org.apache.reef.io.storage.ram

Class RamMap<T>

java.lang.Object

org.apache.reef.io.storage.ram.RamMap<T>

All Implemented Interfaces:

ExternalMap<T>

public class RamMap<T>
extends Object
implements ExternalMap<T>

Simple in-memory ExternalMap implementation. This class does not require any codecs, and so is guaranteed to be instantiable. Therefore, it is the default ExternalMap provided by StorageManagerRam.

Constructor Summary

Constructors

Constructor and Description
RamMap(RamStorageService ramStore)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	containsKey(CharSequence key)
T	get(CharSequence key) Element access
Iterable<Map.Entry<CharSequence,T>>	getAll(Set<? extends CharSequence> keys)
T	put(CharSequence key, T value) Put a record into the map
void	putAll(Map<? extends CharSequence,? extends T> m) Copies all of the mappings from the specified map to this map (optional operation).
T	remove(CharSequence key) Removes the mapping for a key from this map if it is present (optional operation).

Methods inherited from class java.lang.Object

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

Constructor Detail

RamMap

@Inject
public RamMap(RamStorageService ramStore)

Method Detail

containsKey

public boolean containsKey(CharSequence key)

Specified by:

containsKey in interface ExternalMap<T>

Returns:

true, if an entry with the given key exists

get

public T get(CharSequence key)

Description copied from interface: ExternalMap

Element access

Specified by:

get in interface ExternalMap<T>

Returns:

the object stored under key nor null if no such object exists

put

public T put(CharSequence key,
    T value)

Description copied from interface: ExternalMap

Put a record into the map

Specified by:

put in interface ExternalMap<T>

Returns:

the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key, if the implementation supports null values.)

remove

public T remove(CharSequence key)

Description copied from interface: ExternalMap

Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key k to value v such that (key==null ? k==null : key.equals(k)), that mapping is removed. (The map can contain at most one such mapping.) Returns the value to which this map previously associated the key, or null if the map contained no mapping for the key.

If this map permits null values, then a return value of null does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to null.

The map will not contain a mapping for the specified key once the call returns.

Specified by:

remove in interface ExternalMap<T>

Parameters:

key - key whose mapping is to be removed from the map

Returns:

the previous value associated with key, or null if there was no mapping for key.

putAll

public void putAll(Map<? extends CharSequence,? extends T> m)

Description copied from interface: ExternalMap

Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress.

Specified by:

putAll in interface ExternalMap<T>

getAll

public Iterable<Map.Entry<CharSequence,T>> getAll(Set<? extends CharSequence> keys)

Specified by:

getAll in interface ExternalMap<T>