js/ipc/JavaScriptShared.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=8 sw=4 et tw=80:
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #ifndef mozilla_jsipc_JavaScriptShared_h__
   9 #define mozilla_jsipc_JavaScriptShared_h__
  10
  11 #include "mozilla/dom/DOMTypes.h"
  12 #include "mozilla/jsipc/PJavaScript.h"
  13 #include "nsJSUtils.h"
  14 #include "nsFrameMessageManager.h"
  15
  16 namespace mozilla {
  17 namespace jsipc {
  18
  19 typedef uint64_t ObjectId;
  20
  21 class JavaScriptShared;
  22
  23 class CpowIdHolder : public CpowHolder
  24 {
  25   public:
  26     CpowIdHolder(JavaScriptShared *js, const InfallibleTArray<CpowEntry> &cpows)
  27       : js_(js),
  28         cpows_(cpows)
  29     {
  30     }
  31
  32     bool ToObject(JSContext *cx, JS::MutableHandleObject objp);
  33
  34   private:
  35     JavaScriptShared *js_;
  36     const InfallibleTArray<CpowEntry> &cpows_;
  37 };
  38
  39 // Map ids -> JSObjects
  40 class IdToObjectMap
  41 {
  42     typedef js::DefaultHasher<ObjectId> TableKeyHasher;
  43
  44     typedef js::HashMap<ObjectId, JS::Heap<JSObject *>, TableKeyHasher, js::SystemAllocPolicy> Table;
  45
  46   public:
  47     IdToObjectMap();
  48
  49     bool init();
  50     void trace(JSTracer *trc);
  51     void finalize(JSFreeOp *fop);
  52
  53     bool add(ObjectId id, JSObject *obj);
  54     JSObject *find(ObjectId id);
  55     void remove(ObjectId id);
  56
  57   private:
  58     Table table_;
  59 };
  60
  61 // Map JSObjects -> ids
  62 class ObjectToIdMap
  63 {
  64     typedef js::PointerHasher<JSObject *, 3> Hasher;
  65     typedef js::HashMap<JSObject *, ObjectId, Hasher, js::SystemAllocPolicy> Table;
  66
  67   public:
  68     ObjectToIdMap();
  69     ~ObjectToIdMap();
  70
  71     bool init();
  72     void finalize(JSFreeOp *fop);
  73
  74     bool add(JSContext *cx, JSObject *obj, ObjectId id);
  75     ObjectId find(JSObject *obj);
  76     void remove(JSObject *obj);
  77
  78   private:
  79     static void keyMarkCallback(JSTracer *trc, JSObject *key, void *data);
  80
  81     Table *table_;
  82 };
  83
  84 class Logging;
  85
  86 class JavaScriptShared
  87 {
  88   public:
  89     JavaScriptShared(JSRuntime *rt);
  90     virtual ~JavaScriptShared() {}
  91
  92     bool init();
  93
  94     void decref();
  95     void incref();
  96
  97     static const uint32_t OBJECT_EXTRA_BITS  = 1;
  98     static const uint32_t OBJECT_IS_CALLABLE = (1 << 0);
  99
 100     bool Unwrap(JSContext *cx, const InfallibleTArray<CpowEntry> &aCpows, JS::MutableHandleObject objp);
 101     bool Wrap(JSContext *cx, JS::HandleObject aObj, InfallibleTArray<CpowEntry> *outCpows);
 102
 103   protected:
 104     bool toVariant(JSContext *cx, JS::HandleValue from, JSVariant *to);
 105     bool fromVariant(JSContext *cx, const JSVariant &from, JS::MutableHandleValue to);
 106
 107     bool fromDescriptor(JSContext *cx, JS::Handle<JSPropertyDescriptor> desc,
 108                         PPropertyDescriptor *out);
 109     bool toDescriptor(JSContext *cx, const PPropertyDescriptor &in,
 110                       JS::MutableHandle<JSPropertyDescriptor> out);
 111
 112     bool convertIdToGeckoString(JSContext *cx, JS::HandleId id, nsString *to);
 113     bool convertGeckoStringToId(JSContext *cx, const nsString &from, JS::MutableHandleId id);
 114
 115     virtual bool toObjectVariant(JSContext *cx, JSObject *obj, ObjectVariant *objVarp) = 0;
 116     virtual JSObject *fromObjectVariant(JSContext *cx, ObjectVariant objVar) = 0;
 117
 118     static void ConvertID(const nsID &from, JSIID *to);
 119     static void ConvertID(const JSIID &from, nsID *to);
 120
 121     JSObject *findCPOWById(uint32_t objId) {
 122         return cpows_.find(objId);
 123     }
 124     JSObject *findObjectById(uint32_t objId) {
 125         return objects_.find(objId);
 126     }
 127     JSObject *findObjectById(JSContext *cx, uint32_t objId);
 128
 129     static bool LoggingEnabled() { return sLoggingEnabled; }
 130     static bool StackLoggingEnabled() { return sStackLoggingEnabled; }
 131
 132     friend class Logging;
 133
 134     virtual bool isParent() = 0;
 135
 136   protected:
 137     JSRuntime *rt_;
 138     uintptr_t refcount_;
 139
 140     IdToObjectMap objects_;
 141     IdToObjectMap cpows_;
 142
 143     ObjectId lastId_;
 144     ObjectToIdMap objectIds_;
 145
 146     static bool sLoggingInitialized;
 147     static bool sLoggingEnabled;
 148     static bool sStackLoggingEnabled;
 149 };
 150
 151 // Use 47 at most, to be safe, since jsval privates are encoded as doubles.
 152 static const uint64_t MAX_CPOW_IDS = (uint64_t(1) << 47) - 1;
 153
 154 } // namespace jsipc
 155 } // namespace mozilla
 156
 157 #endif