uniconv: optimize the uniconv_conv

1 files changed, 10 insertions, 15 deletions

diff --git a/uniconv.c b/uniconv.c
index e73efa7..9987130 100644
--- a/uniconv.c
+++ b/uniconv.c
@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
+#include <assert.h>
 
 struct _uniconv {
     struct converter *from;
@@ -117,24 +118,18 @@ uniconv_conv(uniconv_t *uc,
 	saved_outbuf = *outbuf;
 	ret = UNICONV_SUCCESS;
 	while (*inleft) {
-	    size_t i = 0;
+	    size_t left = 0;
 	    const char *abuf;
 	    const char *aoutbuf;
 
-	    /* decode a char at a time */
-	    for (i = 1; i <= *inleft; i++) {
-		ucsbuf = &ucs4;
-		abuf = *inbuf;
-		ret = uc->from->decode(uc->from, &abuf, i, &ucsbuf, 1);
-		if (ret < 0 && ret == UNICONV_EINVAL)
-		    continue;
-		break;
-	    }
-	    if (ret == UNICONV_E2BIG)
-		ret = UNICONV_EILSEQ;
-	    if (ret < 0)
+	    ucsbuf = &ucs4;
+	    abuf = *inbuf;
+	    left = *inleft;
+	    ret = uc->from->decode(uc->from, &abuf, left, &ucsbuf, 1);
+	    if (ret < 0 && ret != UNICONV_E2BIG)
 		return ret;
 
+	    assert (ucsbuf - &ucs4 > 0 && ucsbuf - &ucs4 <= 1);
 	    ucs4len = ucsbuf - &ucs4;
 	    ucsbuf = &ucs4;
 	    aoutbuf = *outbuf;
@@ -143,8 +138,8 @@ uniconv_conv(uniconv_t *uc,
 	    *outleft -= *outbuf - aoutbuf;
 	    if (ret < 0)
 		break;
-	    *inleft -= i;
-	    (*inbuf) += i;
+	    *inleft -= abuf - *inbuf;
+	    (*inbuf) = abuf;
 	}
     } else {
 	/* converting pending data in buffer */