Class CharGapList

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.CharSequence, java.lang.Cloneable, ICharListable
    Direct Known Subclasses:
    CharBigList.CharBlock, CharGapList.ReadOnlyList

    public class CharGapList
    extends ICharList
    Class {link CharGapList} combines the strengths of both ArrayList and LinkedList. It is implemented to offer both efficient random access to elements by index (as ArrayList does) and at the same time efficient adding and removing elements to and from beginning and end (as LinkedList does). It also exploits the locality of reference often seen in applications to further improve performance, e.g. for iterating over the list.

    The class can be used as drop-in replacement for ArrayList. It is also source compatible to LinkedList/Deque as it implements all needed methods. It cannot implement Deque however, use #asDeque to get a view implementing it.

    Note that this implementation is not synchronized.

    Note that the iterators provided are not fail-fast.

    See Also:
    List, ArrayList, Serialized Form
    • Field Detail

      • DEBUG_CHECK

        private static final boolean DEBUG_CHECK
        If true the invariants the CharGapList are checked for debugging
        See Also:
        Constant Field Values
      • DEBUG_TRACE

        private static final boolean DEBUG_TRACE
        If true the calls to some methods are traced out for debugging
        See Also:
        Constant Field Values
      • DEBUG_DUMP

        private static final boolean DEBUG_DUMP
        If true the internal state of the CharGapList is traced out for debugging
        See Also:
        Constant Field Values
      • EMPTY_VALUES

        private static char[] EMPTY_VALUES
        Empty array used for default initialization
      • EMPTY

        private static final CharGapList EMPTY
        Unmodifiable empty instance
      • serialVersionUID

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

        public static final int DEFAULT_CAPACITY
        Default capacity for list
        See Also:
        Constant Field Values
      • values

        private char[] values
        Array holding raw data
      • size

        private int size
        Number of elements stored in this CharGapList
      • start

        private int start
        Physical position of first element
      • end

        private int end
        Physical position after last element
      • gapSize

        private int gapSize
        Size of gap (0 if there is no gap)
      • gapIndex

        private int gapIndex
        Logical index of first element after gap (ignored if gapSize=0)
      • gapStart

        private int gapStart
        Physical position of first slot in gap (ignored if gapSize=0)
      • gapAddRight

        private boolean gapAddRight
        If false (default) an element is added on the left side of the gap (favorable for adding after an insertion point, e.g. indexes 5, 6, 7), if true the element is added on the right side of the gap (favorable for adding before an insertion point, e.g. indexes 5, 5, 5)
    • Constructor Detail

      • CharGapList

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

        public CharGapList()
        Construct a list with the default initial capacity.
      • CharGapList

        public CharGapList​(int capacity)
        Construct a list with specified initial capacity.
        Parameters:
        capacity - capacity
      • CharGapList

        public CharGapList​(java.util.Collection<java.lang.Character> coll)
        Construct a list to contain the specified elements. The list will have an initial capacity to hold these elements.
        Parameters:
        coll - collection with elements
      • CharGapList

        public CharGapList​(java.lang.String str)
    • Method Detail

      • EMPTY

        public static CharGapList EMPTY()
        Returns:
        unmodifiable empty instance
      • create

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

        @SafeVarargs
        public static CharGapList create​(char... elems)
        Create new list with specified elements.
        Parameters:
        elems - array with elements
        type - of elements stored in the list
        Returns:
        created list
      • immutable

        public static CharGapList immutable​(java.util.Collection<java.lang.Character> coll)
        Create new immutable list with specified elements. To reduce the needed memory, the list's capacity will be equal to its size.
        Parameters:
        coll - collection with elements
        type - of elements stored in the list
        Returns:
        created list
      • immutable

        @SafeVarargs
        public static CharGapList immutable​(char... elems)
        Create new immutable list with specified elements. To reduce the needed memory, the list's capacity will be equal to its size.
        Parameters:
        elems - array with elements
        type - of elements stored in the list
        Returns:
        created list
      • physIndex

        private final int physIndex​(int idx)
        Calculate index for physical access to an element.
        Parameters:
        idx - logical index of element
        Returns:
        physical index to access element in values[]
      • physIndex

        private int[] physIndex​(int idx0,
                                int idx1)
        Calculate indexes for physical access to a range of elements. The method returns between one and three ranges of physical indexes.
        Parameters:
        idx0 - start index
        idx1 - end index
        Returns:
        array with physical start and end indexes (may contain 0, 2, 4, or 6 elements)
      • doPhysIndex

