Package it.unimi.dsi.fastutil.ints

Class IntBigArrayBigList

java.lang.Object
java.util.AbstractCollection<Integer>
it.unimi.dsi.fastutil.ints.AbstractIntCollection
it.unimi.dsi.fastutil.ints.AbstractIntBigList
it.unimi.dsi.fastutil.ints.IntBigArrayBigList
All Implemented Interfaces:
BigList<Integer>, IntBigList, IntCollection, IntIterable, IntStack, Size64, Stack<Integer>, Serializable, Cloneable, Comparable<BigList<? extends Integer>>, Iterable<Integer>, Collection<Integer>, RandomAccess
public class IntBigArrayBigList
extends AbstractIntBigList
implements RandomAccess, Cloneable, Serializable
A type-specific big list based on a big array; provides some additional methods that use polymorphism to avoid (un)boxing.

This class implements a lightweight, fast, open, optimized, reuse-oriented version of big-array-based big lists. Instances of this class represent a big list with a big array that is enlarged as needed when new entries are created (by doubling the current length), but is never made smaller (even on a clear()). A family of trimming methods lets you control the size of the backing big array; this is particularly useful if you reuse instances of this class. Range checks are equivalent to those of java.util's classes, but they are delayed as much as possible. The backing big array is exposed by the elements() method.

This class implements the bulk methods removeElements(), addElements() and getElements() using high-performance system calls (e.g., System.arraycopy() instead of expensive loops.

See Also:
ArrayList, Serialized Form

  • Field Details

  • Constructor Details

    • IntBigArrayBigList

      public IntBigArrayBigList​(long capacity)
      Creates a new big-array big list with given capacity.
      Parameters:
      capacity - the initial capacity of the array list (may be 0).

    • IntBigArrayBigList

      public IntBigArrayBigList()
      Creates a new big-array big list with DEFAULT_INITIAL_CAPACITY capacity.

    • IntBigArrayBigList

      public IntBigArrayBigList​(IntCollection c)
      Creates a new big-array big list and fills it with a given type-specific collection.
      Parameters:
      c - a type-specific collection that will be used to fill the array list.

    • IntBigArrayBigList

      public IntBigArrayBigList​(IntBigList l)
      Creates a new big-array big list and fills it with a given type-specific list.
      Parameters:
      l - a type-specific list that will be used to fill the array list.

    • IntBigArrayBigList

      public IntBigArrayBigList​(int[][] a)
      Creates a new big-array big list and fills it with the elements of a given big array.

      Note that this constructor makes it easy to build big lists from literal arrays declared as type[][] {{ init_values }}. The only constraint is that the number of initialisation values is below BigArrays.SEGMENT_SIZE.

      Parameters:
      a - a big array whose elements will be used to fill the array list.

    • IntBigArrayBigList

      public IntBigArrayBigList​(int[][] a, long offset, long length)
      Creates a new big-array big list and fills it with the elements of a given big array.

      Note that this constructor makes it easy to build big lists from literal arrays declared as type[][] {{ init_values }}. The only constraint is that the number of initialisation values is below BigArrays.SEGMENT_SIZE.

      Parameters:
      a - a big array whose elements will be used to fill the array list.
      offset - the first element to use.
      length - the number of elements to use.

    • IntBigArrayBigList

      public IntBigArrayBigList​(Iterator<? extends Integer> i)
      Creates a new big-array big list and fills it with the elements returned by an iterator..
      Parameters:
      i - an iterator whose returned elements will fill the array list.

    • IntBigArrayBigList

      public IntBigArrayBigList​(IntIterator i)
      Creates a new big-array big list and fills it with the elements returned by a type-specific iterator..
      Parameters:
      i - a type-specific iterator whose returned elements will fill the array list.

  • Method Details

    • elements

      public int[][] elements()
      Returns the backing big array of this big list.
      Returns:
      the backing big array.

    • wrap

      public static IntBigArrayBigList wrap​(int[][] a, long length)
      Wraps a given big array into a big-array list of given size.
      Parameters:
      a - a big array to wrap.
      length - the length of the resulting big-array list.
      Returns:
      a new big-array list of the given size, wrapping the given big array.

