Package com.carrotsearch.hppc

High Performance Primitive Collections (HPPC) library provides typical data structures (lists, stacks, maps) template-generated for all Java primitive types (byte, int, etc.) to conserve memory and boost performance.

See:
Description

Interface Summary

ArraySizingStrategy	Resizing (growth) strategy for array-backed buffers.
ByteByteAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteByteMap	An associative container with unique binding from keys to a single value.
ByteCharAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteCharMap	An associative container with unique binding from keys to a single value.
ByteCollection	A collection allows basic, efficient operations on sets of elements (difference and intersection).
ByteContainer	A generic container holding bytes.
ByteDeque	A double-linked queue of bytes.
ByteDoubleAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteDoubleMap	An associative container with unique binding from keys to a single value.
ByteFloatAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteFloatMap	An associative container with unique binding from keys to a single value.
ByteIndexedContainer	An indexed container provides random access to elements based on an index.
ByteIntAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteIntMap	An associative container with unique binding from keys to a single value.
ByteLongAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteLongMap	An associative container with unique binding from keys to a single value.
ByteLookupContainer	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
ByteObjectAssociativeContainer<VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteObjectMap<VType>	An associative container with unique binding from keys to a single value.
ByteSet	A set of bytes.
ByteShortAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ByteShortMap	An associative container with unique binding from keys to a single value.
CharByteAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharByteMap	An associative container with unique binding from keys to a single value.
CharCharAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharCharMap	An associative container with unique binding from keys to a single value.
CharCollection	A collection allows basic, efficient operations on sets of elements (difference and intersection).
CharContainer	A generic container holding chars.
CharDeque	A double-linked queue of chars.
CharDoubleAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharDoubleMap	An associative container with unique binding from keys to a single value.
CharFloatAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharFloatMap	An associative container with unique binding from keys to a single value.
CharIndexedContainer	An indexed container provides random access to elements based on an index.
CharIntAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharIntMap	An associative container with unique binding from keys to a single value.
CharLongAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharLongMap	An associative container with unique binding from keys to a single value.
CharLookupContainer	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
CharObjectAssociativeContainer<VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharObjectMap<VType>	An associative container with unique binding from keys to a single value.
CharSet	A set of chars.
CharShortAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
CharShortMap	An associative container with unique binding from keys to a single value.
DoubleByteAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleByteMap	An associative container with unique binding from keys to a single value.
DoubleCharAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleCharMap	An associative container with unique binding from keys to a single value.
DoubleCollection	A collection allows basic, efficient operations on sets of elements (difference and intersection).
DoubleContainer	A generic container holding doubles.
DoubleDeque	A double-linked queue of doubles.
DoubleDoubleAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleDoubleMap	An associative container with unique binding from keys to a single value.
DoubleFloatAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleFloatMap	An associative container with unique binding from keys to a single value.
DoubleIndexedContainer	An indexed container provides random access to elements based on an index.
DoubleIntAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleIntMap	An associative container with unique binding from keys to a single value.
DoubleLongAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleLongMap	An associative container with unique binding from keys to a single value.
DoubleLookupContainer	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
DoubleObjectAssociativeContainer<VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleObjectMap<VType>	An associative container with unique binding from keys to a single value.
DoubleSet	A set of doubles.
DoubleShortAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
DoubleShortMap	An associative container with unique binding from keys to a single value.
FloatByteAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatByteMap	An associative container with unique binding from keys to a single value.
FloatCharAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatCharMap	An associative container with unique binding from keys to a single value.
FloatCollection	A collection allows basic, efficient operations on sets of elements (difference and intersection).
FloatContainer	A generic container holding floats.
FloatDeque	A double-linked queue of floats.
FloatDoubleAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatDoubleMap	An associative container with unique binding from keys to a single value.
FloatFloatAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatFloatMap	An associative container with unique binding from keys to a single value.
FloatIndexedContainer	An indexed container provides random access to elements based on an index.
FloatIntAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatIntMap	An associative container with unique binding from keys to a single value.
FloatLongAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatLongMap	An associative container with unique binding from keys to a single value.
FloatLookupContainer	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
FloatObjectAssociativeContainer<VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatObjectMap<VType>	An associative container with unique binding from keys to a single value.
FloatSet	A set of floats.
FloatShortAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
FloatShortMap	An associative container with unique binding from keys to a single value.
IntByteAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntByteMap	An associative container with unique binding from keys to a single value.
IntCharAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntCharMap	An associative container with unique binding from keys to a single value.
IntCollection	A collection allows basic, efficient operations on sets of elements (difference and intersection).
