Class ObjectFloatWormMap<KType>
- All Implemented Interfaces:
Accountable,ObjectFloatAssociativeContainer<KType>,ObjectFloatMap<KType>,Preallocable,Cloneable,Iterable<ObjectFloatCursor<KType>>
Object to float, implemented using Worm Hashing strategy.
This strategy is appropriate for a medium sized map (less than 2M entries). It takes more time
to put entries in the map because it maintains chains of entries having the same hash. Then the
lookup speed is fast even if the map is heavy loaded or hashes are clustered. On average it takes
slightly less memory than ObjectFloatHashMap: slightly heavier but the load factor is higher
(it varies around 80%) so it enlarges later.
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionfinal classA view of the keys inside this map. -
Field Summary
FieldsModifier and TypeFieldDescriptionprotected intSeed used to ensure the hash iteration order is different from an iteration to another.Object[]The array holding keys.byte[]abs(next[i])=offsetto next chained entry index.protected intMap size (number of entries).float[]The array holding values. -
Constructor Summary
ConstructorsConstructorDescriptionNew instance with sane defaults.ObjectFloatWormMap(int expectedElements) New instance with the provided defaults.ObjectFloatWormMap(ObjectFloatAssociativeContainer<? extends KType> container) Creates a new instance from all key-value pairs of another container. -
Method Summary
Modifier and TypeMethodDescriptionfloatAn equivalent of callingprotected voidallocateBuffers(int capacity) voidclear()Clear all keys and values in the container.clone()Clones this map.booleancontainsKey(KType key) Returnstrueif this container has an association to a value for the given key.voidensureCapacity(int expectedElements) Ensure this container can hold at least the given number of elements without resizing its buffers.booleanCompares the specified object with this set for equality.protected boolean<T extends ObjectFloatProcedure<? super KType>>
TforEach(T procedure) Applies a given procedure to all keys-value pairs in this container.static <KType> ObjectFloatWormMap<KType>from(KType[] keys, float[] values) Creates a new instance from two index-aligned arrays of key-value pairs.floatfloatgetOrDefault(KType key, float defaultValue) inthashCode()protected intbooleanindexExists(int index) floatindexGet(int index) Returns the value associated with an existing key.voidindexInsert(int index, KType key, float value) Inserts a key-value pair for a key that is not present in the map.intReturns 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).floatindexRemove(int index) Removes a key-value pair at an index previously acquired fromObjectFloatMap.indexOf(KType).floatindexReplace(int index, float newValue) Replaces the value associated with an existing key and returns any previous value stored for that key.booleanisEmpty()iterator()Returns a cursor over the entries (key-value pairs) in this map.keys()Returns a collection of keys of this container.protected intProvides the next iteration seed used to build the iteration starting slot and offset increment.floatnoValue()The value returned when there is no value associated to a key in this map.floatPlace a given key and value in the container.intputAll(ObjectFloatAssociativeContainer<? extends KType> container) Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.intputAll(Iterable<? extends ObjectFloatCursor<? extends KType>> iterable) Puts all keys from an iterable cursor to this map, replacing the values of existing keys, if such keys are present.booleanputIfAbsent(KType key, float value) If the specified key is not already associated with a value, associates it with the given value.floatIfkeyexists,putValueis inserted into the map, otherwise any existing value is incremented byadditionValue.longAllocated memory estimationlongBytes that is actually been usedvoidrelease()Removes all elements from the collection and additionally releases any internal buffers.floatRemove all values at the given key.intremoveAll(ObjectContainer<? super KType> other) Removes all keys (and associated values) present in a given container.intremoveAll(ObjectFloatPredicate<? super KType> predicate) Removes all keys (and associated values) for which the predicate returnstrue.intremoveAll(ObjectPredicate<? super KType> predicate) Removes all keys (and associated values) for which the predicate returnstrue.intsize()toString()values()Returns a container view of all values present in this container.visualizeKeyDistribution(int characters) Visually depict the distribution of keys.Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, waitMethods inherited from interface java.lang.Iterable
forEach, spliterator
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Field Details
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keys
The array holding keys. -
values
public float[] valuesThe array holding values. -
next
public byte[] nextabs(next[i])=offsetto next chained entry index.next[i]=0for free bucket.The offset is always forward, and the array is considered circular, meaning that an entry at the end of the array may point to an entry at the beginning with a positive offset.
