Class BigList<E>

All Implemented Interfaces:
Serializable, Cloneable, Iterable<E>, Collection<E>, List<E>, RandomAccess, SequencedCollection<E>, ICollection<E>, IListable<E>
Direct Known Subclasses:
BigList.ReadOnlyBigList

public class BigList<E> extends IList<E>
BigList 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 BigList 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 BigList is accessed by several threads at different positions.

Note that the iterators provided are not fail-fast.

See Also:
  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      UID for serialization
      See Also:
    • DEFAULT_BLOCK_SIZE

      private static final int DEFAULT_BLOCK_SIZE
      Default block size
      See Also:
    • MERGE_THRESHOLD

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

      private static final boolean CHECK
      Set to true for debugging during developing
      See Also:
    • EMPTY

      private static final BigList 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 BigList
    • rootNode

      private BigList.BlockNode<E> rootNode
      The root node in the tree
    • currNode

      private BigList.BlockNode<E> currNode
      Current node
    • currBlockStart

      private int currBlockStart
      Start index of current block
    • currBlockEnd

      private int currBlockEnd
      End index of current block
    • currModify

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

    • BigList

      protected BigList(boolean copy, BigList<E> that)
      Constructor used internally, e.g. for ImmutableBigList.
      Parameters:
      copy - true to copy all instance values from source, if false nothing is done
      that - list to copy
    • BigList

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

      public BigList(int blockSize)
      Constructor.
      Parameters:
      blockSize - block size
    • BigList

      public BigList(Collection<? extends E> coll)
      Create new list with specified elements.
      Parameters:
      coll - collection with element
    • BigList

      private BigList(int blockSize, int firstBlockSize)
      Internal constructor.
      Parameters:
      blockSize - default block size
      firstBlockSize - block size of first block
  • Method Details

    • EMPTY

      public static <EE> BigList<EE> EMPTY()
      Returns:
      unmodifiable empty instance
    • create

      public static <E> BigList<E> create()
      Create new list.
      Type Parameters:
      E - type of elements stored in the list
      Returns:
      created list
    • create

      public static <E> BigList<E> create(Collection<? extends E> coll)
      Create new list with specified elements.
      Type Parameters:
      E - type of elements stored in the list
      Parameters:
      coll - collection with element
      Returns:
      created list
    • create

      public static <E> BigList<E> create(E... elems)
      Create new list with specified elements.
      Type Parameters:
      E - type of elements stored in the list
      Parameters:
      elems - array with elements
      Returns:
      created list
    • blockSize

      public int blockSize()
      Returns block size used for this BigList.
      Returns:
      block size used for this BigList
    • doInit

      private void doInit(int blockSize, int firstBlockSize)
      Initialize BigList.
      Parameters:
      blockSize - default block size
      firstBlockSize - block size of first block
    • crop

      public BigList<E> crop()
      Description copied from class: IList
      Returns a copy this list but without elements. The new list will have the same type as this list.
      Specified by:
      crop in interface ICollection<E>
      Overrides:
      crop in class IList<E>
      Returns:
      an empty copy of this list
    • isReadOnly

      public boolean isReadOnly()
      Description copied from class: IList
      Returns true if this list is either unmodifiable or immutable, false otherwise.
      Specified by:
      isReadOnly in class IList<E>
    • copy

      public BigList<E> 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 interface ICollection<E>
      Specified by:
      copy in class IList<E>
      Returns:
      a modifiable copy of this list
    • clone

      public BigList<E> 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 IList.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 IList<E>
      Returns:
      a modifiable copy of this list
    • doAssign

      protected void doAssign(IList<E> that)
      Description copied from class: IList
      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 IList<E>
      Parameters:
      that - list to copy content from
    • doClone

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

      private BigList.BlockNode<E> copy(BigList.BlockNode<E> node)
      Create a copy of the specified node.
      Parameters:
      node - source node
      Returns:
      newly created copy of source
    • getDefaultElem

      public E getDefaultElem()
      Specified by:
      getDefaultElem in class IList<E>
    • finalize

      protected void finalize()
      Overrides:
      finalize in class Object
    • spliterator

      public Spliterator<E> spliterator()
    • size

      public int size()
      Description copied from interface: IListable
      Return size of list
      Specified by:
      size in interface Collection<E>
      Specified by:
      size in interface IListable<E>
      Specified by:
      size in interface List<E>
      Specified by:
      size in class IList<E>
    • capacity

      public int capacity()
      As BigList grows and shrinks automatically, the term capacity does not really make sense. Therefore always -1 is returned.
      Specified by:
      capacity in class IList<E>
      Returns:
      capacity of this list
    • doGet

      protected E doGet(int index)
      Description copied from class: IList
      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 IList<E>
      Parameters:
      index - index of element to return
      Returns:
      the element at the specified position in this list
    • doSet

      protected E doSet(int index, E elem)
      Description copied from class: IList
      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 IList<E>
      Parameters:
      index - index where element will be placed
      elem - element to set
      Returns:
      old element which was at the position
    • doReSet

      protected E doReSet(int index, E elem)
      Description copied from class: IList
      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 IList<E>
      Parameters:
      index - index where element will be placed
      elem - element to set
      Returns:
      old element which was at the position
    • releaseBlock

      private void releaseBlock()
      Release current block and apply modification if pending.
    • getBlockIndex

      private int getBlockIndex(int index, boolean write, int modify)
      Returns index in block where the element with specified index is located. This method also sets currBlock to remember this last used block.
      Parameters:
      index - list index (0 invalid input: '<'= index invalid input: '<'= size())
      write - true if the block is needed for a write operation (set, add, remove)
      modify - modify instruction (N>0: N elements are added, Ninvalid input: '<'0: N elements are removed, 0 no change)
      Returns:
      relative index within block
    • getBlockIndex2

      private int getBlockIndex2(int index, boolean write, int modify)
    • isOnlyRootBlock