IntContainer	A generic container holding ints.
IntDeque	A double-linked queue of ints.
IntDoubleAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntDoubleMap	An associative container with unique binding from keys to a single value.
IntFloatAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntFloatMap	An associative container with unique binding from keys to a single value.
IntIndexedContainer	An indexed container provides random access to elements based on an index.
IntIntAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntIntMap	An associative container with unique binding from keys to a single value.
IntLongAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntLongMap	An associative container with unique binding from keys to a single value.
IntLookupContainer	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
IntObjectAssociativeContainer<VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntObjectMap<VType>	An associative container with unique binding from keys to a single value.
IntSet	A set of ints.
IntShortAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
IntShortMap	An associative container with unique binding from keys to a single value.
KTypeCollection<KType>	A collection allows basic, efficient operations on sets of elements (difference and intersection).
KTypeContainer<KType>	A generic container holding KTypes.
KTypeDeque<KType>	A double-linked queue of KTypes.
KTypeIndexedContainer<KType>	An indexed container provides random access to elements based on an index.
KTypeLookupContainer<KType>	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
KTypeSet<KType>	A set of KTypes.
KTypeVTypeAssociativeContainer<KType,VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
KTypeVTypeMap<KType,VType>	An associative container with unique binding from keys to a single value.
LongByteAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongByteMap	An associative container with unique binding from keys to a single value.
LongCharAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongCharMap	An associative container with unique binding from keys to a single value.
LongCollection	A collection allows basic, efficient operations on sets of elements (difference and intersection).
LongContainer	A generic container holding longs.
LongDeque	A double-linked queue of longs.
LongDoubleAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongDoubleMap	An associative container with unique binding from keys to a single value.
LongFloatAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongFloatMap	An associative container with unique binding from keys to a single value.
LongIndexedContainer	An indexed container provides random access to elements based on an index.
LongIntAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongIntMap	An associative container with unique binding from keys to a single value.
LongLongAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongLongMap	An associative container with unique binding from keys to a single value.
LongLookupContainer	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
LongObjectAssociativeContainer<VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongObjectMap<VType>	An associative container with unique binding from keys to a single value.
LongSet	A set of longs.
LongShortAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
LongShortMap	An associative container with unique binding from keys to a single value.
ObjectByteAssociativeContainer<KType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectByteMap<KType>	An associative container with unique binding from keys to a single value.
ObjectCharAssociativeContainer<KType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectCharMap<KType>	An associative container with unique binding from keys to a single value.
ObjectCollection<KType>	A collection allows basic, efficient operations on sets of elements (difference and intersection).
ObjectContainer<KType>	A generic container holding KTypes.
ObjectDeque<KType>	A double-linked queue of KTypes.
ObjectDoubleAssociativeContainer<KType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectDoubleMap<KType>	An associative container with unique binding from keys to a single value.
ObjectFloatAssociativeContainer<KType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectFloatMap<KType>	An associative container with unique binding from keys to a single value.
ObjectIndexedContainer<KType>	An indexed container provides random access to elements based on an index.
ObjectIntAssociativeContainer<KType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectIntMap<KType>	An associative container with unique binding from keys to a single value.
ObjectLongAssociativeContainer<KType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectLongMap<KType>	An associative container with unique binding from keys to a single value.
ObjectLookupContainer<KType>	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
ObjectObjectAssociativeContainer<KType,VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectObjectMap<KType,VType>	An associative container with unique binding from keys to a single value.
ObjectSet<KType>	A set of KTypes.
ObjectShortAssociativeContainer<KType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ObjectShortMap<KType>	An associative container with unique binding from keys to a single value.
ShortByteAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortByteMap	An associative container with unique binding from keys to a single value.
ShortCharAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortCharMap	An associative container with unique binding from keys to a single value.
ShortCollection	A collection allows basic, efficient operations on sets of elements (difference and intersection).
ShortContainer	A generic container holding shorts.
ShortDeque	A double-linked queue of shorts.
ShortDoubleAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortDoubleMap	An associative container with unique binding from keys to a single value.
ShortFloatAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortFloatMap	An associative container with unique binding from keys to a single value.
ShortIndexedContainer	An indexed container provides random access to elements based on an index.
ShortIntAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortIntMap	An associative container with unique binding from keys to a single value.
ShortLongAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortLongMap	An associative container with unique binding from keys to a single value.
ShortLookupContainer	Marker interface for containers that can check if they contain a given object in at least time O(log n) and ideally in amortized constant time O(1).
ShortObjectAssociativeContainer<VType>	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortObjectMap<VType>	An associative container with unique binding from keys to a single value.
ShortSet	A set of shorts.
ShortShortAssociativeContainer	An associative container (alias: map, dictionary) from keys to (one or possibly more) values.
ShortShortMap	An associative container with unique binding from keys to a single value.

