Package org.apache.lucene.internal.hppc

Class IntDoubleHashMap

java.lang.Object
org.apache.lucene.internal.hppc.IntDoubleHashMap
All Implemented Interfaces:
Cloneable, Iterable<IntDoubleHashMap.IntDoubleCursor>, Accountable
public class IntDoubleHashMap extends Object implements Iterable<IntDoubleHashMap.IntDoubleCursor>, Accountable, Cloneable
A hash map of int to double, implemented using open addressing with linear probing for collision resolution.

Mostly forked and trimmed from com.carrotsearch.hppc.IntDoubleHashMap

github: https://github.com/carrotsearch/hppc release 0.10.0

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

  • Field Details

    • keys

      public int[] keys
      The array holding keys.

    • values

      public double[] values
      The array holding values.

    • assigned

      protected int assigned
      The number of stored keys (assigned key slots), excluding the special "empty" key, if any (use size() instead).
      See Also:

    • mask

      protected int mask
      Mask for slot scans in keys.

    • resizeAt

      protected int resizeAt
      Expand (rehash) keys when assigned hits this value.

    • hasEmptyKey

      protected boolean hasEmptyKey
      Special treatment for the "empty slot" key marker.

    • loadFactor

      protected double loadFactor
      The load factor for keys.

    • iterationSeed

      protected int iterationSeed
      Seed used to ensure the hash iteration order is different from an iteration to another.

  • Constructor Details

    • IntDoubleHashMap

      public IntDoubleHashMap()
      New instance with sane defaults.

    • IntDoubleHashMap

      public IntDoubleHashMap(int expectedElements)
      New instance with sane defaults.
      Parameters:
      expectedElements - The expected number of elements guaranteed not to cause buffer expansion (inclusive).

    • IntDoubleHashMap

      public IntDoubleHashMap(int expectedElements, double loadFactor)
      New instance with the provided defaults.
      Parameters:
      expectedElements - The expected number of elements guaranteed not to cause a rehash (inclusive).
      loadFactor - The load factor for internal buffers. Insane load factors (zero, full capacity) are rejected by verifyLoadFactor(double).

    • IntDoubleHashMap

      public IntDoubleHashMap(IntDoubleHashMap map)
      Create a hash map from all key-value pairs of another map.

  • Method Details

    • put

      public double put(int key, double value)

    • putAll

      public int putAll(Iterable<? extends IntDoubleHashMap.IntDoubleCursor> iterable)

    • putIfAbsent

      public boolean putIfAbsent(int key, double value)
      Trove-inspired API method. An equivalent of the following code: 
       if (!map.containsKey(key)) map.put(value);
      Parameters:
      key - The key of the value to check.
      value - The value to put if key does not exist.
      Returns:
      true if key did not exist and value was placed in the map.

    • putOrAdd

      public double putOrAdd(int key, double putValue, double incrementValue)
      If key exists, putValue is inserted into the map, otherwise any existing value is incremented by additionValue.
      Parameters:
      key - The key of the value to adjust.
      putValue - The value to put if key does not exist.
      incrementValue - The value to add to the existing value if key exists.
      Returns:
      Returns the current value associated with key (after changes).

    • addTo

      public double addTo(int key, double incrementValue)
      Adds incrementValue to any existing value for the given key or inserts incrementValue if key did not previously exist.
      Parameters:
      key - The key of the value to adjust.
      incrementValue - The value to put or add to the existing value if key exists.
      Returns:
      Returns the current value associated with key (after changes).

    • remove

      public double remove(int key)

    • get

      public double get(int key)

    • getOrDefault

      public double getOrDefault(int key, double defaultValue)

    • containsKey

      public boolean containsKey(int key)

    • indexOf

      public int indexOf(int key)

    • indexExists

      public boolean indexExists(int index)

    • indexGet

      public double indexGet(int index)

    • indexReplace

      public double indexReplace(int index, double newValue)

    • indexInsert

      public void indexInsert(int index, int key, double value)

    • indexRemove

      public double indexRemove(int index)

    • clear

      public void clear()

    • release

      public void release()

    • size

      public int size()

    • isEmpty

      public boolean isEmpty()

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • equalElements

      protected boolean equalElements(IntDoubleHashMap other)
      Return true if all keys of some other container exist in this container.

    • ensureCapacity

      public void ensureCapacity(int expectedElements)
      Ensure this container can hold at least the given number of keys (entries) without resizing its buffers.
      Parameters:
      expectedElements - The total number of keys, inclusive.

    • nextIterationSeed

      protected int nextIterationSeed()
      Provides the next iteration seed used to build the iteration starting slot and offset increment. This method does not need to be synchronized, what matters is that each thread gets a sequence of varying seeds.

    • ramBytesUsed

      public long ramBytesUsed()
      Description copied from interface: Accountable
      Return the memory usage of this object in bytes. Negative values are illegal.
      Specified by:
      ramBytesUsed in interface Accountable

    • iterator

      public Iterator<IntDoubleHashMap.IntDoubleCursor> iterator()
      Specified by:
      iterator in interface Iterable<IntDoubleHashMap.IntDoubleCursor>

    • keys

      public IntDoubleHashMap.KeysContainer keys()
      Returns a specialized view of the keys of this associated container.

    • values

      public IntDoubleHashMap.ValuesContainer values()
      Returns:
      Returns a container with all values stored in this map.

    • clone

      public IntDoubleHashMap clone()
      Overrides:
      clone in class Object

    • toString

      public String toString()
      Convert the contents of this map to a human-friendly string.
      Overrides:
      toString in class Object

    • from

      public static IntDoubleHashMap from(int[] keys, double[] values)
      Creates a hash map from two index-aligned arrays of key-value pairs.

    • hashKey

      protected int hashKey(int key)
      Returns a hash code for the given key.

      The output from this function should evenly distribute keys across the entire integer range.

    • verifyLoadFactor

      protected double verifyLoadFactor(double loadFactor)
      Validate load factor range and return it. Override and suppress if you need insane load factors.

    • rehash

      protected void rehash(int[] fromKeys, double[] fromValues)
      Rehash from old buffers to new buffers.

    • allocateBuffers

      protected void allocateBuffers(int arraySize)
      Allocate new internal buffers. This method attempts to allocate and assign internal buffers atomically (either allocations succeed or not).

    • allocateThenInsertThenRehash

      protected void allocateThenInsertThenRehash(int slot, int pendingKey, double pendingValue)
      This method is invoked when there is a new key/ value pair to be inserted into the buffers but there is not enough empty slots to do so.

      New buffers are allocated. If this succeeds, we know we can proceed with rehashing so we assign the pending element to the previous buffer (possibly violating the invariant of having at least one empty slot) and rehash all keys, substituting new buffers at the end.

    • shiftConflictingKeys

      protected void shiftConflictingKeys(int gapSlot)
      Shift all the slot-conflicting keys and values allocated to (and including) slot.