Age Owner TLA Line data Source code
1 : /*
2 : * Utility functions for handling cvecs
3 : * This file is #included by regcomp.c.
4 : *
5 : * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
6 : *
7 : * Development of this software was funded, in part, by Cray Research Inc.,
8 : * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
9 : * Corporation, none of whom are responsible for the results. The author
10 : * thanks all of them.
11 : *
12 : * Redistribution and use in source and binary forms -- with or without
13 : * modification -- are permitted for any purpose, provided that
14 : * redistributions in source form retain this entire copyright notice and
15 : * indicate the origin and nature of any modifications.
16 : *
17 : * I'd appreciate being given credit for this package in the documentation
18 : * of software which uses it, but that is not a requirement.
19 : *
20 : * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
21 : * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
22 : * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
23 : * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 : * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 : * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 : * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 : * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 : * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 : * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 : *
31 : * src/backend/regex/regc_cvec.c
32 : *
33 : */
34 :
35 : /*
36 : * Notes:
37 : * Only (selected) functions in _this_ file should treat the chr arrays
38 : * of a cvec as non-constant.
39 : */
40 :
41 : /*
42 : * newcvec - allocate a new cvec
43 : */
44 : static struct cvec *
7368 tgl 45 CBC 3934 : newcvec(int nchrs, /* to hold this many chrs... */
46 : int nranges) /* ... and this many ranges */
47 : {
5533 48 3934 : size_t nc = (size_t) nchrs + (size_t) nranges * 2;
49 3934 : size_t n = sizeof(struct cvec) + nc * sizeof(chr);
50 3934 : struct cvec *cv = (struct cvec *) MALLOC(n);
51 :
7188 bruce 52 3934 : if (cv == NULL)
7188 bruce 53 UBC 0 : return NULL;
7188 bruce 54 CBC 3934 : cv->chrspace = nchrs;
5533 tgl 55 3934 : cv->chrs = (chr *) (((char *) cv) + sizeof(struct cvec));
56 3934 : cv->ranges = cv->chrs + nchrs;
7188 bruce 57 3934 : cv->rangespace = nranges;
58 3934 : return clearcvec(cv);
59 : }
60 :
61 : /*
62 : * clearcvec - clear a possibly-new cvec
63 : * Returns pointer as convenience.
64 : */
65 : static struct cvec *
2118 tgl 66 5378 : clearcvec(struct cvec *cv)
67 : {
7188 bruce 68 5378 : assert(cv != NULL);
69 5378 : cv->nchrs = 0;
70 5378 : cv->nranges = 0;
2407 tgl 71 5378 : cv->cclasscode = -1;
7188 bruce 72 5378 : return cv;
73 : }
74 :
75 : /*
76 : * addchr - add a chr to a cvec
77 : */
78 : static void
2118 tgl 79 2116 : addchr(struct cvec *cv, /* character vector */
80 : chr c) /* character to add */
81 : {
4067 82 2116 : assert(cv->nchrs < cv->chrspace);
2424 83 2116 : cv->chrs[cv->nchrs++] = c;
7368 84 2116 : }
85 :
86 : /*
87 : * addrange - add a range to a cvec
88 : */
89 : static void
2118 90 540 : addrange(struct cvec *cv, /* character vector */
91 : chr from, /* first character of range */
92 : chr to) /* last character of range */
93 : {
7188 bruce 94 540 : assert(cv->nranges < cv->rangespace);
2424 tgl 95 540 : cv->ranges[cv->nranges * 2] = from;
96 540 : cv->ranges[cv->nranges * 2 + 1] = to;
7188 bruce 97 540 : cv->nranges++;
7368 tgl 98 540 : }
99 :
100 : /*
101 : * getcvec - get a transient cvec, initialized to empty
102 : *
103 : * The returned cvec is valid only until the next call of getcvec, which
104 : * typically will recycle the space. Callers should *not* free the cvec
105 : * explicitly; it will be cleaned up when the struct vars is destroyed.
106 : *
107 : * This is typically used while interpreting bracket expressions. In that
108 : * usage the cvec is only needed momentarily until we build arcs from it,
109 : * so transientness is a convenient behavior.
110 : */
111 : static struct cvec *
2118 112 1445 : getcvec(struct vars *v, /* context */
113 : int nchrs, /* to hold this many chrs... */
114 : int nranges) /* ... and this many ranges */
115 : {
116 : /* recycle existing transient cvec if large enough */
7188 bruce 117 1445 : if (v->cv != NULL && nchrs <= v->cv->chrspace &&
5533 tgl 118 1444 : nranges <= v->cv->rangespace)
7188 bruce 119 1444 : return clearcvec(v->cv);
120 :
121 : /* nope, make a new one */
122 1 : if (v->cv != NULL)
123 1 : freecvec(v->cv);
5533 tgl 124 1 : v->cv = newcvec(nchrs, nranges);
7188 bruce 125 1 : if (v->cv == NULL)
7188 bruce 126 UBC 0 : ERR(REG_ESPACE);
127 :
7188 bruce 128 CBC 1 : return v->cv;
129 : }
130 :
131 : /*
132 : * freecvec - free a cvec
133 : */
134 : static void
2118 tgl 135 3934 : freecvec(struct cvec *cv)
136 : {
7188 bruce 137 3934 : FREE(cv);
7368 tgl 138 3934 : }
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