//%LICENSE//////////////////////////////////////////////////////////////// // // Licensed to The Open Group (TOG) under one or more contributor license // agreements. Refer to the OpenPegasusNOTICE.txt file distributed with // this work for additional information regarding copyright ownership. // Each contributor licenses this file to you under the OpenPegasus Open // Source License; you may not use this file except in compliance with the // License. // // Permission is hereby granted, free of charge, to any person obtaining a // copy of this software and associated documentation files (the "Software"), // to deal in the Software without restriction, including without limitation // the rights to use, copy, modify, merge, publish, distribute, sublicense, // and/or sell copies of the Software, and to permit persons to whom the // Software is furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included // in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. // IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY // CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE // SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. // ////////////////////////////////////////////////////////////////////////// // //%///////////////////////////////////////////////////////////////////////////// #ifndef Pegasus_StrLit_h #define Pegasus_StrLit_h #include #include #define STRLIT_ARGS(STR) STR, (sizeof(STR)-1) #define STRLIT(STR) StrLit(STRLIT_ARGS(STR)) PEGASUS_NAMESPACE_BEGIN /* The StrLit class and associated macros provide a mechanism for retaining the length C string literals at compile time. This is preferrable to repeated recalculation of the length, usually with strlen(). For example, this: String s("hello world"); Is less efficient than this: String s("hello world", 11); The first form, forces the String constructor to call strlen(), an O(N) operation. This is unfortunate for C string literals since the length can be obtained at compile time with the sizeof operator. For example: String s("hello world", sizeof("hello world") - 1); But repeating the literal twice is error prone, so instead we use the STRLIT_ARGS() macro. String s(STRLIT_ARGS("hello world")); This macro can also be used to define StrLit objects at compile time. For example: const StrLit DEFAULT_HOSTNAME(STRLIT_ARGS("localhost")); You can implement functions that take StrLit objects. For example, we define this function: operator<<(const Buffer&, const StrLit&); This function can be used in two ways. You can pass predefined StrLit object to it like this: Buffer out; out << DEFAULT_HOSTNAME; Or you can use the STRLIT() macro to construct on on the fly: Buffer out; out << STRLIT("localhost"); Note that the latter form would be faster than this, since somebody is going to have to call strlen() eventually. Buffer out; out << "localhost"; At first glance, this may seem like a small optimization, but this technique alone was used to decrease the Pegasus CIM server latency by ten percent (with only moderate application to the XML marshalling routines). */ struct StrLit { StrLit(const char* s, size_t n) : str(s), size((Uint32)n) { } const char* str; const Uint32 size; }; inline Buffer& operator<<(Buffer& out, const StrLit& x) { out.append(x.str, x.size); return out; } PEGASUS_NAMESPACE_END #endif /* Pegasus_StrLit_h */