Package com.carrotsearch.hppc
Class DoubleObjectHashMap<VType>
java.lang.Object
com.carrotsearch.hppc.DoubleObjectHashMap<VType>
- All Implemented Interfaces:
DoubleObjectAssociativeContainer<VType>
,DoubleObjectMap<VType>
,Preallocable
,Cloneable
,Iterable<DoubleObjectCursor<VType>>
- Direct Known Subclasses:
DoubleObjectScatterMap
@Generated(date="2023-09-14T00:00:00+0000",
value="KTypeVTypeHashMap.java")
public class DoubleObjectHashMap<VType>
extends Object
implements DoubleObjectMap<VType>, Preallocable, Cloneable
A hash map of
double
to Object
, implemented using open
addressing with linear probing for collision resolution.
Note: read about important differences between hash and scatter sets.
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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.double[]
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
Object[]
The array holding values. -
Constructor Summary
ConstructorsConstructorDescriptionNew instance with sane defaults.DoubleObjectHashMap
(int expectedElements) New instance with sane defaults.DoubleObjectHashMap
(int expectedElements, double loadFactor) New instance with sane defaults.DoubleObjectHashMap
(int expectedElements, double loadFactor, HashOrderMixingStrategy orderMixer) New instance with the provided defaults.DoubleObjectHashMap
(DoubleObjectAssociativeContainer<? extends VType> container) Create a hash map from all key-value pairs of another container. -
Method Summary
Modifier and TypeMethodDescriptionprotected void
allocateBuffers
(int arraySize) Allocate new internal buffers.protected void
allocateThenInsertThenRehash
(int slot, double 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.void
clear()
Clear all keys and values in the container.clone()
boolean
containsKey
(double 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
(DoubleObjectHashMap<?> other) Return true if all keys of some other container exist in this container.boolean
Compares the specified object with this set for equality.<T extends DoubleObjectProcedure<? super VType>>
TforEach
(T procedure) Applies a given procedure to all keys-value pairs in this container.static <VType> DoubleObjectHashMap<VType>
from
(double[] keys, VType[] values) Creates a hash map from two index-aligned arrays of key-value pairs.get
(double key) getOrDefault
(double key, VType defaultValue) int
hashCode()
protected int
hashKey
(double key) Returns a hash code for the given key.boolean
indexExists
(int index) indexGet
(int index) Returns the value associated with an existing key.void
indexInsert
(int index, double key, VType value) Inserts a key-value pair for a key that is not present in the map.int
indexOf
(double key) 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).indexReplace
(int index, VType 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.Place a given key and value in the container.int
putAll
(DoubleObjectAssociativeContainer<? extends VType> 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 DoubleObjectCursor<? extends VType>> iterable) Puts all key/value pairs from a given iterable into this map.boolean
putIfAbsent
(double key, VType value) Trove-inspired API method.protected void
Rehash from old buffers to new buffers.void
release()
Removes all elements from the collection and additionally releases any internal buffers.remove
(double key) Remove all values at the given key.int
removeAll
(DoubleContainer other) Removes all keys (and associated values) present in a given container.int
removeAll
(DoubleObjectPredicate<? super VType> predicate) Removes all keys (and associated values) for which the predicate returnstrue
.int
removeAll
(DoublePredicate 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
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keys
public double[] keysThe array holding keys. -
values
The 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:
-
hashKey(double)
- "http://issues.carrot2.org/browse/HPPC-80"
- "http://issues.carrot2.org/browse/HPPC-103"
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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:
-
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Constructor Details
-
DoubleObjectHashMap
public DoubleObjectHashMap()New instance with sane defaults. -
DoubleObjectHashMap
public DoubleObjectHashMap(int expectedElements) New instance with sane defaults.- Parameters:
expectedElements
- The expected number of elements guaranteed not to cause buffer expansion (inclusive).
-
DoubleObjectHashMap
public DoubleObjectHashMap(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)
.
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DoubleObjectHashMap
public DoubleObjectHashMap(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.
-
DoubleObjectHashMap
Create a hash map from all key-value pairs of another container.
