/* -*- 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 #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 true if they are the same, false if not. */ inline bool Equals(const nsID& aOther) const { // At the time of this writing, modern compilers (namely Clang) inline this // memcmp call into a single SIMD operation on x86/x86-64 architectures (as // long as we compare to zero rather than returning the full integer return // value), which is measurably more efficient to any manual comparisons we // can do directly. #if defined(__x86_64__) || defined(__i386__) return !memcmp(this, &aOther, sizeof *this); #else // However, on ARM architectures, compilers still tend to generate a direct // memcmp call, which we'd like to avoid. 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]); #endif } 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 // Infallibly duplicate an nsID. Must be freed with free(). nsID* Clone() const; //@} }; #ifndef XPCOM_GLUE_AVOID_NSPR /** * A stack helper class to convert a nsID to a string. Useful * for printing nsIDs. For example: * nsID aID = ...; * printf("%s", nsIDToCString(aID).get()); */ class nsIDToCString { public: explicit nsIDToCString(const nsID& aID) { aID.ToProvidedString(mStringBytes); } const char* get() const { return mStringBytes; } protected: char mStringBytes[NSID_LENGTH]; }; #endif /* * 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 const nsIID& */ #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 \ struct COMTypeInfo; #define NS_DEFINE_STATIC_IID_ACCESSOR(the_interface, the_iid) \ template \ struct the_interface::COMTypeInfo { \ static const nsIID kIID NS_HIDDEN; \ }; \ template \ const nsIID the_interface::COMTypeInfo::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::kIID) #define NS_GET_TEMPLATE_IID(T) (T::template COMTypeInfo::kIID) #endif