1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jspropertytree.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,106 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef jspropertytree_h
1.11 +#define jspropertytree_h
1.12 +
1.13 +#include "jsalloc.h"
1.14 +#include "jspubtd.h"
1.15 +
1.16 +#include "js/HashTable.h"
1.17 +
1.18 +namespace js {
1.19 +
1.20 +class Shape;
1.21 +struct StackShape;
1.22 +
1.23 +struct ShapeHasher {
1.24 + typedef Shape *Key;
1.25 + typedef StackShape Lookup;
1.26 +
1.27 + static inline HashNumber hash(const Lookup &l);
1.28 + static inline bool match(Key k, const Lookup &l);
1.29 +};
1.30 +
1.31 +typedef HashSet<Shape *, ShapeHasher, SystemAllocPolicy> KidsHash;
1.32 +
1.33 +class KidsPointer {
1.34 + private:
1.35 + enum {
1.36 + SHAPE = 0,
1.37 + HASH = 1,
1.38 + TAG = 1
1.39 + };
1.40 +
1.41 + uintptr_t w;
1.42 +
1.43 + public:
1.44 + bool isNull() const { return !w; }
1.45 + void setNull() { w = 0; }
1.46 +
1.47 + bool isShape() const { return (w & TAG) == SHAPE && !isNull(); }
1.48 + Shape *toShape() const {
1.49 + JS_ASSERT(isShape());
1.50 + return reinterpret_cast<Shape *>(w & ~uintptr_t(TAG));
1.51 + }
1.52 + void setShape(Shape *shape) {
1.53 + JS_ASSERT(shape);
1.54 + JS_ASSERT((reinterpret_cast<uintptr_t>(static_cast<Shape *>(shape)) & TAG) == 0);
1.55 + w = reinterpret_cast<uintptr_t>(static_cast<Shape *>(shape)) | SHAPE;
1.56 + }
1.57 +
1.58 + bool isHash() const { return (w & TAG) == HASH; }
1.59 + KidsHash *toHash() const {
1.60 + JS_ASSERT(isHash());
1.61 + return reinterpret_cast<KidsHash *>(w & ~uintptr_t(TAG));
1.62 + }
1.63 + void setHash(KidsHash *hash) {
1.64 + JS_ASSERT(hash);
1.65 + JS_ASSERT((reinterpret_cast<uintptr_t>(hash) & TAG) == 0);
1.66 + w = reinterpret_cast<uintptr_t>(hash) | HASH;
1.67 + }
1.68 +
1.69 +#ifdef DEBUG
1.70 + void checkConsistency(Shape *aKid) const;
1.71 +#endif
1.72 +};
1.73 +
1.74 +class PropertyTree
1.75 +{
1.76 + friend class ::JSFunction;
1.77 +
1.78 + JSCompartment *compartment_;
1.79 +
1.80 + bool insertChild(ExclusiveContext *cx, Shape *parent, Shape *child);
1.81 +
1.82 + PropertyTree();
1.83 +
1.84 + public:
1.85 + /*
1.86 + * Use a lower limit for objects that are accessed using SETELEM (o[x] = y).
1.87 + * These objects are likely used as hashmaps and dictionary mode is more
1.88 + * efficient in this case.
1.89 + */
1.90 + enum {
1.91 + MAX_HEIGHT = 512,
1.92 + MAX_HEIGHT_WITH_ELEMENTS_ACCESS = 128
1.93 + };
1.94 +
1.95 + PropertyTree(JSCompartment *comp)
1.96 + : compartment_(comp)
1.97 + {
1.98 + }
1.99 +
1.100 + JSCompartment *compartment() { return compartment_; }
1.101 +
1.102 + Shape *newShape(ExclusiveContext *cx);
1.103 + Shape *getChild(ExclusiveContext *cx, Shape *parent, StackShape &child);
1.104 + Shape *lookupChild(ThreadSafeContext *cx, Shape *parent, const StackShape &child);
1.105 +};
1.106 +
1.107 +} /* namespace js */
1.108 +
1.109 +#endif /* jspropertytree_h */