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

      private void doGetBlock(int index, int modify)
      Determine node/block for the specified index. The fields currNode, currBlockStart, and currBlockEnd 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, Ninvalid input: '<'0: N elements are removed, 0 no change)
    • doGetBlockLeft

      private boolean doGetBlockLeft(int modify, BigList.BlockNode<E> nextNode, boolean wasLeft)
    • doGetBlockRight

      private boolean doGetBlockRight(int modify, BigList.BlockNode<E> nextNode, boolean wasLeft)
    • addBlock

      private void addBlock(int index, BigList.Block<E> 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, E element)
      Description copied from class: IList
      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 IList<E>
      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
    • doAddSplitBlock

      private void doAddSplitBlock(int index, E element, int pos, BigList.Block<E> newBlock)
    • modify

      private void modify(BigList.BlockNode<E> 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, invalid input: '<'0 for delete)
    • modifyLeftNode

      private void modifyLeftNode(BigList.BlockNode<E> node, int modify)
    • modifyRightNode

      private void modifyRightNode(BigList.BlockNode<E> node, int modify)
    • doRemove

      private BigList.BlockNode<E> doRemove(BigList.BlockNode<E> node)
    • doAddAll

      protected boolean doAddAll(int index, IListable<? extends E> list)
      Description copied from class: IList
      Helper method for adding multiple elements to the list. This default implementation calls doAdd() for adding each element.
      Overrides:
      doAddAll in class IList<E>
      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(IListable<? extends E> list, int addPos, int addLen, int space)
    • doAddAllHead

      private void doAddAllHead(IListable<? extends E> list, int addPos, int addLen, int space)
    • doAddAllMiddle

      private void doAddAllMiddle(IListable<? extends E> list, int addPos)
    • doClear

      protected void doClear()
      Overrides:
      doClear in class IList<E>
    • doRemoveAll

      protected void doRemoveAll(int index, int len)
      Description copied from class: IList
      Remove specified range of elements from list.
      Overrides:
      doRemoveAll in class IList<E>
      Parameters:
      index - index of first element to remove
      len - number of elements to remove
    • doRemoveAll2

      private void doRemoveAll2(int index, int len, int startPos, BigList.BlockNode<E> startNode, BigList.BlockNode<E> endNode)
    • merge

      private void merge(BigList.BlockNode<E> node)
      Merge the specified node with the left or right neighbor if possible.
      Parameters:
      node - candidate node for merge
    • doRemove

      protected E doRemove(int index)
      Description copied from class: IList
      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 IList<E>
      Parameters:
      index - index of element to remove
      Returns:
      removed element
    • unmodifiableList

      public BigList<E> unmodifiableList()
      Description copied from class: IList
      Returns an unmodifiable view of this list. This method allows modules to provide users with "read-only" access to internal lists, where changes made to the original list are visible as query operations on the returned list "read through" to the specified list. Attempts to modify the returned list, whether direct or via its iterator, result in an UnsupportedOperationException. If this list is already unmodifiable, it is returned unchanged. See IList.immutableList() to get an immutable copy of a list.
      Specified by:
      unmodifiableList in class IList<E>
      Returns:
      an unmodifiable view of the specified list
    • immutableList

      public BigList<E> immutableList()
      Description copied from class: IList
      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 IList.unmodifiableList() to get unmodifiable view of a list.
      Specified by:
      immutableList in class IList<E>
      Returns:
      an immutable copy of the specified list
    • doEnsureCapacity

      protected void doEnsureCapacity(int minCapacity)
      Description copied from class: IList
      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 IList<E>
      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 IList<E>
    • doCreate

      protected IList<E> doCreate(int capacity)
      Description copied from class: IList
      Create list with specified capacity.
      Specified by:
      doCreate in class IList<E>
      Parameters:
      capacity - initial capacity (use -1 for default capacity)
      Returns:
      created list
    • sort

      public void sort(int index, int len, Comparator<? super E> comparator)
      Description copied from class: IList
      Sort specified elements in the list using the specified comparator.
      Specified by:
      sort in class IList<E>
      Parameters:
      index - index of first element to sort
      len - number of elements to sort
      comparator - comparator to use for sorting (null means the elements natural ordering should be used)
      See Also:
    • binarySearch

      public <K> int binarySearch(int index, int len, K key, Comparator<? super K> comparator)
      Description copied from class: IList
      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 IList<E>
      Parameters:
      index - index of first element to search
      len - number of elements to search
      key - the value to be searched for
      comparator - the comparator by which the list is ordered. A null value indicates that the elements' natural ordering should be used.
      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:
    • writeObject

      private void writeObject(ObjectOutputStream oos) throws IOException
      Serialize a BigList object.
      Parameters:
      oos - output stream for serialization
      Throws:
      IOException - if serialization fails
    • readObject

      private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException
      Deserialize a BigList object.
      Parameters:
      ois - input stream for serialization
      Throws:
      IOException - if serialization fails
      ClassNotFoundException - if serialization fails
    • checkNode

      private void checkNode(BigList.BlockNode<E> node)
    • checkHeight

      private void checkHeight(BigList.BlockNode<E> node)
    • check

      private void check()