        private int[] doPhysIndex​(int pidx0,
                                  int pidx1)
      • doPhysIndex2

        private int[] doPhysIndex2​(int pidx0,
                                   int pidx1)
      • doAssign

        protected void doAssign​(ICharList that)
        Description copied from class: ICharList
        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 ICharList
        Parameters:
        that - list to copy content from
      • init

        void init()
        Initialize the list to be empty. The list will have the default initial capacity.
      • init

        void init​(java.util.Collection<java.lang.Character> coll)
        Initialize the list to contain the specified elements only. The list will have an initial capacity to hold these elements.
        Parameters:
        coll - collection with elements
      • init

        void init​(char... elems)
        Initialize the list to contain the specified elements only. The list will have an initial capacity to hold these elements.
        Parameters:
        elems - array with elements
      • crop

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

        public CharGapList copy()
        Description copied from class: ICharList
        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.
        Specified by:
        copy in class ICharList
        Returns:
        a modifiable copy of this list
      • clone

        public CharGapList clone()
        Description copied from class: ICharList
        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 ICharList.copy() to .
        Overrides:
        clone in class ICharList
        Returns:
        a modifiable copy of this list
      • isReadOnly

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

        public CharGapList immutableList()
        Description copied from class: ICharList
        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 ICharList.unmodifiableList() to get unmodifiable view of a list.
        Specified by:
        immutableList in class ICharList
        Returns:
        an immutable copy of the specified list
      • doClone

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

        void ensureNormalized​(int minCapacity)
        Normalize data of CharGapList so the elements are found from values[0] to values[size-1]. This method can help to speed up operations like sort or binarySearch.
      • isNormalized

        boolean isNormalized()
        Checks whether elements are stored normalized, i.e. start is at position 0 and there is no gap.
      • init

        void init​(char[] values,
                  int size)
        Initialize all instance fields.
        Parameters:
        values - new values array
        size - new size
      • capacity

        public int capacity()
        Description copied from class: ICharList
        Returns capacity of this list. Note that two lists are considered equal even if they have a distinct capacity. Also the capacity can be changed by operations like clone() etc.
        Specified by:
        capacity in class ICharList
        Returns:
        capacity of this list
      • doGet

        protected char doGet​(int index)
        Description copied from class: ICharList
        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 ICharList
        Parameters:
        index - index of element to return
        Returns:
        the element at the specified position in this list
      • doSet

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

        protected char doReSet​(int index,
                               char elem)
        Description copied from class: ICharList
        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 ICharList
        Parameters:
        index - index where element will be placed
        elem - element to set
        Returns:
        old element which was at the position
      • add

        public boolean add​(char elem)
        Overrides:
        add in class ICharList
      • add

        public void add​(int index,
                        char elem)
        Description copied from class: ICharList
        Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).
        Overrides:
        add in class ICharList
        Parameters:
        index - index at which the specified element is to be inserted
        elem - element to be inserted
      • getAll

        public CharGapList getAll​(int index,
                                  int len)
        Description copied from class: ICharList
        Returns specified range of elements from list.
        Overrides:
        getAll in class ICharList
        Parameters:
        index - index of first element to retrieve
        len - number of elements to retrieve
        Returns:
        list containing the specified range of elements
      • getAll

        public CharGapList getAll​(char elem)
        Description copied from class: ICharList
        Returns all elements in the list equal to the specified element.
        Overrides:
        getAll in class ICharList
        Parameters:
        elem - element to look for
        Returns:
        all elements in the list equal to the specified element
      • map

        public <R> GapList<R> map​(java.util.function.Function<java.lang.Character,​R> mapper)
        Overrides:
        map in class ICharList
      • prepareAddBuffer

        char[] prepareAddBuffer​(int index,
                                int len)
        Prepare direct access to an array buffer for fast adding elements to the list. The size of the list will be increased by len being index+len after the call. The added elements will be initialized to their default value. If not all elements prepared are used, call releaseAddBuffer(int, int) to release them.