Class Summary

BitSet	An "open" BitSet implementation that allows direct access to the array of words storing the bits.
BitSetIterator	An iterator to iterate over set bits in an BitSet.
BoundedProportionalArraySizingStrategy	Array resizing proportional to the current buffer size, optionally kept within the given minimum and maximum growth limits.
ByteArrayDeque	An array-backed deque (doubly linked queue) of bytes.
ByteArrayList	An array-backed list of bytes.
ByteByteOpenHashMap	A hash map of byte to byte, implemented using open addressing with linear probing for collision resolution.
ByteCharOpenHashMap	A hash map of byte to char, implemented using open addressing with linear probing for collision resolution.
ByteDoubleOpenHashMap	A hash map of byte to double, implemented using open addressing with linear probing for collision resolution.
ByteFloatOpenHashMap	A hash map of byte to float, implemented using open addressing with linear probing for collision resolution.
ByteIntOpenHashMap	A hash map of byte to int, implemented using open addressing with linear probing for collision resolution.
ByteLongOpenHashMap	A hash map of byte to long, implemented using open addressing with linear probing for collision resolution.
ByteObjectOpenHashMap<VType>	A hash map of byte to VType, implemented using open addressing with linear probing for collision resolution.
ByteOpenHashSet	A hash set of bytes, implemented using using open addressing with linear probing for collision resolution.
ByteShortOpenHashMap	A hash map of byte to short, implemented using open addressing with linear probing for collision resolution.
ByteStack	An extension to ObjectArrayList adding stack-related utility methods.
CharArrayDeque	An array-backed deque (doubly linked queue) of chars.
CharArrayList	An array-backed list of chars.
CharByteOpenHashMap	A hash map of char to byte, implemented using open addressing with linear probing for collision resolution.
CharCharOpenHashMap	A hash map of char to char, implemented using open addressing with linear probing for collision resolution.
CharDoubleOpenHashMap	A hash map of char to double, implemented using open addressing with linear probing for collision resolution.
CharFloatOpenHashMap	A hash map of char to float, implemented using open addressing with linear probing for collision resolution.
CharIntOpenHashMap	A hash map of char to int, implemented using open addressing with linear probing for collision resolution.
CharLongOpenHashMap	A hash map of char to long, implemented using open addressing with linear probing for collision resolution.
CharObjectOpenHashMap<VType>	A hash map of char to VType, implemented using open addressing with linear probing for collision resolution.
CharOpenHashSet	A hash set of chars, implemented using using open addressing with linear probing for collision resolution.
CharShortOpenHashMap	A hash map of char to short, implemented using open addressing with linear probing for collision resolution.
CharStack	An extension to ObjectArrayList adding stack-related utility methods.
DoubleArrayDeque	An array-backed deque (doubly linked queue) of doubles.
DoubleArrayList	An array-backed list of doubles.
DoubleByteOpenHashMap	A hash map of double to byte, implemented using open addressing with linear probing for collision resolution.
DoubleCharOpenHashMap	A hash map of double to char, implemented using open addressing with linear probing for collision resolution.
DoubleDoubleOpenHashMap	A hash map of double to double, implemented using open addressing with linear probing for collision resolution.
DoubleFloatOpenHashMap	A hash map of double to float, implemented using open addressing with linear probing for collision resolution.
DoubleIntOpenHashMap	A hash map of double to int, implemented using open addressing with linear probing for collision resolution.
DoubleLongOpenHashMap	A hash map of double to long, implemented using open addressing with linear probing for collision resolution.
