Package com.carrotsearch.hppc
Class ObjectByteHashMap<KType>
java.lang.Object
com.carrotsearch.hppc.ObjectByteHashMap<KType>
- All Implemented Interfaces:
ObjectByteAssociativeContainer<KType>
,ObjectByteMap<KType>
,Preallocable
,Cloneable
,Iterable<ObjectByteCursor<KType>>
- Direct Known Subclasses:
ObjectByteIdentityHashMap
,ObjectByteScatterMap
@Generated(date="2024-05-16T08:18:11+0000",
value="KTypeVTypeHashMap.java")
public class ObjectByteHashMap<KType>
extends Object
implements ObjectByteMap<KType>, Preallocable, Cloneable
A hash map of
Object
to byte
, implemented using open
addressing with linear probing for collision resolution.
Note: read about important differences between hash and scatter sets.
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate final class
An iterator implementation foriterator()
.final class
A view of the keys inside this hash map.private final class
An iterator over the set of assigned keys.private final class
A view over the set of values of this map.private final class
An iterator over the set of assigned values. -
Field Summary
FieldsModifier and TypeFieldDescriptionprotected int
The number of stored keys (assigned key slots), excluding the special "empty" key, if any (usesize()
instead).protected boolean
Special treatment for the "empty slot" key marker.protected int
We perturb hash values with a container-unique seed to avoid problems with nearly-sorted-by-hash values on iterations.Object[]
The array holding keys.protected double
The load factor forkeys
.protected int
Mask for slot scans inkeys
.protected HashOrderMixingStrategy
Per-instance hash order mixing strategy.protected int
byte[]
The array holding values. -
Constructor Summary
ConstructorsConstructorDescriptionNew instance with sane defaults.ObjectByteHashMap
(int expectedElements) New instance with sane defaults.ObjectByteHashMap
(int expectedElements, double loadFactor) New instance with sane defaults.ObjectByteHashMap
(int expectedElements, double loadFactor, HashOrderMixingStrategy orderMixer) New instance with the provided defaults.ObjectByteHashMap
(ObjectByteAssociativeContainer<? extends KType> container) Create a hash map from all key-value pairs of another container. -
Method Summary
Modifier and TypeMethodDescriptionbyte
AddsincrementValue
to any existing value for the givenkey
or insertsincrementValue
ifkey
did not previously exist.protected void
allocateBuffers
(int arraySize) Allocate new internal buffers.protected void
allocateThenInsertThenRehash
(int slot, KType pendingKey, byte 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.void
clear()
Clear all keys and values in the container.clone()
boolean
containsKey
(KType key) Returnstrue
if this container has an association to a value for the given key.void
ensureCapacity
(int expectedElements) Ensure this container can hold at least the given number of keys (entries) without resizing its buffers.protected boolean
equalElements
(ObjectByteHashMap<?> other) Return true if all keys of some other container exist in this container.boolean
Compares the specified object with this set for equality.protected boolean
<T extends ObjectByteProcedure<? super KType>>
TforEach
(T procedure) Applies a given procedure to all keys-value pairs in this container.static <KType> ObjectByteHashMap
<KType> from
(KType[] keys, byte[] values) Creates a hash map from two index-aligned arrays of key-value pairs.byte
byte
getOrDefault
(KType key, byte defaultValue) int
hashCode()
protected int
Returns a hash code for the given key.boolean
indexExists
(int index) byte
indexGet
(int index) Returns the value associated with an existing key.void
indexInsert
(int index, KType key, byte value) Inserts a key-value pair for a key that is not present in the map.int
Returns a logical "index" of a given key that can be used to speed up follow-up value setters or getters in certain scenarios (conditional logic).byte
indexReplace
(int index, byte newValue) Replaces the value associated with an existing key and returns any previous value stored for that key.boolean
isEmpty()
iterator()
Returns a cursor over the entries (key-value pairs) in this map.keys()
Returns a specialized view of the keys of this associated container.byte
Place a given key and value in the container.int
putAll
(ObjectByteAssociativeContainer<? extends KType> container) Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.int
putAll
(Iterable<? extends ObjectByteCursor<? extends KType>> iterable) Puts all key/value pairs from a given iterable into this map.boolean
putIfAbsent
(KType key, byte value) Trove-inspired API method.byte
