org.apache.mahout.math.map
Class OpenIntShortHashMap

java.lang.Object
  extended by org.apache.mahout.math.PersistentObject
      extended by org.apache.mahout.math.set.AbstractSet
          extended by org.apache.mahout.math.map.AbstractIntShortMap
              extended by org.apache.mahout.math.map.OpenIntShortHashMap
All Implemented Interfaces:
Serializable, Cloneable

public class OpenIntShortHashMap
extends AbstractIntShortMap

Open hash map from int keys to short values.

See Also:
Serialized Form

Nested Class Summary
 class OpenIntShortHashMap.MapElement
           
 class OpenIntShortHashMap.MapIterator
           
 
Field Summary
protected static byte FREE
           
protected  int freeEntries
          The number of table entries in state==FREE.
protected static byte FULL
           
protected static int NO_KEY_VALUE
           
protected static byte REMOVED
           
protected  byte[] state
          The state of each hash table entry (FREE, FULL, REMOVED).
protected  int[] table
          The hash table keys.
protected  short[] values
          The hash table values.
 
Fields inherited from class org.apache.mahout.math.set.AbstractSet
DEFAULT_CAPACITY, DEFAULT_MAX_LOAD_FACTOR, DEFAULT_MIN_LOAD_FACTOR, distinct, highWaterMark, lowWaterMark, maxLoadFactor, minLoadFactor
 
Constructor Summary
OpenIntShortHashMap()
          Constructs an empty map with default capacity and default load factors.
OpenIntShortHashMap(int initialCapacity)
          Constructs an empty map with the specified initial capacity and default load factors.
OpenIntShortHashMap(int initialCapacity, double minLoadFactor, double maxLoadFactor)
          Constructs an empty map with the specified initial capacity and the specified minimum and maximum load factor.
 
Method Summary
 short adjustOrPutValue(int key, short newValue, short incrValue)
          Check the map for a key.
 void clear()
          Removes all (key,value) associations from the receiver.
 Object clone()
          Returns a deep copy of the receiver.
 boolean containsKey(int key)
          Returns true if the receiver contains the specified key.
 boolean containsValue(short value)
          Returns true if the receiver contains the specified value.
 void ensureCapacity(int minCapacity)
          Ensures that the receiver can hold at least the specified number of associations without needing to allocate new internal memory.
 boolean forEachKey(IntProcedure procedure)
          Applies a procedure to each key of the receiver, if any.
 boolean forEachPair(IntShortProcedure procedure)
          Applies a procedure to each (key,value) pair of the receiver, if any.
 short get(int key)
          Returns the value associated with the specified key.
protected  void getInternalFactors(int[] capacity, double[] minLoadFactor, double[] maxLoadFactor)
          Access for unit tests.
protected  int indexOfInsertion(int key)
           
protected  int indexOfKey(int key)
           
protected  int indexOfValue(short value)
           
 Iterator<OpenIntShortHashMap.MapElement> iterator()
           
 void keys(IntArrayList list)
          Fills all keys contained in the receiver into the specified list.
 void pairsMatching(IntShortProcedure condition, IntArrayList keyList, ShortArrayList valueList)
          Fills all pairs satisfying a given condition into the specified lists.
 boolean put(int key, short value)
          Associates the given key with the given value.
protected  void rehash(int newCapacity)
          Rehashes the contents of the receiver into a new table with a smaller or larger capacity.
 boolean removeKey(int key)
          Removes the given key with its associated element from the receiver, if present.
protected  void setUp(int initialCapacity, double minLoadFactor, double maxLoadFactor)
          Initializes the receiver.
 void trimToSize()
          Trims the capacity of the receiver to be the receiver's current size.
 void values(ShortArrayList list)
          Fills all values contained in the receiver into the specified list.
 
Methods inherited from class org.apache.mahout.math.map.AbstractIntShortMap
copy, equals, hashCode, keys, keysSortedByValue, pairsSortedByKey, pairsSortedByValue, toString, toStringByValue, values
 
Methods inherited from class org.apache.mahout.math.set.AbstractSet
chooseGrowCapacity, chooseHighWaterMark, chooseLowWaterMark, chooseMeanCapacity, chooseShrinkCapacity, equalsMindTheNull, isEmpty, nextPrime, size
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

FREE

protected static final byte FREE
See Also:
Constant Field Values

FULL

protected static final byte FULL
See Also:
Constant Field Values

REMOVED

protected static final byte REMOVED
See Also:
Constant Field Values

NO_KEY_VALUE

protected static final int NO_KEY_VALUE
See Also:
Constant Field Values

table

protected int[] table
The hash table keys.


values

protected short[] values
The hash table values.


state

protected byte[] state
The state of each hash table entry (FREE, FULL, REMOVED).


freeEntries

protected int freeEntries
The number of table entries in state==FREE.

