Package com.carrotsearch.hppc

Class ByteObjectHashMap<VType>

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected int assigned
      The number of stored keys (assigned key slots), excluding the special "empty" key, if any (use size() instead).
      protected boolean hasEmptyKey
      Special treatment for the "empty slot" key marker.
      protected int keyMixer
      We perturb hash values with a container-unique seed to avoid problems with nearly-sorted-by-hash values on iterations.
      byte[] keys
      The array holding keys.
      protected double loadFactor
      The load factor for keys.
      protected int mask
      Mask for slot scans in keys.
      protected HashOrderMixingStrategy orderMixer
      Per-instance hash order mixing strategy.
      protected int resizeAt
      Expand (rehash) keys when assigned hits this value.
      java.lang.Object[] values
      The array holding values.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void allocateBuffers​(int arraySize)
      Allocate new internal buffers.
      protected void allocateThenInsertThenRehash​(int slot, byte 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.
      ByteObjectHashMap<VType> clone()
      boolean containsKey​(byte key)
      Returns true 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​(ByteObjectHashMap<?> other)
      Return true if all keys of some other container exist in this container.
      boolean equals​(java.lang.Object obj)
      Compares the specified object with this set for equality.
      <T extends ByteObjectProcedure<? super VType>>
      T      		 forEach​(T procedure)
      Applies a given procedure to all keys-value pairs in this container.
      static <VType> ByteObjectHashMap<VType> from​(byte[] keys, VType[] values)
      Creates a hash map from two index-aligned arrays of key-value pairs.
      VType get​(byte key)
      VType getOrDefault​(byte key, VType defaultValue)
      int hashCode()
      protected int hashKey​(byte key)
      Returns a hash code for the given key.
      boolean indexExists​(int index)
      VType indexGet​(int index)
      Returns the value associated with an existing key.
      void indexInsert​(int index, byte key, VType value)
      Inserts a key-value pair for a key that is not present in the map.
      int indexOf​(byte 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).
      VType indexReplace​(int index, VType newValue)
      Replaces the value associated with an existing key and returns any previous value stored for that key.
      boolean isEmpty()
      java.util.Iterator<ByteObjectCursor<VType>> iterator()
      Returns a cursor over the entries (key-value pairs) in this map.
      ByteObjectHashMap.KeysContainer keys()
      Returns a specialized view of the keys of this associated container.
      VType put​(byte key, VType value)
      Place a given key and value in the container.
      int putAll​(ByteObjectAssociativeContainer<? 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​(java.lang.Iterable<? extends ByteObjectCursor<? extends VType>> iterable)
      Puts all key/value pairs from a given iterable into this map.
      boolean putIfAbsent​(byte key, VType value)
      Trove-inspired API method.
      protected void rehash​(byte[] fromKeys, VType[] fromValues)
      Rehash from old buffers to new buffers.
      void release()
      Removes all elements from the collection and additionally releases any internal buffers.
      VType remove​(byte key)
      Remove all values at the given key.
      int removeAll​(ByteContainer other)
      Removes all keys (and associated values) present in a given container.
      int removeAll​(ByteObjectPredicate<? super VType> predicate)
      Removes all keys (and associated values) for which the predicate returns true.
      int removeAll​(BytePredicate predicate)
      Removes all keys (and associated values) for which the predicate returns true.
      protected void shiftConflictingKeys​(int gapSlot)
      Shift all the slot-conflicting keys and values allocated to (and including) slot.
      int size()
      java.lang.String toString()
      Convert the contents of this map to a human-friendly string.
      ObjectCollection<VType> values()
      Returns a container view of all values present in this container.
      protected double verifyLoadFactor​(double loadFactor)
      Validate load factor range and return it.
      java.lang.String 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

    • Field Detail

      • keys

        public byte[] keys
        The array holding keys.

      • values

        public java.lang.Object[] values
        The array holding values.

      • keyMixer

        protected int keyMixer
        We perturb hash values with a container-unique seed to avoid problems with nearly-sorted-by-hash values on iterations.
        See Also:
        hashKey(byte), "http://issues.carrot2.org/browse/HPPC-80", "http://issues.carrot2.org/browse/HPPC-103"

      • assigned

        protected int assigned
        The number of stored keys (assigned key slots), excluding the special "empty" key, if any (use size() instead).
        See Also:
        size()

      • mask

        protected int mask
        Mask for slot scans in keys.

      • resizeAt

        protected int resizeAt
        Expand (rehash) keys when assigned hits this value.

      • hasEmptyKey

        protected boolean hasEmptyKey
        Special treatment for the "empty slot" key marker.

      • loadFactor

        protected double loadFactor
        The load factor for keys.

    • Constructor Detail

      • ByteObjectHashMap

        public ByteObjectHashMap()
        New instance with sane defaults.

      • ByteObjectHashMap

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

      • ByteObjectHashMap

        public ByteObjectHashMap​(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 by verifyLoadFactor(double).

      • ByteObjectHashMap

        public ByteObjectHashMap​(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 by verifyLoadFactor(double).
        orderMixer - Hash key order mixing strategy. See HashOrderMixing for predefined implementations. Use constant mixers only if you understand the potential consequences.

    • Method Detail

      • put

        public VType put​(byte key,
                 VType value)
        Place a given key and value in the container.
        Specified by:
        put in interface ByteObjectMap<VType>
        Returns:
        The value previously stored under the given key in the map is returned.

      • putAll

        public int putAll​(ByteObjectAssociativeContainer<? extends VType> container)
        Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.
        Specified by:
        putAll in interface ByteObjectMap<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

        public int putAll​(java.lang.Iterable<? extends ByteObjectCursor<? extends VType>> iterable)
        Puts all key/value pairs from a given iterable into this map.
        Specified by:
        putAll in interface ByteObjectMap<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

        public boolean putIfAbsent​(byte key,
                           VType value)
        Trove-inspired API method. An equivalent of the following code: 
         if (!map.containsKey(key)) map.put(value);
        Parameters:
        key - The key of the value to check.
        value - The value to put if key does not exist.
        Returns:
        true if key did not exist and value was placed in the map.

      • remove

        public VType remove​(byte key)
        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 interface ByteObjectMap<VType>

      • removeAll

        public int removeAll​(ByteContainer other)
        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 interface ByteObjectAssociativeContainer<VType>
        Returns:
        Returns the number of elements actually removed as a result of this call.

      • removeAll

        public int removeAll​(BytePredicate predicate)
        Removes all keys (and associated values) for which the predicate returns true.
        Specified by:
        removeAll in interface ByteObjectAssociativeContainer<VType>
        Returns:
        Returns the number of elements actually removed as a result of this call.

      • get

        public VType get​(byte key)
        Specified by:
        get in interface ByteObjectMap<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).

      • getOrDefault

        public VType getOrDefault​(byte key,
                          VType defaultValue)
        Specified by:
        getOrDefault in interface ByteObjectMap<VType>
        Returns:
        Returns the value associated with the given key or the provided default value if the key is not associated with any value.

      • indexExists

        public boolean indexExists​(int index)
        Specified by:
        indexExists in interface ByteObjectMap<VType>
        Parameters:
        index - The index of a given key, as returned from ByteObjectMap.indexOf(byte).
        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:
        ByteObjectMap.indexOf(byte)

      • indexGet

        public VType indexGet​(int index)
        Returns the value associated with an existing key.
        Specified by:
        indexGet in interface ByteObjectMap<VType>
        Parameters:
        index - The index of an existing key.
        Returns:
        Returns the value currently associated with the key.
        See Also:
        ByteObjectMap.indexOf(byte)

      • indexReplace

        public VType indexReplace​(int index,
                          VType newValue)
        Replaces the value associated with an existing key and returns any previous value stored for that key.
        Specified by:
        indexReplace in interface ByteObjectMap<VType>
        Parameters:
        index - The index of an existing key.
        Returns:
        Returns the previous value associated with the key.
        See Also:
        ByteObjectMap.indexOf(byte)

      • 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 simple ByteObjectMap.clear() should be a better alternative since it'll avoid reallocation.
        Specified by:
        release in interface ByteObjectMap<VType>
        See Also:
        ByteObjectMap.clear()

      • hashCode

        public int hashCode()
        Specified by:
        hashCode in interface ByteObjectMap<VType>
        Overrides:
        hashCode in class java.lang.Object
        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.

      • equals

        public boolean equals​(java.lang.Object obj)
        Compares the specified object with this set for equality. Returns true if and only if the specified object is also a ByteObjectMap and both objects contains exactly the same key-value pairs.
        Specified by:
        equals in interface ByteObjectMap<VType>
        Overrides:
        equals in class java.lang.Object

      • equalElements

        protected boolean equalElements​(ByteObjectHashMap<?> other)
        Return true if all keys of some other container exist in this container. Values are compared using Object.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 interface Preallocable
        Parameters:
        expectedElements - The total number of keys, inclusive.

      • iterator

        public java.util.Iterator<ByteObjectCursor<VType>> 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 to Iterator.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.

        Specified by:
        iterator in interface ByteObjectAssociativeContainer<VType>
        Specified by:
        iterator in interface java.lang.Iterable<VType>

      • forEach

        public <T extends ByteObjectProcedure<? super VType>> T forEach​(T procedure)
        Applies a given procedure to all keys-value pairs in this container. Returns the argument (any subclass of ByteObjectProcedure. 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 interface ByteObjectAssociativeContainer<VType>

      • forEach

        public <T extends ByteObjectPredicate<? super VType>> T forEach​(T predicate)
        Applies a given predicate to all keys-value pairs in this container. Returns the argument (any subclass of ByteObjectPredicate. 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 returns true.
        Specified by:
        forEach in interface ByteObjectAssociativeContainer<VType>

      • values

        public ObjectCollection<VType> values()
        Description copied from interface: ByteObjectAssociativeContainer
        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 interface ByteObjectAssociativeContainer<VType>
        Returns:
        Returns a container with all values stored in this map.

      • toString

        public java.lang.String toString()
        Convert the contents of this map to a human-friendly string.
        Overrides:
        toString in class java.lang.Object

      • visualizeKeyDistribution

        public java.lang.String visualizeKeyDistribution​(int characters)
        Description copied from interface: ByteObjectMap
        Visually depict the distribution of keys.
        Specified by:
        visualizeKeyDistribution in interface ByteObjectMap<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.

      • from

        public static <VType> ByteObjectHashMap<VType> from​(byte[] keys,
                                                    VType[] values)
        Creates a hash map from two index-aligned arrays of key-value pairs.

      • hashKey

        protected int hashKey​(byte 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.

      • verifyLoadFactor

        protected double verifyLoadFactor​(double loadFactor)
        Validate load factor range and return it. Override and suppress if you need insane load factors.

      • rehash

        protected void rehash​(byte[] fromKeys,
                      VType[] fromValues)
        Rehash from old buffers to new buffers.

      • allocateBuffers

        protected void allocateBuffers​(int arraySize)
        Allocate new internal buffers. This method attempts to allocate and assign internal buffers atomically (either allocations succeed or not).

      • allocateThenInsertThenRehash

        protected void allocateThenInsertThenRehash​(int slot,
                                            byte pendingKey,
                                            VType pendingValue)
        This method is invoked when there is a new key/ value pair to be inserted into the buffers but there is not enough empty slots to do so. New buffers are allocated. If this succeeds, we know we can proceed with rehashing so we assign the pending element to the previous buffer (possibly violating the invariant of having at least one empty slot) and rehash all keys, substituting new buffers at the end.

      • shiftConflictingKeys

        protected void shiftConflictingKeys​(int gapSlot)
        Shift all the slot-conflicting keys and values allocated to (and including) slot.