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 : : static struct cvec *
7739 tgl@sss.pgh.pa.us 45 :CBC 3611 : newcvec(int nchrs, /* to hold this many chrs... */
46 : : int nranges) /* ... and this many ranges */
47 : : {
5904 48 : 3611 : size_t nc = (size_t) nchrs + (size_t) nranges * 2;
49 : 3611 : size_t n = sizeof(struct cvec) + nc * sizeof(chr);
50 : 3611 : struct cvec *cv = (struct cvec *) MALLOC(n);
51 : :
7559 bruce@momjian.us 52 [ - + ]: 3611 : if (cv == NULL)
7559 bruce@momjian.us 53 :UBC 0 : return NULL;
7559 bruce@momjian.us 54 :CBC 3611 : cv->chrspace = nchrs;
5904 tgl@sss.pgh.pa.us 55 : 3611 : cv->chrs = (chr *) (((char *) cv) + sizeof(struct cvec));
56 : 3611 : cv->ranges = cv->chrs + nchrs;
7559 bruce@momjian.us 57 : 3611 : cv->rangespace = nranges;
58 : 3611 : return clearcvec(cv);
59 : : }
60 : :
61 : : /*
62 : : * clearcvec - clear a possibly-new cvec
63 : : * Returns pointer as convenience.
64 : : */
65 : : static struct cvec *
2489 tgl@sss.pgh.pa.us 66 : 4748 : clearcvec(struct cvec *cv)
67 : : {
7559 bruce@momjian.us 68 [ - + ]: 4748 : assert(cv != NULL);
69 : 4748 : cv->nchrs = 0;
70 : 4748 : cv->nranges = 0;
2778 tgl@sss.pgh.pa.us 71 : 4748 : cv->cclasscode = -1;
7559 bruce@momjian.us 72 : 4748 : return cv;
73 : : }
74 : :
75 : : /*
76 : : * addchr - add a chr to a cvec
77 : : */
78 : : static void
2489 tgl@sss.pgh.pa.us 79 : 2077 : addchr(struct cvec *cv, /* character vector */
80 : : chr c) /* character to add */
81 : : {
4438 82 [ - + ]: 2077 : assert(cv->nchrs < cv->chrspace);
2795 83 : 2077 : cv->chrs[cv->nchrs++] = c;
7739 84 : 2077 : }
85 : :
86 : : /*
87 : : * addrange - add a range to a cvec
88 : : */
89 : : static void
2489 90 : 287 : addrange(struct cvec *cv, /* character vector */
91 : : chr from, /* first character of range */
92 : : chr to) /* last character of range */
93 : : {
7559 bruce@momjian.us 94 [ - + ]: 287 : assert(cv->nranges < cv->rangespace);
2795 tgl@sss.pgh.pa.us 95 : 287 : cv->ranges[cv->nranges * 2] = from;
96 : 287 : cv->ranges[cv->nranges * 2 + 1] = to;
7559 bruce@momjian.us 97 : 287 : cv->nranges++;
7739 tgl@sss.pgh.pa.us 98 : 287 : }
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 *
2489 112 : 1138 : 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 */
7559 bruce@momjian.us 117 [ + - + + ]: 1138 : if (v->cv != NULL && nchrs <= v->cv->chrspace &&
5904 tgl@sss.pgh.pa.us 118 [ + - ]: 1137 : nranges <= v->cv->rangespace)
7559 bruce@momjian.us 119 : 1137 : return clearcvec(v->cv);
120 : :
121 : : /* nope, make a new one */
122 [ + - ]: 1 : if (v->cv != NULL)
123 : 1 : freecvec(v->cv);
5904 tgl@sss.pgh.pa.us 124 : 1 : v->cv = newcvec(nchrs, nranges);
7559 bruce@momjian.us 125 [ - + ]: 1 : if (v->cv == NULL)
7559 bruce@momjian.us 126 [ # # ]:UBC 0 : ERR(REG_ESPACE);
127 : :
7559 bruce@momjian.us 128 :CBC 1 : return v->cv;
129 : : }
130 : :
131 : : /*
132 : : * freecvec - free a cvec
133 : : */
134 : : static void
2489 tgl@sss.pgh.pa.us 135 : 3611 : freecvec(struct cvec *cv)
136 : : {
7559 bruce@momjian.us 137 : 3611 : FREE(cv);
7739 tgl@sss.pgh.pa.us 138 : 3611 : }
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