Package com.macrofocus.utils

Class IndexedTreeMap<K,V>

java.lang.Object
com.macrofocus.utils.AbstractMap<K,V>
com.macrofocus.utils.IndexedTreeMap<K,V>
Type Parameters:
K - the type of keys maintained by this map
V - the type of mapped values
All Implemented Interfaces:
IndexedNavigableMap<K,V>, Cloneable, Map<K,V>, NavigableMap<K,V>, SequencedMap<K,V>, SortedMap<K,V>
public class IndexedTreeMap<K,V> extends AbstractMap<K,V> implements IndexedNavigableMap<K,V>, Cloneable
A Red-Black tree based NavigableMap implementation. The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time, depending on which constructor is used.

This implementation provides guaranteed log(n) time cost for the containsKey, get, put and remove operations. Algorithms are adaptations of those in Cormen, Leiserson, and Rivest's Introduction to Algorithms.

Note that the ordering maintained by a sorted map (whether or not an explicit comparator is provided) must be consistent with equals if this sorted map is to correctly implement the Map interface. (See Comparable or Comparator for a precise definition of consistent with equals.) This is so because the Map interface is defined in terms of the equals operation, but a map performs all key comparisons using its compareTo (or compare) method, so two keys that are deemed equal by this method are, from the standpoint of the sorted map, equal. The behavior of a sorted map is well-defined even if its ordering is inconsistent with equals; it just fails to obey the general contract of the Map interface.

Note that this implementation is not synchronized. If multiple threads access a map concurrently, and at least one of the threads modifies the map structurally, it must be synchronized externally. (A structural modification is any operation that adds or deletes one or more mappings; merely changing the value associated with an existing key is not a structural modification.) This is typically accomplished by synchronizing on some object that naturally encapsulates the map. If no such object exists, the map should be "wrapped" using the Collections.synchronizedSortedMap method. This is best done at creation time, to prevent accidental unsynchronized access to the map: 

   SortedMap m = Collections.synchronizedSortedMap(new IndexedTreeMap(...));

The iterators returned by the iterator method of the collections returned by all of this class's "collection view methods" are fail-fast: if the map is structurally modified at any time after the iterator is created, in any way except through the iterator's own remove method, the iterator will throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future.

Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.

All Map.Entry pairs returned by methods in this class and its views represent snapshots of mappings at the time they were produced. They do not support the Entry.setValue method. (Note however that it is possible to change mappings in the associated map using put.)

This class is a member of the Java Collections Framework.

Since:
1.2
See Also:

  • Constructor Details

    • IndexedTreeMap

      public IndexedTreeMap()
      Constructs a new, empty tree map, using the natural ordering of its keys. All keys inserted into the map must implement the Comparable interface. Furthermore, all such keys must be mutually comparable: k1.compareTo(k2) must not throw a ClassCastException for any keys k1 and k2 in the map. If the user attempts to put a key into the map that violates this constraint (for example, the user attempts to put a string key into a map whose keys are integers), the put(Object key, Object value) call will throw a ClassCastException.

    • IndexedTreeMap

      public IndexedTreeMap(Comparator<? super K> comparator)
      Constructs a new, empty tree map, ordered according to the given comparator. All keys inserted into the map must be mutually comparable by the given comparator: comparator.compare(k1, k2) must not throw a ClassCastException for any keys k1 and k2 in the map. If the user attempts to put a key into the map that violates this constraint, the put(Object key, Object value) call will throw a ClassCastException.
      Parameters:
      comparator - the comparator that will be used to order this map. If null, the natural ordering of the keys will be used.

  • Method Details

    • size

      public int size()
      Returns the number of key-value mappings in this map.
      Specified by:
      size in interface Map<K,V>
      Overrides:
      size in class AbstractMap<K,V>
      Returns:
      the number of key-value mappings in this map

    • containsKey

      public boolean containsKey(Object key)
      Returns true if this map contains a mapping for the specified key.
      Specified by:
      containsKey in interface Map<K,V>
      Overrides:
      containsKey in class AbstractMap<K,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
      Throws:
      ClassCastException - if the specified key cannot be compared with the keys currently in the map
      NullPointerException - if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys

    • containsValue

      public boolean containsValue(Object value)
      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.
      Specified by:
      containsValue in interface Map<K,V>
      Overrides:
      containsValue in class AbstractMap<K,V>
      Parameters:
      value - value whose presence in this map is to be tested
      Returns:
      true if a mapping to value exists; false otherwise
      Since:
      1.2

    • get

      public V get(Object 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 compares equal to k according to the map's ordering, then this method returns v; otherwise it returns null. (There can be at most one such mapping.)