DoubleObjectOpenHashMap<VType>	A hash map of double to VType, implemented using open addressing with linear probing for collision resolution.
DoubleOpenHashSet	A hash set of doubles, implemented using using open addressing with linear probing for collision resolution.
DoubleShortOpenHashMap	A hash map of double to short, implemented using open addressing with linear probing for collision resolution.
DoubleStack	An extension to ObjectArrayList adding stack-related utility methods.
EmptyArrays	Empty arrays.
FloatArrayDeque	An array-backed deque (doubly linked queue) of floats.
FloatArrayList	An array-backed list of floats.
FloatByteOpenHashMap	A hash map of float to byte, implemented using open addressing with linear probing for collision resolution.
FloatCharOpenHashMap	A hash map of float to char, implemented using open addressing with linear probing for collision resolution.
FloatDoubleOpenHashMap	A hash map of float to double, implemented using open addressing with linear probing for collision resolution.
FloatFloatOpenHashMap	A hash map of float to float, implemented using open addressing with linear probing for collision resolution.
FloatIntOpenHashMap	A hash map of float to int, implemented using open addressing with linear probing for collision resolution.
FloatLongOpenHashMap	A hash map of float to long, implemented using open addressing with linear probing for collision resolution.
FloatObjectOpenHashMap<VType>	A hash map of float to VType, implemented using open addressing with linear probing for collision resolution.
FloatOpenHashSet	A hash set of floats, implemented using using open addressing with linear probing for collision resolution.
FloatShortOpenHashMap	A hash map of float to short, implemented using open addressing with linear probing for collision resolution.
FloatStack	An extension to ObjectArrayList adding stack-related utility methods.
IntArrayDeque	An array-backed deque (doubly linked queue) of ints.
IntArrayList	An array-backed list of ints.
IntByteOpenHashMap	A hash map of int to byte, implemented using open addressing with linear probing for collision resolution.
IntCharOpenHashMap	A hash map of int to char, implemented using open addressing with linear probing for collision resolution.
IntDoubleLinkedSet	A double-linked set of int values.
IntDoubleOpenHashMap	A hash map of int to double, implemented using open addressing with linear probing for collision resolution.
IntFloatOpenHashMap	A hash map of int to float, implemented using open addressing with linear probing for collision resolution.
IntIntOpenHashMap	A hash map of int to int, implemented using open addressing with linear probing for collision resolution.
IntLongOpenHashMap	A hash map of int to long, implemented using open addressing with linear probing for collision resolution.
IntObjectOpenHashMap<VType>	A hash map of int to VType, implemented using open addressing with linear probing for collision resolution.
IntOpenHashSet	A hash set of ints, implemented using using open addressing with linear probing for collision resolution.
IntShortOpenHashMap	A hash map of int to short, implemented using open addressing with linear probing for collision resolution.
IntStack	An extension to ObjectArrayList adding stack-related utility methods.
KTypeArrayDeque<KType>	An array-backed deque (doubly linked queue) of KTypes.
KTypeArrayList<KType>	An array-backed list of KTypes.
KTypeOpenHashSet<KType>	A hash set of KTypes, implemented using using open addressing with linear probing for collision resolution.
KTypeStack<KType>	An extension to ObjectArrayList adding stack-related utility methods.
KTypeVTypeOpenHashMap<KType,VType>	A hash map of KType to VType, implemented using open addressing with linear probing for collision resolution.
LongArrayDeque	An array-backed deque (doubly linked queue) of longs.
LongArrayList	An array-backed list of longs.
LongByteOpenHashMap	A hash map of long to byte, implemented using open addressing with linear probing for collision resolution.
