[Minor] Lua_text: Add exclude_chars method

diff --git a/src/lua/lua_text.c b/src/lua/lua_text.c
index 5c01a239b087610d24a196a33a6714d3e5bafcf2..69fd9c52921bf9456d8416602595e784c5c63c2b 100644 (file)
--- a/src/lua/lua_text.c
+++ b/src/lua/lua_text.c
@@ -103,6 +103,15 @@ LUA_FUNCTION_DEF (text, at);
  */
 LUA_FUNCTION_DEF (text, bytes);
 LUA_FUNCTION_DEF (text, take_ownership);
+/***
+ * @method rspamd_text:exclude_chars(set_to_exclude, [always_copy])
+ * Returns a text (if owned, then the original text is modified, if not, then it is copied and owned)
+ * where all chars from `set_to_exclude` are removed
+ * @param {string} set_to_exclude characters to exclude
+ * @param {boolean} always_copy always copy the source text
+ * @return {tspamd_text} modified or copied text
+ */
+LUA_FUNCTION_DEF (text, exclude_chars);
 LUA_FUNCTION_DEF (text, gc);
 LUA_FUNCTION_DEF (text, eq);
 
@@ -123,6 +132,7 @@ static const struct luaL_reg textlib_m[] = {
                LUA_INTERFACE_DEF (text, split),
                LUA_INTERFACE_DEF (text, at),
                LUA_INTERFACE_DEF (text, bytes),
+               LUA_INTERFACE_DEF (text, exclude_chars),
                {"write", lua_text_save_in_file},
                {"__len", lua_text_len},
                {"__tostring", lua_text_str},
@@ -888,6 +898,73 @@ lua_text_wipe (lua_State *L)
        return 0;
 }
 
+#define BITOP(a,b,op) \
+               ((a)[(gsize)(b)/(8*sizeof *(a))] op (gsize)1<<((gsize)(b)%(8*sizeof *(a))))
+
+static gint
+lua_text_exclude_chars (lua_State *L)
+{
+       LUA_TRACE_POINT;
+       struct rspamd_lua_text *t = lua_check_text (L, 1);
+       gssize patlen;
+       const gchar *pat = lua_tolstring (L, 2, &patlen), *p, *end;
+       gchar *dest, *d;
+       gsize byteset[32 / sizeof(gsize)]; /* Bitset for ascii */
+       gboolean copy = TRUE;
+       guint *plen;
+
+       if (t != NULL && pat && patlen > 0) {
+               if (lua_isboolean (L, 3)) {
+                       copy = lua_toboolean (L, 3);
+               }
+               else if (t->flags & RSPAMD_TEXT_FLAG_OWN) {
+                       copy = FALSE;
+               }
+
+               if (!copy) {
+                       dest = (gchar *)t->start;
+                       plen = &t->len;
+                       lua_pushvalue (L, 1); /* Push text as a result */
+               }
+               else {
+                       /* We need to copy read only text */
+                       struct rspamd_lua_text *nt;
+
+                       dest = g_malloc (t->len);
+                       nt = lua_newuserdata (L, sizeof (*nt));
+                       rspamd_lua_setclass (L, "rspamd{text}", -1);
+                       nt->len = t->len;
+                       nt->flags = RSPAMD_TEXT_FLAG_OWN;
+                       memcpy (dest, t->start, t->len);
+                       nt->start = dest;
+                       plen = &nt->len;
+               }
+
+               /* Fill pattern bitset */
+               memset (byteset, 0, sizeof byteset);
+               for (; patlen > 0 && BITOP (byteset, *(guchar *)pat, |=); pat++, patlen --);
+
+               p = t->start;
+               end = t->start + t->len;
+               d = dest;
+
+               while (p < end) {
+                       if (!BITOP (byteset, *(guchar *)p, &)) {
+                               *d++ = *p;
+                       }
+
+                       p ++;
+               }
+
+               *(plen) = d - dest;
+       }
+       else {
+               return luaL_error (L, "invalid arguments");
+       }
+
+       return 1;
+}
+
 static gint
 lua_load_text (lua_State * L)
 {