        Example:

         int index = list.size()
         int len = 1000;
         byte[] values = list.getAddBuffer(index, len)
         int read = inputstream.read(values, index, len)
         list.releaseAddBuffer(index, read)
         
        Parameters:
        index - index of first buffer position (must be equal to the size of the list)
        len - number of elements which the buffer can held
        Returns:
        array holding the elements of the list
      • releaseAddBuffer

        void releaseAddBuffer​(int index,
                              int len)
        Releases the buffer retrieved by prepareAddBuffer(int, int). The size of the list will be index+len after the call.
        Parameters:
        index - index of first buffer position as passed to prepareAddBuffer(int, int)
        len - number of elements used in the buffer
      • doAdd

        protected boolean doAdd​(int index,
                                char elem)
        Description copied from class: ICharList
        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 ICharList
        Parameters:
        index - index where element should be added (-1 means it is up to the implementation to choose the index)
        elem - element to add
        Returns:
        true if element has been added, false otherwise
      • doAddCreateNewGap

        private int doAddCreateNewGap​(int index,
                                      int physIdx)
      • doAddCreateNewGap2

        private int doAddCreateNewGap2​(int index,
                                       int physIdx)
      • doAddMoveExistingGap

        private int doAddMoveExistingGap​(int index,
                                         int physIdx)
      • doAddMoveExistingGap2

        private int doAddMoveExistingGap2​(int index,
                                          int physIdx,
                                          int gapEnd,
                                          boolean moveLeft)
      • moveDataWithGap

        private void moveDataWithGap​(int src,
                                     int dst,
                                     int len)
        Move a range of elements in the values array and adjust the gap. The elements are first copied and the source range is then filled with null.
        Parameters:
        src - start index of source range
        dst - start index of destination range
        len - number of elements to move
      • moveData

        private void moveData​(int src,
                              int dst,
                              int len)
        Move a range of elements in the values array. The elements are first copied and the source range is then filled with null.
        Parameters:
        src - start index of source range
        dst - start index of destination range
        len - number of elements to move
      • remove

        public char remove​(int index)
        Overrides:
        remove in class ICharList
      • doRemove

        protected char doRemove​(int index)
        Description copied from class: ICharList
        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 ICharList
        Parameters:
        index - index of element to remove
        Returns:
        removed element
      • doRemoveMiddle

        private void doRemoveMiddle​(int index,
                                    int physIdx)
      • doRemoveMoveExistingGap

        private void doRemoveMoveExistingGap​(int index,
                                             int physIdx)
      • doEnsureCapacity

        protected void doEnsureCapacity​(int minCapacity)
        Description copied from class: ICharList
        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 ICharList
        Parameters:
        minCapacity - the desired minimum capacity
      • calculateNewCapacity

        int calculateNewCapacity​(int minCapacity)
        Calculate new capacity. The capacity will not shrink, so the returned capacity can be equal to values.length.
        Parameters:
        minCapacity - the desired minimum capacity
        Returns:
        the new capacity to use
      • trimToSize

        public void trimToSize()
        Trims the capacity of this CharGapList instance to be the list's current size. An application can use this operation to minimize the storage of an instance.
        Specified by:
        trimToSize in class ICharList
      • doGetAll

        protected void doGetAll​(char[] array,
                                int index,
                                int len)
        Description copied from class: ICharList
        Helper method to fill the specified elements in an array.
        Overrides:
        doGetAll in class ICharList
        Parameters:
        array - array to store the list elements
        index - index of first element to copy
        len - number of elements to copy
      • writeObject

        private void writeObject​(java.io.ObjectOutputStream oos)
                          throws java.io.IOException
        Serialize a CharGapList 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 CharGapList object.
        Parameters:
        ois - input stream for serialization
        Throws:
        java.io.IOException - if serialization fails
        java.lang.ClassNotFoundException - if serialization fails
      • doCreate

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

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

        protected boolean doRemoveAllFast​(int index,
                                          int len)
        Remove specified range of elements from list as specialized fast operation.
        Parameters:
        index - index of first element to remove
        len - number of elements to remove
        Returns:
        true if removal could be done, false otherwise
      • sort

        public void sort​(int index,
                         int len)
        Description copied from class: ICharList
        Sort specified elements in the list using the specified comparator.
        Specified by:
        sort in class ICharList
        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,
                                char key)
        Description copied from class: ICharList
        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 ICharList
        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)
      • debugCheck

        private void debugCheck()
        Private method to check invariant of CharGapList. It is only used for debugging.
      • debugState

        private int debugState()
        Private method to determine state of CharGapList. It is only used for debugging.
        Returns:
        state in which CharGapList is
      • debugDump

        private void debugDump()
        Private method to dump fields of CharGapList. It is only called if the code is run in development mode.
      • debugPrint

        private java.lang.String debugPrint​(char[] values)
        Print array values into string.
        Parameters:
        values - array with values
        Returns:
        string representing array values
      • debugLog

        private void debugLog​(java.lang.String msg)
        Private method write logging output. It is only used for debugging.
        Parameters:
        msg - message to write out
      • create

        public static CharGapList create​(java.lang.String str)
      • init

        public void init​(java.lang.String str)