LongCharOpenHashMap	A hash map of long to char, implemented using open addressing with linear probing for collision resolution.
LongDoubleOpenHashMap	A hash map of long to double, implemented using open addressing with linear probing for collision resolution.
LongFloatOpenHashMap	A hash map of long to float, implemented using open addressing with linear probing for collision resolution.
LongIntOpenHashMap	A hash map of long to int, implemented using open addressing with linear probing for collision resolution.
LongLongOpenHashMap	A hash map of long to long, implemented using open addressing with linear probing for collision resolution.
LongObjectOpenHashMap<VType>	A hash map of long to VType, implemented using open addressing with linear probing for collision resolution.
LongOpenHashSet	A hash set of longs, implemented using using open addressing with linear probing for collision resolution.
LongShortOpenHashMap	A hash map of long to short, implemented using open addressing with linear probing for collision resolution.
LongStack	An extension to ObjectArrayList adding stack-related utility methods.
ObjectArrayDeque<KType>	An array-backed deque (doubly linked queue) of KTypes.
ObjectArrayList<KType>	An array-backed list of KTypes.
ObjectByteOpenHashMap<KType>	A hash map of KType to byte, implemented using open addressing with linear probing for collision resolution.
ObjectCharOpenHashMap<KType>	A hash map of KType to char, implemented using open addressing with linear probing for collision resolution.
ObjectDoubleOpenHashMap<KType>	A hash map of KType to double, implemented using open addressing with linear probing for collision resolution.
ObjectFloatOpenHashMap<KType>	A hash map of KType to float, implemented using open addressing with linear probing for collision resolution.
ObjectIntOpenHashMap<KType>	A hash map of KType to int, implemented using open addressing with linear probing for collision resolution.
ObjectLongOpenHashMap<KType>	A hash map of KType to long, implemented using open addressing with linear probing for collision resolution.
ObjectObjectOpenHashMap<KType,VType>	A hash map of KType to VType, implemented using open addressing with linear probing for collision resolution.
ObjectOpenHashSet<KType>	A hash set of KTypes, implemented using using open addressing with linear probing for collision resolution.
ObjectShortOpenHashMap<KType>	A hash map of KType to short, implemented using open addressing with linear probing for collision resolution.
ObjectStack<KType>	An extension to ObjectArrayList adding stack-related utility methods.
ShortArrayDeque	An array-backed deque (doubly linked queue) of shorts.
ShortArrayList	An array-backed list of shorts.
ShortByteOpenHashMap	A hash map of short to byte, implemented using open addressing with linear probing for collision resolution.
ShortCharOpenHashMap	A hash map of short to char, implemented using open addressing with linear probing for collision resolution.
ShortDoubleOpenHashMap	A hash map of short to double, implemented using open addressing with linear probing for collision resolution.
ShortFloatOpenHashMap	A hash map of short to float, implemented using open addressing with linear probing for collision resolution.
ShortIntOpenHashMap	A hash map of short to int, implemented using open addressing with linear probing for collision resolution.
ShortLongOpenHashMap	A hash map of short to long, implemented using open addressing with linear probing for collision resolution.
ShortObjectOpenHashMap<VType>	A hash map of short to VType, implemented using open addressing with linear probing for collision resolution.
ShortOpenHashSet	A hash set of shorts, implemented using using open addressing with linear probing for collision resolution.
ShortShortOpenHashMap	A hash map of short to short, implemented using open addressing with linear probing for collision resolution.
ShortStack	An extension to ObjectArrayList adding stack-related utility methods.
XorShiftRandom	XorShift pseudo random number generator.

