gecko-dev/xpcom/glue/nsID.h
Nicholas Nethercote f584cb3bd0 Bug 1255655 - Const-ify named CIDs. r=froydnj.
There are about 600 of these, at 16 bytes each, and this change makes all of
them shareable between processes

--HG--
extra : rebase_source : b1824f0a022389aeb02d925c4d788e5a671bf782
2016-03-11 14:32:39 +11:00

155 lines
3.9 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 nsID_h__
#define nsID_h__
#include <string.h>
#include "nscore.h"
#define NSID_LENGTH 39
/**
* A "unique identifier". This is modeled after OSF DCE UUIDs.
*/
struct nsID
{
/**
* @name Identifier values
*/
//@{
uint32_t m0;
uint16_t m1;
uint16_t m2;
uint8_t m3[8];
//@}
/**
* @name Methods
*/
//@{
/**
* Ensures everything is zeroed out.
*/
void Clear();
/**
* Equivalency method. Compares this nsID with another.
* @return <b>true</b> if they are the same, <b>false</b> if not.
*/
inline bool Equals(const nsID& aOther) const
{
// Unfortunately memcmp isn't faster than this.
return
(((uint32_t*)&m0)[0] == ((uint32_t*)&aOther.m0)[0]) &&
(((uint32_t*)&m0)[1] == ((uint32_t*)&aOther.m0)[1]) &&
(((uint32_t*)&m0)[2] == ((uint32_t*)&aOther.m0)[2]) &&
(((uint32_t*)&m0)[3] == ((uint32_t*)&aOther.m0)[3]);
}
inline bool operator==(const nsID& aOther) const
{
return Equals(aOther);
}
/**
* nsID Parsing method. Turns a {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
* string into an nsID
*/
bool Parse(const char* aIDStr);
#ifndef XPCOM_GLUE_AVOID_NSPR
/**
* nsID string encoder. Returns an allocated string in
* {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} format. Caller should free string.
* YOU SHOULD ONLY USE THIS IF YOU CANNOT USE ToProvidedString() BELOW.
*/
char* ToString() const;
/**
* nsID string encoder. Builds a string in
* {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} format, into a char[NSID_LENGTH]
* buffer provided by the caller (for instance, on the stack).
*/
void ToProvidedString(char (&aDest)[NSID_LENGTH]) const;
#endif // XPCOM_GLUE_AVOID_NSPR
//@}
};
/*
* Class IDs
*/
typedef nsID nsCID;
// Define an CID
#define NS_DEFINE_CID(_name, _cidspec) \
const nsCID _name = _cidspec
#define NS_DEFINE_NAMED_CID(_name) \
static const nsCID k##_name = _name
#define REFNSCID const nsCID&
/**
* An "interface id" which can be used to uniquely identify a given
* interface.
*/
typedef nsID nsIID;
/**
* A macro shorthand for <tt>const nsIID&<tt>
*/
#define REFNSIID const nsIID&
/**
* Define an IID
* obsolete - do not use this macro
*/
#define NS_DEFINE_IID(_name, _iidspec) \
const nsIID _name = _iidspec
/**
* A macro to build the static const IID accessor method. The Dummy
* template parameter only exists so that the kIID symbol will be linked
* properly (weak symbol on linux, gnu_linkonce on mac, multiple-definitions
* merged on windows). Dummy should always be instantiated as "void".
*/
#define NS_DECLARE_STATIC_IID_ACCESSOR(the_iid) \
template<typename T, typename U> \
struct COMTypeInfo;
#define NS_DEFINE_STATIC_IID_ACCESSOR(the_interface, the_iid) \
template<typename T> \
struct the_interface::COMTypeInfo<the_interface, T> { \
static const nsIID kIID NS_HIDDEN; \
}; \
template<typename T> \
const nsIID the_interface::COMTypeInfo<the_interface, T>::kIID NS_HIDDEN = the_iid;
/**
* A macro to build the static const CID accessor method
*/
#define NS_DEFINE_STATIC_CID_ACCESSOR(the_cid) \
static const nsID& GetCID() {static const nsID cid = the_cid; return cid;}
#define NS_GET_IID(T) (T::COMTypeInfo<T, void>::kIID)
#define NS_GET_TEMPLATE_IID(T) (T::template COMTypeInfo<T, void>::kIID)
#endif