The offset is always forward, but the sign of the offset encodes head/tail of chain.
next[i] > 0 for the first head-of-chain entry (within [1,WormUtil.maxOffset(int)]),next[i] < 0 for the subsequent tail-of-chain entries (within [-WormUtil.maxOffset(int),-1]. For the last entry in the chain,abs(next[i])=WormUtil.END_OF_CHAIN. -
size
protected int sizeMap size (number of entries). -
iterationSeed
protected int iterationSeedSeed used to ensure the hash iteration order is different from an iteration to another.
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Constructor Details
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ObjectFloatWormMap
public ObjectFloatWormMap()New instance with sane defaults. -
ObjectFloatWormMap
public ObjectFloatWormMap(int expectedElements) New instance with the provided defaults.There is no load factor parameter as this map enlarges automatically. In practice the load factor varies around 80% (between 75% and 90%). The load factor is 100% for tiny maps.
- Parameters:
expectedElements- The expected number of elements. The capacity of the map is calculated based on it.
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ObjectFloatWormMap
Creates a new instance from all key-value pairs of another container.
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Method Details
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from
Creates a new instance from two index-aligned arrays of key-value pairs. -
clone
Clones this map. The cloning operation is efficient because it copies directly the internal arrays, without having to put entries in the cloned map. The cloned map has the same entries and the same capacity as this map. -
noValue
public float noValue()The value returned when there is no value associated to a key in this map. This method can be extended to change it. -
size
public int size()- Specified by:
sizein interfaceObjectFloatAssociativeContainer<KType>- Returns:
- Returns the current size (number of assigned keys) in the container.
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isEmpty
public boolean isEmpty()- Specified by:
isEmptyin interfaceObjectFloatAssociativeContainer<KType>- Returns:
- Return
trueif this hash map contains no assigned keys.
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get
- Specified by:
getin interfaceObjectFloatMap<KType>- Returns:
- Returns the value associated with the given key or the default
value for the value type, if the key is not associated with any
value. For numeric value types, this default value is 0, for
object types it is
null.
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getOrDefault
- Specified by:
getOrDefaultin interfaceObjectFloatMap<KType>- 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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put
Place a given key and value in the container.- Specified by:
putin interfaceObjectFloatMap<KType>- Returns:
- The value previously stored under the given key in the map is returned.
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putAll
Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.- Specified by:
putAllin interfaceObjectFloatMap<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.
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putAll
Puts all keys from an iterable cursor to this map, replacing the values of existing keys, if such keys are present.- Specified by:
putAllin interfaceObjectFloatMap<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.
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putOrAdd
Ifkeyexists,putValueis inserted into the map, otherwise any existing value is incremented byadditionValue.- Specified by:
putOrAddin interfaceObjectFloatMap<KType>- Parameters:
key- The key of the value to adjust.putValue- The value to put ifkeydoes not exist.incrementValue- The value to add to the existing value ifkeyexists.- Returns:
- Returns the current value associated with
key(after changes).
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addTo
An equivalent of callingputOrAdd(key, additionValue, additionValue);
- Specified by:
addToin interfaceObjectFloatMap<KType>- Parameters:
key- The key of the value to adjust.additionValue- The value to put or add to the existing value ifkeyexists.- Returns:
- Returns the current value associated with
key(after changes).
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putIfAbsent
Description copied from interface:ObjectFloatMapIf the specified key is not already associated with a value, associates it with the given value.- Specified by:
putIfAbsentin interfaceObjectFloatMap<KType>- Parameters:
key- The key of the value to check.value- The value to put ifkeydoes not exist.- Returns:
trueifkeydid not exist andvaluewas placed in the map.
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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:
removein interfaceObjectFloatMap<KType>
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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:
removeAllin interfaceObjectFloatAssociativeContainer<KType>- Returns:
- Returns the number of elements actually removed as a result of this call.
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removeAll
Removes all keys (and associated values) for which the predicate returnstrue.- Specified by:
removeAllin interfaceObjectFloatAssociativeContainer<KType>- Returns:
- Returns the number of elements actually removed as a result of this call.