      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 Map<K,V>
      Overrides:
      get in class AbstractMap<K,V>
      Throws:
      ClassCastException - if the specified key cannot be compared with the keys currently in the map
      NullPointerException - if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys

    • comparator

      public Comparator<? super K> comparator()
      Specified by:
      comparator in interface SortedMap<K,V>

    • firstKey

      public K firstKey()
      Specified by:
      firstKey in interface SortedMap<K,V>

    • lastKey

      public K lastKey()
      Specified by:
      lastKey in interface SortedMap<K,V>

    • putAll

      public void putAll(Map<? extends K,? extends V> map)
      Copies all of the mappings from the specified map to this map. These mappings replace any mappings that this map had for any of the keys currently in the specified map.
      Specified by:
      putAll in interface Map<K,V>
      Overrides:
      putAll in class AbstractMap<K,V>
      Parameters:
      map - mappings to be stored in this map
      Throws:
      ClassCastException - if the class of a key or value in the specified map prevents it from being stored in this map
      NullPointerException - if the specified map is null or the specified map contains a null key and this map does not permit null keys

    • debug

      public void debug() throws Exception
      Throws:
      Exception

    • dbg

      public void dbg()

    • put

      public V put(K key, V value)
      Associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the old value is replaced.
      Specified by:
      put in interface Map<K,V>
      Overrides:
      put in class AbstractMap<K,V>
      Parameters:
      key - key with which the specified value is to be associated
      value - value to be associated with the specified key
      Returns:
      the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key.)
      Throws:
      ClassCastException - if the specified key cannot be compared with the keys currently in the map
      NullPointerException - if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys

    • remove

      public V remove(Object key)
      Removes the mapping for this key from this IndexedTreeMap if present.
      Specified by:
      remove in interface Map<K,V>
      Overrides:
      remove in class AbstractMap<K,V>
      Parameters:
      key - key for which mapping should be removed
      Returns:
      the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key.)
      Throws:
      ClassCastException - if the specified key cannot be compared with the keys currently in the map
      NullPointerException - if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys

    • clear

      public void clear()
      Removes all of the mappings from this map. The map will be empty after this call returns.
      Specified by:
      clear in interface Map<K,V>
      Overrides:
      clear in class AbstractMap<K,V>

    • firstEntry

      public Map.Entry<K,V> firstEntry()
      Specified by:
      firstEntry in interface NavigableMap<K,V>
      Specified by:
      firstEntry in interface SequencedMap<K,V>
      Since:
      1.6

    • lastEntry

      public Map.Entry<K,V> lastEntry()
      Specified by:
      lastEntry in interface NavigableMap<K,V>
      Specified by:
      lastEntry in interface SequencedMap<K,V>
      Since:
      1.6

    • pollFirstEntry

      public Map.Entry<K,V> pollFirstEntry()
      Specified by:
      pollFirstEntry in interface NavigableMap<K,V>
      Specified by:
      pollFirstEntry in interface SequencedMap<K,V>
      Since:
      1.6

    • pollLastEntry

      public Map.Entry<K,V> pollLastEntry()
      Specified by:
      pollLastEntry in interface NavigableMap<K,V>
      Specified by:
      pollLastEntry in interface SequencedMap<K,V>
      Since:
      1.6

    • lowerEntry

      public Map.Entry<K,V> lowerEntry(K key)
      Specified by:
      lowerEntry in interface NavigableMap<K,V>
      Since:
      1.6

    • lowerKey

      public K lowerKey(K key)
      Specified by:
      lowerKey in interface NavigableMap<K,V>
      Since:
      1.6

    • floorEntry

      public Map.Entry<K,V> floorEntry(K key)
      Specified by:
      floorEntry in interface NavigableMap<K,V>
      Since:
      1.6

    • floorKey

      public K floorKey(K key)
      Specified by:
      floorKey in interface NavigableMap<K,V>
      Since:
      1.6

