/*
* When the jschars reside in a freshly allocated buffer the memory can be used
* as a new JSAtom's storage without copying. The contract is that the caller no
* longer owns the memory and this method is responsible for freeing the memory.
*/
MOZ_ALWAYS_INLINE
static JSAtom *
AtomizeAndtake(ExclusiveContext *cx, jschar *tbchars, size_t length, InternBehavior ib)
{
JS_ASSERT(tbchars[length] == 0);
if (JSAtom *s = cx->staticStrings().lookup(tbchars, length)) {
js_free(tbchars);
return s;
}
AtomHasher::Lookup lookup(tbchars, length);
AtomSet::Ptr pp = cx->permanentAtoms().readonlyThreadsafeLookup(lookup);
if (pp) {
js_free(tbchars);
return pp->asPtr();
}
AutoLockForExclusiveAccess lock(cx);
/*
* If a GC occurs at js_NewStringCopy then |p| will still have the correct
* hash, allowing us to avoid rehashing it. Even though the hash is
* unchanged, we need to re-lookup the table position because a last-ditch
* GC will potentially free some table entries.
*/
AtomSet& atoms = cx->atoms();
AtomSet::AddPtr p = atoms.lookupForAdd(lookup);
if (p) {
JSAtom *atom = p->asPtr();
p->setTagged(bool(ib));
js_free(tbchars);
return atom;
}
AutoCompartment ac(cx, cx->atomsCompartment());
JSFlatString *flat = js_NewString<NoGC>(cx, tbchars, length);
if (!flat) {
js_free(tbchars);
js_ReportOutOfMemory(cx);
return nullptr;
}
JSAtom *atom = flat->morphAtomizedStringIntoAtom();
if (!atoms.relookupOrAdd(p, lookup, AtomStateEntry(atom, bool(ib)))) {
js_ReportOutOfMemory(cx); /* SystemAllocPolicy does not report OOM. */
return nullptr;
}
return atom;
}
/*
* Callers passing OwnChars have freshly allocated *pchars and thus this
* memory can be used as a new JSAtom's buffer without copying. When this flag
* is set, the contract is that callers will free *pchars iff *pchars == NULL.
*/
JS_ALWAYS_INLINE
static JSAtom *
AtomizeInline(JSContext *cx, const jschar **pchars, size_t length,
InternBehavior ib, OwnCharsBehavior ocb = CopyChars)
{
const jschar *chars = *pchars;
if (JSAtom *s = JSAtom::lookupStatic(chars, length))
return s;
AutoLockAtomsCompartment lock(cx);
AtomSet &atoms = cx->runtime->atomState.atoms;
AtomSet::AddPtr p = atoms.lookupForAdd(AtomHasher::Lookup(chars, length));
if (p) {
JSAtom *atom = p->asPtr();
p->setTagged(bool(ib));
return atom;
}
SwitchToCompartment sc(cx, cx->runtime->atomsCompartment);
JSFixedString *key;
if (ocb == TakeCharOwnership) {
key = js_NewString(cx, const_cast<jschar *>(chars), length);
if (!key)
return NULL;
*pchars = NULL; /* Called should not free *pchars. */
} else {
JS_ASSERT(ocb == CopyChars);
key = js_NewStringCopyN(cx, chars, length);
if (!key)
return NULL;
}
/*
* We have to relookup the key as the last ditch GC invoked from the
* string allocation or OOM handling may unlock the atomsCompartment.
*
* N.B. this avoids recomputing the hash but still has a potential
* (# collisions * # chars) comparison cost in the case of a hash
* collision!
*/
AtomHasher::Lookup lookup(chars, length);
if (!atoms.relookupOrAdd(p, lookup, AtomStateEntry((JSAtom *) key, bool(ib)))) {
JS_ReportOutOfMemory(cx); /* SystemAllocPolicy does not report */
return NULL;
}
return key->morphAtomizedStringIntoAtom();
}
MOZ_ALWAYS_INLINE
static JSAtom *
AtomizeAndCopyChars(ExclusiveContext *cx, const CharT *tbchars, size_t length, InternBehavior ib)
{
if (JSAtom *s = cx->staticStrings().lookup(tbchars, length))
return s;
AtomHasher::Lookup lookup(tbchars, length);
// Note: when this function is called while the permanent atoms table is
// being initialized (in initializeAtoms()), |permanentAtoms| is not yet
// initialized so this lookup is always skipped. Only once
// transformToPermanentAtoms() is called does |permanentAtoms| get
// initialized and then this lookup will go ahead.
