mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-25 22:01:30 +00:00
62 lines
1.9 KiB
C++
62 lines
1.9 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 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/. */
|
|
|
|
#ifndef nsJSThingHashtable_h__
|
|
#define nsJSThingHashtable_h__
|
|
|
|
#include "nsHashKeys.h"
|
|
#include "nsBaseHashtable.h"
|
|
|
|
namespace JS {
|
|
template<class T>
|
|
class Heap;
|
|
} /* namespace JS */
|
|
|
|
/**
|
|
* A wrapper for hash keys that sets ALLOW_MEMMOVE to false.
|
|
*
|
|
* This is used in the implementation of nsJSThingHashtable and is not intended
|
|
* to be used directly.
|
|
*
|
|
* It is necessary for hash tables containing JS::Heap<T> values as these must
|
|
* be copied rather than memmoved.
|
|
*/
|
|
template<class T>
|
|
class nsHashKeyDisallowMemmove : public T
|
|
{
|
|
public:
|
|
explicit nsHashKeyDisallowMemmove(const typename T::KeyTypePointer aKey) : T(aKey) {}
|
|
enum { ALLOW_MEMMOVE = false };
|
|
};
|
|
|
|
|
|
/**
|
|
* Templated hashtable class for use on the heap where the values are JS GC things.
|
|
*
|
|
* Storing JS GC thing pointers on the heap requires wrapping them in a
|
|
* JS::Heap<T>, and this class takes care of that while presenting an interface
|
|
* in terms of the wrapped type T.
|
|
*
|
|
* For example, to store a hashtable mapping strings to JSObject pointers, you
|
|
* can declare a data member like this:
|
|
*
|
|
* nsJSThingHashtable<nsStringHashKey, JSObject*> mStringToObjectMap;
|
|
*
|
|
* See nsBaseHashtable for complete declaration
|
|
* @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
|
|
* for a complete specification.
|
|
* @param DataType the datatype being wrapped, must be a JS GC thing.
|
|
* @see nsInterfaceHashtable, nsClassHashtable
|
|
*/
|
|
template<class KeyClass, class DataType>
|
|
class nsJSThingHashtable
|
|
: public nsBaseHashtable<nsHashKeyDisallowMemmove<KeyClass>,
|
|
JS::Heap<DataType>, DataType>
|
|
{
|
|
};
|
|
|
|
#endif // nsJSThingHashtable_h__
|