    • ceilingEntry

      public Map.Entry<K,V> ceilingEntry(K key)
      Specified by:
      ceilingEntry in interface NavigableMap<K,V>
      Since:
      1.6

    • ceilingKey

      public K ceilingKey(K key)
      Specified by:
      ceilingKey in interface NavigableMap<K,V>
      Since:
      1.6

    • higherEntry

      public Map.Entry<K,V> higherEntry(K key)
      Specified by:
      higherEntry in interface NavigableMap<K,V>
      Since:
      1.6

    • higherKey

      public K higherKey(K key)
      Specified by:
      higherKey in interface NavigableMap<K,V>
      Since:
      1.6

    • exactKey

      public K exactKey(int index)
      Description copied from interface: IndexedNavigableMap
      Returns the key located at the index offset from the beginning of the sorted map
      Specified by:
      exactKey in interface IndexedNavigableMap<K,V>
      Parameters:
      index - index of the key
      Returns:
      the key key located at the index (@code index) offset from the beginning of the sorted map

    • keyIndex

      public int keyIndex(K key)
      Description copied from interface: IndexedNavigableMap
      Searches the specified tree map for the specified key using the put algorithm. Calculates its offset from the beginning of the sorted map using weights.
      Specified by:
      keyIndex in interface IndexedNavigableMap<K,V>
      Parameters:
      key - the key
      Returns:
      index of the search key, if it is contained in the tree map; otherwise a NullPointerException is thrown

    • exactEntry

      public com.macrofocus.utils.IndexedTreeMap.Entry<K,V> exactEntry(int index)
      Description copied from interface: IndexedNavigableMap
      Returns a key-value mapping associated with the key located at the index offset from the beginning of the sorted map
      Specified by:
      exactEntry in interface IndexedNavigableMap<K,V>
      Parameters:
      index - index of the key
      Returns:
      the entry with the key key located at the index (@code index) offset from the beginning of the sorted map

    • keySet

      public Set<K> keySet()
      Returns a Set view of the keys contained in this map. The set's iterator returns the keys in ascending order. 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 Map<K,V>
      Specified by:
      keySet in interface SortedMap<K,V>
      Overrides:
      keySet in class AbstractMap<K,V>

    • descendingKeySet

      public NavigableSet<K> descendingKeySet()
      Specified by:
      descendingKeySet in interface NavigableMap<K,V>
      Since:
      1.6

    • values

      public Collection<V> values()
      Returns a Collection view of the values contained in this map. The collection's iterator returns the values in ascending order of the corresponding keys. 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:
      values in interface Map<K,V>
      Specified by:
      values in interface SortedMap<K,V>
      Overrides:
      values in class AbstractMap<K,V>

    • entrySet

      public Set<Map.Entry<K,V>> entrySet()
      Returns a Set view of the mappings contained in this map. The set's iterator returns the entries in ascending key order. 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, or through the setValue operation on a map entry returned by the iterator) 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:
      entrySet in interface Map<K,V>
      Specified by:
      entrySet in interface SortedMap<K,V>
      Specified by:
      entrySet in class AbstractMap<K,V>

    • descendingMap

      public NavigableMap<K,V> descendingMap()
      Specified by:
      descendingMap in interface NavigableMap<K,V>
      Since:
      1.6

    • subMap

      public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)
      Specified by:
      subMap in interface NavigableMap<K,V>
      Since:
      1.6

    • headMap

      public NavigableMap<K,V> headMap(K toKey, boolean inclusive)
      Specified by:
      headMap in interface NavigableMap<K,V>
      Since:
      1.6

    • tailMap

      public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive)
      Specified by:
      tailMap in interface NavigableMap<K,V>
      Since:
      1.6

    • subMap

      public SortedMap<K,V> subMap(K fromKey, K toKey)
      Specified by:
      subMap in interface NavigableMap<K,V>
      Specified by:
      subMap in interface SortedMap<K,V>

    • headMap

      public SortedMap<K,V> headMap(K toKey)
      Specified by:
      headMap in interface NavigableMap<K,V>
      Specified by:
      headMap in interface SortedMap<K,V>

    • tailMap

      public SortedMap<K,V> tailMap(K fromKey)
      Specified by:
      tailMap in interface NavigableMap<K,V>
      Specified by:
      tailMap in interface SortedMap<K,V>