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0ad/source/scriptinterface/third_party/ObjectToIDMap.h
2015-06-14 23:45:15 +00:00

128 lines
3.2 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=80:
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Providing a map-like structure with JSObject pointers (actually their hash) as keys
* with correct garbage collection handling (JSObjects can move in memory).
*
* The code in this class was copied from here and modified to work in our environment.
* * https://mxr.mozilla.org/mozilla-esr31/source/js/ipc/JavaScriptShared.h
* * https://mxr.mozilla.org/mozilla-esr31/source/js/ipc/JavaScriptShared.cpp
*
* When updating SpiderMonkey, you most likely have to reintegrate an updated version
* of the class(es) in this file. The best way is probably to get a diff between the
* original files and integrate that because this file is heavily modified from the
* original version.
*/
#ifndef INCLUDED_OBJECTTOIDMAP
#define INCLUDED_OBJECTTOIDMAP
#include "scriptinterface/ScriptRuntime.h"
#include "scriptinterface/ScriptTypes.h"
#include <stdint.h>
// Map JSObjects -> ids
template <typename T>
class ObjectIdCache
{
typedef js::PointerHasher<JSObject *, 3> Hasher;
typedef js::HashMap<JSObject *, T, Hasher, js::SystemAllocPolicy> ObjectIdTable;
NONCOPYABLE(ObjectIdCache);
public:
ObjectIdCache(shared_ptr<ScriptRuntime> rt)
: table_(nullptr), m_rt(rt)
{
JS_AddExtraGCRootsTracer(m_rt->m_rt, ObjectIdCache::Trace, this);
}
~ObjectIdCache()
{
if (table_) {
m_rt->AddDeferredFinalizationObject(std::shared_ptr<void>((void*)table_, DeleteObjectIDTable));
table_ = nullptr;
}
JS_RemoveExtraGCRootsTracer(m_rt->m_rt, ObjectIdCache::Trace, this);
}
bool init()
{
MOZ_ASSERT(!table_);
table_ = new ObjectIdTable(js::SystemAllocPolicy());
return table_ && table_->init(32);
}
void trace(JSTracer *trc)
{
for (typename ObjectIdTable::Range r(table_->all()); !r.empty(); r.popFront()) {
JSObject *obj = r.front().key();
JS_CallObjectTracer(trc, &obj, "ipc-id");
MOZ_ASSERT(obj == r.front().key());
}
}
bool add(JSContext *cx, JSObject *obj, T id)
{
if (!table_->put(obj, id))
return false;
JS_StoreObjectPostBarrierCallback(cx, keyMarkCallback, obj, table_);
return true;
}
bool find(JSObject *obj, T& ret)
{
typename ObjectIdTable::Ptr p = table_->lookup(obj);
if (!p)
return false;
ret = p->value();
return true;
}
void remove(JSObject *obj)
{
table_->remove(obj);
}
bool empty()
{
return table_->empty();
}
bool has(JSObject* obj)
{
return table_->has(obj);
}
private:
static void keyMarkCallback(JSTracer *trc, JSObject *key, void *data)
{
ObjectIdTable* table = static_cast<ObjectIdTable*>(data);
JSObject *prior = key;
JS_CallObjectTracer(trc, &key, "ObjectIdCache::table_ key");
table->rekeyIfMoved(prior, key);
}
static void Trace(JSTracer *trc, void *data)
{
reinterpret_cast<ObjectIdCache*>(data)->trace(trc);
}
static void DeleteObjectIDTable(void* table)
{
delete (ObjectIdTable*)table;
}
shared_ptr<ScriptRuntime> m_rt;
ObjectIdTable *table_;
};
#endif // INCLUDED_OBJECTTOIDMAP