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php5  5.3.10
pcre_refcount.c
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00001 /*************************************************
00002 *      Perl-Compatible Regular Expressions       *
00003 *************************************************/
00004 
00005 /* PCRE is a library of functions to support regular expressions whose syntax
00006 and semantics are as close as possible to those of the Perl 5 language.
00007 
00008                        Written by Philip Hazel
00009            Copyright (c) 1997-2008 University of Cambridge
00010 
00011 -----------------------------------------------------------------------------
00012 Redistribution and use in source and binary forms, with or without
00013 modification, are permitted provided that the following conditions are met:
00014 
00015     * Redistributions of source code must retain the above copyright notice,
00016       this list of conditions and the following disclaimer.
00017 
00018     * Redistributions in binary form must reproduce the above copyright
00019       notice, this list of conditions and the following disclaimer in the
00020       documentation and/or other materials provided with the distribution.
00021 
00022     * Neither the name of the University of Cambridge nor the names of its
00023       contributors may be used to endorse or promote products derived from
00024       this software without specific prior written permission.
00025 
00026 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00027 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00028 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00029 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
00030 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
00031 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
00032 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00033 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00034 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
00035 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00036 POSSIBILITY OF SUCH DAMAGE.
00037 -----------------------------------------------------------------------------
00038 */
00039 
00040 
00041 /* This module contains the external function pcre_refcount(), which is an
00042 auxiliary function that can be used to maintain a reference count in a compiled
00043 pattern data block. This might be helpful in applications where the block is
00044 shared by different users. */
00045 
00046 
00047 #include "config.h"
00048 
00049 #include "pcre_internal.h"
00050 
00051 
00052 /*************************************************
00053 *           Maintain reference count             *
00054 *************************************************/
00055 
00056 /* The reference count is a 16-bit field, initialized to zero. It is not
00057 possible to transfer a non-zero count from one host to a different host that
00058 has a different byte order - though I can't see why anyone in their right mind
00059 would ever want to do that!
00060 
00061 Arguments:
00062   argument_re   points to compiled code
00063   adjust        value to add to the count
00064 
00065 Returns:        the (possibly updated) count value (a non-negative number), or
00066                 a negative error number
00067 */
00068 
00069 PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
00070 pcre_refcount(pcre *argument_re, int adjust)
00071 {
00072 real_pcre *re = (real_pcre *)argument_re;
00073 if (re == NULL) return PCRE_ERROR_NULL;
00074 re->ref_count = (-adjust > re->ref_count)? 0 :
00075                 (adjust + re->ref_count > 65535)? 65535 :
00076                 re->ref_count + adjust;
00077 return re->ref_count;
00078 }
00079 
00080 /* End of pcre_refcount.c */