MINOR: hlua: Add regex class

This patch simply brings HAProxy internal regex system to the Lua API.
Lua doesn't embed regexes, now it inherits from the regexes compiled
with haproxy.

doc/lua-api/index.rst

@@ -1890,6 +1890,70 @@ Socket class
   :param class_socket socket: Is the manipulated Socket.
   :param integer value: The timeout value.
 
+.. _regex_class:
+
+Regex class
+===========
+
+.. js:class:: Regex
+
+  This class allows the usage of HAProxy regexes because classic lua doesn't
+  provides regexes. This class inherits the HAProxy compilation options, so the
+  regexes can be libc regex, pcre regex or pcre JIT regex.
+
+  The expression matching number is limited to 20 per regex. The only available
+  option is case sensitive.
+
+  Because regexes compilation is a heavy process, it is better to define all
+  your regexes in the **body context** and use it during the runtime.
+
+.. code-block:: lua
+
+  -- Create the regex
+  st, regex = Regex.new("needle (..) (...)", true);
+
+  -- Check compilation errors
+  if st == false then
+    print "error: " .. regex
+  end
+
+  -- Match the regexes
+  print(regex:exec("Looking for a needle in the haystack")) -- true
+  print(regex:exec("Lokking for a cat in the haystack"))    -- false
+
+  -- Extract words
+  st, list = regex:match("Looking for a needle in the haystack")
+  print(st)      -- true
+  print(list[1]) -- needle in the
+  print(list[2]) -- in
+  print(list[3]) -- the
+
+.. js:function:: Regex.new(regex, case_sensitive)
+
+  Create and compile a regex.
+
+  :param string regex: The regular expression according with the libc or pcre
+    standard
+  :param boolean case_sensitive: Match is case sensitive or not.
+  :returns: boolean status and :ref:`regex_class` or string containing fail reason.
+
+.. js:function:: Regex.exec(regex, str)
+
+  Execute the regex.
+
+  :param class_regex regex: A :ref:`regex_class` object.
+  :param string str: The input string will be compared with the compiled regex.
+  :returns: a boolean status according with the match result.
+
+.. js:function:: Regex.match(regex, str)
+
+  Execute the regex and return matched expressions.
+
+  :param class_map map: A :ref:`regex_class` object.
+  :param string str: The input string will be compared with the compiled regex.
+  :returns: a boolean status according with the match result, and
+    a table containing all the string matched in order of declaration.
+
 .. _map_class:
 
 Map class

include/types/hlua.h

@@ -24,6 +24,7 @@
 #define CLASS_PROXY        "Proxy"
 #define CLASS_SERVER       "Server"
 #define CLASS_LISTENER     "Listener"
+#define CLASS_REGEX        "Regex"
 
 struct stream;
 

src/hlua_fcn.c

@@ -36,6 +36,7 @@ static int class_concat_ref;
 static int class_proxy_ref;
 static int class_server_ref;
 static int class_listener_ref;
+static int class_regex_ref;
 
 #define STATS_LEN (MAX((int)ST_F_TOTAL_FIELDS, (int)INF_TOTAL_FIELDS))
 
@@ -1076,6 +1077,90 @@ int hlua_match_addr(lua_State *L)
 	return 1;
 }
 
+static struct my_regex *hlua_check_regex(lua_State *L, int ud)
+{
+	return (hlua_checkudata(L, ud, class_regex_ref));
+}
+
+static int hlua_regex_comp(struct lua_State *L)
+{
+	struct my_regex *regex;
+	const char *str;
+	int cs;
+	char *err;
+
+	str = luaL_checkstring(L, 1);
+	luaL_argcheck(L, lua_isboolean(L, 2), 2, NULL);
+	cs = lua_toboolean(L, 2);
+
+	regex = lua_newuserdata(L, sizeof(*regex));
+
+	err = NULL;
+	if (!regex_comp(str, regex, cs, 1, &err)) {
+		lua_pushboolean(L, 0); /* status error */
+		lua_pushstring(L, err); /* Reason */
+		free(err);
+		return 2;
+	}
+
+	lua_pushboolean(L, 1); /* Status ok */
+
+	/* Create object */
+	lua_newtable(L);
+	lua_pushvalue(L, -3); /* Get the userdata pointer. */
+	lua_rawseti(L, -2, 0);
+	lua_rawgeti(L, LUA_REGISTRYINDEX, class_regex_ref);
+	lua_setmetatable(L, -2);
+	return 2;
+}
+
+static int hlua_regex_exec(struct lua_State *L)
+{
+	struct my_regex *regex;
+	const char *str;
+	size_t len;
+
+	regex = hlua_check_regex(L, 1);
+	str = luaL_checklstring(L, 2, &len);
+
+	lua_pushboolean(L, regex_exec2(regex, (char *)str, len));
+
+	return 1;
+}
+
+static int hlua_regex_match(struct lua_State *L)
+{
+	struct my_regex *regex;
+	const char *str;
+	size_t len;
+	regmatch_t pmatch[20];
+	int ret;
+	int i;
+
+	regex = hlua_check_regex(L, 1);
+	str = luaL_checklstring(L, 2, &len);
+
+	ret = regex_exec_match2(regex, (char *)str, len, 20, pmatch, 0);
+	lua_pushboolean(L, ret);
+	lua_newtable(L);
+	if (ret) {
+		for (i = 0; i < 20 && pmatch[i].rm_so != -1; i++) {
+			lua_pushlstring(L, str + pmatch[i].rm_so, pmatch[i].rm_eo - pmatch[i].rm_so);
+			lua_rawseti(L, -2, i + 1);
+		}
+	}
+	return 2;
+}
+
+static int hlua_regex_free(struct lua_State *L)
+{
+	struct my_regex *regex;
+
+	regex = hlua_check_regex(L, 1);
+	regex_free(regex);
+	return 0;
+}
+
 int hlua_fcn_reg_core_fcn(lua_State *L)
 {
 	if (!hlua_concat_init(L))
@@ -1092,6 +1177,24 @@ int hlua_fcn_reg_core_fcn(lua_State *L)
 	hlua_class_function(L, "match_addr", hlua_match_addr);
 	hlua_class_function(L, "tokenize", hlua_tokenize);
 
+	/* Create regex object. */
+	lua_newtable(L);
+	hlua_class_function(L, "new", hlua_regex_comp);
+
+	lua_newtable(L); /* The metatable. */
+	lua_pushstring(L, "__index");
+	lua_newtable(L);
+	hlua_class_function(L, "exec", hlua_regex_exec);
+	hlua_class_function(L, "match", hlua_regex_match);
+	lua_rawset(L, -3); /* -> META["__index"] = TABLE */
+	hlua_class_function(L, "__gc", hlua_regex_free);
+
+	lua_pushvalue(L, -1); /* Duplicate the metatable reference. */
+	class_regex_ref = hlua_register_metatable(L, CLASS_REGEX);
+
+	lua_setmetatable(L, -2);
+	lua_setglobal(L, CLASS_REGEX); /* Create global object called Regex */
+
 	/* Create listener object. */
 	lua_newtable(L);
 	lua_pushstring(L, "__index");