Package it.unimi.dsi.fastutil.objects

Class ObjectBigArrayBigList<K>

java.lang.Object
java.util.AbstractCollection<K>
it.unimi.dsi.fastutil.objects.AbstractObjectCollection<K>
it.unimi.dsi.fastutil.objects.AbstractObjectBigList<K>
it.unimi.dsi.fastutil.objects.ObjectBigArrayBigList<K>
All Implemented Interfaces:
BigList<K>, ObjectBigList<K>, ObjectCollection<K>, ObjectIterable<K>, Size64, Stack<K>, Serializable, Cloneable, Comparable<BigList<? extends K>>, Iterable<K>, Collection<K>, RandomAccess
public class ObjectBigArrayBigList<K>
extends AbstractObjectBigList<K>
implements RandomAccess, Cloneable, Serializable
A type-specific big-array-based big list; 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. If an instance of this class was created by wrapping, backing-array reallocations will be performed using reflection, so that elements() can return a big array of the same type of the original big array; the comments about efficiency made in ObjectArrays apply here.

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

    • ObjectBigArrayBigList

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

    • ObjectBigArrayBigList

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

    • ObjectBigArrayBigList

      public ObjectBigArrayBigList​(ObjectCollection<? extends K> 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.

    • ObjectBigArrayBigList

      public ObjectBigArrayBigList​(ObjectBigList<? extends K> 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.

    • ObjectBigArrayBigList

      public ObjectBigArrayBigList​(K[][] 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.

    • ObjectBigArrayBigList

      public ObjectBigArrayBigList​(K[][] 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.

    • ObjectBigArrayBigList

      public ObjectBigArrayBigList​(Iterator<? extends K> 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.

    • ObjectBigArrayBigList

      public ObjectBigArrayBigList​(ObjectIterator<? extends K> 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 K[][] elements()
      Returns the backing big array of this big list.

      If this big-array big list was created by wrapping a given big array, it is guaranteed that the type of the returned big array will be the same. Otherwise, the returned big array will be an big array of objects.

      Returns:
      the backing big array.

    • wrap

      public static <K> ObjectBigArrayBigList<K> wrap​(K[][] 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 <K> ObjectBigArrayBigList<K> wrap​(K[][] 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, K k)
      Description copied from class: AbstractObjectBigList
      Inserts the specified element at the specified position in this big list (optional operation).

      This implementation always throws an UnsupportedOperationException.

      Specified by:
      add in interface BigList<K>
      Overrides:
      add in class AbstractObjectBigList<K>
      Parameters:
      index - a position in the big list.
      k - an element to be inserted.
      See Also:
      List.add(int,Object)

    • add

      public boolean add​(K k)
      Description copied from class: AbstractObjectBigList

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

      Specified by:
      add in interface Collection<K>
      Overrides:
      add in class AbstractObjectBigList<K>

    • get

      public K get​(long index)
      Description copied from interface: BigList
      Returns the element at the specified position.
      Specified by:
      get in interface BigList<K>
      Parameters:
      index - a position in the big list.
      Returns:
      the element at the specified position.
      See Also:
      List.get(int)

    • indexOf

      public long indexOf​(Object k)
      Description copied from interface: BigList
      Returns the index of the first occurrence of the specified element in this big list, or -1 if this big list does not contain the element.
      Specified by:
      indexOf in interface BigList<K>
      Overrides:
      indexOf in class AbstractObjectBigList<K>
      Parameters:
      k - the object to search for.
      Returns:
      the index of the first occurrence of the specified element in this big list, or -1 if this big list does not contain the element.
      See Also:
      List.indexOf(Object)

    • lastIndexOf

      public long lastIndexOf​(Object k)
      Description copied from interface: BigList
      Returns the index of the last occurrence of the specified element in this big list, or -1 if this big list does not contain the element.
      Specified by:
      lastIndexOf in interface BigList<K>
      Overrides:
      lastIndexOf in class AbstractObjectBigList<K>
      Parameters:
      k - the object to search for.
      Returns:
      the index of the last occurrence of the specified element in this big list, or -1 if this big list does not contain the element.
      See Also:
      List.lastIndexOf(Object)

    • remove

      public K remove​(long index)
      Description copied from class: AbstractObjectBigList
      Removes the element at the specified position.

      This implementation always throws an UnsupportedOperationException.

      Specified by:
      remove in interface BigList<K>
      Overrides:
      remove in class AbstractObjectBigList<K>
      Parameters:
      index - a position in the big list.
      Returns:
      the element previously at the specified position.
      See Also:
      List.remove(int)

    • remove

      public boolean remove​(Object k)
      Specified by:
      remove in interface Collection<K>
      Overrides:
      remove in class AbstractCollection<K>

    • set

      public K set​(long index, K k)
      Description copied from class: AbstractObjectBigList
      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 BigList<K>
      Overrides:
      set in class AbstractObjectBigList<K>
      Parameters:
      index - a position in the big list.
      k - the element to be stored at the specified position.
      Returns:
      the element previously at the specified positions.
      See Also:
      List.set(int,Object)

    • removeAll

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

    • clear

      public void clear()
      Description copied from class: AbstractObjectBigList

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

      Specified by:
      clear in interface Collection<K>
      Overrides:
      clear in class AbstractObjectBigList<K>

    • 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<K>
      Overrides:
      size in class AbstractObjectBigList<K>
      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<K>
      Specified by:
      isEmpty in interface Stack<K>
      Overrides:
      isEmpty in class AbstractCollection<K>
      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, Object[][] 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 ObjectBigList<K>
      Overrides:
      getElements in class AbstractObjectBigList<K>
      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 ObjectBigList<K>
      Overrides:
      removeElements in class AbstractObjectBigList<K>
      Parameters:
      from - the start index (inclusive).
      to - the end index (exclusive).

    • addElements

      public void addElements​(long index, K[][] a, long offset, long length)
      Adds elements to this type-specific list using optimized system calls.
      Specified by:
      addElements in interface ObjectBigList<K>
      Overrides:
      addElements in class AbstractObjectBigList<K>
      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 ObjectBigListIterator<K> listIterator​(long index)
      Description copied from class: AbstractObjectBigList
      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<K>
      Specified by:
      listIterator in interface ObjectBigList<K>
      Overrides:
      listIterator in class AbstractObjectBigList<K>
      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 ObjectBigArrayBigList<K> clone()

    • equals

      public boolean equals​(ObjectBigArrayBigList<K> 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​(ObjectBigArrayBigList<? extends K> 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.