[Minor] Add fast paths for utf8 conversions

diff --git a/src/libmime/mime_encoding.c b/src/libmime/mime_encoding.c
index e97c390b8c582ad82482631abb0555d9c5cbf74a..36c37f10b4dd6e8766e780208823f46687d5f749 100644 (file)
--- a/src/libmime/mime_encoding.c
+++ b/src/libmime/mime_encoding.c
@@ -255,12 +255,26 @@ rspamd_mime_detect_charset (const rspamd_ftok_t *in, rspamd_mempool_t *pool)
        gchar *ret = NULL, *h, *t;
        struct rspamd_charset_substitution *s;
        const gchar *cset;
+       rspamd_ftok_t utf8_tok;
        UErrorCode uc_err = U_ZERO_ERROR;
 
        if (sub_hash == NULL) {
                rspamd_mime_encoding_substitute_init ();
        }
 
+       /* Fast path */
+       RSPAMD_FTOK_ASSIGN (&utf8_tok, "utf-8");
+
+       if (rspamd_ftok_casecmp (in, &utf8_tok) == 0) {
+               return UTF8_CHARSET;
+       }
+
+       RSPAMD_FTOK_ASSIGN (&utf8_tok, "utf8");
+
+       if (rspamd_ftok_casecmp (in, &utf8_tok) == 0) {
+               return UTF8_CHARSET;
+       }
+
        ret = rspamd_mempool_ftokdup (pool, in);
        rspamd_charset_normalize (ret);
 
@@ -320,6 +334,21 @@ rspamd_mime_text_to_utf8 (rspamd_mempool_t *pool,
        UErrorCode uc_err = U_ZERO_ERROR;
        UConverter *utf8_converter;
        struct rspamd_charset_converter *conv;
+       rspamd_ftok_t cset_tok;
+
+       /* Check if already utf8 */
+       RSPAMD_FTOK_FROM_STR (&cset_tok, in_enc);
+
+       if (rspamd_mime_charset_utf_check (&cset_tok, input, len,
+                       FALSE)) {
+               d = rspamd_mempool_alloc (pool, len);
+               memcpy (d, input, len);
+               if (olen) {
+                       *olen = len;
+               }
+
+               return d;
+       }
 
        conv = rspamd_mime_get_converter_cached (in_enc, pool, TRUE, &uc_err);
        utf8_converter = rspamd_get_utf8_converter ();