[libexif-cvs] exif/exif utils.c,1.9,1.10

[Lutz M. <lu...@us...>]

Update of /cvsroot/libexif/exif/exif
In directory sc8-pr-cvs6.sourceforge.net:/tmp/cvs-serv20512/exif

Modified Files:
	utils.c 
Log Message:
2008-02-10  Lutz Mueller <lu...@us...>

	Patch by Alexander Drozdov <dza...@mt...>:

	* exif/utils.c (exif_tag_from_string): Speed improvements.


Index: utils.c
===================================================================
RCS file: /cvsroot/libexif/exif/exif/utils.c,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -p -d -r1.9 -r1.10
--- utils.c	27 Apr 2005 06:44:22 -0000	1.9
+++ utils.c	10 Feb 2008 09:20:17 -0000	1.10
@@ -23,104 +23,37 @@
 
 #include <string.h>
 #include <stdlib.h>
+#include <stdio.h>
 
 ExifTag
 exif_tag_from_string (const char *string)
 {
 	ExifTag tag;
-	unsigned int i, number, factor;
+	unsigned int i, number;
 	const char *name;
 
 	if (!string)
 		return 0xffff;
 
-	/* Is the string a tag's name or title? */
-	for (tag = 0xffff; tag > 0; tag--) {
-		name = exif_tag_get_name (tag);
-		if (name && !strcmp (string, name))
-			return (tag);
-		name = exif_tag_get_title (tag);
-		if (name && !strcmp (string, name))
-			return (tag);
-	}
-
 	/* Is the string a decimal number? */
 	if (strspn (string, "0123456789") == strlen (string))
 		return (atoi (string));
 
 	/* Is the string a hexadecimal number? */
-	for (i = 0; i < strlen (string); i++)
-		if (string[i] == 'x')
-			break;
-	if (i == strlen (string))
-		return 0xffff;
+	if (sscanf (string, "0x%x%n", &number, &i) == 1 && !string[i])
+		return ((ExifTag)number);
 
-	string += i + 1;
-        tag = 0;
-        for (i = strlen (string); i > 0; i--) {
-                switch (string[i - 1]) {
-                case '0':
-                        number = 0;
-                        break;
-                case '1':
-                        number = 1;
-                        break;
-                case '2':
-                        number = 2;
-                        break;
-                case '3':
-                        number = 3;
-                        break;
-                case '4':
-                        number = 4;
-                        break;
-                case '5':
-                        number = 5;
-                        break;
-                case '6':
-                        number = 6;
-                        break;
-                case '7':
-                        number = 7;
-                        break;
-                case '8':
-                        number = 8;
-                        break;
-                case '9':
-                        number = 9;
-                        break;
-                case 'a':
-                case 'A':
-                        number = 10;
-                        break;
-                case 'b':
-                case 'B':
-                        number = 11;
-                        break;
-                case 'c':
-                case 'C':
-                        number = 12;
-                        break;
-                case 'd':
-                case 'D':
-                        number = 13;
-                        break;
-                case 'e':
-                case 'E':
-                        number = 14;
-                        break; 
-                case 'f':
-                case 'F':
-                        number = 15;
-                        break; 
-                default:
-                        return (0);
-                }
-                factor = 1 << ((strlen (string) - i) * 4);
-                tag += (number * factor);
-        }
+	/* Is the string a tag's name? */
+	if ((tag = exif_tag_from_name (string)) != 0)
+		return (tag);
 
-        return (tag);
+	/* Is the string a tag's title? */
+	for (tag = 0xffff; (int)tag > 0; tag--) {
+		name = exif_tag_get_title (tag);
+		if (name && !strcmp (string, name))
+			return (tag);
+	}
+	return (0xffff);
 }
 
 ExifIfd