grep: use mbclen cache more effectively

* src/grep.c (buffer_textbin, contains_encoding_error):
Use mb_clen for speed.
(buffer_textbin): Bypass mb_clen in unibyte locales.
(main): Always initialize the cache, since it's sometimes used in
unibyte locales now.  Initialize it before contains_encoding_error
might be called.
* src/search.h (SEARCH_INLINE): New macro.
(mbclen_cache): Now extern decl.
(mb_clen): New inline function.
* src/searchutils.c (SEARCH_INLINE, SYSTEM_INLINE): Define.
(mbclen_cache): Now extern.
(build_mbclen_cache): Put 1 into the cache when mbrlen returns 0.
(mb_goback): Use mb_len for speed, and rely on it returning nonzero.
* src/system.h (SYSTEM_INLINE): New macro.
(to_uchar): Use it.

1 files changed, 14 insertions, 12 deletions

diff --git a/src/searchutils.c b/src/searchutils.c
index 18dd584e..9edc7855 100644
--- a/src/searchutils.c
+++ b/src/searchutils.c
@@ -17,12 +17,16 @@
    02110-1301, USA.  */
 
 #include <config.h>
-#include <assert.h>
+
+#define SEARCH_INLINE _GL_EXTERN_INLINE
+#define SYSTEM_INLINE _GL_EXTERN_INLINE
 #include "search.h"
 
+#include <assert.h>
+
 #define NCHAR (UCHAR_MAX + 1)
 
-static size_t mbclen_cache[NCHAR];
+size_t mbclen_cache[NCHAR];
 
 void
 kwsinit (kwset_t *kwset)
@@ -218,7 +222,8 @@ build_mbclen_cache (void)
       char c = i;
       unsigned char uc = i;
       mbstate_t mbs = { 0 };
-      mbclen_cache[uc] = mbrlen (&c, 1, &mbs);
+      size_t len = mbrlen (&c, 1, &mbs);
+      mbclen_cache[uc] = len ? len : 1;
     }
 }
 
@@ -244,20 +249,17 @@ mb_goback (char const **mb_start, char const *cur, char const *end)
 
   while (p < cur)
     {
-      size_t mbclen = mbclen_cache[to_uchar (*p)];
-
-      if (mbclen == (size_t) -2)
-        mbclen = mbrlen (p, end - p, &cur_state);
+      size_t clen = mb_clen (p, end - p, &cur_state);
 
-      if (! (0 < mbclen && mbclen < (size_t) -2))
+      if ((size_t) -2 <= clen)
         {
-          /* An invalid sequence, or a truncated multibyte character, or
-             a null wide character.  Treat it as a single byte character.  */
-          mbclen = 1;
+          /* An invalid sequence, or a truncated multibyte character.
+             Treat it as a single byte character.  */
+          clen = 1;
           memset (&cur_state, 0, sizeof cur_state);
         }
       p0 = p;
-      p += mbclen;
+      p += clen;
     }
 
   *mb_start = p;