package org.ujmp.core.collections.list; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.ConcurrentModificationException; import java.util.Enumeration; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.ListIterator; import java.util.NoSuchElementException; import java.util.RandomAccess; import java.util.Vector; /** * Resizable-array implementation of the <tt>List</tt> interface. Implements all * optional list operations, and permits all elements, including <tt>null</tt>. * In addition to implementing the <tt>List</tt> interface, this class provides * methods to manipulate the size of the array that is used internally to store * the list. (This class is roughly equivalent to <tt>Vector</tt>, except that * it is unsynchronized.) * * <p> * The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>, * <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant time. * The <tt>add</tt> operation runs in <i>amortized constant time</i>, that is, * adding n elements requires O(n) time. All of the other operations run in * linear time (roughly speaking). The constant factor is low compared to that * for the <tt>LinkedList</tt> implementation. * * <p> * Each <tt>ArrayList</tt> instance has a <i>capacity</i>. The capacity is the * size of the array used to store the elements in the list. It is always at * least as large as the list size. As elements are added to an ArrayList, its * capacity grows automatically. The details of the growth policy are not * specified beyond the fact that adding an element has constant amortized time * cost. * * <p> * An application can increase the capacity of an <tt>ArrayList</tt> instance * before adding a large number of elements using the <tt>ensureCapacity</tt> * operation. This may reduce the amount of incremental reallocation. * * <p> * <strong>Note that this implementation is not synchronized.</strong> If * multiple threads access an <tt>ArrayList</tt> instance concurrently, and at * least one of the threads modifies the list structurally, it <i>must</i> be * synchronized externally. (A structural modification is any operation that * adds or deletes one or more elements, or explicitly resizes the backing * array; merely setting the value of an element is not a structural * modification.) This is typically accomplished by synchronizing on some object * that naturally encapsulates the list. * * If no such object exists, the list should be "wrapped" using the * {@link Collections#synchronizedList Collections.synchronizedList} method. * This is best done at creation time, to prevent accidental unsynchronized * access to the list: * * <pre> * List list = Collections.synchronizedList(new ArrayList(...)); * </pre> * * <p> * <a name="fail-fast"/> The iterators returned by this class's * {@link #iterator() iterator} and {@link #listIterator(int) listIterator} * methods are <em>fail-fast</em>: if the list is structurally modified at any * time after the iterator is created, in any way except through the iterator's * own {@link ListIterator#remove() remove} or {@link ListIterator#add(Object) * add} methods, the iterator will throw a * {@link ConcurrentModificationException}. Thus, in the face of concurrent * modification, the iterator fails quickly and cleanly, rather than risking * arbitrary, non-deterministic behavior at an undetermined time in the future. * * <p> * Note that the fail-fast behavior of an iterator cannot be guaranteed as it * is, generally speaking, impossible to make any hard guarantees in the * presence of unsynchronized concurrent modification. Fail-fast iterators throw * {@code ConcurrentModificationException} on a best-effort basis. Therefore, it * would be wrong to write a program that depended on this exception for its * correctness: <i>the fail-fast behavior of iterators should be used only to * detect bugs.</i> * * <p> * This class is a member of the <a href="{@docRoot} * /../technotes/guides/collections/index.html"> Java Collections Framework</a>. * * @author Josh Bloch * @author Neal Gafter * @see Collection * @see List * @see LinkedList * @see Vector * @since 1.2 */ public class FastArrayList<E> extends AbstractList<E> implements List<E>, RandomAccess, Cloneable, java.io.Serializable { private static final long serialVersionUID = 8683452581122892189L; /** * Default initial capacity. */ private static final int DEFAULT_CAPACITY = 10; /** * Shared empty array instance used for empty instances. */ private static final Object[] EMPTY_ELEMENTDATA = {}; private boolean hashCodeUpToDate = false; private int hashCode = -1; /** * The array buffer into which the elements of the ArrayList are stored. The * capacity of the ArrayList is the length of this array buffer. Any empty * ArrayList with elementData == EMPTY_ELEMENTDATA will be expanded to * DEFAULT_CAPACITY when the first element is added. */ private transient Object[] elementData; /** * The size of the ArrayList (the number of elements it contains). * * @serial */ private int size; /** * Constructs an empty list with the specified initial capacity. * * @param initialCapacity * the initial capacity of the list * @throws IllegalArgumentException * if the specified initial capacity is negative */ public FastArrayList(int initialCapacity) { super(); if (initialCapacity < 0) throw new IllegalArgumentException("Illegal Capacity: " + initialCapacity); this.elementData = new Object[initialCapacity]; } /** * Constructs an empty list with an initial capacity of ten. */ public FastArrayList() { super(); this.elementData = EMPTY_ELEMENTDATA; } /** * Constructs a list containing the elements of the specified collection, in * the order they are returned by the collection's iterator. * * @param c * the collection whose elements are to be placed into this list * @throws NullPointerException * if the specified collection is null */ public FastArrayList(Collection<? extends E> c) { elementData = c.toArray(); size = elementData.length; // c.toArray might (incorrectly) not return Object[] (see 6260652) if (elementData.getClass() != Object[].class) elementData = Arrays.copyOf(elementData, size, Object[].class); } public FastArrayList(E... c) { elementData = c.clone(); size = elementData.length; // c.toArray might (incorrectly) not return Object[] (see 6260652) if (elementData.getClass() != Object[].class) elementData = Arrays.copyOf(elementData, size, Object[].class); } public FastArrayList(Enumeration<E> enumeration) { super(); this.elementData = EMPTY_ELEMENTDATA; while (enumeration.hasMoreElements()) { add((E) enumeration.nextElement()); } } public int hashCode() { if (!hashCodeUpToDate) { hashCode = super.hashCode(); hashCodeUpToDate = true; } return hashCode; } /** * Trims the capacity of this <tt>ArrayList</tt> instance to be the list's * current size. An application can use this operation to minimize the * storage of an <tt>ArrayList</tt> instance. */ public void trimToSize() { modCount++; if (size < elementData.length) { elementData = Arrays.copyOf(elementData, size); } } /** * Increases the capacity of this <tt>ArrayList</tt> instance, if necessary, * to ensure that it can hold at least the number of elements specified by * the minimum capacity argument. * * @param minCapacity * the desired minimum capacity */ public void ensureCapacity(int minCapacity) { int minExpand = (elementData != EMPTY_ELEMENTDATA) // any size if real element table ? 0 // larger than default for empty table. It's already supposed to // be // at default size. : DEFAULT_CAPACITY; if (minCapacity > minExpand) { ensureExplicitCapacity(minCapacity); } } private void ensureCapacityInternal(int minCapacity) { if (elementData == EMPTY_ELEMENTDATA) { minCapacity = Math.max(DEFAULT_CAPACITY, minCapacity); } ensureExplicitCapacity(minCapacity); } private void ensureExplicitCapacity(int minCapacity) { modCount++; // overflow-conscious code if (minCapacity - elementData.length > 0) grow(minCapacity); } /** * The maximum size of array to allocate. Some VMs reserve some header words * in an array. Attempts to allocate larger arrays may result in * OutOfMemoryError: Requested array size exceeds VM limit */ private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; /** * Increases the capacity to ensure that it can hold at least the number of * elements specified by the minimum capacity argument. * * @param minCapacity * the desired minimum capacity */ private void grow(int minCapacity) { // overflow-conscious code int oldCapacity = elementData.length; int newCapacity = oldCapacity + (oldCapacity >> 1); if (newCapacity - minCapacity < 0) newCapacity = minCapacity; if (newCapacity - MAX_ARRAY_SIZE > 0) newCapacity = hugeCapacity(minCapacity); // minCapacity is usually close to size, so this is a win: elementData = Arrays.copyOf(elementData, newCapacity); } private static int hugeCapacity(int minCapacity) { if (minCapacity < 0) // overflow throw new OutOfMemoryError(); return (minCapacity > MAX_ARRAY_SIZE) ? Integer.MAX_VALUE : MAX_ARRAY_SIZE; } /** * Returns the number of elements in this list. * * @return the number