Constructor Detail

OpenIntShortHashMap

public OpenIntShortHashMap()
Constructs an empty map with default capacity and default load factors.


OpenIntShortHashMap

public OpenIntShortHashMap(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.

OpenIntShortHashMap

public OpenIntShortHashMap(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).
Method Detail

clear

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

Specified by:
clear in class AbstractSet

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 AbstractIntShortMap
Returns:
true if the receiver contains the specified key.

containsValue

public boolean containsValue(short value)
Returns true if the receiver contains the specified value.

Overrides:
containsValue in class AbstractIntShortMap
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 AbstractSet
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 AbstractIntShortMap
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(IntShortProcedure 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 AbstractIntShortMap
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 short 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 AbstractIntShortMap
Parameters:
key - the key to be searched for.
Returns:
the value associated with the specified key; 0 if no such key is present.

indexOfInsertion

protected int indexOfInsertion(int key)
Parameters:
key - the key to be added to the receiver.
Returns:
the index where the key would need to be inserted, if it is not already contained. Returns -index-1 if the key is already contained at slot index. Therefore, if the returned index < 0, then it is already contained at slot -index-1. If the returned index >= 0, then it is NOT already contained and should be inserted at slot index.

indexOfKey

protected int indexOfKey(int key)
Parameters:
key - the key to be searched in the receiver.
Returns:
the index where the key is contained in the receiver, returns -1 if the key was not found.

indexOfValue

protected int indexOfValue(short value)
Parameters:
value - the value to be searched in the receiver.
Returns:
the index where the value is contained in the receiver, returns -1 if the value was not found.

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

iterator

public Iterator<OpenIntShortHashMap.MapElement> iterator()

pairsMatching

public void pairsMatching(IntShortProcedure condition,
                          IntArrayList keyList,
                          ShortArrayList 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:

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

Overrides:
pairsMatching in class AbstractIntShortMap
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,
                   short value)
Associates the given key with the given value. Replaces any old (key,someOtherValue) association, if existing.

Specified by:
put in class AbstractIntShortMap
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.

adjustOrPutValue

public short adjustOrPutValue(int key,
                              short newValue,
                              short incrValue)
Description copied from class: AbstractIntShortMap
Check the map for a key. If present, add an increment to the value. If absent, store a specified value.

Overrides:
adjustOrPutValue in class AbstractIntShortMap
Parameters:
key - the key.
newValue - the value to store if the key is not currently in the map.
incrValue - the value to be added to the current value in the map.

rehash

protected void rehash(int newCapacity)
Rehashes the contents of the receiver into a new table with a smaller or larger capacity. This method is called automatically when the number of keys in the receiver exceeds the high water mark or falls below the low water mark.


removeKey

public boolean removeKey(int key)
Removes the given key with its associated element from the receiver, if present.

Specified by:
removeKey in class AbstractIntShortMap
Parameters:
key - the key to be removed from the receiver.
Returns:
true if the receiver contained the specified key, false otherwise.

setUp

protected final void setUp(int initialCapacity,
                           double minLoadFactor,
                           double maxLoadFactor)
Initializes the receiver.

Overrides:
setUp in class AbstractSet
Parameters:
initialCapacity - the initial capacity of the receiver.
minLoadFactor - the minLoadFactor of the receiver.
maxLoadFactor - the maxLoadFactor of the receiver.
Throws:
IllegalArgumentException - if initialCapacity < 0 || (minLoadFactor < 0.0 || minLoadFactor >= 1.0) || (maxLoadFactor <= 0.0 || maxLoadFactor >= 1.0) || (minLoadFactor >= maxLoadFactor).

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 AbstractSet

values

public void values(ShortArrayList 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 AbstractIntShortMap
Parameters:
list - the list to be filled, can have any size.

getInternalFactors

protected void getInternalFactors(int[] capacity,
                                  double[] minLoadFactor,
                                  double[] maxLoadFactor)
Access for unit tests.

Parameters:
capacity -
minLoadFactor -
maxLoadFactor -


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