Package com.tangosol.util

Class BinaryRadixTree

  • All Implemented Interfaces:
    BinaryLongMap
    public class BinaryRadixTree
extends Object
implements BinaryLongMap
    A BinaryRadixTree is a memory-optimized radix tree (aka a Patricia trie) that is intended to efficiently store a mapping from Binary values to long values. The BinaryRadixTree is not thread safe; to make it safe in a multi-threaded scenario, access must be synchronized and the Iterators returned from the BinaryRadixTree can only be used within the scope of synchronization within which they were obtained.
    Since:
    Coherence 3.7
    Author:
    cp 2010-06-06

    • Constructor Detail

      • BinaryRadixTree

        public BinaryRadixTree()
        Construct an empty BinaryRadixTree.

    • Method Detail

      • get

        public long get​(Binary binKey)
        Find the specified key in the map and return the value associated with it.
        Specified by:
        get in interface BinaryLongMap
        Parameters:
        binKey - a Binary key
        Returns:
        the value associated with the specified key, or 0L if the specified key is not in the map

      • put

        public void put​(Binary binKey,
                long lValue)
        Blindly store the passed value for the specified key, adding the key if it is not already in the map, or replacing the current value if the key is in the map.

        Note that associating the value zero with a key is analogous to removing the key.

        Specified by:
        put in interface BinaryLongMap
        Parameters:
        binKey - the Binary key to add or update
        lValue - the value to associate with the key

      • putIfAbsent

        public boolean putIfAbsent​(Binary binKey,
                           long lValue)
        Store the passed value for the specified key, only if the key does not currently exist in the map.

        Note that associating the value zero with a key using this method will have no effect, since were that key already present, there would be no change, and were it not present, the value zero is analogous to removing the key, which again is no change (since it is not present).

        Specified by:
        putIfAbsent in interface BinaryLongMap
        Parameters:
        binKey - a Binary key
        lValue - the new value to associate with the passed key
        Returns:
        true iff the key was not present in the map, and now it is present in the map associated with the passed value

      • replace

        public boolean replace​(Binary binKey,
                       long lValueOld,
                       long lValueNew)
        Store the passed "new" value for the specified key, only if the current value associated with the specified key is the same as the specified "old" value.

        Note that replacing the value of zero is analogous to putIfAbsent, and associating the value zero with a key using this method is the same as remove passing the old value to match.

        Specified by:
        replace in interface BinaryLongMap
        Parameters:
        binKey - a Binary key
        lValueOld - the assumed old value to replace
        lValueNew - the new value to associate with the passed key
        Returns:
        true iff the key was associated with the passed "old" value, and now it is associated with the passed "new" value

      • remove

        public void remove​(Binary binKey)
        Blindly remove the specified Binary key from the map.
        Specified by:
        remove in interface BinaryLongMap
        Parameters:
        binKey - a Binary key

      • remove

        public boolean remove​(Binary binKey,
                      long lValue)
        Remove the specified Binary key from the map iff it exists in the map and is associated with the specified value.

        Note that removing an association whose value is zero has no effect.

        Specified by:
        remove in interface BinaryLongMap
        Parameters:
        binKey - a Binary key
        lValue - the value that the key must have in order to be removed
        Returns:
        true iff the map contained the key, it was associated with the specified value, and has now been removed

      • clear

        public void clear()
        Initialize the map to an empty state.
        Specified by:
        clear in interface BinaryLongMap

      • size

        public int size()
        Determine the size of the map.
        Specified by:
        size in interface BinaryLongMap
        Returns:
        the number of unique keys stored in the map

      • keys

        public Iterator<Binary> keys()
        Obtain an iterator of the keys stored in the map.
        Specified by:
        keys in interface BinaryLongMap
        Returns:
        an Iterator of Binary keys

      • visit

        public void visit​(Binary binKey,
                  BinaryLongMap.EntryVisitor visitor)
        Apply the specified visitor to the entry associated with the specified key, if the entry exists or may be added. The visited entry may or may not logically exist in the BinaryLongMap (e.g. it may be associated with a value of 0L) but is guaranteed to be safe to be added or removed (via BinaryLongMap.Entry.setValue(long)).
        Specified by:
        visit in interface BinaryLongMap
        Parameters:
        binKey - the key to visit
        visitor - the visitor to apply

      • internKeys

        public void internKeys​(Object o)
        Internal opaque method: De-duplicate keys.

        To reduce memory footprint, the tree supports de-duplication of byte[] values used internally by the tree. To execute the de-duping process, create an empty byte[][] of a prime size, and pass it to the internKeys() method of each available BinaryRadixTree.

        Do not pre-populate the byte[][] or modify any of its contents.

        Note: This method does not require external synchronization.

        Specified by:
        internKeys in interface BinaryLongMap
        Parameters:
        o - an opaque byte[][] used to accumulate "intern()" byte[] values

      • sizeof

        protected long sizeof()
        Return the number of bytes retained by this BinaryLongMap.
        Returns:
        the number of bytes retained by this BinaryLongMap