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| author | Nikita Popov <nikita.ppv@gmail.com> | 2019-03-18 12:57:43 +0100 |
|---|---|---|
| committer | Nikita Popov <nikita.ppv@gmail.com> | 2019-03-18 16:58:48 +0100 |
| commit | 2b9acd37f0a13572684dde80e3e56d5c1b2ec045 (patch) | |
| tree | ca4e1541d2e998a2d0d4f9ed5ac5c71418edd45e /ext/pcre/php_pcre.c | |
| parent | 8c9d8c3f667e4cedc7499b49dcc52644dac17c53 (diff) | |
| download | php-git-2b9acd37f0a13572684dde80e3e56d5c1b2ec045.tar.gz | |
Fixed bug #72685
We currently have a large performance problem when implementing lexers
working on UTF-8 strings in PHP. This kind of code tends to perform a
large number of matches at different offsets on a single string. This
is generally fast. However, if /u mode is used, the full string will
be UTF-8 validated on each match. This results in quadratic runtime.
This patch fixes the issue by adding a IS_STR_VALID_UTF8 flag, which
is set when we have determined that the string is valid UTF8 and
further validation is skipped.
A limitation of this approach is that we can't set the flag for interned
strings. I think this is not a problem for this use-case which will
generally work on dynamic data. If we want to use this flag for other
purposes as well (mbstring?) then it might be worthwhile to UTF-8 validate
strings during interning. But right now this doesn't seem useful.
Diffstat (limited to 'ext/pcre/php_pcre.c')
| -rw-r--r-- | ext/pcre/php_pcre.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c index d18ab6ae32..e1c46842b9 100644 --- a/ext/pcre/php_pcre.c +++ b/ext/pcre/php_pcre.c @@ -1104,7 +1104,8 @@ PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str, } } - options = (pce->compile_options & PCRE2_UTF) ? 0 : PCRE2_NO_UTF_CHECK; + options = (pce->compile_options & PCRE2_UTF) && !(GC_FLAGS(subject_str) & IS_STR_VALID_UTF8) + ? 0 : PCRE2_NO_UTF_CHECK; /* Execute the regular expression. */ #ifdef HAVE_PCRE_JIT_SUPPORT @@ -1403,8 +1404,12 @@ error: efree(subpat_names); } - /* Did we encounter an error? */ if (PCRE_G(error_code) == PHP_PCRE_NO_ERROR) { + /* If there was no error and we're in /u mode, remember that the string is valid UTF-8. */ + if ((pce->compile_options & PCRE2_UTF) && !ZSTR_IS_INTERNED(subject_str)) { + GC_ADD_FLAGS(subject_str, IS_STR_VALID_UTF8); + } + RETVAL_LONG(matched); } else { RETVAL_FALSE; |