if (cx->isPermanentAtomsInitialized()) {
AtomSet::Ptr pp = cx->permanentAtoms().readonlyThreadsafeLookup(lookup);
if (pp)
return pp->asPtr();
}
AutoLockForExclusiveAccess lock(cx);
AtomSet& atoms = cx->atoms();
AtomSet::AddPtr p = atoms.lookupForAdd(lookup);
if (p) {
JSAtom *atom = p->asPtr();
p->setTagged(bool(ib));
return atom;
}
AutoCompartment ac(cx, cx->atomsCompartment());
JSFlatString *flat = NewStringCopyN<NoGC>(cx, tbchars, length);
if (!flat) {
// Grudgingly forgo last-ditch GC. The alternative would be to release
// the lock, manually GC here, and retry from the top. If you fix this,
// please also fix or comment the similar case in Symbol::new_.
ReportOutOfMemory(cx);
return nullptr;
}
JSAtom *atom = flat->morphAtomizedStringIntoAtom();
// We have held the lock since looking up p, and the operations we've done
// since then can't GC; therefore the atoms table has not been modified and
// p is still valid.
if (!atoms.add(p, AtomStateEntry(atom, bool(ib)))) {
ReportOutOfMemory(cx); /* SystemAllocPolicy does not report OOM. */
return nullptr;
}
return atom;
}
/*
* When the jschars reside in a freshly allocated buffer the memory can be used
* as a new JSAtom's storage without copying. The contract is that the caller no
* longer owns the memory and this method is responsible for freeing the memory.
*/
JS_ALWAYS_INLINE
static JSAtom *
AtomizeAndTakeOwnership(JSContext *cx, const jschar *tbchars, size_t length,
InternBehavior ib)
{
JS_ASSERT(tbchars[length] == 0);
if (JSAtom *s = cx->runtime->staticStrings.lookup(tbchars, length)) {
js_free((void*)tbchars);
return s;
}
/*
* If a GC occurs at js_NewStringCopy then |p| will still have the correct
* hash, allowing us to avoid rehashing it. Even though the hash is
* unchanged, we need to re-lookup the table position because a last-ditch
* GC will potentially free some table entries.
*/
AtomSet& atoms = cx->runtime->atoms;
AtomSet::AddPtr p = atoms.lookupForAdd(AtomHasher::Lookup(tbchars, length));
SkipRoot skipHash(cx, &p); /* Prevent the hash from being poisoned. */
if (p) {
JSAtom *atom = p->asPtr();
p->setTagged(bool(ib));
js_free((void*)tbchars);
return atom;
}
AutoEnterAtomsCompartment ac(cx);
JSFlatString *flat = js_NewString<CanGC>(cx, const_cast<jschar*>(tbchars), length);
if (!flat) {
js_free((void*)tbchars);
return NULL;
}
JSAtom *atom = flat->morphAtomizedStringIntoAtom();
if (!atoms.relookupOrAdd(p, AtomHasher::Lookup(tbchars, length),
AtomStateEntry(atom, bool(ib)))) {
JS_ReportOutOfMemory(cx); /* SystemAllocPolicy does not report OOM. */
return NULL;
}
return atom;
}
JS_ALWAYS_INLINE
static JSAtom *
AtomizeAndCopyChars(ExclusiveContext *cx, const jschar *tbchars, size_t length, InternBehavior ib)
{
if (JSAtom *s = cx->staticStrings().lookup(tbchars, length))
return s;
/*
* If a GC occurs at js_NewStringCopy then |p| will still have the correct
* hash, allowing us to avoid rehashing it. Even though the hash is
* unchanged, we need to re-lookup the table position because a last-ditch
* GC will potentially free some table entries.
*/
AutoLockForExclusiveAccess lock(cx);
AtomSet& atoms = cx->atoms();
AtomSet::AddPtr p = atoms.lookupForAdd(AtomHasher::Lookup(tbchars, length));
SkipRoot skipHash(cx, &p); /* Prevent the hash from being poisoned. */
if (p) {
JSAtom *atom = p->asPtr();
p->setTagged(bool(ib));
return atom;
}
AutoCompartment ac(cx, cx->atomsCompartment());
JSFlatString *flat = js_NewStringCopyN<allowGC>(cx, tbchars, length);
if (!flat)
return NULL;
JSAtom *atom = flat->morphAtomizedStringIntoAtom();
if (!atoms.relookupOrAdd(p, AtomHasher::Lookup(tbchars, length),
AtomStateEntry(atom, bool(ib)))) {
if (allowGC)
js_ReportOutOfMemory(cx); /* SystemAllocPolicy does not report OOM. */
return NULL;
}
return atom;
}
