org.mozilla.javascript.ObjArray Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of rhino-runtime Show documentation
Show all versions of rhino-runtime Show documentation
Rhino is an open-source implementation of JavaScript written entirely in Java.
It is typically embedded into Java applications to provide scripting to end users.
The newest version!
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
/**
* 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 {
private 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);
}
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];
}
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);
}
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);
}
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;
/* fall through */ case 1:
if (N == 1) {
f1 = value;
break;
}
tmp = f1;
f1 = value;
value = tmp;
/* fall through */ case 2:
if (N == 2) {
f2 = value;
break;
}
tmp = f2;
f2 = value;
value = tmp;
/* fall through */ case 3:
if (N == 3) {
f3 = value;
break;
}
tmp = f3;
f3 = value;
value = tmp;
/* fall through */ case 4:
if (N == 4) {
f4 = value;
break;
}
tmp = f4;
f4 = value;
value = tmp;
index = FIELDS_STORE_SIZE;
/* fall through */ 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;
}
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;
/* fall through */ case 1:
if (N == 1) {
f1 = null;
break;
}
f1 = f2;
/* fall through */ case 2:
if (N == 2) {
f2 = null;
break;
}
f2 = f3;
/* fall through */ case 3:
if (N == 3) {
f3 = null;
break;
}
f3 = f4;
/* fall through */ case 4:
if (N == 4) {
f4 = null;
break;
}
f4 = data[0];
index = FIELDS_STORE_SIZE;
/* fall through */ 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);
}
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);
/* fall through */ case 5:
array[offset + 4] = f4;
/* fall through */ case 4:
array[offset + 3] = f3;
/* fall through */ case 3:
array[offset + 2] = f2;
/* fall through */ case 2:
array[offset + 1] = f1;
/* fall through */ case 1:
array[offset + 0] = f0;
/* fall through */ 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;
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy