diff options
Diffstat (limited to 'src/backend/regex/regc_cvec.c')
| -rw-r--r-- | src/backend/regex/regc_cvec.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/backend/regex/regc_cvec.c b/src/backend/regex/regc_cvec.c index fb6f06b5243..580a693161e 100644 --- a/src/backend/regex/regc_cvec.c +++ b/src/backend/regex/regc_cvec.c @@ -77,6 +77,7 @@ static void addchr(struct cvec * cv, /* character vector */ chr c) /* character to add */ { + assert(cv->nchrs < cv->chrspace); cv->chrs[cv->nchrs++] = (chr) c; } @@ -95,17 +96,27 @@ addrange(struct cvec * cv, /* character vector */ } /* - * getcvec - get a cvec, remembering it as v->cv + * 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); |