Package org.magicwerk.brownies.collections

Class BigList<E>

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<E>, java.util.Collection<E>, java.util.List<E>, java.util.RandomAccess, 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:
    Serialized Form

    • Constructor Detail

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

    • Method Detail

      • 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​(java.util.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

      • 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 modifiable 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. Use IList.clone() if a read-only list should not be copied.

        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 clone 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 get a modifiable list in any case.

        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 clone 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

      • doClear

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

      • finalize

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

      • doRelease

        protected void doRelease()

      • release

        public void release()
        Explicitly release this instance of BigList by unreferencing all blocks. Calling this method manually can improve sharing of blocks as their reference count is updated before the GC is running. Note that you must not use the instance after calling release (typically NullPointerException will result).

      • spliterator

        public java.util.Spliterator<E> spliterator()

      • size

        public int size()
        Description copied from interface: IListable
        Return size of list
        Specified by:
        size in interface java.util.Collection<E>
        Specified by:
        size in interface IListable<E>
        Specified by:
        size in interface java.util.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

      • 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

      • 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

      • 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

      • 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,
                 java.util.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:
        Arrays.sort(int[])

      • binarySearch

        public <K> int binarySearch​(int index,
                            int len,
                            K key,
                            java.util.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:
        Arrays.binarySearch(long[], long)