Package org.magicwerk.brownies.collections.primitive

Class ShortBigList

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, IShortListable
    Direct Known Subclasses:
    ShortBigList.ReadOnlyShortBigList
    public class ShortBigList
extends IShortList
    ShortBigList is a list optimized for storing large number of elements. It stores the elements in fixed size blocks and the blocks itself are maintained in a tree for fast access. It also offers specialized methods for bulk processing of elements. Also copying a ShortBigList is efficiently possible as its implemented using a copy-on-write approach.

    Note that this implementation is not synchronized. Due to data caching used for exploiting locality of reference, performance can decrease if ShortBigList is accessed by several threads at different positions.

    Note that the iterators provided are not fail-fast.

    See Also:
    Serialized Form

    • Field Detail

      • serialVersionUID

        private static final long serialVersionUID
        UID for serialization
        See Also:
        Constant Field Values

      • DEFAULT_BLOCK_SIZE

        private static final int DEFAULT_BLOCK_SIZE
        Default block size
        See Also:
        Constant Field Values

      • MERGE_THRESHOLD

        private static final float MERGE_THRESHOLD
        If two adjacent blocks both less than MERGE_THRESHOLD*blockSize elements, they are merged
        See Also:
        Constant Field Values

      • FILL_THRESHOLD

        private static final float FILL_THRESHOLD
        If an element is added to the list at the head or tail, the block is only filled until it has FILL_THRESHOLD*blockSize elements (so there is room for insertion without need to split).
        See Also:
        Constant Field Values

      • CHECK

        private static final boolean CHECK
        Set to true for debugging during developing
        See Also:
        Constant Field Values

      • EMPTY

        private static final ShortBigList EMPTY
        Unmodifiable empty instance

      • blockSize

        private int blockSize
        Number of elements stored at maximum in a block

      • size

        private int size
        Number of elements stored in this ShortBigList

      • currShortBlockStart

        private int currShortBlockStart
        Start index of current block

      • currShortBlockEnd

        private int currShortBlockEnd
        End index of current block

      • currModify

        private int currModify
        Modify value which must be applied before this block is not current any more

    • Constructor Detail

      • ShortBigList

        protected ShortBigList​(boolean copy,
                       ShortBigList that)
        Constructor used internally, e.g. for ImmutableShortBigList.
        Parameters:
        copy - true to copy all instance values from source, if false nothing is done
        that - list to copy

      • ShortBigList

        public ShortBigList()
        Default constructor. The default block size is used.

      • ShortBigList

        public ShortBigList​(int blockSize)
        Constructor.
        Parameters:
        blockSize - block size

      • ShortBigList

        public ShortBigList​(java.util.Collection<java.lang.Short> coll)
        Create new list with specified elements.
        Parameters:
        coll - collection with element

      • ShortBigList

        private ShortBigList​(int blockSize,
                     int firstShortBlockSize)
        Internal constructor.
        Parameters:
        blockSize - default block size
        firstShortBlockSize - block size of first block

    • Method Detail

      • EMPTY

        public static ShortBigList EMPTY()
        Returns:
        unmodifiable empty instance

      • create

        public static ShortBigList create​(java.util.Collection<java.lang.Short> coll)
        Create new list with specified elements.
        Parameters:
        coll - collection with element
        type - of elements stored in the list
        Returns:
        created list

      • create

        public static ShortBigList create​(short... elems)
        Create new list with specified elements.
        Parameters:
        elems - array with elements
        type - of elements stored in the list
        Returns:
        created list

      • blockSize

        public int blockSize()
        Returns block size used for this ShortBigList.
        Returns:
        block size used for this ShortBigList

      • doInit

        private void doInit​(int blockSize,
                    int firstShortBlockSize)
        Initialize ShortBigList.
        Parameters:
        blockSize - default block size
        firstShortBlockSize - block size of first block

      • crop

        public ShortBigList crop()
        Description copied from class: IShortList
        Returns a copy this list but without elements. The new list will have the same type as this list.
        Overrides:
        crop in class IShortList
        Returns:
        an empty copy of this list

      • isReadOnly

        public boolean isReadOnly()
        Description copied from class: IShortList
        Returns true if this list is either unmodifiable or immutable, false otherwise.
        Specified by:
        isReadOnly in class IShortList

      • copy

        public ShortBigList copy()
        Returns a shallow copy of this list. The new list will contain the same elements as the source list, i.e. the elements themselves are not copied. The capacity of the list will be set to the number of elements, i.e. size and capacity are equal. This returned list will be modifiable, i.e. a read-only list will be copied and be modifiable again.

        The copy is realized by a copy-on-write approach so also really large lists can efficiently be handled.