of elements in this list */ public int size() { return size; } /** * Returns <tt>true</tt> if this list contains no elements. * * @return <tt>true</tt> if this list contains no elements */ public boolean isEmpty() { return size == 0; } /** * Returns <tt>true</tt> if this list contains the specified element. More * formally, returns <tt>true</tt> if and only if this list contains at * least one element <tt>e</tt> such that * <tt>(o==null ? e==null : o.equals(e))</tt>. * * @param o * element whose presence in this list is to be tested * @return <tt>true</tt> if this list contains the specified element */ public boolean contains(Object o) { return indexOf(o) >= 0; } /** * Returns the index of the first occurrence of the specified element in * this list, or -1 if this list does not contain the element. More * formally, returns the lowest index <tt>i</tt> such that * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, * or -1 if there is no such index. */ public int indexOf(Object o) { if (o == null) { for (int i = 0; i < size; i++) if (elementData[i] == null) return i; } else { for (int i = 0; i < size; i++) if (o.equals(elementData[i])) return i; } return -1; } /** * Returns the index of the last occurrence of the specified element in this * list, or -1 if this list does not contain the element. More formally, * returns the highest index <tt>i</tt> such that * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, * or -1 if there is no such index. */ public int lastIndexOf(Object o) { if (o == null) { for (int i = size - 1; i >= 0; i--) if (elementData[i] == null) return i; } else { for (int i = size - 1; i >= 0; i--) if (o.equals(elementData[i])) return i; } return -1; } /** * Returns a shallow copy of this <tt>ArrayList</tt> instance. (The elements * themselves are not copied.) * * @return a clone of this <tt>ArrayList</tt> instance */ public Object clone() { try { @SuppressWarnings("unchecked") FastArrayList<E> v = (FastArrayList<E>) super.clone(); v.elementData = Arrays.copyOf(elementData, size); v.modCount = 0; return v; } catch (CloneNotSupportedException e) { // this shouldn't happen, since we are Cloneable throw new InternalError(); } } /** * Returns an array containing all of the elements in this list in proper * sequence (from first to last element). * * <p> * The returned array will be "safe" in that no references to it are * maintained by this list. (In other words, this method must allocate a new * array). The caller is thus free to modify the returned array. * * <p> * This method acts as bridge between array-based and collection-based APIs. * * @return an array containing all of the elements in this list in proper * sequence */ public Object[] toArray() { return Arrays.copyOf(elementData, size); } /** * Returns an array containing all of the elements in this list in proper * sequence (from first to last element); the runtime type of the returned * array is that of the specified array. If the list fits in the specified * array, it is returned therein. Otherwise, a new array is allocated with * the runtime type of the specified array and the size of this list. * * <p> * If the list fits in the specified array with room to spare (i.e., the * array has more elements than the list), the element in the array * immediately following the end of the collection is set to <tt>null</tt>. * (This is useful in determining the length of the list <i>only</i> if the * caller knows that the list does not contain any null elements.) * * @param a * the array into which the elements of the list are to be * stored, if it is big enough; otherwise, a new array of the * same runtime type is allocated for this purpose. * @return an array containing the elements of the list * @throws ArrayStoreException * if the runtime type of the specified array is not a supertype * of the runtime type of every element in this list * @throws NullPointerException * if the specified array is null */ @SuppressWarnings("unchecked") public <T> T[] toArray(T[] a) { if (a.length < size) // Make a new array of a's runtime type, but my contents: return (T[]) Arrays.copyOf(elementData, size, a.getClass()); System.arraycopy(elementData, 0, a, 0, size); if (a.length > size) a[size] = null; return a; } // Positional Access Operations @SuppressWarnings("unchecked") E elementData(int index) { return (E) elementData[index]; } /** * Returns the element at the specified position in this list. * * @param index * index of the element to return * @return the element at the specified