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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
commit46651ce6fe013220ed397add242004d764fc0153 (patch)
tree6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/backend/regex/regc_cvec.c
parentInitial commit. (diff)
downloadpostgresql-14-46651ce6fe013220ed397add242004d764fc0153.tar.xz
postgresql-14-46651ce6fe013220ed397add242004d764fc0153.zip
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/backend/regex/regc_cvec.c')
-rw-r--r--src/backend/regex/regc_cvec.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/src/backend/regex/regc_cvec.c b/src/backend/regex/regc_cvec.c
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+/*
+ * 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.
+ *
+ * src/backend/regex/regc_cvec.c
+ *
+ */
+
+/*
+ * Notes:
+ * Only (selected) functions in _this_ file should treat the chr arrays
+ * of a cvec as non-constant.
+ */
+
+/*
+ * newcvec - allocate a new cvec
+ */
+static struct cvec *
+newcvec(int nchrs, /* to hold this many chrs... */
+ int nranges) /* ... and this many ranges */
+{
+ size_t nc = (size_t) nchrs + (size_t) nranges * 2;
+ size_t n = sizeof(struct cvec) + nc * sizeof(chr);
+ struct cvec *cv = (struct cvec *) MALLOC(n);
+
+ if (cv == NULL)
+ return NULL;
+ cv->chrspace = nchrs;
+ cv->chrs = (chr *) (((char *) cv) + sizeof(struct cvec));
+ cv->ranges = cv->chrs + nchrs;
+ cv->rangespace = nranges;
+ return clearcvec(cv);
+}
+
+/*
+ * clearcvec - clear a possibly-new cvec
+ * Returns pointer as convenience.
+ */
+static struct cvec *
+clearcvec(struct cvec *cv)
+{
+ assert(cv != NULL);
+ cv->nchrs = 0;
+ cv->nranges = 0;
+ cv->cclasscode = -1;
+ 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->chrs[cv->nchrs++] = 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] = from;
+ cv->ranges[cv->nranges * 2 + 1] = to;
+ cv->nranges++;
+}
+
+/*
+ * getcvec - get a transient cvec, initialized to empty
+ *
+ * The returned cvec is valid only until the next call of getcvec, which
+ * typically will recycle the space. Callers should *not* free the cvec
+ * explicitly; it will be cleaned up when the struct vars is destroyed.
+ *
+ * This is typically used while interpreting bracket expressions. In that
+ * usage the cvec is only needed momentarily until we build arcs from it,
+ * so transientness is a convenient behavior.
+ */
+static struct cvec *
+getcvec(struct vars *v, /* context */
+ int nchrs, /* to hold this many chrs... */
+ int nranges) /* ... and this many ranges */
+{
+ /* recycle existing transient cvec if large enough */
+ if (v->cv != NULL && nchrs <= v->cv->chrspace &&
+ nranges <= v->cv->rangespace)
+ return clearcvec(v->cv);
+
+ /* nope, make a new one */
+ if (v->cv != NULL)
+ freecvec(v->cv);
+ v->cv = newcvec(nchrs, nranges);
+ if (v->cv == NULL)
+ ERR(REG_ESPACE);
+
+ return v->cv;
+}
+
+/*
+ * freecvec - free a cvec
+ */
+static void
+freecvec(struct cvec *cv)
+{
+ FREE(cv);
+}