feature: add "U" regex option to ngx_lua's ngx.re API

diff --git a/src/ngx_http_lua_regex.c b/src/ngx_http_lua_regex.c
index 41d0701..7772cbe 100644
--- a/src/ngx_http_lua_regex.c
+++ b/src/ngx_http_lua_regex.c
@@ -1097,6 +1097,10 @@ ngx_http_lua_ngx_re_parse_opts(lua_State *L, ngx_lua_regex_compile_t *re,
                 re->options |= PCRE_UTF8;
                 break;
 
+            case 'U':
+                re->options |= PCRE_UTF8|PCRE_NO_UTF8_CHECK;
+                break;
+
             case 'x':
                 re->options |= PCRE_EXTENDED;
                 break;
diff --git a/t/034-match.t b/t/034-match.t
index 6efefe7..f37d923 100644
--- a/t/034-match.t
+++ b/t/034-match.t
@@ -9,7 +9,7 @@ use Test::Nginx::Socket;
 
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 2 + 10);
+plan tests => repeat_each() * (blocks() * 2 + 12);
 
 #no_diff();
 no_long_string();
@@ -945,3 +945,32 @@ error: pcre_exec\(\) failed: -10 on "你.*?" using "你好"
 --- no_error_log
 [error]
 
+
+
+=== TEST 43: UTF-8 mode without UTF-8 sequence checks
+--- config
+    location /re {
+        content_by_lua '
+            m = ngx.re.match("你好", ".", "U")
+            if m then
+                ngx.say(m[0])
+            else
+                ngx.say("not matched!")
+            end
+        ';
+    }
+--- stap
+F(ngx_lua_regex_compile) {
+    printf("regex opts: %x\n", $rc->options)
+}
+
+--- stap_out
+regex opts: 2800
+
+--- request
+    GET /re
+--- response_body
+你
+--- no_error_log
+[error]
+

It looks much simpler, but according to my simple test, the PCRE_NO_UTF8_CHECK dose not really be set, below is the test

server
{
    listen 80;
    server_name test;
    access_log /data/logs/test-access.log combined_x;
    error_log  /data/logs/test-error.log debug;
    location /
    {
        content_by_lua '
          local key = string.rep ("张", 30000)
          local it, err = ngx.re.gmatch(key, ".", "Usoj")
          while true do
            local m, err = it()
            if not m then break end
          end
        ';
    }
}

[root@test ngx_openresty-1.2.7.6]# time curl "http://test/"

real 0m7.028s
user 0m0.002s
sys 0m0.000s

and compared with my patch

[root@test ngx_openresty-1.2.7.5-with-pcreutf-noutfcheckpatch]# time curl "http://test/"

real 0m0.013s
user 0m0.000s
sys 0m0.003s

I do think this maybe something wrong in the libpcre or misusing of pcre_exec, and tomorrow i will do a deeper test.

anyway, thanks a lot.