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removeAll
Removes all keys (and associated values) for which the predicate returnstrue.- Specified by:
removeAllin interfaceObjectFloatAssociativeContainer<KType>- Returns:
- Returns the number of elements actually removed as a result of this call.
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forEach
Applies a given procedure to all keys-value pairs in this container. Returns the argument (any subclass ofObjectFloatProcedure. 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:
forEachin interfaceObjectFloatAssociativeContainer<KType>
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forEach
Applies a given predicate to all keys-value pairs in this container. Returns the argument (any subclass ofObjectFloatPredicate. 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:
forEachin interfaceObjectFloatAssociativeContainer<KType>
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keys
Returns a collection of keys of 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:
keysin interfaceObjectFloatAssociativeContainer<KType>
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values
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:
valuesin interfaceObjectFloatAssociativeContainer<KType>
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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
indexfield inside the cursor gives the internal index inside the container's implementation. The interpretation of this index depends on to the container. -
containsKey
Returnstrueif this container has an association to a value for the given key.- Specified by:
containsKeyin interfaceObjectFloatAssociativeContainer<KType>
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clear
public void clear()Clear all keys and values in the container.- Specified by:
clearin interfaceObjectFloatMap<KType>- See Also:
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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 simpleObjectFloatMap.clear()should be a better alternative since it'll avoid reallocation.- Specified by:
releasein interfaceObjectFloatMap<KType>- See Also:
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equals
Compares the specified object with this set for equality. Returnstrueif and only if the specified object is also aObjectFloatMapand both objects contains exactly the same key-value pairs.- Specified by:
equalsin interfaceObjectFloatMap<KType>- Overrides:
equalsin classObject
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equals
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hashCode
public int hashCode()- Specified by:
hashCodein interfaceObjectFloatMap<KType>- Overrides:
hashCodein 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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hashKey
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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:
indexOfin interfaceObjectFloatMap<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.
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indexExists
public boolean indexExists(int index) - Specified by:
indexExistsin interfaceObjectFloatMap<KType>- Parameters:
index- The index of a given key, as returned fromObjectFloatMap.indexOf(KType).- Returns:
- Returns
trueif 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
public float indexGet(int index) Returns the value associated with an existing key.- Specified by:
indexGetin interfaceObjectFloatMap<KType>- Parameters:
index- The index of an existing key.- Returns:
- Returns the value currently associated with the key.
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indexReplace
public float indexReplace(int index, float newValue) Replaces the value associated with an existing key and returns any previous value stored for that key.- Specified by:
indexReplacein interfaceObjectFloatMap<KType>- Parameters:
index- The index of an existing key.- Returns:
- Returns the previous value associated with the key.
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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:
indexInsertin interfaceObjectFloatMap<KType>- Parameters:
index- The index of a previously non-existing key, as returned fromObjectFloatMap.indexOf(KType).- See Also:
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indexRemove
public float indexRemove(int index) Removes a key-value pair at an index previously acquired fromObjectFloatMap.indexOf(KType).- Specified by:
indexRemovein interfaceObjectFloatMap<KType>- Parameters:
index- The index of the key to remove, as returned fromObjectFloatMap.indexOf(KType).- Returns:
- Returns the previous value associated with the key.
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toString
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ensureCapacity
public void ensureCapacity(int expectedElements) Ensure this container can hold at least the given number of elements without resizing its buffers.- Specified by:
ensureCapacityin interfacePreallocable- Parameters:
expectedElements- The total number of elements, inclusive.
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visualizeKeyDistribution
Visually depict the distribution of keys.- Specified by:
visualizeKeyDistributionin interfaceObjectFloatMap<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.
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ramBytesAllocated
public long ramBytesAllocated()Allocated memory estimation- Specified by:
ramBytesAllocatedin interfaceAccountable- Returns:
- Ram allocated in bytes
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ramBytesUsed
public long ramBytesUsed()Bytes that is actually been used- Specified by:
ramBytesUsedin interfaceAccountable- Returns:
- Ram used in bytes
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allocateBuffers
protected void allocateBuffers(int capacity) -
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.
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