position in this list * @throws IndexOutOfBoundsException * {@inheritDoc} */ @SuppressWarnings("unchecked") public E get(int index) { return (E) elementData[index]; } /** * Replaces the element at the specified position in this list with the * specified element. * * @param index * index of the element to replace * @param element * element to be stored at the specified position * @return the element previously at the specified position * @throws IndexOutOfBoundsException * {@inheritDoc} */ public E set(int index, E element) { hashCodeUpToDate = false; E oldValue = elementData(index); elementData[index] = element; return oldValue; } /** * Appends the specified element to the end of this list. * * @param e * element to be appended to this list * @return <tt>true</tt> (as specified by {@link Collection#add}) */ public boolean add(E e) { hashCodeUpToDate = false; ensureCapacityInternal(size + 1); // Increments modCount!! elementData[size++] = e; return true; } /** * 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). * * @param index * index at which the specified element is to be inserted * @param element * element to be inserted * @throws IndexOutOfBoundsException * {@inheritDoc} */ public void add(int index, E element) { hashCodeUpToDate = false; ensureCapacityInternal(size + 1); // Increments modCount!! System.arraycopy(elementData, index, elementData, index + 1, size - index); elementData[index] = element; size++; } /** * Removes the element at the specified position in this list. Shifts any * subsequent elements to the left (subtracts one from their indices). * * @param index * the index of the element to be removed * @return the element that was removed from the list * @throws IndexOutOfBoundsException * {@inheritDoc} */ public E remove(int index) { hashCodeUpToDate = false; modCount++; E oldValue = elementData(index); int numMoved = size - index - 1; if (numMoved > 0) System.arraycopy(elementData, index + 1, elementData, index, numMoved); elementData[--size] = null; // clear to let GC do its work return oldValue; } /** * Removes the first occurrence of the specified element from this list, if * it is present. If the list does not contain the element, it is unchanged. * More formally, removes the element with the lowest index <tt>i</tt> such * that * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt> * (if such an element exists). Returns <tt>true</tt> if this list contained * the specified element (or equivalently, if this list changed as a result * of the call). * * @param o * element to be removed from this list, if present * @return <tt>true</tt> if this list contained the specified element */ public boolean remove(Object o) { hashCodeUpToDate = false; if (o == null) { for (int index = 0; index < size; index++) if (elementData[index] == null) { fastRemove(index); return true; } } else { for (int index = 0; index < size; index++) if (o.equals(elementData[index])) { fastRemove(index); return true; } } return false; } /* * Private remove method that skips bounds checking and does not return the * value removed. */ private void fastRemove(int index) { modCount++; int numMoved = size - index - 1; if (numMoved > 0) System.arraycopy(elementData, index + 1, elementData, index, numMoved); elementData[--size] = null; // clear to let GC do its work } /** * Removes all of the elements from this list. The list will be empty after * this call returns. */ public void clear() { hashCodeUpToDate = false; modCount++; // clear to let GC do its work for (int i = 0; i < size; i++) elementData[i] = null; size = 0; } /** * Appends all of the elements in the specified collection to the end of * this list, in the order that they are returned by the specified * collection's Iterator. The behavior of this operation is undefined if the * specified collection is modified while the operation is in progress. * (This implies that the behavior of this call is undefined if the * specified collection is this list, and this list is nonempty.) * * @param c * collection containing elements to be added to this list * @return <tt>true</tt> if this list changed as a result of the call * @throws NullPointerException * if the specified collection is null */ public boolean addAll(Collection<? extends E> c) { hashCodeUpToDate = false; Object[] a = c.toArray(); int numNew = a.length; ensureCapacityInternal(size + numNew); // Increments modCount System.arraycopy(a, 0, elementData, size, numNew); size += numNew; return numNew != 0; } /** * Inserts all of the elements