Package org.apache.lucene.internal.hppc

Class IntObjectHashMap<VType>

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

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

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 Object[] 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

    • IntObjectHashMap

      public IntObjectHashMap()
      New instance with sane defaults.

    • IntObjectHashMap

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

    • IntObjectHashMap

      public IntObjectHashMap(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).

    • IntObjectHashMap

      public IntObjectHashMap(IntObjectHashMap<VType> map)
      Create a hash map from all key-value pairs of another map.

  • Method Details

    • put

      public VType put(int key, VType value)

    • putAll

      public int putAll(Iterable<? extends IntObjectHashMap.IntObjectCursor<? extends VType>> iterable)

    • putIfAbsent

      public boolean putIfAbsent(int key, VType 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.

    • remove

      public VType remove(int key)

    • get

      public VType get(int key)

    • getOrDefault

      public VType getOrDefault(int key, VType defaultValue)

    • containsKey

      public boolean containsKey(int key)

    • indexOf

      public int indexOf(int key)

    • indexExists

      public boolean indexExists(int index)

    • indexGet

      public VType indexGet(int index)

    • indexReplace

      public VType indexReplace(int index, VType newValue)

    • indexInsert

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

    • indexRemove

      public VType 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(IntObjectHashMap<?> 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.

    • iterator

      public Iterator<IntObjectHashMap.IntObjectCursor<VType>> iterator()
      Specified by:
      iterator in interface Iterable<VType>

    • 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

    • keys

      public IntObjectHashMap<VType>.KeysContainer keys()
      Returns a specialized view of the keys of this associated container.

    • values

      public IntObjectHashMap<VType>.ValuesContainer values()
      Returns:
      Returns a container with all values stored in this map.

    • clone

      public IntObjectHashMap<VType> 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 <VType> IntObjectHashMap<VType> from(int[] keys, VType[] 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, VType[] 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, VType 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.