bool
js::XDRAtom(XDRState<mode> *xdr, MutableHandleAtom atomp)
{
AssertCanGC();
if (mode == XDR_ENCODE) {
uint32_t nchars = atomp->length();
if (!xdr->codeUint32(&nchars))
return false;
jschar *chars = const_cast<jschar *>(atomp->getChars(xdr->cx()));
if (!chars)
return false;
return xdr->codeChars(chars, nchars);
}
/* Avoid JSString allocation for already existing atoms. See bug 321985. */
uint32_t nchars;
if (!xdr->codeUint32(&nchars))
return false;
JSContext *cx = xdr->cx();
JSAtom *atom;
#if IS_LITTLE_ENDIAN
/* Directly access the little endian chars in the XDR buffer. */
const jschar *chars = reinterpret_cast<const jschar *>(xdr->buf.read(nchars * sizeof(jschar)));
atom = AtomizeChars<CanGC>(cx, chars, nchars);
#else
/*
* We must copy chars to a temporary buffer to convert between little and
* big endian data.
*/
jschar *chars;
jschar stackChars[256];
if (nchars <= ArrayLength(stackChars)) {
chars = stackChars;
} else {
/*
* This is very uncommon. Don't use the tempLifoAlloc arena for this as
* most allocations here will be bigger than tempLifoAlloc's default
* chunk size.
*/
chars = cx->runtime->pod_malloc<jschar>(nchars);
if (!chars)
return false;
}
JS_ALWAYS_TRUE(xdr->codeChars(chars, nchars));
atom = AtomizeChars<CanGC>(cx, chars, nchars);
if (chars != stackChars)
js_free(chars);
#endif /* !IS_LITTLE_ENDIAN */
if (!atom)
return false;
atomp.set(atom);
return true;
}
bool
js::XDRAtom(XDRState<mode> *xdr, MutableHandleAtom atomp)
{
if (mode == XDR_ENCODE) {
static_assert(JSString::MAX_LENGTH <= INT32_MAX, "String length must fit in 31 bits");
uint32_t length = atomp->length();
uint32_t lengthAndEncoding = (length << 1) | uint32_t(atomp->hasLatin1Chars());
if (!xdr->codeUint32(&lengthAndEncoding))
return false;
JS::AutoCheckCannotGC nogc;
return atomp->hasLatin1Chars()
? xdr->codeChars(atomp->latin1Chars(nogc), length)
: xdr->codeChars(const_cast<char16_t*>(atomp->twoByteChars(nogc)), length);
}
/* Avoid JSString allocation for already existing atoms. See bug 321985. */
uint32_t lengthAndEncoding;
if (!xdr->codeUint32(&lengthAndEncoding))
return false;
uint32_t length = lengthAndEncoding >> 1;
bool latin1 = lengthAndEncoding & 0x1;
JSContext *cx = xdr->cx();
JSAtom *atom;
if (latin1) {
const Latin1Char *chars = reinterpret_cast<const Latin1Char *>(xdr->buf.read(length));
atom = AtomizeChars(cx, chars, length);
} else {
#if IS_LITTLE_ENDIAN
/* Directly access the little endian chars in the XDR buffer. */
const char16_t *chars = reinterpret_cast<const char16_t *>(xdr->buf.read(length * sizeof(char16_t)));
atom = AtomizeChars(cx, chars, length);
#else
/*
* We must copy chars to a temporary buffer to convert between little and
* big endian data.
*/
char16_t *chars;
char16_t stackChars[256];
if (length <= ArrayLength(stackChars)) {
chars = stackChars;
} else {
/*
* This is very uncommon. Don't use the tempLifoAlloc arena for this as
* most allocations here will be bigger than tempLifoAlloc's default
* chunk size.
*/
chars = cx->runtime()->pod_malloc<char16_t>(length);
if (!chars)
return false;
}
JS_ALWAYS_TRUE(xdr->codeChars(chars, length));
atom = AtomizeChars(cx, chars, length);
if (chars != stackChars)
js_free(chars);
#endif /* !IS_LITTLE_ENDIAN */
}
if (!atom)
return false;
atomp.set(atom);
return true;
}