Package com.carrotsearch.hppc Description

High Performance Primitive Collections (HPPC) library provides typical data structures (lists, stacks, maps) template-generated for all Java primitive types (byte, int, etc.) to conserve memory and boost performance.

Why HPPC?

The Java Collections package is in many ways excellent, but it cannot be used for primitive types and autoboxing introduced in Java 1.5 kills the runtime performance (increased memory use, garbage collector overhead).

This library has different design goals than Java Collections (and many other collection packages). For example, the internals of each class are open and subject to free hacking and tuning up to one's wishes.

Why not other primitive collection libraries?

There are a few projects implementing collections over primitive types: fastutil, PCJ, GNU Trove, Apache Mahout (ported COLT collections), Apache Primitive Collections.

Some of these are LGPL-ed, a license type many commercial companies tend to avoid at all costs; other projects above are no longer maintained or complete. There is also a tendency to write tightly encapsulated code (private internals), implementing the API of standard Java packages and striving for fast error-recovery. Although these are good programming practices, they are not always practical (in many computationally intense applications access to the collection class' internals is a bliss). HPPC has a slightly different set of goals.

Assumptions and goals of HPPC

We assume that:

• The programmer knows what he's doing and may wish to access internal storage of a given collection's class directly (not using predefined iterators, for example).
• Vast majority of scenarios use single-threaded access. There is little point in repeated verification of concurrent modifications, for example.
• The programs (algorithms) that use primitive collections are unit-tested and regression-tested during development, so their behavior in production systems does not have to be restrictively verified (we can assume the code using the collection class won't violate the given set of assertions).

From these assumptions stem the following design drivers:

• Data types in the HPPC are as simple as possible and expose internal storage for any optimisations one may wish to do from within the end-application code.
• Verification of parameter and state validity is done optionally using assertions. This means that contracts are only checked if requested at runtime (using Java 1.4+ -ea switch). When the algorithm is tested and verified, it can run with no additional overhead from contract checks.
• We tried to avoid complex interface hierarchies, although certain interfaces are defined for clarity. The programmer should still choose a proper data structure at design-time and he should know what he's doing.
• HPPC provides utilities for the most common tasks like filtering, iterating or joining collections, but these utilities are usually more expensive than implementing a low-level direct access to the data storage (which may be done if needed).
• There is no special support for data serialization.
• The implementation is not thread safe and does not attempt to provide fast-failing concurrency problems detection.

Design and implementation assumptions

• We want HPPC class templates to be implemented using regular Java (with generics) so that typical programming tools can be used for development, testing, etc.
• We want HPPC class templates to be usable as generic-collection classes (for boxed numeric types or any other Object types), but at the same time we want specialized classes automatically-generated for primitive-types (to limit memory consumption and boost performance due to JIT optimisations).

Interfaces and their relation to Java Collections API

HPPC is not strictly modeled after Java Collections API, although we did try to make the APIs look similar enough for comfortable use. One particular thing largerly missing in HPPC are view projections (sublists or views over the collection of keys or values). Certain classes provide such views (like ObjectObjectOpenHashMap), but for the most part, specific methods are provided that accept ranges or closure-like filters. If performance is still unsatisfactory, the internals of each class are available for direct manipulation.

Rough relationships between Java Collections classes and HPPC classes are presented in the table below.

Relationships between HPPC and Java Collections.

	Java Collections	HPPC (primitives)	HPPC (generics)
bit sets	java.util.BitSet	BitSet	n/a
array-backed lists	java.util.ArrayList, java.util.Vector	[type]ArrayList	ObjectArrayList<T>
stacks	java.util.Stack	[type]Stack	ObjectStack<T>
deques	java.util.ArrayDeque	[type]ArrayDeque	ObjectArrayDeque<T>
hash maps (dictionaries)	java.util.HashMap	[keyType][valueType]OpenHashMap	ObjectObjectOpenHashMap<K, V> [keyType]ObjectOpenHashMap<V> Object[valueType]OpenHashMap<K>

The method-level API of the corresponding types is also similar, but distinct differences exist (consult the JavaDoc of each class).

Interfaces and container inheritance

HPPC's interfaces are modeled to encapsulate the common functionality enforced from all the classes that implement a given interface. The interface hierarchy is loosely inspired by STL.

An overview of interfaces and their relationship to data structures implemented in HPPC is depicted graphically in ObjectContainer.