/*
* Copyright (C) 2003-2011 eXo Platform SAS.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.etk.common.utils;
import java.io.IOException;
import java.io.Writer;
import java.lang.reflect.Constructor;
import org.etk.common.logging.Logger;
/**
* Created by The eXo Platform SAS
* Author : eXoPlatform
* thanhvucong.78@google.com
* Aug 4, 2011
*/
public class StringBundler {
public static final int UNSAFE_CREATE_THRESHOLD = GetterUtil.getInteger(System.getProperty(StringBundler.class.getName() + ".unsafe.create.threshold"));
public StringBundler() {
_array = new String[_DEFAULT_ARRAY_CAPACITY];
}
public StringBundler(int initialCapacity) {
if (initialCapacity <= 0) {
throw new IllegalArgumentException();
}
_array = new String[initialCapacity];
}
public StringBundler(String s) {
_array = new String[_DEFAULT_ARRAY_CAPACITY];
_array[0] = s;
_arrayIndex = 1;
}
public StringBundler(String[] stringArray) {
this(stringArray, 0);
}
public StringBundler(String[] stringArray, int extraSpace) {
_array = new String[stringArray.length + extraSpace];
for (int i = 0; i < stringArray.length; i++) {
String s = stringArray[i];
if ((s != null) && (s.length() > 0)) {
_array[_arrayIndex++] = s;
}
}
}
public StringBundler append(boolean b) {
if (b) {
return append(_TRUE);
}
else {
return append(_FALSE);
}
}
public StringBundler append(char c) {
return append(String.valueOf(c));
}
public StringBundler append(char[] charArray) {
if (charArray == null) {
return append("null");
}
else {
return append(new String(charArray));
}
}
public StringBundler append(double d) {
return append(Double.toString(d));
}
public StringBundler append(float f) {
return append(Float.toString(f));
}
public StringBundler append(int i) {
return append(Integer.toString(i));
}
public StringBundler append(long l) {
return append(Long.toString(l));
}
public StringBundler append(Object obj) {
return append(String.valueOf(obj));
}
public StringBundler append(String s) {
if (s == null) {
s = StringPool.NULL;
}
if (s.length() == 0) {
return this;
}
if (_arrayIndex >= _array.length) {
expandCapacity(_array.length * 2);
}
_array[_arrayIndex++] = s;
return this;
}
public StringBundler append(String[] stringArray) {
if ((stringArray == null) || (stringArray.length == 0)) {
return this;
}
if ((_array.length - _arrayIndex) < stringArray.length) {
expandCapacity((_array.length + stringArray.length) * 2);
}
for (int i = 0; i < stringArray.length; i++) {
String s = stringArray[i];
if ((s != null) && (s.length() > 0)) {
_array[_arrayIndex++] = s;
}
}
return this;
}
public StringBundler append(StringBundler sb) {
if ((sb == null) || (sb._arrayIndex == 0)) {
return this;
}
if ((_array.length - _arrayIndex) < sb._arrayIndex) {
expandCapacity((_array.length + sb._arrayIndex) * 2);
}
System.arraycopy(sb._array, 0, _array, _arrayIndex, sb._arrayIndex);
_arrayIndex += sb._arrayIndex;
return this;
}
public int capacity() {
return _array.length;
}
public int index() {
return _arrayIndex;
}
public int length() {
int length = 0;
for (int i = 0; i < _arrayIndex; i++) {
length += _array[i].length();
}
return length;
}
public void setIndex(int newIndex) {
if (newIndex < 0) {
throw new ArrayIndexOutOfBoundsException(newIndex);
}
if (newIndex > _array.length) {
String[] newArray = new String[newIndex];
System.arraycopy(_array, 0, newArray, 0, _arrayIndex);
_array = newArray;
}
if (_arrayIndex < newIndex) {
for (int i = _arrayIndex; i < newIndex; i++) {
_array[i] = StringPool.BLANK;
}
}
if (_arrayIndex > newIndex) {
for (int i = newIndex; i < _arrayIndex; i++) {
_array[i] = null;
}
}
_arrayIndex = newIndex;
}
public void setStringAt(String s, int index) {
if ((index < 0) || (index >= _arrayIndex)) {
throw new ArrayIndexOutOfBoundsException(index);
}
_array[index] = s;
}
public String stringAt(int index) {
if ((index < 0) || (index >= _arrayIndex)) {
throw new ArrayIndexOutOfBoundsException(index);
}
return _array[index];
}
public String toString() {
if (_arrayIndex == 0) {
return StringPool.BLANK;
}
if (_arrayIndex == 1) {
return _array[0];
}
if (_arrayIndex == 2) {
return _array[0].concat(_array[1]);
}
int length = 0;
for (int i = 0; i < _arrayIndex; i++) {
length += _array[i].length();
}
if ((_unsafeStringConstructor != null) &&
(length >= UNSAFE_CREATE_THRESHOLD)) {
return unsafeCreate(_array, _arrayIndex, length);
}
else if (_arrayIndex == 3) {
return _array[0].concat(_array[1]).concat(_array[2]);
}
else {
return safeCreate(_array, _arrayIndex, length);
}
}
public void writeTo(Writer writer) throws IOException {
for (int i = 0; i < _arrayIndex; i++) {
writer.write(_array[i]);
}
}
protected void expandCapacity(int newCapacity) {
String[] newArray = new String[newCapacity];
System.arraycopy(_array, 0, newArray, 0, _arrayIndex);
_array = newArray;
}
protected String safeCreate(String[] array, int index, int length) {
StringBuilder sb = new StringBuilder(length);
for (int i = 0; i < index; i++) {
sb.append(array[i]);
}
return sb.toString();
}
protected String unsafeCreate(String[] array, int index, int length) {
char[] charArray = new char[length];
int offset = 0;
for (int i = 0; i < index; i++) {
String s = array[i];
s.getChars(0, s.length(), charArray, offset);
offset += s.length();
}
try {
return _unsafeStringConstructor.newInstance(0, length, charArray);
}
catch (Exception e) {
throw new IllegalStateException(e);
}
}
private static final int _DEFAULT_ARRAY_CAPACITY = 16;
private static final String _FALSE = "false";
private static final String _TRUE = "true";
private static Logger _log = Logger.getLogger(StringBundler.class);
private static Constructor<String> _unsafeStringConstructor;
static {
if (UNSAFE_CREATE_THRESHOLD > 0) {
try {
_unsafeStringConstructor = String.class.getDeclaredConstructor(
int.class, int.class, char[].class);
_unsafeStringConstructor.setAccessible(true);
}
catch (Exception e) {
_log.error("", e);
}
}
}
private String[] _array;
private int _arrayIndex;
}