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package com.mayabot.nlp.hppc;

import java.util.Arrays;

/**
 * An array-backed list of ints.
 */

public class IntArrayList {

    public final static int DEFAULT_EXPECTED_ELEMENTS = 4;

    /**
     * An immutable empty buffer (array).
     */
    public final static
    int[] EMPTY_ARRAY = new int[0];


    /**
     * Internal array for storing the list. The array may be larger than the current size
     * ({@link #size()}).
     */
    public int[] buffer = EMPTY_ARRAY;

    /**
     * Current number of elements stored in {@link #buffer}.
     */
    public int elementsCount;

    /**
     * Buffer resizing strategy.
     */
    protected final ArraySizingStrategy resizer;

    /**
     * New instance with sane defaults.
     */
    public IntArrayList() {
        this(DEFAULT_EXPECTED_ELEMENTS);
    }

    /**
     * New instance with sane defaults.
     *
     * @param expectedElements The expected number of elements guaranteed not to cause buffer
     *                         expansion (inclusive).
     */
    public IntArrayList(int expectedElements) {
        this(expectedElements, new BoundedProportionalArraySizingStrategy());
    }


    /**
     * New instance with sane defaults.
     *
     * @param expectedElements The expected number of elements guaranteed not to cause buffer
     *                         expansion (inclusive).
     * @param resizer          Underlying buffer sizing strategy.
     */
    public IntArrayList(int expectedElements, ArraySizingStrategy resizer) {
        assert resizer != null;
        this.resizer = resizer;
        ensureCapacity(expectedElements);
    }


    public void add(int e1) {
        ensureBufferSpace(1);
        buffer[elementsCount++] = e1;
    }

    /**
     * Appends two elements at the end of the list. To add more than two elements,
     * use add (vararg-version) or access the buffer directly (tight
     * loop).
     */
    public void add(int e1, int e2) {
        ensureBufferSpace(2);
        buffer[elementsCount++] = e1;
        buffer[elementsCount++] = e2;
    }

    /**
     * Add all elements from a range of given array to the list.
     */
    public void add(int[] elements, int start, int length) {
        assert length >= 0 : "Length must be >= 0";

        ensureBufferSpace(length);
        System.arraycopy(elements, start, buffer, elementsCount, length);
        elementsCount += length;
    }

    /**
     * Vararg-signature method for adding elements at the end of the list.
     * 

* This method is handy, but costly if used in tight loops (anonymous array * passing) *

*/ /* */ public final void add(int... elements) { add(elements, 0, elements.length); } public int get(int index) { assert (index >= 0 && index < size()) : "Index " + index + " out of bounds [" + 0 + ", " + size() + ")."; return buffer[index]; } public int set(int index, int e1) { assert (index >= 0 && index < size()) : "Index " + index + " out of bounds [" + 0 + ", " + size() + ")."; final int v = buffer[index]; buffer[index] = e1; return v; } public int remove(int index) { assert (index >= 0 && index < size()) : "Index " + index + " out of bounds [" + 0 + ", " + size() + ")."; final int v = buffer[index]; if (index + 1 < elementsCount) { System.arraycopy(buffer, index + 1, buffer, index, elementsCount - index - 1); } elementsCount--; buffer[elementsCount] = 0; return v; } public boolean contains(int e1) { return indexOf(e1) >= 0; } public int indexOf(int e1) { for (int i = 0; i < elementsCount; i++) { if (((buffer[i]) == (e1))) { return i; } } return -1; } public int lastIndexOf(int e1) { for (int i = elementsCount - 1; i >= 0; i--) { if (((buffer[i]) == (e1))) { return i; } } return -1; } public boolean isEmpty() { return elementsCount == 0; } /** * Ensure this container can hold at least the given number of elements * without resizing its buffers. * * @param expectedElements The total number of elements, inclusive. */ public void ensureCapacity(int expectedElements) { final int bufferLen = (buffer == null ? 0 : buffer.length); if (expectedElements > bufferLen) { ensureBufferSpace(expectedElements - size()); } } /** * Ensures the internal buffer has enough free slots to store * expectedAdditions. Increases internal buffer size if needed. */ protected void ensureBufferSpace(int expectedAdditions) { final int bufferLen = (buffer == null ? 0 : buffer.length); if (elementsCount + expectedAdditions > bufferLen) { final int newSize = resizer.grow(bufferLen, elementsCount, expectedAdditions); assert newSize >= elementsCount + expectedAdditions : "Resizer failed to" + " return sensible new size: " + newSize + " <= " + (elementsCount + expectedAdditions); this.buffer = Arrays.copyOf(buffer, newSize); } } /** * Truncate or expand the list to the new size. If the list is truncated, the * buffer will not be reallocated (use {@link #trimToSize()} if you need a * truncated buffer), but the truncated values will be reset to the default * value (zero). If the list is expanded, the elements beyond the current size * are initialized with JVM-defaults (zero or null values). */ public void resize(int newSize) { if (newSize <= buffer.length) { if (newSize < elementsCount) { Arrays.fill(buffer, newSize, elementsCount, 0); } else { Arrays.fill(buffer, elementsCount, newSize, 0); } } else { ensureCapacity(newSize); } this.elementsCount = newSize; } public int size() { return elementsCount; } /** * Trim the internal buffer to the current size. */ public void trimToSize() { if (size() != this.buffer.length) { this.buffer = toArray(); } } /** * Sets the number of stored elements to zero. Releases and initializes the * internal storage array to default values. To clear the list without * cleaning the buffer, simply set the {@link #elementsCount} field to zero. */ public void clear() { Arrays.fill(buffer, 0, elementsCount, 0); this.elementsCount = 0; } /** * Sets the number of stored elements to zero and releases the internal * storage array. */ public void release() { this.buffer = EMPTY_ARRAY; this.elementsCount = 0; } /** *

The returned array is sized to match exactly * the number of elements of the stack.

*/ public int[] toArray() { return Arrays.copyOf(buffer, elementsCount); } /** * Clone this object. The returned clone will reuse the same hash function and * array resizing strategy. */ @Override public IntArrayList clone() { try { /* */ final IntArrayList cloned = (IntArrayList) super.clone(); cloned.buffer = buffer.clone(); return cloned; } catch (CloneNotSupportedException e) { throw new RuntimeException(e); } } @Override public int hashCode() { int h = 1, max = elementsCount; for (int i = 0; i < max; i++) { h = 31 * h + mix32(this.buffer[i]); } return h; } /** * Returns true only if the other object is an instance of * the same class and with the same elements. */ @Override public boolean equals(Object obj) { return obj != null && getClass() == obj.getClass() && equalElements(getClass().cast(obj)); } /** * MH3's plain finalization step. */ private static int mix32(int k) { k = (k ^ (k >>> 16)) * 0x85ebca6b; k = (k ^ (k >>> 13)) * 0xc2b2ae35; return k ^ (k >>> 16); } protected boolean equalElements(IntArrayList other) { int max = size(); if (other.size() != max) { return false; } for (int i = 0; i < max; i++) { if (!((other.get(i)) == (get(i)))) { return false; } } return true; } /** * Create a list from a variable number of arguments or an array of int. * The elements are copied from the argument to the internal buffer. */ /* */ public static IntArrayList from(int... elements) { final IntArrayList list = new IntArrayList(elements.length); list.add(elements); return list; } }




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