The Tor Browser: js/src/jspropertytree.h@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     2  * vim: set ts=8 sts=4 et sw=4 tw=99:

     3  * This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #ifndef jspropertytree_h

     8 #define jspropertytree_h

    10 #include "jsalloc.h"

    11 #include "jspubtd.h"

    13 #include "js/HashTable.h"

    15 namespace js {

    17 class Shape;

    18 struct StackShape;

    20 struct ShapeHasher {

    21     typedef Shape *Key;

    22     typedef StackShape Lookup;

    24     static inline HashNumber hash(const Lookup &l);

    25     static inline bool match(Key k, const Lookup &l);

    26 };

    28 typedef HashSet<Shape *, ShapeHasher, SystemAllocPolicy> KidsHash;

    30 class KidsPointer {

    31   private:

    32     enum {

    33         SHAPE = 0,

    34         HASH  = 1,

    35         TAG   = 1

    36     };

    38     uintptr_t w;

    40   public:

    41     bool isNull() const { return !w; }

    42     void setNull() { w = 0; }

    44     bool isShape() const { return (w & TAG) == SHAPE && !isNull(); }

    45     Shape *toShape() const {

    46         JS_ASSERT(isShape());

    47         return reinterpret_cast<Shape *>(w & ~uintptr_t(TAG));

    48     }

    49     void setShape(Shape *shape) {

    50         JS_ASSERT(shape);

    51         JS_ASSERT((reinterpret_cast<uintptr_t>(static_cast<Shape *>(shape)) & TAG) == 0);

    52         w = reinterpret_cast<uintptr_t>(static_cast<Shape *>(shape)) | SHAPE;

    53     }

    55     bool isHash() const { return (w & TAG) == HASH; }

    56     KidsHash *toHash() const {

    57         JS_ASSERT(isHash());

    58         return reinterpret_cast<KidsHash *>(w & ~uintptr_t(TAG));

    59     }

    60     void setHash(KidsHash *hash) {

    61         JS_ASSERT(hash);

    62         JS_ASSERT((reinterpret_cast<uintptr_t>(hash) & TAG) == 0);

    63         w = reinterpret_cast<uintptr_t>(hash) | HASH;

    64     }

    66 #ifdef DEBUG

    67     void checkConsistency(Shape *aKid) const;

    68 #endif

    69 };

    71 class PropertyTree

    72 {

    73     friend class ::JSFunction;

    75     JSCompartment *compartment_;

    77     bool insertChild(ExclusiveContext *cx, Shape *parent, Shape *child);

    79     PropertyTree();

    81   public:

    82     /*

    83      * Use a lower limit for objects that are accessed using SETELEM (o[x] = y).

    84      * These objects are likely used as hashmaps and dictionary mode is more

    85      * efficient in this case.

    86      */

    87     enum {

    88         MAX_HEIGHT = 512,

    89         MAX_HEIGHT_WITH_ELEMENTS_ACCESS = 128

    90     };

    92     PropertyTree(JSCompartment *comp)

    93         : compartment_(comp)

    94     {

    95     }

    97     JSCompartment *compartment() { return compartment_; }

    99     Shape *newShape(ExclusiveContext *cx);

   100     Shape *getChild(ExclusiveContext *cx, Shape *parent, StackShape &child);

   101     Shape *lookupChild(ThreadSafeContext *cx, Shape *parent, const StackShape &child);

   102 };

   104 } /* namespace js */

   106 #endif /* jspropertytree_h */

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