in the specified collection into this list, * starting at the specified position. Shifts the element currently at that * position (if any) and any subsequent elements to the right (increases * their indices). The new elements will appear in the list in the order * that they are returned by the specified collection's iterator. * * @param index * index at which to insert the first element from the specified * collection * @param c * collection containing elements to be added to this list * @return <tt>true</tt> if this list changed as a result of the call * @throws IndexOutOfBoundsException * {@inheritDoc} * @throws NullPointerException * if the specified collection is null */ public boolean addAll(int index, Collection<? extends E> c) { hashCodeUpToDate = false; Object[] a = c.toArray(); int numNew = a.length; ensureCapacityInternal(size + numNew); // Increments modCount int numMoved = size - index; if (numMoved > 0) System.arraycopy(elementData, index, elementData, index + numNew, numMoved); System.arraycopy(a, 0, elementData, index, numNew); size += numNew; return numNew != 0; } /** * Removes from this list all of the elements whose index is between * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. Shifts any * succeeding elements to the left (reduces their index). This call shortens * the list by {@code (toIndex - fromIndex)} elements. (If * {@code toIndex==fromIndex}, this operation has no effect.) * * @throws IndexOutOfBoundsException * if {@code fromIndex} or {@code toIndex} is out of range ( * {@code fromIndex < 0 || * fromIndex >= size() || * toIndex > size() || * toIndex < fromIndex}) */ protected void removeRange(int fromIndex, int toIndex) { modCount++; int numMoved = size - toIndex; System.arraycopy(elementData, toIndex, elementData, fromIndex, numMoved); // clear to let GC do its work int newSize = size - (toIndex - fromIndex); for (int i = newSize; i < size; i++) { elementData[i] = null; } size = newSize; } /** * Removes from this list all of its elements that are contained in the * specified collection. * * @param c * collection containing elements to be removed from this list * @return {@code true} if this list changed as a result of the call * @throws ClassCastException * if the class of an element of this list is incompatible with * the specified collection (<a * href="Collection.html#optional-restrictions">optional</a>) * @throws NullPointerException * if this list contains a null element and the specified * collection does not permit null elements (<a * href="Collection.html#optional-restrictions">optional</a>), * or if the specified collection is null * @see Collection#contains(Object) */ public boolean removeAll(Collection<?> c) { hashCodeUpToDate = false; return batchRemove(c, false); } /** * Retains only the elements in this list that are contained in the * specified collection. In other words, removes from this list all of its * elements that are not contained in the specified collection. * * @param c * collection containing elements to be retained in this list * @return {@code true} if this list changed as a result of the call * @throws ClassCastException * if the class of an element of this list is incompatible with * the specified collection (<a * href="Collection.html#optional-restrictions">optional</a>) * @throws NullPointerException * if this list contains a null element and the specified * collection does not permit null elements (<a * href="Collection.html#optional-restrictions">optional</a>), * or if the specified collection is null * @see Collection#contains(Object) */ public boolean retainAll(Collection<?> c) { hashCodeUpToDate = false; return batchRemove(c, true); } private boolean batchRemove(Collection<?> c, boolean complement) { final Object[] elementData = this.elementData; int r = 0, w = 0; boolean modified = false; try { for (; r < size; r++) if (c.contains(elementData[r]) == complement) elementData[w++] = elementData[r]; } finally { // Preserve behavioral compatibility with AbstractCollection, // even if c.contains() throws. if (r != size) { System.arraycopy(elementData, r, elementData, w, size - r); w += size - r; } if (w != size) { // clear to let GC do its work for (int i = w; i < size; i++) elementData[i] = null; modCount += size - w; size = w; modified = true; } } return modified; } /** * Save the state of the <tt>ArrayList</tt> instance to a stream (that is, * serialize it). * * @serialData The length of the array backing the <tt>ArrayList</tt> * instance is emitted (int), followed