Ifkey
exists,putValue
is inserted into the map, otherwise any existing value is incremented byadditionValue
.protected void
Rehash from old buffers to new buffers.void
release()
Removes all elements from the collection and additionally releases any internal buffers.byte
Remove all values at the given key.int
removeAll
(ObjectContainer<? super KType> other) Removes all keys (and associated values) present in a given container.int
removeAll
(ObjectBytePredicate<? super KType> predicate) Removes all keys (and associated values) for which the predicate returnstrue
.int
removeAll
(ObjectPredicate<? super KType> predicate) Removes all keys (and associated values) for which the predicate returnstrue
.protected void
shiftConflictingKeys
(int gapSlot) Shift all the slot-conflicting keys and values allocated to (and including)slot
.int
size()
toString()
Convert the contents of this map to a human-friendly string.values()
Returns a container view of all values present in this container.protected double
verifyLoadFactor
(double loadFactor) Validate load factor range and return it.visualizeKeyDistribution
(int characters) Visually depict the distribution of keys.Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.lang.Iterable
forEach, spliterator
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Field Details
-
keys
The array holding keys. -
values
public byte[] valuesThe array holding values. -
keyMixer
protected int keyMixerWe perturb hash values with a container-unique seed to avoid problems with nearly-sorted-by-hash values on iterations.- See Also:
-
assigned
protected int assignedThe number of stored keys (assigned key slots), excluding the special "empty" key, if any (usesize()
instead).- See Also:
-
mask
protected int maskMask for slot scans inkeys
. -
resizeAt
protected int resizeAt -
hasEmptyKey
protected boolean hasEmptyKeySpecial treatment for the "empty slot" key marker. -
loadFactor
protected double loadFactorThe load factor forkeys
. -
orderMixer
Per-instance hash order mixing strategy.- See Also:
-
-
Constructor Details
-
ObjectByteHashMap
public ObjectByteHashMap()New instance with sane defaults. -
ObjectByteHashMap
public ObjectByteHashMap(int expectedElements) New instance with sane defaults.- Parameters:
expectedElements
- The expected number of elements guaranteed not to cause buffer expansion (inclusive).
-
ObjectByteHashMap
public ObjectByteHashMap(int expectedElements, double loadFactor) New instance with sane defaults.- Parameters:
expectedElements
- The expected number of elements guaranteed not to cause buffer expansion (inclusive).loadFactor
- The load factor for internal buffers. Insane load factors (zero, full capacity) are rejected byverifyLoadFactor(double)
.
-
ObjectByteHashMap
public ObjectByteHashMap(int expectedElements, double loadFactor, HashOrderMixingStrategy orderMixer) 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 byverifyLoadFactor(double)
.orderMixer
- Hash key order mixing strategy. SeeHashOrderMixing
for predefined implementations. Use constant mixers only if you understand the potential consequences.
-
ObjectByteHashMap
Create a hash map from all key-value pairs of another container.
-
-
Method Details
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put
Place a given key and value in the container.- Specified by:
put
in interfaceObjectByteMap<KType>
- Returns:
- The value previously stored under the given key in the map is returned.
-
putAll
Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.- Specified by:
putAll
in interfaceObjectByteMap<KType>
- Returns:
- Returns the number of keys added to the map as a result of this call (not previously present in the map). Values of existing keys are overwritten.
-
putAll
Puts all key/value pairs from a given iterable into this map.- Specified by:
putAll
in interfaceObjectByteMap<KType>
- Returns:
- Returns the number of keys added to the map as a result of this call (not previously present in the map). Values of existing keys are overwritten.
-
putIfAbsent
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 ifkey
does not exist.- Returns:
true
ifkey
did not exist andvalue
was placed in the map.
-
putOrAdd
Ifkey
exists,putValue
is inserted into the map, otherwise any existing value is incremented byadditionValue
.- Specified by:
putOrAdd
in interfaceObjectByteMap<KType>
- Parameters:
key
- The key of the value to adjust.putValue
- The value to put ifkey
does not exist.incrementValue
- The value to add to the existing value ifkey
exists.- Returns:
- Returns the current value associated with
key
(after changes).
