org.bukkit.metadata

Class MetadataStoreBase<T>

java.lang.Object

org.bukkit.metadata.MetadataStoreBase<T>

public abstract class MetadataStoreBase<T>
extends Object

Constructor Summary

Constructors

Constructor and Description
MetadataStoreBase()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract String	disambiguate(T subject, String metadataKey) Creates a unique name for the object receiving metadata by combining unique data from the subject with a metadataKey.
List<MetadataValue>	getMetadata(T subject, String metadataKey) Returns all metadata values attached to an object.
boolean	hasMetadata(T subject, String metadataKey) Tests to see if a metadata attribute has been set on an object.
void	invalidateAll(Plugin owningPlugin) Invalidates all metadata in the metadata store that originates from the given plugin.
void	removeMetadata(T subject, String metadataKey, Plugin owningPlugin) Removes a metadata item owned by a plugin from a subject.
void	setMetadata(T subject, String metadataKey, MetadataValue newMetadataValue) Adds a metadata value to an object.

Methods inherited from class java.lang.Object

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

Constructor Detail

MetadataStoreBase

public MetadataStoreBase()

Method Detail

setMetadata

public void setMetadata(T subject,
               String metadataKey,
               MetadataValue newMetadataValue)

Adds a metadata value to an object. Each metadata value is owned by a specific Plugin. If a plugin has already added a metadata value to an object, that value will be replaced with the value of newMetadataValue. Multiple plugins can set independent values for the same metadataKey without conflict.

Implementation note: I considered using a ReadWriteLock for controlling access to metadataMap, but decided that the added overhead wasn't worth the finer grained access control.

Bukkit is almost entirely single threaded so locking overhead shouldn't pose a problem.

Parameters:

subject - The object receiving the metadata.

metadataKey - A unique key to identify this metadata.

newMetadataValue - The metadata value to apply.

Throws:

IllegalArgumentException - If value is null, or the owning plugin is null

See Also:

MetadataStore.setMetadata(Object, String, MetadataValue)

getMetadata

public List<MetadataValue> getMetadata(T subject,
                              String metadataKey)

Returns all metadata values attached to an object. If multiple have attached metadata, each will value will be included.

Parameters:

subject - the object being interrogated.

metadataKey - the unique metadata key being sought.

Returns:

A list of values, one for each plugin that has set the requested value.

See Also:

MetadataStore.getMetadata(Object, String)

hasMetadata

public boolean hasMetadata(T subject,
                  String metadataKey)

Tests to see if a metadata attribute has been set on an object.

Parameters:

subject - the object upon which the has-metadata test is performed.

metadataKey - the unique metadata key being queried.

Returns:

the existence of the metadataKey within subject.

removeMetadata

public void removeMetadata(T subject,
                  String metadataKey,
                  Plugin owningPlugin)

Removes a metadata item owned by a plugin from a subject.

Parameters:

subject - the object to remove the metadata from.

metadataKey - the unique metadata key identifying the metadata to remove.

owningPlugin - the plugin attempting to remove a metadata item.

Throws:

IllegalArgumentException - If plugin is null

See Also:

MetadataStore.removeMetadata(Object, String, org.bukkit.plugin.Plugin)

invalidateAll

public void invalidateAll(Plugin owningPlugin)

Invalidates all metadata in the metadata store that originates from the given plugin. Doing this will force each invalidated metadata item to be recalculated the next time it is accessed.

Parameters:

owningPlugin - the plugin requesting the invalidation.

Throws:

IllegalArgumentException - If plugin is null

See Also:

MetadataStore.invalidateAll(org.bukkit.plugin.Plugin)

disambiguate

protected abstract String disambiguate(T subject,
                  String metadataKey)

Creates a unique name for the object receiving metadata by combining unique data from the subject with a metadataKey.

The name created must be globally unique for the given object and any two equivalent objects must generate the same unique name. For example, two Player objects must generate the same string if they represent the same player, even if the objects would fail a reference equality test.

Parameters:

subject - The object for which this key is being generated.

metadataKey - The name identifying the metadata value.

Returns:

a unique metadata key for the given subject.