jdbm.helper

Class LRUCache.LRU

java.lang.Object

jdbm.helper.LRUCache.LRU

Enclosing class:

LRUCache<K,V>

private class LRUCache.LRU
extends java.lang.Object

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.concurrent.locks.Lock	lock Lock protecting the list
private ExplicitList<LRUCache.CacheEntry>	mostRecentVersions List of entries representing most recent versions
private int	numSnapshotsCreated Number of snaphot versions created
private ExplicitList<LRUCache.CacheEntry>	snapshotVersions List of snapshot entries

Constructor Summary

Constructors

Modifier	Constructor and Description
private	LRU()

Method Summary

Modifier and Type	Method and Description
void	addToLRU(LRUCache.CacheEntry entry) add the new entry to the head of the lru
void	addToSnapshots(LRUCache.CacheEntry entry) Removes the entry from the lru list and Adds the entry to the list of snapshot entries.
LRUCache.CacheEntry	findVictim(int latchIndex) Finds a freeable entry from the lru.
java.util.concurrent.locks.Lock	getLock()
void	moveToTail(LRUCache.CacheEntry entry) Moves the entry to the cold end of the lru.
void	touch(LRUCache.CacheEntry entry) Increases the hotness of the given entry

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

mostRecentVersions

private ExplicitList<LRUCache.CacheEntry> mostRecentVersions

List of entries representing most recent versions

snapshotVersions

private ExplicitList<LRUCache.CacheEntry> snapshotVersions

List of snapshot entries

lock

private java.util.concurrent.locks.Lock lock

Lock protecting the list

numSnapshotsCreated

private int numSnapshotsCreated

Number of snaphot versions created

Constructor Detail

LRU

private LRU()

Method Detail

getLock

public java.util.concurrent.locks.Lock getLock()

addToLRU

public void addToLRU(LRUCache.CacheEntry entry)

add the new entry to the head of the lru

Parameters:

entry - new entry to be added

addToSnapshots

public void addToSnapshots(LRUCache.CacheEntry entry)

Removes the entry from the lru list and Adds the entry to the list of snapshot entries. Entry should a most recent entry.

Parameters:

entry - cache entry to be made snapshot

moveToTail

public void moveToTail(LRUCache.CacheEntry entry)

Moves the entry to the cold end of the lru. Entry should be a most recent entry

Parameters:

entry - entry to be made cold

touch

public void touch(LRUCache.CacheEntry entry)

Increases the hotness of the given entry

Parameters:

entry - cache entry for which we will increase hotness

findVictim

public LRUCache.CacheEntry findVictim(int latchIndex)

Finds a freeable entry from the lru. Lru lock is held at entry and exit.

Parameters:

latchIndex - index of the hash lock that is held at entry

Returns: