Package gnu.trove.map.hash

Class TByteObjectHashMap<V>

java.lang.Object
gnu.trove.impl.hash.THash
gnu.trove.impl.hash.TPrimitiveHash
gnu.trove.impl.hash.TByteHash
gnu.trove.map.hash.TByteObjectHashMap<V>
All Implemented Interfaces:
TByteObjectMap<V>, Externalizable, Serializable
public class TByteObjectHashMap<V> extends TByteHash implements TByteObjectMap<V>, Externalizable
An open addressed Map implementation for byte keys and Object values. Created: Sun Nov 4 08:52:45 2001
See Also:

  • Field Details

    • _values

      protected transient V[] _values
      the values of the map

    • no_entry_key

      protected byte no_entry_key
      the value that represents null in the key set.

  • Constructor Details

    • TByteObjectHashMap

      public TByteObjectHashMap()
      Creates a new TByteObjectHashMap instance with the default capacity and load factor.

    • TByteObjectHashMap

      public TByteObjectHashMap(int initialCapacity)
      Creates a new TByteObjectHashMap instance with a prime capacity equal to or greater than initialCapacity and with the default load factor.
      Parameters:
      initialCapacity - an int value

    • TByteObjectHashMap

      public TByteObjectHashMap(int initialCapacity, float loadFactor)
      Creates a new TByteObjectHashMap instance with a prime capacity equal to or greater than initialCapacity and with the specified load factor.
      Parameters:
      initialCapacity - an int value
      loadFactor - a float value

    • TByteObjectHashMap

      public TByteObjectHashMap(int initialCapacity, float loadFactor, byte noEntryKey)
      Creates a new TByteObjectHashMap instance with a prime value at or near the specified capacity and load factor.
      Parameters:
      initialCapacity - used to find a prime capacity for the table.
      loadFactor - used to calculate the threshold over which rehashing takes place.
      noEntryKey - the value used to represent null in the key set.

    • TByteObjectHashMap

      public TByteObjectHashMap(TByteObjectMap<? extends V> map)
      Creates a new TByteObjectHashMap that contains the entries in the map passed to it.
      Parameters:
      map - the TByteObjectMap to be copied.

  • Method Details

    • setUp

      protected int setUp(int initialCapacity)
      initializes the hashtable to a prime capacity which is at least initialCapacity + 1.
      Overrides:
      setUp in class TByteHash
      Parameters:
      initialCapacity - an int value
      Returns:
      the actual capacity chosen

    • rehash

      protected void rehash(int newCapacity)
      Rehashes the set.
      Specified by:
      rehash in class THash
      Parameters:
      newCapacity - an int value

    • getNoEntryKey

      public byte getNoEntryKey()
      Returns the value that represents null in the TByteObjectMap.keySet(). The default value is generally zero, but can be configured during construction of the collection.
      Specified by:
      getNoEntryKey in interface TByteObjectMap<V>
      Returns:
      the value that represents a null value in this collection.

    • containsKey

      public boolean containsKey(byte key)
      Returns true if this map contains a mapping for the specified key. More formally, returns true if and only if this map contains a mapping for a key k such that key.equals(k). (There can be at most one such mapping.)
      Specified by:
      containsKey in interface TByteObjectMap<V>
      Parameters:
      key - key whose presence in this map is to be tested
      Returns:
      true if this map contains a mapping for the specified key

    • containsValue

      public boolean containsValue(Object val)
      Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that (value==null ? v==null : value.equals(v)). This operation will probably require time linear in the map size for most implementations of the Map interface.
      Specified by:
      containsValue in interface TByteObjectMap<V>
      Parameters:
      val - value whose presence in this map is to be tested
      Returns:
      true if this map maps one or more keys to the specified value

    • get

      public V get(byte key)
      Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

      More formally, if this map contains a mapping from a key k to a value v such that (key==null ? k==null : key.equals(k)), then this method returns v; otherwise it returns null. (There can be at most one such mapping.)

      If this map permits null values, then a return value of null does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to null. The containsKey operation may be used to distinguish these two cases.

      Specified by:
      get in interface TByteObjectMap<V>
      Parameters:
      key - the key whose associated value is to be returned
      Returns:
      the byte value to which the specified key is mapped, or null if this map contains no mapping for the key

    • put

      public V put(byte key, V value)
      Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)
      Specified by:
      put in interface TByteObjectMap<V>
      Parameters:
      key - key with which the specified value is to be associated
      value - an byte value value to be associated with the specified key
      Returns:
      the previous value associated with key, or no_entry_value if there was no mapping for key. (A no_entry_value return can also indicate that the map previously associated null with key, if the implementation supports null values.)
      See Also:

    • putIfAbsent

      public V putIfAbsent(byte key, V value)
      Inserts a key/value pair into the map if the specified key is not already associated with a value.
      Specified by:
      putIfAbsent in interface TByteObjectMap<V>
      Parameters:
      key - key with which the specified value is to be associated
      value - an byte value to be associated with the specified key
      Returns:
      the previous value associated with key, or null if none was found.

    • remove

      public V remove(byte key)
      Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key k to value v such that key.equals(k), that mapping is removed. (The map can contain at most one such mapping.)

      Returns the value to which this map previously associated the key, or null if the map contained no mapping for the key.

      If this map permits null values, then a return value of null does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to null.

      The map will not contain a mapping for the specified key once the call returns.

      Specified by:
      remove in interface TByteObjectMap<V>
      Parameters:
      key - key whose mapping is to be removed from the map
      Returns:
      the previous byte value associated with key, or null if there was no mapping for key.

    • removeAt

      protected void removeAt(int index)
      Releases the element currently stored at index.
      Overrides:
      removeAt in class TByteHash
      Parameters:
      index - an int value

    • putAll

      public void putAll(Map<? extends Byte,? extends V> map)
      Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress.
      Specified by:
      putAll in interface TByteObjectMap<V>
      Parameters:
      map - mappings to be stored in this map

    • putAll

      public void putAll(TByteObjectMap<? extends V> map)
      Put all the entries from the given map into this map.
      Specified by:
      putAll in interface TByteObjectMap<V>
      Parameters:
      map - The map from which entries will be obtained to put into this map.

    • clear

      public void clear()
      Empties the collection.
      Specified by:
      clear in interface TByteObjectMap<V>
      Overrides:
      clear in class THash

    • keySet

      public TByteSet keySet()
      Returns a TByteSet view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.
      Specified by:
      keySet in interface TByteObjectMap<V>
      Returns:
      a set view of the keys contained in this map

    • keys

      public byte[] keys()
      Returns a copy of the keys of the map as an array. Changes to the array of keys will not be reflected in the map nor vice-versa.
      Specified by:
      keys in interface TByteObjectMap<V>
      Returns:
      a copy of the keys of the map as an array.

    • keys

      public byte[] keys(byte[] dest)
      Returns a copy of the keys of the map as an array. Changes to the array of keys will not be reflected in the map nor vice-versa.
      Specified by:
      keys in interface TByteObjectMap<V>
      Parameters:
      dest - the array into which the elements of the list are to be stored, if it is big enough; otherwise, a new array of the same type is allocated for this purpose.
      Returns:
      the keys of the map as an array.

    • valueCollection

      public Collection<V> valueCollection()
      Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.
      Specified by:
      valueCollection in interface TByteObjectMap<V>
      Returns:
      a collection view of the values contained in this map

    • values

      public Object[] values()
      Returns the values of the map as an Object array. Note that the array returned is typed as an Object[] and may not be cast to a more specific type. See TByteObjectMap.values(Object[]) for a version which allows specifically typed arrays. Changes to the array of values will not be reflected in the map nor vice-versa.
      Specified by:
      values in interface TByteObjectMap<V>
      Returns:
      the values of the map as an array of byte values.

    • values

      public V[] values(V[] dest)
      Returns the values of the map using an existing array. Changes to the array of values will not be reflected in the map nor vice-versa.
      Specified by:
      values in interface TByteObjectMap<V>
      Parameters:
      dest - the array into which the elements of the list are to be stored, if it is big enough; otherwise, a new array of the same type is allocated for this purpose.
      Returns:
      the values of the map as an array of byte values.

    • iterator

      public TByteObjectIterator<V> iterator()
      Returns a TByteObjectIterator with access to this map's keys and values.
      Specified by:
      iterator in interface TByteObjectMap<V>
      Returns:
      a TByteObjectIterator with access to this map's keys and values.

    • forEachKey

      public boolean forEachKey(TByteProcedure procedure)
      Executes procedure for each key in the map.
      Specified by:
      forEachKey in interface TByteObjectMap<V>
      Parameters:
      procedure - a TObjectProcedure value
      Returns:
      false if the loop over the keys terminated because the procedure returned false for some key.

    • forEachValue

      public boolean forEachValue(TObjectProcedure<? super V> procedure)
      Executes procedure for each value in the map.
      Specified by:
      forEachValue in interface TByteObjectMap<V>
      Parameters:
      procedure - a TObjectProcedure value
      Returns:
      false if the loop over the values terminated because the procedure returned false for some value.

    • forEachEntry

      public boolean forEachEntry(TByteObjectProcedure<? super V> procedure)
      Executes procedure for each key/value entry in the map.
      Specified by:
      forEachEntry in interface TByteObjectMap<V>
      Parameters:
      procedure - a TByteObjectProcedure value
      Returns:
      false if the loop over the entries terminated because the procedure returned false for some entry.

    • retainEntries

      public boolean retainEntries(TByteObjectProcedure<? super V> procedure)
      Retains only those entries in the map for which the procedure returns a true value.
      Specified by:
      retainEntries in interface TByteObjectMap<V>
      Parameters:
      procedure - determines which entries to keep
      Returns:
      true if the map was modified.

    • transformValues

      public void transformValues(TObjectFunction<V,V> function)
      Transform the values in this map using function.
      Specified by:
      transformValues in interface TByteObjectMap<V>
      Parameters:
      function - a TObjectFunction value

    • equals

      public boolean equals(Object other)
      Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings. More formally, two maps m1 and m2 represent the same mappings if m1.entrySet().equals(m2.entrySet()). This ensures that the equals method works properly across different implementations of the Map interface.
      Specified by:
      equals in interface TByteObjectMap<V>
      Overrides:
      equals in class Object
      Parameters:
      other - object to be compared for equality with this map
      Returns:
      true if the specified object is equal to this map

    • hashCode

      public int hashCode()
      Returns the hash code value for this map. The hash code of a map is defined to be the sum of the hash codes of each entry in the map's entrySet() view. This ensures that m1.equals(m2) implies that m1.hashCode()==m2.hashCode() for any two maps m1 and m2, as required by the general contract of Object.hashCode().
      Specified by:
      hashCode in interface TByteObjectMap<V>
      Overrides:
      hashCode in class Object
      Returns:
      the hash code value for this map
      See Also:

    • writeExternal

      public void writeExternal(ObjectOutput out) throws IOException
      Specified by:
      writeExternal in interface Externalizable
      Overrides:
      writeExternal in class THash
      Throws:
      IOException

    • readExternal

      public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
      Specified by:
      readExternal in interface Externalizable
      Overrides:
      readExternal in class THash
      Throws:
      IOException
      ClassNotFoundException

    • toString

      public String toString()
      Overrides:
      toString in class Object