-
addTo
AddsincrementValue
to any existing value for the givenkey
or insertsincrementValue
ifkey
did not previously exist.- Specified by:
addTo
in interfaceObjectByteMap<KType>
- Parameters:
key
- The key of the value to adjust.incrementValue
- The value to put or add to the existing value ifkey
exists.- Returns:
- Returns the current value associated with
key
(after changes).
-
remove
Remove all values at the given key. The default value for the key type is returned if the value does not exist in the map.- Specified by:
remove
in interfaceObjectByteMap<KType>
-
removeAll
Removes all keys (and associated values) present in a given container. An alias to:keys().removeAll(container)
but with no additional overhead.- Specified by:
removeAll
in interfaceObjectByteAssociativeContainer<KType>
- Returns:
- Returns the number of elements actually removed as a result of this call.
-
removeAll
Removes all keys (and associated values) for which the predicate returnstrue
.- Specified by:
removeAll
in interfaceObjectByteAssociativeContainer<KType>
- Returns:
- Returns the number of elements actually removed as a result of this call.
-
removeAll
Removes all keys (and associated values) for which the predicate returnstrue
.- Specified by:
removeAll
in interfaceObjectByteAssociativeContainer<KType>
- Returns:
- Returns the number of elements actually removed as a result of this call.
-
get
- Specified by:
get
in interfaceObjectByteMap<KType>
- Returns:
- Returns the value associated with the given key or the default value for the key type, if the key is not associated with any value. Important note: For primitive type values, the value returned for a non-existing key may not be the default value of the primitive type (it may be any value previously assigned to that slot).
-
getOrDefault
- Specified by:
getOrDefault
in interfaceObjectByteMap<KType>
- Returns:
- Returns the value associated with the given key or the provided default value if the key is not associated with any value.
-
containsKey
Returnstrue
if this container has an association to a value for the given key.- Specified by:
containsKey
in interfaceObjectByteAssociativeContainer<KType>
-
indexOf
Returns a logical "index" of a given key that can be used to speed up follow-up value setters or getters in certain scenarios (conditional logic). The semantics of "indexes" are not strictly defined. Indexes may (and typically won't be) contiguous. The index is valid only between map modifications (it will not be affected by read-only operations like iteration or value retrievals).- Specified by:
indexOf
in interfaceObjectByteMap<KType>
- Parameters:
key
- The key to locate in the map.- Returns:
- A non-negative value of the logical "index" of the key in the map or a negative value if the key did not exist.
- See Also:
-
indexExists
public boolean indexExists(int index) - Specified by:
indexExists
in interfaceObjectByteMap<KType>
- Parameters:
index
- The index of a given key, as returned fromObjectByteMap.indexOf(KType)
.- Returns:
- Returns
true
if the index corresponds to an existing key or false otherwise. This is equivalent to checking whether the index is a positive value (existing keys) or a negative value (non-existing keys). - See Also:
-
indexGet
public byte indexGet(int index) Returns the value associated with an existing key.- Specified by:
indexGet
in interfaceObjectByteMap<KType>
- Parameters:
index
- The index of an existing key.- Returns:
- Returns the value currently associated with the key.
- See Also:
-
indexReplace
public byte indexReplace(int index, byte newValue) Replaces the value associated with an existing key and returns any previous value stored for that key.- Specified by:
indexReplace
in interfaceObjectByteMap<KType>
- Parameters:
index
- The index of an existing key.- Returns:
- Returns the previous value associated with the key.
- See Also:
-
indexInsert
Inserts a key-value pair for a key that is not present in the map. This method may help in avoiding double recalculation of the key's hash.- Specified by:
indexInsert
in interfaceObjectByteMap<KType>
- Parameters:
index
- The index of a previously non-existing key, as returned fromObjectByteMap.indexOf(KType)
.- See Also:
-
clear
public void clear()Clear all keys and values in the container.- Specified by:
clear
in interfaceObjectByteMap<KType>
- See Also:
-
release
public void release()Removes all elements from the collection and additionally releases any internal buffers. Typically, if the object is to be reused, a simpleObjectByteMap.clear()
should be a better alternative since it'll avoid reallocation.- Specified by:
release
in interfaceObjectByteMap<KType>
- See Also:
-
size
public int size()- Specified by:
size
in interfaceObjectByteAssociativeContainer<KType>
- Returns:
- Returns the current size (number of assigned keys) in the container.