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Method Details
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put
Place a given key and value in the container.- Specified by:
put
in interfaceDoubleObjectMap<VType>
- 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 interfaceDoubleObjectMap<VType>
- 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 interfaceDoubleObjectMap<VType>
- 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.
-
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 interfaceDoubleObjectMap<VType>
-
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 interfaceDoubleObjectAssociativeContainer<VType>
- 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 interfaceDoubleObjectAssociativeContainer<VType>
- 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 interfaceDoubleObjectAssociativeContainer<VType>
- Returns:
- Returns the number of elements actually removed as a result of this call.
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get
- Specified by:
get
in interfaceDoubleObjectMap<VType>
- 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).
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getOrDefault
- Specified by:
getOrDefault
in interfaceDoubleObjectMap<VType>
- Returns:
- Returns the value associated with the given key or the provided default value if the key is not associated with any value.
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containsKey
public boolean containsKey(double key) Returnstrue
if this container has an association to a value for the given key.- Specified by:
containsKey
in interfaceDoubleObjectAssociativeContainer<VType>
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indexOf
public int indexOf(double key) 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 interfaceDoubleObjectMap<VType>
- 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 interfaceDoubleObjectMap<VType>
- Parameters:
index
- The index of a given key, as returned fromDoubleObjectMap.indexOf(double)
.- 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:
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indexGet
Returns the value associated with an existing key.- Specified by:
indexGet
in interfaceDoubleObjectMap<VType>
- Parameters:
index
- The index of an existing key.- Returns:
- Returns the value currently associated with the key.
- See Also:
-
indexReplace
Replaces the value associated with an existing key and returns any previous value stored for that key.- Specified by:
indexReplace
in interfaceDoubleObjectMap<VType>
- 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 interfaceDoubleObjectMap<VType>
- Parameters:
index
- The index of a previously non-existing key, as returned fromDoubleObjectMap.indexOf(double)
.- See Also:
-
clear
public void clear()Clear all keys and values in the container.- Specified by:
clear
in interfaceDoubleObjectMap<VType>
- 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 simpleDoubleObjectMap.clear()
should be a better alternative since it'll avoid reallocation.- Specified by:
release
in interfaceDoubleObjectMap<VType>
- See Also:
-
size
public int size()- Specified by:
size
in interfaceDoubleObjectAssociativeContainer<VType>
- Returns:
- Returns the current size (number of assigned keys) in the container.
-
isEmpty
public boolean isEmpty()- Specified by:
isEmpty
in interfaceDoubleObjectAssociativeContainer<VType>
- Returns:
- Return
true
if this hash map contains no assigned keys.
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hashCode
public int hashCode()- Specified by:
hashCode
in interfaceDoubleObjectMap<VType>
- 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 aDoubleObjectMap
and both objects contains exactly the same key-value pairs.- Specified by:
equals
in interfaceDoubleObjectMap<VType>
- Overrides:
equals
in classObject
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equalElements
Return true if all keys of some other container exist in this container. Values are compared usingObject.equals(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 ofDoubleObjectProcedure
. 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 interfaceDoubleObjectAssociativeContainer<VType>
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forEach
Applies a given predicate to all keys-value pairs in this container. Returns the argument (any subclass ofDoubleObjectPredicate
. 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 interfaceDoubleObjectAssociativeContainer<VType>
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keys
Returns a specialized view of the keys of this associated container. The view additionally implementsObjectLookupContainer
.- Specified by:
keys
in interfaceDoubleObjectAssociativeContainer<VType>
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values
Description copied from interface:DoubleObjectAssociativeContainer
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 interfaceDoubleObjectAssociativeContainer<VType>
- Returns:
- Returns a container with all values stored in this map.
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clone
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toString
Convert the contents of this map to a human-friendly string. -
visualizeKeyDistribution
Description copied from interface:DoubleObjectMap
Visually depict the distribution of keys.- Specified by:
visualizeKeyDistribution
in interfaceDoubleObjectMap<VType>
- 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.
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from
Creates a hash map from two index-aligned arrays of key-value pairs. -
hashKey
protected int hashKey(double key) 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.
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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
.
-