org.jibx.util
Class StringIntSizedMap

java.lang.Object
  org.jibx.util.StringIntSizedMap

public class StringIntSizedMap
extends Object

Fixed size hash map using String values as keys mapped to primitive int values.

Author:

Dennis M. Sosnoski

Field Summary

static double	DEFAULT_FILL_FRACTION Default fill fraction for sizing of tables.
static int	DEFAULT_NOT_FOUND Default value returned when key not found in table.
protected int	m_arraySize Size of array used for keys.
protected int	m_hitOffset Offset added (modulo table size) to slot number on collision.
protected String[]	m_keyTable Array of key table slots.
protected int	m_notFoundValue Value returned when key not found in table.
protected int[]	m_valueTable Array of value table slots.

Constructor Summary

StringIntSizedMap(int count)
Constructor with only value count specified.

StringIntSizedMap(int count, double fill, int miss)
Constructor with full specification.

StringIntSizedMap(int count, int miss)
Constructor with value count and miss value specified.

Method Summary

int	add(String key, int value) Add an entry to the table.
void	clear() Set the table to the empty state.
boolean	containsKey(String key) Check if an entry is present in the table.
int	get(String key) Find an entry in the table.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_FILL_FRACTION

public static final double DEFAULT_FILL_FRACTION

Default fill fraction for sizing of tables.

See Also:

Constant Field Values

DEFAULT_NOT_FOUND

public static final int DEFAULT_NOT_FOUND

Default value returned when key not found in table.

See Also:

Constant Field Values

m_arraySize

protected final int m_arraySize

Size of array used for keys.

m_keyTable

protected final String[] m_keyTable

Array of key table slots.

m_valueTable

protected final int[] m_valueTable

Array of value table slots.

m_notFoundValue

protected final int m_notFoundValue

Value returned when key not found in table.

m_hitOffset

protected final int m_hitOffset

Offset added (modulo table size) to slot number on collision.

Constructor Detail

StringIntSizedMap

public StringIntSizedMap(int count,
                         double fill,
                         int miss)

Constructor with full specification.

Parameters:

count - number of values to assume in sizing of table

fill - fraction fill for table (maximum of 0.7, to prevent excessive collisions)

miss - value returned when key not found in table

StringIntSizedMap

public StringIntSizedMap(int count,
                         int miss)

Constructor with value count and miss value specified. Uses default fill fraction.

Parameters:

count - number of values to assume in initial sizing of table

miss - value returned when key not found in table

StringIntSizedMap

public StringIntSizedMap(int count)

Constructor with only value count specified. Uses default fill fraction and miss value.

Parameters:

count - number of values to assume in initial sizing of table

Method Detail

add

public int add(String key,
               int value)

Add an entry to the table. If the key is already present in the table, this replaces the existing value associated with the key.

Parameters:

key - key to be added to table (non-null)

value - associated value for key

Returns:

value previously associated with key, or reserved not found value if key not previously present in table

containsKey

public final boolean containsKey(String key)

Check if an entry is present in the table. This method is supplied to support the use of values matching the reserved not found value.

Parameters:

key - key for entry to be found

Returns:

true if key found in table, false if not

get

public final int get(String key)

Find an entry in the table.

Parameters:

key - key for entry to be returned

Returns:

value for key, or reserved not found value if key not found

clear

public void clear()

Set the table to the empty state.