//%2005////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
// Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
// Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation, The Open Group.
// Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; VERITAS Software Corporation; The Open Group.
//
// 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.
//
//==============================================================================
//
// Author: Mike Brasher, Inova Europe (mike-brasher@austin.rr.com)
//
//%/////////////////////////////////////////////////////////////////////////////

#ifndef Pegasus_StrLit_h
#define Pegasus_StrLit_h

#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/Buffer.h>

#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(n) { }
    const char* str;
    const size_t size;
};

inline Buffer& operator<<(Buffer& out, const StrLit& x)
{
    out.append(x.str, x.size-1);
    return out;
}

PEGASUS_NAMESPACE_END

#endif /* Pegasus_StrLit_h */