Class AbstractMemoryDataStore<V extends Serializable>

java.lang.Object

com.google.api.client.util.store.AbstractDataStore<V>

com.google.api.client.util.store.AbstractMemoryDataStore<V>

Type Parameters:

V - serializable type of the mapped value

All Implemented Interfaces:

DataStore<V>

Direct Known Subclasses:

FileDataStoreFactory.FileDataStore, MemoryDataStoreFactory.MemoryDataStore

public class AbstractMemoryDataStore<V extends Serializable>
extends AbstractDataStore<V>

Abstract, thread-safe, in-memory implementation of a data store factory.

Field Summary

Fields

Modifier and Type	Field	Description
protected HashMap<String,byte[]>	keyValueMap	Data store map from the key to the value.
private final Lock	lock	Lock on access to the store.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractMemoryDataStore(DataStoreFactory dataStoreFactory, String id)

Method Summary

Modifier and Type	Method	Description
final DataStore<V>	clear()	Deletes all of the stored keys and values.
boolean	containsKey(String key)	Returns whether the store contains the given key.
boolean	containsValue(V value)	Returns whether the store contains the given value.
DataStore<V>	delete(String key)	Deletes the stored key and value based on the given key, or ignored if the key doesn't already exist.
final V	get(String key)	Returns the stored value for the given key or null if not found.
boolean	isEmpty()	Returns whether there are any stored keys.
final Set<String>	keySet()	Returns the unmodifiable set of all stored keys.
void	save()	Persist the key-value map into storage at the end of set(String, V), delete(String), and clear().
final DataStore<V>	set(String key, V value)	Stores the given value for the given key (replacing any existing value).
int	size()	Returns the number of stored keys.
String	toString()
final Collection<V>	values()	Returns the unmodifiable collection of all stored values.

Methods inherited from class AbstractDataStore

getDataStoreFactory, getId

Methods inherited from class Object

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

Field Details

lock

private final Lock lock

Lock on access to the store.

keyValueMap

protected HashMap<String,byte[]> keyValueMap

Data store map from the key to the value.

Constructor Details

AbstractMemoryDataStore

protected AbstractMemoryDataStore(DataStoreFactory dataStoreFactory,
 String id)

Parameters:

dataStoreFactory - data store factory

id - data store ID

Method Details

keySet

public final Set<String> keySet()
                         throws IOException

Description copied from interface: DataStore

Returns the unmodifiable set of all stored keys.

Order of the keys is not specified.

Throws:

IOException

values

public final Collection<V> values()
                           throws IOException

Description copied from interface: DataStore

Returns the unmodifiable collection of all stored values.

Throws:

IOException

get

public final V get(String key)
            throws IOException

Description copied from interface: DataStore

Returns the stored value for the given key or null if not found.

Parameters:

key - key or null for null result

Throws:

IOException

set

public final DataStore<V> set(String key,
 V value)
                       throws IOException

Description copied from interface: DataStore

Stores the given value for the given key (replacing any existing value).

Parameters:

key - key

value - value object

Throws:

IOException

delete

public DataStore<V> delete(String key)
                    throws IOException

Description copied from interface: DataStore

Deletes the stored key and value based on the given key, or ignored if the key doesn't already exist.

Parameters:

key - key or null to ignore

Throws:

IOException

clear

public final DataStore<V> clear()
                         throws IOException

Description copied from interface: DataStore

Deletes all of the stored keys and values.

Throws:

IOException

containsKey

public boolean containsKey(String key)
                    throws IOException

Description copied from class: AbstractDataStore

Returns whether the store contains the given key.

Default implementation is to call DataStore.get(String) and check if it is null.

Specified by:

containsKey in interface DataStore<V extends Serializable>

Overrides:

containsKey in class AbstractDataStore<V extends Serializable>

Throws:

IOException

containsValue

public boolean containsValue(V value)
                      throws IOException

Description copied from class: AbstractDataStore

Returns whether the store contains the given value.

Default implementation is to call Collection.contains(Object) on DataStore.values().

Specified by:

containsValue in interface DataStore<V extends Serializable>

Overrides:

containsValue in class AbstractDataStore<V extends Serializable>

Throws:

IOException

isEmpty

public boolean isEmpty()
                throws IOException

Description copied from class: AbstractDataStore

Returns whether there are any stored keys.

Default implementation is to check if AbstractDataStore.size() is 0.

Specified by:

isEmpty in interface DataStore<V extends Serializable>

Overrides:

isEmpty in class AbstractDataStore<V extends Serializable>

Throws:

IOException

size

public int size()
         throws IOException

Description copied from class: AbstractDataStore

Returns the number of stored keys.

Default implementation is to call Set.size() on DataStore.keySet().

Specified by:

size in interface DataStore<V extends Serializable>

Overrides:

size in class AbstractDataStore<V extends Serializable>

Throws:

IOException

save

public void save()
          throws IOException

Persist the key-value map into storage at the end of set(String, V), delete(String), and clear().

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object