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* The Universal Permissive License (UPL), Version 1.0
*
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* copyright rights in the Software, and any and all patent rights owned or
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* the Larger Works (as defined below), to deal in both
*
* (a) the Software, and
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* (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
* one is included with the Software each a "Larger Work" to which the Software
* is contributed by such licensors),
*
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* Software and the Larger Work(s), and to sublicense the foregoing rights on
* either these or other terms.
*
* This license is subject to the following condition:
*
* The above copyright notice and either this complete permission notice or at a
* minimum a reference to the UPL must be included in all copies or substantial
* portions of the Software.
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package com.oracle.truffle.js.builtins.helper;
import java.util.*;
import com.oracle.truffle.api.CompilerDirectives.*;
import com.oracle.truffle.js.runtime.JSRuntime;
String escape/unescape utility class. Used by B.2.1 escape() and B.2.2 unescape() methods as
defined in ECMAScript 5.1.
/**
* String escape/unescape utility class. Used by B.2.1 escape() and B.2.2 unescape() methods as
* defined in ECMAScript 5.1.
*
*/
public final class StringEscape {
private static final BitSet dontEscapeSet;
private StringEscape() {
// should not be constructed
}
static {
BitSet unescaped = new BitSet(128);
unescaped.set('a', 'z' + 1);
unescaped.set('A', 'Z' + 1);
unescaped.set('0', '9' + 1);
unescaped.set('@');
unescaped.set('*');
unescaped.set('_');
unescaped.set('+');
unescaped.set('-');
unescaped.set('.');
unescaped.set('/');
dontEscapeSet = unescaped;
}
@TruffleBoundary
public static String escape(String s) {
int len = s.length();
StringBuilder out = null;
for (int i = 0; i < len; i++) {
int c = s.charAt(i);
if (dontEscapeSet.get(c)) {
if (out != null) {
out.append((char) c);
}
} else {
if (out == null) {
out = allocBuffer(s, i, len + 16);
}
out.append('%');
if (c < 256) {
char ch = hexChar((c >> 4) & 0xF);
out.append(ch);
ch = hexChar(c & 0xF);
out.append(ch);
} else {
out.append('u');
char ch = hexChar((c >> 12) & 0xF);
out.append(ch);
ch = hexChar((c >> 8) & 0xF);
out.append(ch);
ch = hexChar((c >> 4) & 0xF);
out.append(ch);
ch = hexChar(c & 0xF);
out.append(ch);
}
}
}
return out != null ? out.toString() : s;
}
@TruffleBoundary
public static String unescape(String string) {
int len = string.length();
StringBuilder builder = null;
int k = 0;
while (k < len) {
char c = string.charAt(k);
if (c == '%') {
if (builder == null) {
builder = allocBuffer(string, k, len);
}
if (k <= (len - 6)) {
if (unescapeU0000(string, builder, k)) {
k += 6;
continue;
}
}
if (k <= (len - 3)) {
if (unescape00(string, builder, k)) {
k += 3;
continue;
}
}
}
if (builder != null) {
builder.append(c);
}
k++;
}
return builder != null ? builder.toString() : string;
}
private static StringBuilder allocBuffer(String s, int i, int estimatedLength) {
StringBuilder newBuffer = new StringBuilder(estimatedLength);
if (i > 0) {
newBuffer.append(s, 0, i);
}
return newBuffer;
}
private static boolean unescapeU0000(String string, StringBuilder builder, int k) {
char c1 = string.charAt(k + 1);
if (c1 == 'u') {
char c2 = string.charAt(k + 2);
char c3 = string.charAt(k + 3);
char c4 = string.charAt(k + 4);
char c5 = string.charAt(k + 5);
if (JSRuntime.isHex(c2) && JSRuntime.isHex(c3) && JSRuntime.isHex(c4) && JSRuntime.isHex(c5)) {
char newC = (char) (hexVal(c2) * 16 * 16 * 16 + hexVal(c3) * 16 * 16 + hexVal(c4) * 16 + hexVal(c5));
builder.append(newC);
return true;
}
}
return false;
}
private static boolean unescape00(String string, StringBuilder builder, int k) {
char c1 = string.charAt(k + 1);
char c2 = string.charAt(k + 2);
if (JSRuntime.isHex(c1) && JSRuntime.isHex(c2)) {
char newC = (char) (hexVal(c1) * 16 + hexVal(c2));
builder.append(newC);
return true;
}
return false;
}
private static char hexChar(int value) {
if (value < 10) {
return (char) ('0' + value);
} else {
return (char) ('A' + value - 10);
}
}
private static int hexVal(char c) {
int value = JSRuntime.valueInHex(c);
if (value < 0) {
assert false : "not a hex character";
return 0;
}
return value;
}
}