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| author | dkf <donal.k.fellows@manchester.ac.uk> | 2010-02-01 11:19:28 (GMT) |
|---|---|---|
| committer | dkf <donal.k.fellows@manchester.ac.uk> | 2010-02-01 11:19:28 (GMT) |
| commit | 8dc76eca1beb59a4b83d3a8465e445a23ce9b4fb (patch) | |
| tree | bcbbb1be2539993ae7b60ac93724fef8f6851b67 /generic/regexec.c | |
| parent | 0ef0708322e51a6c0a8c283ec573d5f74cf03d58 (diff) | |
| download | tcl-8dc76eca1beb59a4b83d3a8465e445a23ce9b4fb.zip tcl-8dc76eca1beb59a4b83d3a8465e445a23ce9b4fb.tar.gz tcl-8dc76eca1beb59a4b83d3a8465e445a23ce9b4fb.tar.bz2 | |
[Bug 2942697]: Rework the RE engine so that certain pathological patterns are
matched much more rapidly. Many thanks to Tom Lane for dianosing this issue
and providing an initial patch.
Diffstat (limited to 'generic/regexec.c')
| -rw-r--r-- | generic/regexec.c | 66 |
1 files changed, 34 insertions, 32 deletions
diff --git a/generic/regexec.c b/generic/regexec.c index 3eb73d1..be459d3 100644 --- a/generic/regexec.c +++ b/generic/regexec.c @@ -784,16 +784,23 @@ chr *end; /* end of same */ /* iterate until satisfaction or failure */ for (;;) { /* try this midpoint on for size */ - er = cdissect(v, t->left, begin, mid); - if (er == REG_OKAY && - longest(v, d2, mid, end, (int *)NULL) == end && - (er = cdissect(v, t->right, mid, end)) == - REG_OKAY) - break; /* NOTE BREAK OUT */ - if (er != REG_OKAY && er != REG_NOMATCH) { - freedfa(d); - freedfa(d2); - return er; + if (longest(v, d2, mid, end, NULL) == end) { + er = cdissect(v, t->left, begin, mid); + if (er == REG_OKAY) { + er = cdissect(v, t->right, mid, end); + if (er == REG_OKAY) { + /* satisfaction */ + MDEBUG(("successful\n")); + freedfa(d); + freedfa(d2); + return REG_OKAY; + } + } + if ((er != REG_OKAY) && (er != REG_NOMATCH)) { + freedfa(d); + freedfa(d2); + return er; + } } /* that midpoint didn't work, find a new one */ @@ -817,12 +824,6 @@ chr *end; /* end of same */ zapmem(v, t->left); zapmem(v, t->right); } - - /* satisfaction */ - MDEBUG(("successful\n")); - freedfa(d); - freedfa(d2); - return REG_OKAY; } /* @@ -877,16 +878,23 @@ chr *end; /* end of same */ /* iterate until satisfaction or failure */ for (;;) { /* try this midpoint on for size */ - er = cdissect(v, t->left, begin, mid); - if (er == REG_OKAY && - longest(v, d2, mid, end, (int *)NULL) == end && - (er = cdissect(v, t->right, mid, end)) == - REG_OKAY) - break; /* NOTE BREAK OUT */ - if (er != REG_OKAY && er != REG_NOMATCH) { - freedfa(d); - freedfa(d2); - return er; + if (longest(v, d2, mid, end, NULL) == end) { + er = cdissect(v, t->left, begin, mid); + if (er == REG_OKAY) { + er = cdissect(v, t->right, mid, end); + if (er == REG_OKAY) { + /* satisfaction */ + MDEBUG(("successful\n")); + freedfa(d); + freedfa(d2); + return REG_OKAY; + } + } + if (er != REG_OKAY && er != REG_NOMATCH) { + freedfa(d); + freedfa(d2); + return er; + } } /* that midpoint didn't work, find a new one */ @@ -910,12 +918,6 @@ chr *end; /* end of same */ zapmem(v, t->left); zapmem(v, t->right); } - - /* satisfaction */ - MDEBUG(("successful\n")); - freedfa(d); - freedfa(d2); - return REG_OKAY; } /* |