-
isEmpty
public boolean isEmpty()- Specified by:
isEmpty
in interfaceObjectByteAssociativeContainer<KType>
- Returns:
- Return
true
if this hash map contains no assigned keys.
-
hashCode
public int hashCode()- Specified by:
hashCode
in interfaceObjectByteMap<KType>
- Overrides:
hashCode
in classObject
- Returns:
- A hash code of elements stored in the map. The hash code is defined as a sum of hash codes of keys and values stored within the set). Because sum is commutative, this ensures that different order of elements in a set does not affect the hash code.
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equals
Compares the specified object with this set for equality. Returns true if and only if the specified object is also aObjectByteMap
and both objects contains exactly the same key-value pairs.- Specified by:
equals
in interfaceObjectByteMap<KType>
- Overrides:
equals
in classObject
-
equalElements
Return true if all keys of some other container exist in this container. Equality comparison is performed with this object'sequals(Object, Object)
method. -
ensureCapacity
public void ensureCapacity(int expectedElements) Ensure this container can hold at least the given number of keys (entries) without resizing its buffers.- Specified by:
ensureCapacity
in interfacePreallocable
- Parameters:
expectedElements
- The total number of keys, inclusive.
-
iterator
Returns a cursor over the entries (key-value pairs) in this map. The iterator is implemented as a cursor and it returns the same cursor instance on every call toIterator.next()
. To read the current key and value use the cursor's public fields. An example is shown below.for (IntShortCursor c : intShortMap) { System.out.println("index=" + c.index + " key=" + c.key + " value=" + c.value); }
The
index
field inside the cursor gives the internal index inside the container's implementation. The interpretation of this index depends on to the container. -
forEach
Applies a given procedure to all keys-value pairs in this container. Returns the argument (any subclass ofObjectByteProcedure
. This lets the caller to call methods of the argument by chaining the call (even if the argument is an anonymous type) to retrieve computed values, for example.- Specified by:
forEach
in interfaceObjectByteAssociativeContainer<KType>
-
forEach
Applies a given predicate to all keys-value pairs in this container. Returns the argument (any subclass ofObjectBytePredicate
. This lets the caller to call methods of the argument by chaining the call (even if the argument is an anonymous type) to retrieve computed values, for example. The iteration is continued as long as the predicate returnstrue
.- Specified by:
forEach
in interfaceObjectByteAssociativeContainer<KType>
-
keys
Returns a specialized view of the keys of this associated container. The view additionally implementsObjectLookupContainer
.- Specified by:
keys
in interfaceObjectByteAssociativeContainer<KType>
-
values
Description copied from interface:ObjectByteAssociativeContainer
Returns a container view of all values present in this container. The returned collection is a view over the key set and any modifications (if allowed) introduced to the collection will propagate to the associative container immediately.- Specified by:
values
in interfaceObjectByteAssociativeContainer<KType>
- Returns:
- Returns a container with all values stored in this map.
-
clone
-
toString
Convert the contents of this map to a human-friendly string. -
visualizeKeyDistribution
Description copied from interface:ObjectByteMap
Visually depict the distribution of keys.- Specified by:
visualizeKeyDistribution
in interfaceObjectByteMap<KType>
- Parameters:
characters
- The number of characters to "squeeze" the entire buffer into.- Returns:
- Returns a sequence of characters where '.' depicts an empty fragment of the internal buffer and 'X' depicts full or nearly full capacity within the buffer's range and anything between 1 and 9 is between.
-
from
Creates a hash map from two index-aligned arrays of key-value pairs. -
hashKey
Returns a hash code for the given key.The default implementation mixes the hash of the key with
keyMixer
to differentiate hash order of keys between hash containers. Helps alleviate problems resulting from linear conflict resolution in open addressing.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
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
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
. -
equals
-