libbb: speed up bb_get_chunk_from_file()

Use _getc_nolock() in bb_get_chunk_from_file() and perform code
page translation on the resulting string.  This speeds up grep by
another factor of two.

(GitHub issue #278)

1 files changed, 9 insertions, 0 deletions

diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c
index 929bab78a..ce5c7810e 100644
--- a/libbb/get_line_from_file.c
+++ b/libbb/get_line_from_file.c
@@ -16,7 +16,11 @@ char* FAST_FUNC bb_get_chunk_from_file(FILE *file, size_t *end)
         size_t idx = 0;
         char *linebuf = NULL;
 
+#if ENABLE_PLATFORM_MINGW32
+        while ((ch = _getc_nolock(file)) != EOF) {
+#else
         while ((ch = getc(file)) != EOF) {
+#endif
                 /* grow the line buffer as necessary */
                 if (!(idx & 0xff)) {
                         if (idx == ((size_t)-1) - 0xff)
@@ -41,6 +45,11 @@ char* FAST_FUNC bb_get_chunk_from_file(FILE *file, size_t *end)
                 linebuf = xrealloc(linebuf, idx + 1);
                 linebuf[idx] = '\0';
         }
+#if ENABLE_PLATFORM_MINGW32
+        if (idx && isatty(fileno(file)) &&
+                        GetStdHandle(STD_INPUT_HANDLE) != INVALID_HANDLE_VALUE)
+                OemToCharBuff(linebuf, linebuf, idx);
+#endif
         return linebuf;
 }