jspropertytree.cpp
/* -*- Mode: c++; c-basic-offset: 4; tab-width: 40; indent-tabs-mode: nil -*- */
/* vim: set ts=40 sw=4 et tw=99: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Mozilla SpiderMonkey property tree implementation
*
* The Initial Developer of the Original Code is
* Mozilla Foundation
* Portions created by the Initial Developer are Copyright (C) 2002-2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Brendan Eich <brendan@mozilla.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include <new>
#include "jstypes.h"
#include "jsprf.h"
#include "jsapi.h"
#include "jscntxt.h"
#include "jsgc.h"
#include "jspropertytree.h"
#include "jsscope.h"
#include "jsobjinlines.h"
#include "jsscopeinlines.h"
using namespace js;
inline HashNumber
ShapeHasher::hash(const Lookup l)
{
return l->hash();
}
inline bool
ShapeHasher::match(const Key k, const Lookup l)
{
return l->matches(k);
}
Shape *
PropertyTree::newShape(JSContext *cx)
{
Shape *shape = js_NewGCShape(cx);
if (!shape) {
JS_ReportOutOfMemory(cx);
return NULL;
}
return shape;
}
static KidsHash *
HashChildren(Shape *kid1, Shape *kid2)
{
KidsHash *hash = OffTheBooks::new_<KidsHash>();
if (!hash || !hash->init(2)) {
Foreground::delete_(hash);
return NULL;
}
JS_ALWAYS_TRUE(hash->putNew(kid1));
JS_ALWAYS_TRUE(hash->putNew(kid2));
return hash;
}
bool
PropertyTree::insertChild(JSContext *cx, Shape *parent, Shape *child)
{
JS_ASSERT(!parent->inDictionary());
JS_ASSERT(!child->parent);
JS_ASSERT(!child->inDictionary());
JS_ASSERT(!JSID_IS_VOID(parent->propid));
JS_ASSERT(!JSID_IS_VOID(child->propid));
JS_ASSERT(cx->compartment == compartment);
JS_ASSERT(child->compartment() == parent->compartment());
KidsPointer *kidp = &parent->kids;
if (kidp->isNull()) {
child->setParent(parent);
kidp->setShape(child);
return true;
}
if (kidp->isShape()) {
Shape *shape = kidp->toShape();
JS_ASSERT(shape != child);
JS_ASSERT(!shape->matches(child));
KidsHash *hash = HashChildren(shape, child);
if (!hash) {
JS_ReportOutOfMemory(cx);
return false;
}
kidp->setHash(hash);
child->setParent(parent);
return true;
}
if (!kidp->toHash()->putNew(child)) {
JS_ReportOutOfMemory(cx);
return false;
}
child->setParent(parent);
return true;
}
void
Shape::removeChild(Shape *child)
{
JS_ASSERT(!child->inDictionary());
JS_ASSERT(!JSID_IS_VOID(propid));
KidsPointer *kidp = &kids;
if (kidp->isShape()) {
JS_ASSERT(kidp->toShape() == child);
kids.setNull();
return;
}
kidp->toHash()->remove(child);
}
Shape *
PropertyTree::getChild(JSContext *cx, Shape *parent, const Shape &child)
{
Shape *shape;
JS_ASSERT(parent);
JS_ASSERT(!JSID_IS_VOID(parent->propid));
/*
* The property tree has extremely low fan-out below its root in
* popular embeddings with real-world workloads. Patterns such as
* defining closures that capture a constructor's environment as
* getters or setters on the new object that is passed in as
* |this| can significantly increase fan-out below the property
* tree root -- see bug 335700 for details.
