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Closure Compiler is a JavaScript optimizing compiler. It parses your
JavaScript, analyzes it, removes dead code and rewrites and minimizes
what's left. It also checks syntax, variable references, and types, and
warns about common JavaScript pitfalls. It is used in many of Google's
JavaScript apps, including Gmail, Google Web Search, Google Maps, and
Google Docs.
/*
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Igor Bukanov
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
package com.google.javascript.rhino;
import java.io.Serializable;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
/**
* Implementation of resizable array with focus on minimizing memory
* usage by storing few initial array elements in object fields. Can also
* be used as a stack.
*/
public class ObjArray implements Serializable
{
static final long serialVersionUID = 4174889037736658296L;
public ObjArray() { }
public final boolean isSealed()
{
return sealed;
}
public final void seal()
{
sealed = true;
}
public final boolean isEmpty()
{
return size == 0;
}
public final int size()
{
return size;
}
public final void setSize(int newSize)
{
if (newSize < 0) throw new IllegalArgumentException();
if (sealed) throw onSeledMutation();
int N = size;
if (newSize < N) {
for (int i = newSize; i != N; ++i) {
setImpl(i, null);
}
} else if (newSize > N) {
if (newSize > FIELDS_STORE_SIZE) {
ensureCapacity(newSize);
}
}
size = newSize;
}
public final Object get(int index)
{
if (!(0 <= index && index < size)) throw onInvalidIndex(index, size);
return getImpl(index);
}
public final void set(int index, Object value)
{
if (!(0 <= index && index < size)) throw onInvalidIndex(index, size);
if (sealed) throw onSeledMutation();
setImpl(index, value);
}
@SuppressWarnings("fallthrough")
private Object getImpl(int index)
{
switch (index) {
case 0: return f0;
case 1: return f1;
case 2: return f2;
case 3: return f3;
case 4: return f4;
}
return data[index - FIELDS_STORE_SIZE];
}
@SuppressWarnings("fallthrough")
private void setImpl(int index, Object value)
{
switch (index) {
case 0: f0 = value; break;
case 1: f1 = value; break;
case 2: f2 = value; break;
case 3: f3 = value; break;
case 4: f4 = value; break;
default: data[index - FIELDS_STORE_SIZE] = value;
}
}
public int indexOf(Object obj)
{
int N = size;
for (int i = 0; i != N; ++i) {
Object current = getImpl(i);
if (current == obj || (current != null && current.equals(obj))) {
return i;
}
}
return -1;
}
public int lastIndexOf(Object obj)
{
for (int i = size; i != 0;) {
--i;
Object current = getImpl(i);
if (current == obj || (current != null && current.equals(obj))) {
return i;
}
}
return -1;
}
public final Object peek()
{
int N = size;
if (N == 0) throw onEmptyStackTopRead();
return getImpl(N - 1);
}
@SuppressWarnings("fallthrough")
public final Object pop()
{
if (sealed) throw onSeledMutation();
int N = size;
--N;
Object top;
switch (N) {
case -1: throw onEmptyStackTopRead();
case 0: top = f0; f0 = null; break;
case 1: top = f1; f1 = null; break;
case 2: top = f2; f2 = null; break;
case 3: top = f3; f3 = null; break;
case 4: top = f4; f4 = null; break;
default:
top = data[N - FIELDS_STORE_SIZE];
data[N - FIELDS_STORE_SIZE] = null;
}
size = N;
return top;
}
public final void push(Object value)
{
add(value);
}
public final void add(Object value)
{
if (sealed) throw onSeledMutation();
int N = size;
if (N >= FIELDS_STORE_SIZE) {
ensureCapacity(N + 1);
}
size = N + 1;
setImpl(N, value);
}
@SuppressWarnings("fallthrough")
public final void add(int index, Object value)
{
int N = size;
if (!(0 <= index && index <= N)) throw onInvalidIndex(index, N + 1);
if (sealed) throw onSeledMutation();
Object tmp;
switch (index) {
