1/*************************************************
2*      Perl-Compatible Regular Expressions       *
3*************************************************/
4
5/* PCRE is a library of functions to support regular expressions whose syntax
6and semantics are as close as possible to those of the Perl 5 language.
7
8                       Written by Philip Hazel
9           Copyright (c) 1997-2012 University of Cambridge
10
11-----------------------------------------------------------------------------
12Redistribution and use in source and binary forms, with or without
13modification, are permitted provided that the following conditions are met:
14
15    * Redistributions of source code must retain the above copyright notice,
16      this list of conditions and the following disclaimer.
17
18    * Redistributions in binary form must reproduce the above copyright
19      notice, this list of conditions and the following disclaimer in the
20      documentation and/or other materials provided with the distribution.
21
22    * Neither the name of the University of Cambridge nor the names of its
23      contributors may be used to endorse or promote products derived from
24      this software without specific prior written permission.
25
26THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36POSSIBILITY OF SUCH DAMAGE.
37-----------------------------------------------------------------------------
38*/
39
40
41/* This module contains the external function pcre_refcount(), which is an
42auxiliary function that can be used to maintain a reference count in a compiled
43pattern data block. This might be helpful in applications where the block is
44shared by different users. */
45
46
47#ifdef HAVE_CONFIG_H
48#include "config.h"
49#endif
50
51#include "pcre_internal.h"
52
53
54/*************************************************
55*           Maintain reference count             *
56*************************************************/
57
58/* The reference count is a 16-bit field, initialized to zero. It is not
59possible to transfer a non-zero count from one host to a different host that
60has a different byte order - though I can't see why anyone in their right mind
61would ever want to do that!
62
63Arguments:
64  argument_re   points to compiled code
65  adjust        value to add to the count
66
67Returns:        the (possibly updated) count value (a non-negative number), or
68                a negative error number
69*/
70
71#if defined COMPILE_PCRE8
72PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
73pcre_refcount(pcre *argument_re, int adjust)
74#elif defined COMPILE_PCRE16
75PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
76pcre16_refcount(pcre16 *argument_re, int adjust)
77#elif defined COMPILE_PCRE32
78PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
79pcre32_refcount(pcre32 *argument_re, int adjust)
80#endif
81{
82REAL_PCRE *re = (REAL_PCRE *)argument_re;
83if (re == NULL) return PCRE_ERROR_NULL;
84if (re->magic_number != MAGIC_NUMBER) return PCRE_ERROR_BADMAGIC;
85if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
86re->ref_count = (-adjust > re->ref_count)? 0 :
87                (adjust + re->ref_count > 65535)? 65535 :
88                re->ref_count + adjust;
89return re->ref_count;
90}
91
92/* End of pcre_refcount.c */
93