convertOldestHotToCold	back to summary
private void convertOldestHotToCold()

evict	back to summary
private void evict() Evict cold entries (resident and non-resident) until the memory limit is reached. The new entry is added as a cold entry, except if it is the only entry.

evictBlock	back to summary
private void evictBlock()

find

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pack-priv CacheLongKeyLIRS.Entry<V> find(long key, int hash)

Try to find an entry in the map.

Parameters

key:long: the key
hash:int: the hash

Returns:CacheLongKeyLIRS.Entry<V>

the entry (might be a non-resident)

get

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pack-priv synchronized V get(CacheLongKeyLIRS.Entry<V> e)

Get the value from the given entry. This method adjusts the internal state of the cache sometimes, to ensure commonly used entries stay in the cache.

Parameters

e:CacheLongKeyLIRS.Entry<V>: the entry

Returns:V

the value, or null if there is no resident entry

getNewMapLen

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pack-priv int getNewMapLen()

Calculate the new number of hash table buckets if the internal map should be re-sized.

Returns:int: 0 if no resizing is needed, or the new length

keys

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pack-priv synchronized List<Long> keys(boolean cold, boolean nonResident)

Get the list of keys. This method allows to read the internal state of the cache.

Parameters

cold:boolean: if true, only keys for the cold entries are returned
nonResident:boolean: true for non-resident entries

Returns:List<Long>

the key list

keySet

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pack-priv synchronized Set<Long> keySet()

Get the set of keys for resident entries.

Returns:Set<Long>: the set of keys

pruneStack	back to summary
private void pruneStack() Ensure the last entry of the stack is cold.

put

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pack-priv synchronized V put(long key, int hash, V value, long memory)

Add an entry to the cache. The entry may or may not exist in the cache yet. This method will usually mark unknown entries as cold and known entries as hot.

Parameters

key:long: the key (may not be null)
hash:int: the hash
value:V: the value (may not be null)
memory:long: the memory used for the given entry

Returns:V

the old value, or null if there was no resident entry

remove

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pack-priv synchronized V remove(long key, int hash)

Remove an entry. Both resident and non-resident entries can be removed.

Parameters

key:long: the key (may not be null)
hash:int: the hash

Returns:V

the old value, or null if there was no resident entry

removeFromQueue	back to summary
private void removeFromQueue(CacheLongKeyLIRS.Entry<V> e)

removeFromStack

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private void removeFromStack(CacheLongKeyLIRS.Entry<V> e)

Remove the entry from the stack. The head itself must not be removed.

Parameters

e:CacheLongKeyLIRS.Entry<V>: the entry

setMaxMemory

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pack-priv void setMaxMemory(long maxMemory)

Set the maximum memory this cache should use. This will not immediately cause entries to get removed however; it will only change the limit. To resize the internal array, call the clear method.

Parameters

maxMemory:long: the maximum size (1 or larger) in bytes

trimNonResidentQueue	back to summary
pack-priv void trimNonResidentQueue()

public Class CacheLongKeyLIRS<V>

Nested and Inner Type Summary

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public Class CacheLongKeyLIRS.Config

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pack-priv Class CacheLongKeyLIRS.Entry<V>

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private Class CacheLongKeyLIRS.Segment<V>

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