Age Owner Branch data 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 : : * Note: in current usage, nchrs and nranges are never so large that we risk
45 : : * integer overflow in these size calculations, even with 32-bit size_t.
46 : : */
47 : : static struct cvec *
8515 tgl@sss.pgh.pa.us 48 :CBC 5148 : newcvec(int nchrs, /* to hold this many chrs... */
49 : : int nranges) /* ... and this many ranges */
50 : : {
6680 51 : 5148 : size_t nc = (size_t) nchrs + (size_t) nranges * 2;
52 : 5148 : size_t n = sizeof(struct cvec) + nc * sizeof(chr);
53 : 5148 : struct cvec *cv = (struct cvec *) MALLOC(n);
54 : :
8335 bruce@momjian.us 55 [ - + ]: 5148 : if (cv == NULL)
8335 bruce@momjian.us 56 :UBC 0 : return NULL;
8335 bruce@momjian.us 57 :CBC 5148 : cv->chrspace = nchrs;
6680 tgl@sss.pgh.pa.us 58 : 5148 : cv->chrs = (chr *) (((char *) cv) + sizeof(struct cvec));
59 : 5148 : cv->ranges = cv->chrs + nchrs;
8335 bruce@momjian.us 60 : 5148 : cv->rangespace = nranges;
61 : 5148 : return clearcvec(cv);
62 : : }
63 : :
64 : : /*
65 : : * clearcvec - clear a possibly-new cvec
66 : : * Returns pointer as convenience.
67 : : */
68 : : static struct cvec *
3265 tgl@sss.pgh.pa.us 69 : 6533 : clearcvec(struct cvec *cv)
70 : : {
8335 bruce@momjian.us 71 [ - + ]: 6533 : assert(cv != NULL);
72 : 6533 : cv->nchrs = 0;
73 : 6533 : cv->nranges = 0;
3554 tgl@sss.pgh.pa.us 74 : 6533 : cv->cclasscode = -1;
8335 bruce@momjian.us 75 : 6533 : return cv;
76 : : }
77 : :
78 : : /*
79 : : * addchr - add a chr to a cvec
80 : : */
81 : : static void
3265 tgl@sss.pgh.pa.us 82 : 2533 : addchr(struct cvec *cv, /* character vector */
83 : : chr c) /* character to add */
84 : : {
5214 85 [ - + ]: 2533 : assert(cv->nchrs < cv->chrspace);
3571 86 : 2533 : cv->chrs[cv->nchrs++] = c;
8515 87 : 2533 : }
88 : :
89 : : /*
90 : : * addrange - add a range to a cvec
91 : : */
92 : : static void
3265 93 : 351 : addrange(struct cvec *cv, /* character vector */
94 : : chr from, /* first character of range */
95 : : chr to) /* last character of range */
96 : : {
8335 bruce@momjian.us 97 [ - + ]: 351 : assert(cv->nranges < cv->rangespace);
3571 tgl@sss.pgh.pa.us 98 : 351 : cv->ranges[cv->nranges * 2] = from;
99 : 351 : cv->ranges[cv->nranges * 2 + 1] = to;
8335 bruce@momjian.us 100 : 351 : cv->nranges++;
8515 tgl@sss.pgh.pa.us 101 : 351 : }
102 : :
103 : : /*
104 : : * getcvec - get a transient cvec, initialized to empty
105 : : *
106 : : * The returned cvec is valid only until the next call of getcvec, which
107 : : * typically will recycle the space. Callers should *not* free the cvec
108 : : * explicitly; it will be cleaned up when the struct vars is destroyed.
109 : : *
110 : : * This is typically used while interpreting bracket expressions. In that
111 : : * usage the cvec is only needed momentarily until we build arcs from it,
112 : : * so transientness is a convenient behavior.
113 : : */
114 : : static struct cvec *
3265 115 : 1386 : getcvec(struct vars *v, /* context */
116 : : int nchrs, /* to hold this many chrs... */
117 : : int nranges) /* ... and this many ranges */
118 : : {
119 : : /* recycle existing transient cvec if large enough */
8335 bruce@momjian.us 120 [ + - + + ]: 1386 : if (v->cv != NULL && nchrs <= v->cv->chrspace &&
6680 tgl@sss.pgh.pa.us 121 [ + - ]: 1385 : nranges <= v->cv->rangespace)
8335 bruce@momjian.us 122 : 1385 : return clearcvec(v->cv);
123 : :
124 : : /* nope, make a new one */
125 [ + - ]: 1 : if (v->cv != NULL)
126 : 1 : freecvec(v->cv);
6680 tgl@sss.pgh.pa.us 127 : 1 : v->cv = newcvec(nchrs, nranges);
8335 bruce@momjian.us 128 [ - + ]: 1 : if (v->cv == NULL)
8335 bruce@momjian.us 129 [ # # ]:UBC 0 : ERR(REG_ESPACE);
130 : :
8335 bruce@momjian.us 131 :CBC 1 : return v->cv;
132 : : }
133 : :
134 : : /*
135 : : * freecvec - free a cvec
136 : : */
137 : : static void
3265 tgl@sss.pgh.pa.us 138 : 5148 : freecvec(struct cvec *cv)
139 : : {
8335 bruce@momjian.us 140 : 5148 : FREE(cv);
8515 tgl@sss.pgh.pa.us 141 : 5148 : }
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