    • wrap

      public static IntBigArrayBigList wrap​(int[][] a)
      Wraps a given big array into a big-array big list.
      Parameters:
      a - a big array to wrap.
      Returns:
      a new big-array big list wrapping the given array.

    • ensureCapacity

      public void ensureCapacity​(long capacity)
      Ensures that this big-array big list can contain the given number of entries without resizing.
      Parameters:
      capacity - the new minimum capacity for this big-array big list.

    • add

      public void add​(long index, int k)
      Description copied from class: AbstractIntBigList
      Inserts the specified element at the specified position in this type-specific big list (optional operation).

      This implementation always throws an UnsupportedOperationException.

      Specified by:
      add in interface IntBigList
      Overrides:
      add in class AbstractIntBigList
      See Also:
      BigList.add(long,Object)

    • add

      public boolean add​(int k)
      Description copied from class: AbstractIntBigList
      Ensures that this collection contains the specified element (optional operation).

      This implementation always throws an UnsupportedOperationException.

      This implementation delegates to the type-specific version of BigList.add(long, Object).

      Specified by:
      add in interface IntCollection
      Overrides:
      add in class AbstractIntBigList
      See Also:
      Collection.add(Object)

    • getInt

      public int getInt​(long index)
      Description copied from interface: IntBigList
      Returns the element at the specified position.
      Specified by:
      getInt in interface IntBigList
      See Also:
      BigList.get(long)

    • indexOf

      public long indexOf​(int k)
      Description copied from interface: IntBigList
      Returns the index of the first occurrence of the specified element in this type-specific big list, or -1 if this big list does not contain the element.
      Specified by:
      indexOf in interface IntBigList
      Overrides:
      indexOf in class AbstractIntBigList
      See Also:
      BigList.indexOf(Object)

    • lastIndexOf

      public long lastIndexOf​(int k)
      Description copied from interface: IntBigList
      Returns the index of the last occurrence of the specified element in this type-specific big list, or -1 if this big list does not contain the element.
      Specified by:
      lastIndexOf in interface IntBigList
      Overrides:
      lastIndexOf in class AbstractIntBigList
      See Also:
      BigList.lastIndexOf(Object)

    • removeInt

      public int removeInt​(long index)
      Description copied from class: AbstractIntBigList
      Removes the element at the specified position.

      This implementation always throws an UnsupportedOperationException.

      Specified by:
      removeInt in interface IntBigList
      Overrides:
      removeInt in class AbstractIntBigList
      See Also:
      BigList.remove(long)

    • rem

      public boolean rem​(int k)
      Description copied from class: AbstractIntBigList
      Removes a single instance of the specified element from this collection, if it is present (optional operation).

      This implementation delegates to indexOf().

      Specified by:
      rem in interface IntCollection
      Overrides:
      rem in class AbstractIntBigList
      See Also:
      Collection.remove(Object)

    • set

      public int set​(long index, int k)
      Description copied from class: AbstractIntBigList
      Replaces the element at the specified position in this big list with the specified element (optional operation).

      This implementation always throws an UnsupportedOperationException.

      Specified by:
      set in interface IntBigList
      Overrides:
      set in class AbstractIntBigList
      See Also:
      BigList.set(long,Object)

    • removeAll

      public boolean removeAll​(IntCollection c)
      Description copied from interface: IntCollection
      Remove from this collection all elements in the given type-specific collection.
      Specified by:
      removeAll in interface IntCollection
      Overrides:
      removeAll in class AbstractIntCollection
      Parameters:
      c - a type-specific collection.
      Returns:
      true if this collection changed as a result of the call.
      See Also:
      Collection.removeAll(Collection)

    • removeAll

      public boolean removeAll​(Collection<?> c)
      Specified by:
      removeAll in interface Collection<Integer>
      Overrides:
      removeAll in class AbstractCollection<Integer>

    • clear

      public void clear()
      Description copied from class: AbstractIntBigList

      This implementation delegates to AbstractIntBigList.removeElements(long, long).

