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Diffstat (limited to 'src/backend/regex/regc_cvec.c')
| -rw-r--r-- | src/backend/regex/regc_cvec.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/backend/regex/regc_cvec.c b/src/backend/regex/regc_cvec.c new file mode 100644 index 00000000000..3b4e6ddb61b --- /dev/null +++ b/src/backend/regex/regc_cvec.c @@ -0,0 +1,194 @@ +/* + * Utility functions for handling cvecs + * This file is #included by regcomp.c. + * + * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved. + * + * Development of this software was funded, in part, by Cray Research Inc., + * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics + * Corporation, none of whom are responsible for the results. The author + * thanks all of them. + * + * Redistribution and use in source and binary forms -- with or without + * modification -- are permitted for any purpose, provided that + * redistributions in source form retain this entire copyright notice and + * indicate the origin and nature of any modifications. + * + * I'd appreciate being given credit for this package in the documentation + * of software which uses it, but that is not a requirement. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL + * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * $Header: /cvsroot/pgsql/src/backend/regex/regc_cvec.c,v 1.1 2003/02/05 17:41:32 tgl Exp $ + * + */ + +/* + * newcvec - allocate a new cvec + */ +static struct cvec * +newcvec(int nchrs, /* to hold this many chrs... */ + int nranges, /* ... and this many ranges... */ + int nmcces) /* ... and this many MCCEs */ +{ + size_t n; + size_t nc; + struct cvec *cv; + + nc = (size_t)nchrs + (size_t)nmcces*(MAXMCCE+1) + (size_t)nranges*2; + n = sizeof(struct cvec) + (size_t)(nmcces-1)*sizeof(chr *) + + nc*sizeof(chr); + cv = (struct cvec *)MALLOC(n); + if (cv == NULL) { + return NULL; + } + cv->chrspace = nchrs; + cv->chrs = (chr *)&cv->mcces[nmcces]; /* chrs just after MCCE ptrs */ + cv->mccespace = nmcces; + cv->ranges = cv->chrs + nchrs + nmcces*(MAXMCCE+1); + cv->rangespace = nranges; + return clearcvec(cv); +} + +/* + * clearcvec - clear a possibly-new cvec + * Returns pointer as convenience. + */ +static struct cvec * +clearcvec(struct cvec *cv) +{ + int i; + + assert(cv != NULL); + cv->nchrs = 0; + assert(cv->chrs == (chr *)&cv->mcces[cv->mccespace]); + cv->nmcces = 0; + cv->nmccechrs = 0; + cv->nranges = 0; + for (i = 0; i < cv->mccespace; i++) { + cv->mcces[i] = NULL; + } + + return cv; +} + +/* + * addchr - add a chr to a cvec + */ +static void +addchr(struct cvec *cv, /* character vector */ + chr c) /* character to add */ +{ + assert(cv->nchrs < cv->chrspace - cv->nmccechrs); + cv->chrs[cv->nchrs++] = (chr)c; +} + +/* + * addrange - add a range to a cvec + */ +static void +addrange(struct cvec *cv, /* character vector */ + chr from, /* first character of range */ + chr to) /* last character of range */ +{ + assert(cv->nranges < cv->rangespace); + cv->ranges[cv->nranges*2] = (chr)from; + cv->ranges[cv->nranges*2 + 1] = (chr)to; + cv->nranges++; +} + +/* + * addmcce - add an MCCE to a cvec + */ +static void +addmcce(struct cvec *cv, /* character vector */ + chr *startp, /* beginning of text */ + chr *endp) /* just past end of text */ +{ + int len; + int i; + chr *s; + chr *d; + + if (startp == NULL && endp == NULL) { + return; + } + len = endp - startp; + assert(len > 0); + assert(cv->nchrs + len < cv->chrspace - cv->nmccechrs); + assert(cv->nmcces < cv->mccespace); + d = &cv->chrs[cv->chrspace - cv->nmccechrs - len - 1]; + cv->mcces[cv->nmcces++] = d; + for (s = startp, i = len; i > 0; s++, i--) { + *d++ = *s; + } + *d++ = 0; /* endmarker */ + assert(d == &cv->chrs[cv->chrspace - cv->nmccechrs]); + cv->nmccechrs += len + 1; +} + +/* + * haschr - does a cvec contain this chr? + */ +static int /* predicate */ +haschr(struct cvec *cv, /* character vector */ + chr c) /* character to test for */ +{ + int i; + chr *p; + + for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--) { + if (*p == c) { + return 1; + } + } + for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--) { + if ((*p <= c) && (c <= *(p+1))) { + return 1; + } + } + return 0; +} + +/* + * getcvec - get a cvec, remembering it as v->cv + */ +static struct cvec * +getcvec(struct vars *v, /* context */ + int nchrs, /* to hold this many chrs... */ + int nranges, /* ... and this many ranges... */ + int nmcces) /* ... and this many MCCEs */ +{ + if (v->cv != NULL && nchrs <= v->cv->chrspace && + nranges <= v->cv->rangespace && nmcces <= v->cv->mccespace) { + return clearcvec(v->cv); + } + + if (v->cv != NULL) { + freecvec(v->cv); + } + v->cv = newcvec(nchrs, nranges, nmcces); + if (v->cv == NULL) { + ERR(REG_ESPACE); + } + + return v->cv; +} + +/* + * freecvec - free a cvec + */ +static void +freecvec(struct cvec *cv) +{ + FREE(cv); +} |