by all of its elements * (each an <tt>Object</tt>) in the proper order. */ private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException { // Write out element count, and any hidden stuff int expectedModCount = modCount; s.defaultWriteObject(); // Write out size as capacity for behavioural compatibility with clone() s.writeInt(size); // Write out all elements in the proper order. for (int i = 0; i < size; i++) { s.writeObject(elementData[i]); } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } } /** * Reconstitute the <tt>ArrayList</tt> instance from a stream (that is, * deserialize it). */ private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { elementData = EMPTY_ELEMENTDATA; // Read in size, and any hidden stuff s.defaultReadObject(); // Read in capacity s.readInt(); // ignored if (size > 0) { // be like clone(), allocate array based upon size not capacity ensureCapacityInternal(size); Object[] a = elementData; // Read in all elements in the proper order. for (int i = 0; i < size; i++) { a[i] = s.readObject(); } } } /** * Returns a list iterator over the elements in this list (in proper * sequence), starting at the specified position in the list. The specified * index indicates the first element that would be returned by an initial * call to {@link ListIterator#next next}. An initial call to * {@link ListIterator#previous previous} would return the element with the * specified index minus one. * * <p> * The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. * * @throws IndexOutOfBoundsException * {@inheritDoc} */ public ListIterator<E> listIterator(int index) { if (index < 0 || index > size) throw new IndexOutOfBoundsException("Index: " + index); return new ListItr(index); } /** * Returns a list iterator over the elements in this list (in proper * sequence). * * <p> * The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. * * @see #listIterator(int) */ public ListIterator<E> listIterator() { return new ListItr(0); } /** * Returns an iterator over the elements in this list in proper sequence. * * <p> * The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>. * * @return an iterator over the elements in this list in proper sequence */ public Iterator<E> iterator() { return new Itr(); } /** * An optimized version of AbstractList.Itr */ private class Itr implements Iterator<E> { int cursor; // index of next element to return int lastRet = -1; // index of last element returned; -1 if no such public boolean hasNext() { return cursor != size; } @SuppressWarnings("unchecked") public E next() { int i = cursor; if (i >= size) throw new NoSuchElementException(); Object[] elementData = FastArrayList.this.elementData; if (i >= elementData.length) throw new ConcurrentModificationException(); cursor = i + 1; return (E) elementData[lastRet = i]; } public void remove() { if (lastRet < 0) throw new IllegalStateException(); try { FastArrayList.this.remove(lastRet); cursor = lastRet; lastRet = -1; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } } } /** * An optimized version of AbstractList.ListItr */ private class ListItr extends Itr implements ListIterator<E> { ListItr(int index) { super(); cursor = index; } public boolean hasPrevious() { return cursor != 0; } public int nextIndex() { return cursor; } public int previousIndex() { return cursor - 1; } @SuppressWarnings("unchecked") public E previous() { int i = cursor - 1; if (i < 0) throw new NoSuchElementException(); Object[] elementData = FastArrayList.this.elementData; if (i >= elementData.length) throw new ConcurrentModificationException(); cursor = i; return (E) elementData[lastRet = i]; } public void set(E e) { if (lastRet < 0) throw new IllegalStateException(); try { FastArrayList.this.set(lastRet, e); } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } } public void add(E e) { try { int i = cursor; FastArrayList.this.add(i, e); cursor = i + 1; lastRet = -1; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } } } /** * Returns a view of the portion of this list between the specified * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. (If * {@code fromIndex} and {@code toIndex} are equal, the returned list is * empty.) The returned list is backed by this list, so non-structural * changes in the returned list are reflected in this list, and vice-versa. * The returned list supports all of the optional list operations. * * <p> * This method eliminates the need for explicit range operations (of the * sort that commonly exist for arrays). Any operation