      Specified by:
      clear in interface Collection<Integer>
      Overrides:
      clear in class AbstractIntBigList

    • size64

      public long size64()
      Description copied from interface: Size64
      Returns the size of this data structure as a long.
      Specified by:
      size64 in interface Size64
      Returns:
      the size of this data structure.

    • size

      public void size​(long size)
      Description copied from interface: BigList
      Sets the size of this big list.

      If the specified size is smaller than the current size, the last elements are discarded. Otherwise, they are filled with 0/null/false.

      Specified by:
      size in interface BigList<Integer>
      Overrides:
      size in class AbstractIntBigList
      Parameters:
      size - the new size.

    • isEmpty

      public boolean isEmpty()
      Description copied from interface: Stack
      Checks whether the stack is empty.
      Specified by:
      isEmpty in interface Collection<Integer>
      Specified by:
      isEmpty in interface Stack<Integer>
      Overrides:
      isEmpty in class AbstractCollection<Integer>
      Returns:
      true if the stack is empty.

    • trim

      public void trim()
      Trims this big-array big list so that the capacity is equal to the size.
      See Also:
      ArrayList.trimToSize()

    • trim

      public void trim​(long n)
      Trims the backing big array if it is too large. If the current big array length is smaller than or equal to n, this method does nothing. Otherwise, it trims the big-array length to the maximum between n and size64().

      This method is useful when reusing big lists. Clearing a big list leaves the big-array length untouched. If you are reusing a big list many times, you can call this method with a typical size to avoid keeping around a very large big array just because of a few large transient big lists.

      Parameters:
      n - the threshold for the trimming.

    • getElements

      public void getElements​(long from, int[][] a, long offset, long length)
      Copies element of this type-specific list into the given big array using optimized system calls.
      Specified by:
      getElements in interface IntBigList
      Overrides:
      getElements in class AbstractIntBigList
      Parameters:
      from - the start index (inclusive).
      a - the destination big array.
      offset - the offset into the destination array where to store the first element copied.
      length - the number of elements to be copied.

    • removeElements

      public void removeElements​(long from, long to)
      Removes elements of this type-specific list using optimized system calls.
      Specified by:
      removeElements in interface IntBigList
      Overrides:
      removeElements in class AbstractIntBigList
      Parameters:
      from - the start index (inclusive).
      to - the end index (exclusive).

    • addElements

      public void addElements​(long index, int[][] a, long offset, long length)
      Adds elements to this type-specific list using optimized system calls.
      Specified by:
      addElements in interface IntBigList
      Overrides:
      addElements in class AbstractIntBigList
      Parameters:
      index - the index at which to add elements.
      a - the big array containing the elements.
      offset - the offset of the first element to add.
      length - the number of elements to add.

    • listIterator

      public IntBigListIterator listIterator​(long index)
      Description copied from class: AbstractIntBigList
      Returns a type-specific list iterator on this type-specific big list starting at a given index.

      Note that this specification strengthens the one given in BigList.listIterator(long).

      This implementation is based on the random-access methods.

      Specified by:
      listIterator in interface BigList<Integer>
      Specified by:
      listIterator in interface IntBigList
      Overrides:
      listIterator in class AbstractIntBigList
      Parameters:
      index - index of first element to be returned from the big-list iterator.
      Returns:
      a big-list iterator of the elements in this big list, starting at the specified position in this big list.
      See Also:
      BigList.listIterator(long)

    • clone

      public IntBigArrayBigList clone()

    • equals

      public boolean equals​(IntBigArrayBigList l)
      Compares this type-specific big-array list to another one.

      This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.

      Parameters:
      l - a type-specific big-array list.
      Returns:
      true if the argument contains the same elements of this type-specific big-array list.

    • compareTo

      public int compareTo​(IntBigArrayBigList l)
      Compares this big list to another big list.

      This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.

      Parameters:
      l - a big list.
      Returns:
      a negative integer, zero, or a positive integer as this big list is lexicographically less than, equal to, or greater than the argument.