edu.umd.cloud9.io.map
Class HMapIFW

java.lang.Object
  edu.umd.cloud9.util.map.HMapIF
      edu.umd.cloud9.io.map.HMapIFW

All Implemented Interfaces:

MapIF, Serializable, Cloneable, Writable

public class HMapIFW
extends HMapIF
implements Writable

Writable representing a map where keys are ints and values are floats.

One notable feature of this class is the ability to support lazy decoding, controlled by the setLazyDecodeFlag(boolean) method. In lazy decoding mode, when an object of this type is deserialized, key-value pairs are not inserted into the map, but rather held in arrays. The reduces memory used in cases where random access to values is not required. In lazy decoding mode, the raw keys and values may be fetched by the getKeys() and getValues() methods, respectively. The map can be subsequently populated with the decode() method.

Author:

Jimmy Lin

See Also:

Serialized Form

Constructor Summary

HMapIFW()
Creates a HMapIFW object.

Method Summary

static HMapIFW	create(byte[] bytes) Creates a HMapIFW object from a byte array.
static HMapIFW	create(DataInput in) Creates a HMapIFW object from a DataInput.
void	decode() In lazy decoding mode, populates the map with deserialized data.
int[]	getKeys() In lazy decoding mode, returns an array of all the keys if the map hasn't been decoded yet.
static boolean	getLazyDecodeFlag() Returns the value of the lazy decoding flag
float[]	getValues() In lazy decoding mode, returns an array of all the values if the map hasn't been decoded yet.
boolean	isDecoded() Returns whether or not this map has been decoded.
void	plus(HMapIFW m) Adds values from keys of another map to this map.
void	readFields(DataInput in) Deserializes the map.
byte[]	serialize() Returns the serialized representation of this object as a byte array.
static void	setLazyDecodeFlag(boolean b) Sets the lazy decoding flag.
int	size() Returns the number of key-value mappings in this map.
void	write(DataOutput out) Serializes the map.

Methods inherited from class edu.umd.cloud9.util.map.HMapIF

clear, clone, containsKey, containsValue, dot, entrySet, get, getEntriesSortedByValue, getEntriesSortedByValue, isEmpty, keySet, length, normalize, plus, put, putAll, remove, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.umd.cloud9.util.map.MapIF

equals, hashCode

Constructor Detail

HMapIFW

public HMapIFW()

Creates a HMapIFW object.

Method Detail

readFields

public void readFields(DataInput in)
                throws IOException

Deserializes the map.

Specified by:

readFields in interface Writable

Parameters:

in - source for raw byte representation

Throws:

IOException

decode

public void decode()

In lazy decoding mode, populates the map with deserialized data. Otherwise, does nothing.

Throws:

IOException

isDecoded

public boolean isDecoded()

Returns whether or not this map has been decoded. If not in lazy decoding mode, this method always return true.

write

public void write(DataOutput out)
           throws IOException

Serializes the map.

Specified by:

write in interface Writable

Parameters:

out - where to write the raw byte representation

Throws:

IOException

serialize

public byte[] serialize()
                 throws IOException

Returns the serialized representation of this object as a byte array.

Returns:

byte array representing the serialized representation of this object

Throws:

IOException

create

public static HMapIFW create(DataInput in)
                      throws IOException

Creates a HMapIFW object from a DataInput.

Parameters:

in - source for reading the serialized representation

Returns:

a newly-created HMapIFW object

Throws:

IOException

create

public static HMapIFW create(byte[] bytes)
                      throws IOException

Creates a HMapIFW object from a byte array.

Parameters:

bytes - raw serialized representation

Returns:

a newly-created HMapIFW object

Throws:

IOException

setLazyDecodeFlag

public static void setLazyDecodeFlag(boolean b)

Sets the lazy decoding flag.

getLazyDecodeFlag

public static boolean getLazyDecodeFlag()

Returns the value of the lazy decoding flag

getKeys

public int[] getKeys()

In lazy decoding mode, returns an array of all the keys if the map hasn't been decoded yet. Otherwise, returns null.

Returns:

an array of all the keys

getValues

public float[] getValues()

In lazy decoding mode, returns an array of all the values if the map hasn't been decoded yet. Otherwise, returns null.

Returns:

an array of all the values

plus

public void plus(HMapIFW m)

Adds values from keys of another map to this map. This map will be decoded if it hasn't already been decode. The other map need not be decoded.

Parameters:

m - the other map

size

public int size()

Description copied from interface: MapIF

Returns the number of key-value mappings in this map.

Specified by:

size in interface MapIF

Overrides:

size in class HMapIF

Returns:

the number of key-value mappings in this map