that expects a list * can be used as a range operation by passing a subList view instead of a * whole list. For example, the following idiom removes a range of elements * from a list: * * <pre> * list.subList(from, to).clear(); * </pre> * * Similar idioms may be constructed for {@link #indexOf(Object)} and * {@link #lastIndexOf(Object)}, and all of the algorithms in the * {@link Collections} class can be applied to a subList. * * <p> * The semantics of the list returned by this method become undefined if the * backing list (i.e., this list) is <i>structurally modified</i> in any way * other than via the returned list. (Structural modifications are those * that change the size of this list, or otherwise perturb it in such a * fashion that iterations in progress may yield incorrect results.) * * @throws IndexOutOfBoundsException * {@inheritDoc} * @throws IllegalArgumentException * {@inheritDoc} */ public List<E> subList(int fromIndex, int toIndex) { subListRangeCheck(fromIndex, toIndex, size); return new SubList(this, 0, fromIndex, toIndex); } static void subListRangeCheck(int fromIndex, int toIndex, int size) { if (fromIndex < 0) throw new IndexOutOfBoundsException("fromIndex = " + fromIndex); if (toIndex > size) throw new IndexOutOfBoundsException("toIndex = " + toIndex); if (fromIndex > toIndex) throw new IllegalArgumentException("fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")"); } private class SubList extends java.util.AbstractList<E> implements RandomAccess { private final FastArrayList<E> parent; private final int parentOffset; private final int offset; int size; SubList(FastArrayList<E> parent, int offset, int fromIndex, int toIndex) { this.parent = parent; this.parentOffset = fromIndex; this.offset = offset + fromIndex; this.size = toIndex - fromIndex; this.modCount = FastArrayList.this.modCount; } public E set(int index, E e) { E oldValue = FastArrayList.this.elementData(offset + index); FastArrayList.this.elementData[offset + index] = e; return oldValue; } public E get(int index) { return FastArrayList.this.elementData(offset + index); } public int size() { return this.size; } public void add(int index, E e) { parent.add(parentOffset + index, e); this.modCount = parent.modCount; this.size++; } public E remove(int index) { E result = parent.remove(parentOffset + index); this.modCount = parent.modCount; this.size--; return result; } protected void removeRange(int fromIndex, int toIndex) { parent.removeRange(parentOffset + fromIndex, parentOffset + toIndex); this.modCount = parent.modCount; this.size -= toIndex - fromIndex; } public boolean addAll(Collection<? extends E> c) { return addAll(this.size, c); } public boolean addAll(int index, Collection<? extends E> c) { int cSize = c.size(); if (cSize == 0) return false; parent.addAll(parentOffset + index, c); this.modCount = parent.modCount; this.size += cSize; return true; } public Iterator<E> iterator() { return listIterator(0); } public ListIterator<E> listIterator(final int index) { final int offset = this.offset; return new ListIterator<E>() { int cursor = index; int lastRet = -1; public boolean hasNext() { return cursor != SubList.this.size; } @SuppressWarnings("unchecked") public E next() { int i = cursor; if (i >= SubList.this.size) throw new NoSuchElementException(); Object[] elementData = FastArrayList.this.elementData; if (offset + i >= elementData.length) throw new ConcurrentModificationException(); cursor = i + 1; return (E) elementData[offset + (lastRet = i)]; } public boolean hasPrevious() { return cursor != 0; } @SuppressWarnings("unchecked") public E previous() { int i = cursor - 1; if (i < 0) throw new NoSuchElementException(); Object[] elementData = FastArrayList.this.elementData; if (offset + i >= elementData.length) throw new ConcurrentModificationException(); cursor = i; return (E) elementData[offset + (lastRet = i)]; } public int nextIndex() { return cursor; } public int previousIndex() { return cursor - 1; } public void remove() { if (lastRet < 0) throw new IllegalStateException(); try { SubList.this.remove(lastRet); cursor = lastRet; lastRet = -1; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } } public void set(E e) { if (lastRet < 0) throw new IllegalStateException(); try { FastArrayList.this.set(offset + lastRet, e); } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } } public void add(E e) { try { int i = cursor; SubList.this.add(i, e); cursor = i + 1; lastRet = -1; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } } }; } } }