JSAtom *
js_AtomizeString(JSContext *cx, JSString *str, uintN flags)
{
jsval v;
JSAtomState *state;
JSDHashTable *table;
JSAtomHashEntry *entry;
JSString *key;
uint32 gen;
JS_ASSERT(!(flags & ~(ATOM_PINNED|ATOM_INTERNED|ATOM_TMPSTR|ATOM_NOCOPY)));
JS_ASSERT_IF(flags & ATOM_NOCOPY, flags & ATOM_TMPSTR);
if (str->isAtomized())
return (JSAtom *) STRING_TO_JSVAL(str);
size_t length = str->length();
if (length == 1) {
jschar c = str->chars()[0];
if (c < UNIT_STRING_LIMIT)
return (JSAtom *) STRING_TO_JSVAL(JSString::unitString(c));
}
/*
* Here we know that JSString::intStringTable covers only 256 (or at least
* not 1000 or more) chars. We rely on order here to resolve the unit vs.
* int string atom identity issue by giving priority to unit strings for
* '0' through '9' (see JSString::intString in jsstrinlines.h).
*/
JS_STATIC_ASSERT(INT_STRING_LIMIT <= 999);
if (2 <= length && length <= 3) {
const jschar *chars = str->chars();
if ('1' <= chars[0] && chars[0] <= '9' &&
'0' <= chars[1] && chars[1] <= '9' &&
(length == 2 || ('0' <= chars[2] && chars[2] <= '9'))) {
jsint i = (chars[0] - '0') * 10 + chars[1] - '0';
if (length == 3)
i = i * 10 + chars[2] - '0';
if (jsuint(i) < INT_STRING_LIMIT)
return (JSAtom *) STRING_TO_JSVAL(JSString::intString(i));
}
}
state = &cx->runtime->atomState;
table = &state->stringAtoms;
JS_LOCK(cx, &state->lock);
entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, str, JS_DHASH_ADD));
if (!entry)
goto failed_hash_add;
if (entry->keyAndFlags != 0) {
key = (JSString *)ATOM_ENTRY_KEY(entry);
} else {
/*
* We created a new hashtable entry. Unless str is already allocated
* from the GC heap and flat, we have to release state->lock as
* string construction is a complex operation. For example, it can
* trigger GC which may rehash the table and make the entry invalid.
*/
++table->generation;
if (!(flags & ATOM_TMPSTR) && str->isFlat()) {
str->flatClearMutable();
key = str;
} else {
gen = table->generation;
JS_UNLOCK(cx, &state->lock);
if (flags & ATOM_TMPSTR) {
if (flags & ATOM_NOCOPY) {
key = js_NewString(cx, str->flatChars(), str->flatLength());
if (!key)
return NULL;
/* Finish handing off chars to the GC'ed key string. */
str->mChars = NULL;
} else {
key = js_NewStringCopyN(cx, str->flatChars(), str->flatLength());
if (!key)
return NULL;
}
} else {
JS_ASSERT(str->isDependent());
if (!js_UndependString(cx, str))
return NULL;
key = str;
}
JS_LOCK(cx, &state->lock);
if (table->generation == gen) {
JS_ASSERT(entry->keyAndFlags == 0);
} else {
entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, key,
JS_DHASH_ADD));
if (!entry)
goto failed_hash_add;
if (entry->keyAndFlags != 0) {
key = (JSString *)ATOM_ENTRY_KEY(entry);
goto finish;
}
++table->generation;
}
}
INIT_ATOM_ENTRY(entry, key);
key->flatSetAtomized();
}
finish:
ADD_ATOM_ENTRY_FLAGS(entry, flags & (ATOM_PINNED | ATOM_INTERNED));
JS_ASSERT(key->isAtomized());
v = STRING_TO_JSVAL(key);
cx->weakRoots.lastAtom = v;
JS_UNLOCK(cx, &state->lock);
return (JSAtom *)v;
failed_hash_add:
JS_UNLOCK(cx, &state->lock);
JS_ReportOutOfMemory(cx);
return NULL;
}
