1 karl  1.3 //%2006////////////////////////////////////////////////////////////////////////

  2 mike  1.1 //
  3           // Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
  4           // Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
  5           // Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
  6           // IBM Corp.; EMC Corporation, The Open Group.
  7           // Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
  8           // IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
  9           // Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
 10           // EMC Corporation; VERITAS Software Corporation; The Open Group.

 11 karl  1.3 // Copyright (c) 2006 Hewlett-Packard Development Company, L.P.; IBM Corp.;
 12           // EMC Corporation; Symantec Corporation; The Open Group.

 13 mike  1.1 //
 14           // Permission is hereby granted, free of charge, to any person obtaining a copy
 15           // of this software and associated documentation files (the "Software"), to
 16           // deal in the Software without restriction, including without limitation the
 17           // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 18           // sell copies of the Software, and to permit persons to whom the Software is
 19           // furnished to do so, subject to the following conditions:

 20 karl  1.3 // 

 21 mike  1.1 // THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
 22           // ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
 23           // "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
 24           // LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 25           // PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 26           // HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 27           // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 28           // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 29           //
 30           //==============================================================================
 31           //
 32           // Author: Mike Brasher, Inova Europe (mike-brasher@austin.rr.com)
 33           //
 34           //%/////////////////////////////////////////////////////////////////////////////
 35           
 36           #ifndef Pegasus_StrLit_h
 37           #define Pegasus_StrLit_h
 38           
 39           #include <Pegasus/Common/Config.h>
 40           #include <Pegasus/Common/Buffer.h>
 41           
 42 mike  1.1 #define STRLIT_ARGS(STR) STR, (sizeof(STR)-1)
 43           #define STRLIT(STR) StrLit(STRLIT_ARGS(STR))
 44           
 45           PEGASUS_NAMESPACE_BEGIN
 46           
 47           /*  The StrLit class and associated macros provide a mechanism for retaining the
 48               length C string literals at compile time. This is preferrable to repeated
 49               recalculation of the length, usually with strlen(). For example, this:
 50              
 51           	String s("hello world");
 52           
 53               Is less efficient than this:
 54           
 55           	String s("hello world", 11);
 56           
 57               The first form, forces the String constructor to call strlen(), an O(N)
 58               operation. This is unfortunate for C string literals since the length can 
 59               be obtained at compile time with the sizeof operator. For example:
 60           
 61           	String s("hello world", sizeof("hello world") - 1);
 62           
 63 mike  1.1     But repeating the literal twice is error prone, so instead we use the
 64               STRLIT_ARGS() macro.
 65           
 66           	String s(STRLIT_ARGS("hello world"));
 67           
 68               This macro can also be used to define StrLit objects at compile time.
 69               For example:
 70           
 71           	const StrLit DEFAULT_HOSTNAME(STRLIT_ARGS("localhost"));
 72           
 73               You can implement functions that take StrLit objects. For example, we 
 74               define this function:
 75           
 76           	operator<<(const Buffer&, const StrLit&);
 77           
 78               This function can be used in two ways. You can pass predefined StrLit
 79               object to it like this:
 80           
 81           	Buffer out;
 82           	out << DEFAULT_HOSTNAME;
 83           
 84 mike  1.1     Or you can use the STRLIT() macro to construct on on the fly:
 85           
 86           	Buffer out;
 87           	out << STRLIT("localhost");
 88           
 89               Note that the latter form would be faster than this, since somebody
 90               is going to have to call strlen() eventually.
 91           
 92           	Buffer out;
 93           	out << "localhost";
 94           
 95               At first glance, this may seem like a small optimization, but this 
 96               technique alone was used to decrease the Pegasus CIM server latency 
 97               by ten percent (with only moderate application to the XML marshalling 
 98               routines).
 99           */
100           struct StrLit
101           {
102               StrLit(const char* s, size_t n) : str(s), size(n) { }
103               const char* str;
104               const size_t size;
105 mike  1.1 };
106           
107           inline Buffer& operator<<(Buffer& out, const StrLit& x)
108           {

109 mike  1.2     out.append(x.str, x.size);

110 mike  1.1     return out;
111           }
112           
113           PEGASUS_NAMESPACE_END
114           
115           #endif /* Pegasus_StrLit_h */