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'rapiddweller Common' is an open source Java library forked from Databene Commons by Volker Bergmann. It provides extensions to the Java core library by utility classes, abstract concepts and concrete implementations.

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/*
 * Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.rapiddweller.common.array;

import com.rapiddweller.common.converter.ToStringConverter;

/**
 * Helper class for constructing int arrays.
 * Created: 27.12.2010 07:45:22
 *
 * @author Volker Bergmann
 * @since 1.0.6
 */
public class IntArrayBuilder {

  private static final int DEFAULT_INITIAL_CAPACITY = 10;

  // constructors ------------------------------------------------------------

  /**
   * The Buffer.
   */
  protected int[] buffer;
  /**
   * The Item count.
   */
  protected int itemCount;

  // constructors ------------------------------------------------------------

  /**
   * Instantiates a new Int array builder.
   */
  public IntArrayBuilder() {
    this(DEFAULT_INITIAL_CAPACITY);
  }

  /**
   * Instantiates a new Int array builder.
   *
   * @param initialCapacity the initial capacity
   */
  public IntArrayBuilder(int initialCapacity) {
    this.buffer = createBuffer(initialCapacity);
  }

  // interface ---------------------------------------------------------------

  /**
   * Length int.
   *
   * @return the int
   */
  public int length() {
    return itemCount;
  }

  /**
   * Get int.
   *
   * @param index the index
   * @return the int
   */
  public int get(int index) {
    return this.buffer[index];
  }

  /**
   * Set.
   *
   * @param index the index
   * @param value the value
   */
  public void set(int index, int value) {
    if (index < this.buffer.length) {
      this.buffer[index] = value;
    } else {
      for (int i = buffer.length; i < index; i++) {
        add(0);
      }
      add(value);
    }
  }

  /**
   * Add int array builder.
   *
   * @param item the item
   * @return the int array builder
   */
  public IntArrayBuilder add(int item) {
    if (this.buffer == null) {
      throw new UnsupportedOperationException("ArrayBuilder cannot be reused after invoking toArray()");
    }
    if (itemCount >= buffer.length - 1) {
      int[] newBuffer = createBuffer(buffer.length * 2);
      System.arraycopy(buffer, 0, newBuffer, 0, buffer.length);
      this.buffer = newBuffer;
    }
    buffer[itemCount++] = item;
    return this;
  }

  /**
   * Add all.
   *
   * @param elements the elements
   */
  public void addAll(int[] elements) {
    addAll(elements, 0, elements.length);
  }

  /**
   * Add all.
   *
   * @param elements  the elements
   * @param fromIndex the from index
   * @param toIndex   the to index
   */
  public void addAll(int[] elements, int fromIndex, int toIndex) {
    for (int i = fromIndex; i < toIndex; i++) {
      add(elements[i]);
    }
  }

  // private helper method -------------------------------------------------------------------------------------------

  private static int[] createBuffer(int capacity) {
    return new int[capacity];
  }

  /**
   * Get and delete buffer int [ ].
   *
   * @return the int [ ]
   */
  public int[] getAndDeleteBuffer() {
    if (this.buffer == null) {
      throw new UnsupportedOperationException("buffer already deleted");
    }
    return this.buffer;
  }

  /**
   * To array int [ ].
   *
   * @return the int [ ]
   */
  public int[] toArray() {
    if (this.buffer == null) {
      throw new UnsupportedOperationException("buffer was deleted");
    }
    int[] result = new int[this.itemCount];
    System.arraycopy(buffer, 0, result, 0, this.itemCount);
    this.itemCount = 0;
    buffer = null;
    return result;
  }

  @Override
  public String toString() {
    StringBuilder builder = new StringBuilder();
    for (int i = 0; i < itemCount; i++) {
      if (i > 0) {
        builder.append(", ");
      }
      builder.append(ToStringConverter.convert(buffer[i], ""));
    }
    return builder.toString();
  }

}