        Specified by:
        copy in class IShortList
        Returns:
        a modifiable copy of this list

      • clone

        public ShortBigList clone()
        Returns a shallow copy of this list. The new list will contain the same elements as the source list, i.e. the elements themselves are not copied. The capacity of the list will be set to the number of elements, i.e. size and capacity are equal. If the list is read-only, the same list is returned without change. Use IShortList.copy() to .

        The copy is realized by a copy-on-write approach so also really large lists can efficiently be handled.

        Overrides:
        clone in class IShortList
        Returns:
        a modifiable copy of this list

      • doAssign

        protected void doAssign​(IShortList that)
        Description copied from class: IShortList
        Assign this list the content of the that list. This is done by bitwise copying so the that list should not be used afterwards.
        Specified by:
        doAssign in class IShortList
        Parameters:
        that - list to copy content from

      • doClone

        protected void doClone​(IShortList that)
        Description copied from class: IShortList
        Initialize this object after the bitwise copy has been made by Object.clone().
        Specified by:
        doClone in class IShortList
        Parameters:
        that - source object

      • finalize

        protected void finalize()
        Overrides:
        finalize in class java.lang.Object

      • capacity

        public int capacity()
        As ShortBigList grows and shrinks automatically, the term capacity does not really make sense. Therefore always -1 is returned.
        Specified by:
        capacity in class IShortList
        Returns:
        capacity of this list

      • doGet

        protected short doGet​(int index)
        Description copied from class: IShortList
        Helper method for getting an element from the list. This is the only method which really gets an element. Override if you need to validity checks before getting.
        Specified by:
        doGet in class IShortList
        Parameters:
        index - index of element to return
        Returns:
        the element at the specified position in this list

      • doSet

        protected short doSet​(int index,
                      short elem)
        Description copied from class: IShortList
        Helper method for setting an element in the list. This is the only method which really sets an element. Override if you need to validity checks before setting.
        Specified by:
        doSet in class IShortList
        Parameters:
        index - index where element will be placed
        elem - element to set
        Returns:
        old element which was at the position

      • doReSet

        protected short doReSet​(int index,
                        short elem)
        Description copied from class: IShortList
        Sets an element at specified position. This method is used internally if existing elements will be moved etc. Override if you need to validity checks.
        Specified by:
        doReSet in class IShortList
        Parameters:
        index - index where element will be placed
        elem - element to set
        Returns:
        old element which was at the position

      • releaseShortBlock

        private void releaseShortBlock()
        Release current block and apply modification if pending.

      • getShortBlockIndex

        private int getShortBlockIndex​(int index,
                               boolean write,
                               int modify)
        Returns index in block where the element with specified index is located. This method also sets currShortBlock to remember this last used block.
        Parameters:
        index - list index (0 <= index <= size())
        write - true if the block is needed for a write operation (set, add, remove)
        modify - modify instruction (N>0: N elements are added, N<0: N elements are removed, 0 no change)
        Returns:
        relative index within block

      • getShortBlockIndex2

        private int getShortBlockIndex2​(int index,
                                boolean write,
                                int modify)

      • isOnlyRootShortBlock

        private boolean isOnlyRootShortBlock()
        Returns:
        true if there is only the root block, false otherwise

      • doGetShortBlock

        private void doGetShortBlock​(int index,
                             int modify)
        Determine node/block for the specified index. The fields currNode, currShortBlockStart, and currShortBlockEnd are set. During the traversing the tree node, the nodes relative positions are changed according to the modify instruction.
        Parameters:
        index - list index for which block must be determined
        modify - modify instruction (N>0: N elements are added, N<0: N elements are removed, 0 no change)

      • addShortBlock

        private void addShortBlock​(int index,
                           ShortBigList.ShortBlock obj)
        Adds a new element to the list.
        Parameters:
        index - the index to add before
        obj - the element to add

      • doAdd

        protected boolean doAdd​(int index,
                        short element)
        Description copied from class: IShortList
        Helper method for adding an element to the list. This is the only method which really adds an element. Override if you need to validity checks before adding.
        Specified by:
        doAdd in class IShortList
        Parameters:
        index - index where element should be added (-1 means it is up to the implementation to choose the index)
        element - element to add
        Returns:
        true if element has been added, false otherwise

      • doAddSplitShortBlock

        private void doAddSplitShortBlock​(int index,
                                  short element,
                                  int pos,
                                  ShortBigList.ShortBlock newShortBlock)

      • modify

        private void modify​(ShortBigList.ShortBlockNode node,
                    int modify)
        Modify relativePosition of all nodes starting from the specified node.
        Parameters:
        node - node whose position value must be changed
        modify - modify value (>0 for add, <0 for delete)

