Package gov.nasa.worldwind.cache

Class ShapeDataCache

java.lang.Object

gov.nasa.worldwind.cache.ShapeDataCache

All Implemented Interfaces:

java.lang.Iterable<ShapeDataCache.ShapeDataCacheEntry>

public class ShapeDataCache
extends java.lang.Object
implements java.lang.Iterable<ShapeDataCache.ShapeDataCacheEntry>

Provides a mechanism to manage globe-specific representations of shapes. Typically used to manage per-globe state when the application associates the same shape with multiple WorldWindows.

This cache limits the amount of time an entry remains in the cache unused. The maximum unused time may be specified. Entries unused within the specified duration are removed from the cache each time getEntry(gov.nasa.worldwind.globes.Globe) is called.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ShapeDataCache.ShapeDataCacheEntry

Field Summary

Fields

Modifier and Type	Field	Description
protected java.util.HashMap<GlobeStateKey,ShapeDataCache.ShapeDataCacheEntry>	entries	This cache's map of entries.
protected long	maxTimeSinceLastUsed	The maximum number of milliseconds an entry may remain in the cache without being used.

Constructor Summary

Constructors

Constructor	Description
ShapeDataCache(long maxTimeSinceLastUsed)	Construct a cache with a specified entry lifetime.

Method Summary

Modifier and Type	Method	Description
void	addEntry(ShapeDataCache.ShapeDataCacheEntry entry)	Adds a specified entry to the cache or replaces an entry associated with the same globe.
void	clearExtents()	Set to null the extent field of all entries in this cache.
ShapeDataCache.ShapeDataCacheEntry	getEntry(Globe globe)	Retrieves a specified entry from the cache.
java.util.Iterator<ShapeDataCache.ShapeDataCacheEntry>	iterator()
void	removeAllEntries()	Remove all entries from this cache.
void	setAllExpired(boolean isExpired)	Set all entries in this cache to a specified expiration state.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

entries

protected java.util.HashMap<GlobeStateKey,ShapeDataCache.ShapeDataCacheEntry> entries

This cache's map of entries. Typically one entry per open window.

maxTimeSinceLastUsed

protected long maxTimeSinceLastUsed

The maximum number of milliseconds an entry may remain in the cache without being used.

Constructor Detail

ShapeDataCache

public ShapeDataCache(long maxTimeSinceLastUsed)

Construct a cache with a specified entry lifetime.

Parameters:

maxTimeSinceLastUsed - the maximum number of milliseconds an entry may remain in the cache without being used.

Method Detail

iterator

public java.util.Iterator<ShapeDataCache.ShapeDataCacheEntry> iterator()

Specified by:

iterator in interface java.lang.Iterable<ShapeDataCache.ShapeDataCacheEntry>

addEntry

public void addEntry(ShapeDataCache.ShapeDataCacheEntry entry)

Adds a specified entry to the cache or replaces an entry associated with the same globe.

Parameters:

entry - the entry to add. If null, the cache remains unchanged.

getEntry

public ShapeDataCache.ShapeDataCacheEntry getEntry(Globe globe)

Retrieves a specified entry from the cache.

Note: Each time this method is called the cache is cleared of dead entries, as defined by their last-used time relative to this cache's maximum unused time.

Parameters:

globe - the globe the entry is associated with.

Returns:

the entry if it exists, otherwise null.

setAllExpired

public void setAllExpired(boolean isExpired)

Set all entries in this cache to a specified expiration state.

Parameters:

isExpired - the expiration state.

clearExtents

public void clearExtents()

Set to null the extent field of all entries in this cache.

removeAllEntries

public void removeAllEntries()

Remove all entries from this cache.