case 0:
if (N == 0) { f0 = value; break; }
tmp = f0; f0 = value; value = tmp;
case 1:
if (N == 1) { f1 = value; break; }
tmp = f1; f1 = value; value = tmp;
case 2:
if (N == 2) { f2 = value; break; }
tmp = f2; f2 = value; value = tmp;
case 3:
if (N == 3) { f3 = value; break; }
tmp = f3; f3 = value; value = tmp;
case 4:
if (N == 4) { f4 = value; break; }
tmp = f4; f4 = value; value = tmp;
index = FIELDS_STORE_SIZE;
default:
ensureCapacity(N + 1);
if (index != N) {
System.arraycopy(data, index - FIELDS_STORE_SIZE,
data, index - FIELDS_STORE_SIZE + 1,
N - index);
}
data[index - FIELDS_STORE_SIZE] = value;
}
size = N + 1;
}
@SuppressWarnings("fallthrough")
public final void remove(int index)
{
int N = size;
if (!(0 <= index && index < N)) throw onInvalidIndex(index, N);
if (sealed) throw onSeledMutation();
--N;
switch (index) {
case 0:
if (N == 0) { f0 = null; break; }
f0 = f1;
case 1:
if (N == 1) { f1 = null; break; }
f1 = f2;
case 2:
if (N == 2) { f2 = null; break; }
f2 = f3;
case 3:
if (N == 3) { f3 = null; break; }
f3 = f4;
case 4:
if (N == 4) { f4 = null; break; }
f4 = data[0];
index = FIELDS_STORE_SIZE;
default:
if (index != N) {
System.arraycopy(data, index - FIELDS_STORE_SIZE + 1,
data, index - FIELDS_STORE_SIZE,
N - index);
}
data[N - FIELDS_STORE_SIZE] = null;
}
size = N;
}
public final void clear()
{
if (sealed) throw onSeledMutation();
int N = size;
for (int i = 0; i != N; ++i) {
setImpl(i, null);
}
size = 0;
}
public final Object[] toArray()
{
Object[] array = new Object[size];
toArray(array, 0);
return array;
}
public final void toArray(Object[] array)
{
toArray(array, 0);
}
@SuppressWarnings("fallthrough")
public final void toArray(Object[] array, int offset)
{
int N = size;
switch (N) {
default:
System.arraycopy(data, 0, array, offset + FIELDS_STORE_SIZE,
N - FIELDS_STORE_SIZE);
case 5: array[offset + 4] = f4;
case 4: array[offset + 3] = f3;
case 3: array[offset + 2] = f2;
case 2: array[offset + 1] = f1;
case 1: array[offset + 0] = f0;
case 0: break;
}
}
private void ensureCapacity(int minimalCapacity)
{
int required = minimalCapacity - FIELDS_STORE_SIZE;
if (required <= 0) throw new IllegalArgumentException();
if (data == null) {
int alloc = FIELDS_STORE_SIZE * 2;
if (alloc < required) {
alloc = required;
}
data = new Object[alloc];
} else {
int alloc = data.length;
if (alloc < required) {
if (alloc <= FIELDS_STORE_SIZE) {
alloc = FIELDS_STORE_SIZE * 2;
} else {
alloc *= 2;
}
if (alloc < required) {
alloc = required;
}
Object[] tmp = new Object[alloc];
if (size > FIELDS_STORE_SIZE) {
System.arraycopy(data, 0, tmp, 0,
size - FIELDS_STORE_SIZE);
}
data = tmp;
}
}
}
private static RuntimeException onInvalidIndex(int index, int upperBound)
{
// \u2209 is "NOT ELEMENT OF"
String msg = index+" \u2209 [0, "+upperBound+')';
throw new IndexOutOfBoundsException(msg);
}
private static RuntimeException onEmptyStackTopRead()
{
throw new RuntimeException("Empty stack");
}
private static RuntimeException onSeledMutation()
{
throw new IllegalStateException("Attempt to modify sealed array");
}
private void writeObject(ObjectOutputStream os) throws IOException
{
os.defaultWriteObject();
int N = size;
for (int i = 0; i != N; ++i) {
Object obj = getImpl(i);
os.writeObject(obj);
}
}
private void readObject(ObjectInputStream is)
throws IOException, ClassNotFoundException
{
is.defaultReadObject(); // It reads size
int N = size;
if (N > FIELDS_STORE_SIZE) {
data = new Object[N - FIELDS_STORE_SIZE];
}
for (int i = 0; i != N; ++i) {
Object obj = is.readObject();
setImpl(i, obj);
}
}
// Number of data elements
private int size;
private boolean sealed;
private static final int FIELDS_STORE_SIZE = 5;
private transient Object f0, f1, f2, f3, f4;
private transient Object[] data;
}