      • doAddAll

        protected boolean doAddAll​(int index,
                           IShortListable list)
        Description copied from class: IShortList
        Helper method for adding multiple elements to the list. This default implementation calls doAdd() for adding each element.
        Overrides:
        doAddAll in class IShortList
        Parameters:
        index - index where element should be added (-1 is valid for adding at the end)
        list - list with elements to add
        Returns:
        true if elements have been added, false otherwise

      • doAddAllTail

        private void doAddAllTail​(IShortListable list,
                          int addPos,
                          int addLen,
                          int space)

      • doAddAllHead

        private void doAddAllHead​(IShortListable list,
                          int addPos,
                          int addLen,
                          int space)

      • doAddAllMiddle

        private void doAddAllMiddle​(IShortListable list,
                            int addPos)

      • doRemoveAll

        protected void doRemoveAll​(int index,
                           int len)
        Description copied from class: IShortList
        Remove specified range of elements from list.
        Overrides:
        doRemoveAll in class IShortList
        Parameters:
        index - index of first element to remove
        len - number of elements to remove

      • merge

        private void merge​(ShortBigList.ShortBlockNode node)
        Merge the specified node with the left or right neighbor if possible.
        Parameters:
        node - candidate node for merge

      • doRemove

        protected short doRemove​(int index)
        Description copied from class: IShortList
        Helper method to remove an element. This is the only method which really removes an element. Override if you need to validity checks before removing.
        Specified by:
        doRemove in class IShortList
        Parameters:
        index - index of element to remove
        Returns:
        removed element

      • immutableList

        public ShortBigList immutableList()
        Description copied from class: IShortList
        Returns an immutable copy of this list. The returned list is independent from the original list, i.e. changes done later are not seen. Attempts to modify the returned list, whether direct or via its iterator, result in an UnsupportedOperationException. If this list is already immutable, it is returned unchanged. See IShortList.unmodifiableList() to get unmodifiable view of a list.
        Specified by:
        immutableList in class IShortList
        Returns:
        an immutable copy of the specified list

      • doEnsureCapacity

        protected void doEnsureCapacity​(int minCapacity)
        Description copied from class: IShortList
        Increases the capacity of this list instance, if necessary, to ensure that it can hold at least the number of elements specified by the minimum capacity argument.
        Specified by:
        doEnsureCapacity in class IShortList
        Parameters:
        minCapacity - the desired minimum capacity

      • trimToSize

        public void trimToSize()
        Pack as many elements in the blocks as allowed. An application can use this operation to minimize the storage of an instance.
        Specified by:
        trimToSize in class IShortList

      • doCreate

        protected IShortList doCreate​(int capacity)
        Description copied from class: IShortList
        Create list with specified capacity.
        Specified by:
        doCreate in class IShortList
        Parameters:
        capacity - initial capacity (use -1 for default capacity)
        Returns:
        created list

      • sort

        public void sort​(int index,
                 int len)
        Description copied from class: IShortList
        Sort specified elements in the list using the specified comparator.
        Specified by:
        sort in class IShortList
        Parameters:
        index - index of first element to sort
        len - number of elements to sort
        See Also:
        Arrays.sort(int[])

      • binarySearch

        public int binarySearch​(int index,
                        int len,
                        short key)
        Description copied from class: IShortList
        Searches the specified range for an object using the binary search algorithm.

        Note that the method is defined to work with an arbitrary type <K>. This allows to search directly for a key field in the object without the need to construct an object containing the key: 

        
  persons.binarySearch("john", new SearchByName());

  class SearchByName implements Comparator<Object> {
 	 public int compare(Object o1, Object o2) {
 	   String s1 = (o1 instanceof String) ? (String) o1 : ((Name) o1).getName();
 	   String s2 = (o2 instanceof String) ? (String) o2 : ((Name) o2).getName();
 	   return s1.compareTo(s2);
 	 }
  }
  /
        Specified by:
        binarySearch in class IShortList
        Parameters:
        index - index of first element to search
        len - number of elements to search
        key - the value to be searched for
        Returns:
        index of the search key, if it is contained in the array; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element greater than the key, or a.length if all elements in the array are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.
        See Also:
        Arrays.binarySearch(long[], long)

      • writeObject

        private void writeObject​(java.io.ObjectOutputStream oos)
                  throws java.io.IOException
        Serialize a ShortBigList object.
        Parameters:
        oos - output stream for serialization
        Throws:
        java.io.IOException - if serialization fails

      • readObject

        private void readObject​(java.io.ObjectInputStream ois)
                 throws java.io.IOException,
                        java.lang.ClassNotFoundException
        Deserialize a ShortBigList object.
        Parameters:
        ois - input stream for serialization
        Throws:
        java.io.IOException - if serialization fails
        java.lang.ClassNotFoundException - if serialization fails

      • check

        private void check()