*/
KidsPointer *kidp = &parent->kids;
if (kidp->isShape()) {
shape = kidp->toShape();
if (shape->matches(&child))
return shape;
} else if (kidp->isHash()) {
shape = *kidp->toHash()->lookup(&child);
if (shape)
return shape;
} else {
/* If kidp->isNull(), we always insert. */
}
shape = newShape(cx);
if (!shape)
return NULL;
new (shape) Shape(child.propid, child.rawGetter, child.rawSetter, child.slot, child.attrs,
child.flags, child.shortid, js_GenerateShape(cx));
if (!insertChild(cx, parent, shape))
return NULL;
return shape;
}
void
Shape::finalize(JSContext *cx)
{
if (!inDictionary()) {
if (parent && parent->isMarked())
parent->removeChild(this);
if (kids.isHash())
cx->delete_(kids.toHash());
}
freeTable(cx);
}
#ifdef DEBUG
void
KidsPointer::checkConsistency(const Shape *aKid) const
{
if (isShape()) {
JS_ASSERT(toShape() == aKid);
} else {
JS_ASSERT(isHash());
KidsHash *hash = toHash();
KidsHash::Ptr ptr = hash->lookup(aKid);
JS_ASSERT(*ptr == aKid);
}
}
void
Shape::dump(JSContext *cx, FILE *fp) const
{
JS_ASSERT(!JSID_IS_VOID(propid));
if (JSID_IS_INT(propid)) {
fprintf(fp, "[%ld]", (long) JSID_TO_INT(propid));
} else if (JSID_IS_DEFAULT_XML_NAMESPACE(propid)) {
fprintf(fp, "<default XML namespace>");
} else {
JSLinearString *str;
if (JSID_IS_ATOM(propid)) {
str = JSID_TO_ATOM(propid);
} else {
JS_ASSERT(JSID_IS_OBJECT(propid));
JSString *s = js_ValueToString(cx, IdToValue(propid));
fputs("object ", fp);
str = s ? s->ensureLinear(cx) : NULL;
}
if (!str)
fputs("<error>", fp);
else
FileEscapedString(fp, str, '"');
}
fprintf(fp, " g/s %p/%p slot %u attrs %x ",
JS_FUNC_TO_DATA_PTR(void *, rawGetter),
JS_FUNC_TO_DATA_PTR(void *, rawSetter),
slot, attrs);
if (attrs) {
int first = 1;
fputs("(", fp);
#define DUMP_ATTR(name, display) if (attrs & JSPROP_##name) fputs(" " #display + first, fp), first = 0
DUMP_ATTR(ENUMERATE, enumerate);
DUMP_ATTR(READONLY, readonly);
DUMP_ATTR(PERMANENT, permanent);
DUMP_ATTR(GETTER, getter);
DUMP_ATTR(SETTER, setter);
DUMP_ATTR(SHARED, shared);
#undef DUMP_ATTR
fputs(") ", fp);
}
fprintf(fp, "flags %x ", flags);
if (flags) {
int first = 1;
fputs("(", fp);
#define DUMP_FLAG(name, display) if (flags & name) fputs(" " #display + first, fp), first = 0
DUMP_FLAG(HAS_SHORTID, has_shortid);
DUMP_FLAG(METHOD, method);
DUMP_FLAG(IN_DICTIONARY, in_dictionary);
#undef DUMP_FLAG
fputs(") ", fp);
}
fprintf(fp, "shortid %d\n", shortid);
}
void
Shape::dumpSubtree(JSContext *cx, int level, FILE *fp) const
{
if (!parent) {
JS_ASSERT(level == 0);
JS_ASSERT(JSID_IS_EMPTY(propid));
fprintf(fp, "class %s emptyShape %u\n", clasp->name, shapeid);
} else {
fprintf(fp, "%*sid ", level, "");
dump(cx, fp);
}
if (!kids.isNull()) {
++level;
if (kids.isShape()) {
Shape *kid = kids.toShape();
JS_ASSERT(kid->parent == this);
kid->dumpSubtree(cx, level, fp);
} else {
const KidsHash &hash = *kids.toHash();
for (KidsHash::Range range = hash.all(); !range.empty(); range.popFront()) {
Shape *kid = range.front();
JS_ASSERT(kid->parent == this);
kid->dumpSubtree(cx, level, fp);
}
}
}
}
void
js::PropertyTree::dumpShapes(JSContext *cx)
{
static bool init = false;
static FILE *dumpfp = NULL;
if (!init) {
init = true;
const char *name = getenv("JS_DUMP_SHAPES_FILE");
if (!name)
return;
dumpfp = fopen(name, "a");
}
if (!dumpfp)
return;
JSRuntime *rt = cx->runtime;
fprintf(dumpfp, "rt->gcNumber = %lu", (unsigned long)rt->gcNumber);
for (JSCompartment **c = rt->compartments.begin(); c != rt->compartments.end(); ++c) {
if (rt->gcCurrentCompartment != NULL && rt->gcCurrentCompartment != *c)
continue;
fprintf(dumpfp, "*** Compartment %p ***\n", (void *)*c);
typedef JSCompartment::EmptyShapeSet HS;
HS &h = (*c)->emptyShapes;
for (HS::Range r = h.all(); !r.empty(); r.popFront()) {
Shape *empty = r.front();
empty->dumpSubtree(cx, 0, dumpfp);
putc('\n', dumpfp);
}
}
}
#endif