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 org.apache.servicemix.bundles.rhino
Show all versions of org.apache.servicemix.bundles.rhino
This OSGi bundle wraps rhino and rhino-engine ${pkgVersion} jar files.
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 - 2024 Weber Informatics LLC | Privacy Policy