cern.colt.map
Class OpenIntObjectHashMap

java.lang.Object
  cern.colt.PersistentObject
      cern.colt.map.AbstractMap
          cern.colt.map.AbstractIntObjectMap
              cern.colt.map.OpenIntObjectHashMap

All Implemented Interfaces:

Cloneable, Serializable

public class OpenIntObjectHashMap

extends AbstractIntObjectMap

Hash map holding (key,value) associations of type (int-->Object); Automatically grows and shrinks as needed; Implemented using open addressing with double hashing. First see the package summary and javadoc tree view to get the broad picture. Overrides many methods for performance reasons only.

Version:

1.0, 09/24/99

See Also:

HashMap, Serialized Form

OpenIntObjectHashMap

public OpenIntObjectHashMap()

Constructs an empty map with default capacity and default load factors.

OpenIntObjectHashMap

public OpenIntObjectHashMap(int initialCapacity)

Constructs an empty map with the specified initial capacity and default load factors.

Parameters:

initialCapacity - the initial capacity of the map.

Throws:

IllegalArgumentException - if the initial capacity is less than zero.

OpenIntObjectHashMap

public OpenIntObjectHashMap(int initialCapacity,
                            double minLoadFactor,
                            double maxLoadFactor)

Constructs an empty map with the specified initial capacity and the specified minimum and maximum load factor.

Parameters:

initialCapacity - the initial capacity.

minLoadFactor - the minimum load factor.

maxLoadFactor - the maximum load factor.

Throws:

IllegalArgumentException - if initialCapacity < 0 || (minLoadFactor < 0.0 || minLoadFactor >= 1.0) || (maxLoadFactor <= 0.0 || maxLoadFactor >= 1.0) || (minLoadFactor >= maxLoadFactor).

clear

public void clear()

Removes all (key,value) associations from the receiver. Implicitly calls trimToSize().

Specified by:

clear in class AbstractMap

clone

public Object clone()

Returns a deep copy of the receiver.

Overrides:

clone in class PersistentObject

Returns:

a deep copy of the receiver.

containsKey

public boolean containsKey(int key)

Returns true if the receiver contains the specified key.

Overrides:

containsKey in class AbstractIntObjectMap

Returns:

true if the receiver contains the specified key.

containsValue

public boolean containsValue(Object value)

Returns true if the receiver contains the specified value.

Overrides:

containsValue in class AbstractIntObjectMap

Returns:

true if the receiver contains the specified value.

ensureCapacity

public void ensureCapacity(int minCapacity)

Ensures that the receiver can hold at least the specified number of associations without needing to allocate new internal memory. If necessary, allocates new internal memory and increases the capacity of the receiver.

This method never need be called; it is for performance tuning only. Calling this method before put()ing a large number of associations boosts performance, because the receiver will grow only once instead of potentially many times and hash collisions get less probable.

Overrides:

ensureCapacity in class AbstractMap

Parameters:

minCapacity - the desired minimum capacity.

forEachKey

public boolean forEachKey(IntProcedure procedure)

Applies a procedure to each key of the receiver, if any. Note: Iterates over the keys in no particular order. Subclasses can define a particular order, for example, "sorted by key". All methods which can be expressed in terms of this method (most methods can) must guarantee to use the same order defined by this method, even if it is no particular order. This is necessary so that, for example, methods keys and values will yield association pairs, not two uncorrelated lists.

Specified by:

forEachKey in class AbstractIntObjectMap

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all keys where iterated over, true otherwise.

forEachPair

public boolean forEachPair(IntObjectProcedure procedure)

Applies a procedure to each (key,value) pair of the receiver, if any. Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

Overrides:

forEachPair in class AbstractIntObjectMap

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all keys where iterated over, true otherwise.

get

public Object get(int key)

Returns the value associated with the specified key. It is often a good idea to first check with containsKey(int) whether the given key has a value associated or not, i.e. whether there exists an association for the given key or not.

Specified by:

get in class AbstractIntObjectMap

Parameters:

key - the key to be searched for.

Returns:

the value associated with the specified key; null if no such key is present.

keyOf

public int keyOf(Object value)

Returns the first key the given value is associated with. It is often a good idea to first check with containsValue(Object) whether there exists an association from a key to this value. Search order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

Overrides:

keyOf in class AbstractIntObjectMap

Parameters:

value - the value to search for.

Returns:

the first key for which holds get(key) == value; returns Integer.MIN_VALUE if no such key exists.

keys

public void keys(IntArrayList list)

Fills all keys contained in the receiver into the specified list. Fills the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

This method can be used to iterate over the keys of the receiver.

Overrides:

keys in class AbstractIntObjectMap

Parameters:

list - the list to be filled, can have any size.

pairsMatching

public void pairsMatching(IntObjectProcedure condition,
                          IntArrayList keyList,
                          ObjectArrayList valueList)

Fills all pairs satisfying a given condition into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists both have a new size, the number of pairs satisfying the condition. Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

Example:

IntObjectProcedure condition = new IntObjectProcedure() { // match even keys only
        public boolean apply(int key, Object value) { return key%2==0; }
}
keys = (8,7,6), values = (1,2,2) --> keyList = (6,8), valueList = (2,1)

Overrides:

pairsMatching in class AbstractIntObjectMap

Parameters:

condition - the condition to be matched. Takes the current key as first and the current value as second argument.

keyList - the list to be filled with keys, can have any size.

valueList - the list to be filled with values, can have any size.

put

public boolean put(int key,
                   Object value)

Associates the given key with the given value. Replaces any old (key,someOtherValue) association, if existing.

Specified by:

put in class AbstractIntObjectMap

Parameters:

key - the key the value shall be associated with.

value - the value to be associated.

Returns:

true if the receiver did not already contain such a key; false if the receiver did already contain such a key - the new value has now replaced the formerly associated value.

removeKey

public boolean removeKey(int key)

Removes the given key with its associated element from the receiver, if present.

Specified by:

removeKey in class AbstractIntObjectMap

Parameters:

key - the key to be removed from the receiver.

Returns:

true if the receiver contained the specified key, false otherwise.

trimToSize

public void trimToSize()

Trims the capacity of the receiver to be the receiver's current size. Releases any superfluous internal memory. An application can use this operation to minimize the storage of the receiver.

Overrides:

trimToSize in class AbstractMap

values

public void values(ObjectArrayList list)

Fills all values contained in the receiver into the specified list. Fills the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

This method can be used to iterate over the values of the receiver.

Overrides:

values in class AbstractIntObjectMap

Parameters:

list - the list to be filled, can have any size.