hex_to_bytes(): simpler replacement for `get_oid_hex_segment()`

Now that `get_oid_hex_segment()` does less, it makes sense to rename
it and simplify its semantics:

* Instead of a `hex_len` parameter, which was the number of hex
characters (and had to be even), use a `len` parameter, which is the
number of resulting bytes. This removes then need for the check that
`hex_len` is even and to divide it by two to determine the number of
bytes. For good hygiene, declare the `len` parameter to be `size_t`
instead of `unsigned int`.

* Change the order of the arguments to the more traditional (dst,
src, len).

* Rename the function to `hex_to_bytes()`.

* Remove a loop variable: just count `len` down instead.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/notes.c b/notes.c
index e83f5e81363a9eadef850a89ada36551ad29b797..355669dcfbf1d1c226be3f1bd32438edf8667234 100644 (file)
--- a/notes.c
+++ b/notes.c
@@ -335,25 +335,18 @@ static void note_tree_free(struct int_node *tree)
 }
 
 /*
 }
 
 /*

- * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
- * - hex      - Partial SHA1 segment in ASCII hex format
- * - hex_len  - Length of above segment. Must be multiple of 2 between 0 and 40
- * - oid      - Partial SHA1 value is written here
- * Return 0 on success or -1 on error (invalid arguments or input not
- * in hex format).
+ * Read `len` pairs of hexadecimal digits from `hex` and write the
+ * values to `binary` as `len` bytes. Return 0 on success, or -1 if
+ * the input does not consist of hex digits).

  */
  */

-static int get_oid_hex_segment(const char *hex, unsigned int hex_len,
-               unsigned char *oid)
+static int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)

 {
 {

-       unsigned int i, len = hex_len >> 1;
-       if (hex_len % 2 != 0)
-               return -1;
-       for (i = 0; i < len; i++) {
+       for (; len; len--, hex += 2) {

                unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
                unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);

+

                if (val & ~0xff)
                        return -1;
                if (val & ~0xff)
                        return -1;

-               *oid++ = val;
-               hex += 2;
+               *binary++ = val;

        }
        return 0;
 }
        }
        return 0;
 }


@@ -438,8 +431,8 @@ static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
                                /* notes must be blobs */
                                goto handle_non_note;
 
                                /* notes must be blobs */
                                goto handle_non_note;
 

-                       if (get_oid_hex_segment(entry.path, path_len,
-                                               object_oid.hash + prefix_len))
+                       if (hex_to_bytes(object_oid.hash + prefix_len, entry.path,
+                                        GIT_SHA1_RAWSZ - prefix_len))

                                goto handle_non_note; /* entry.path is not a SHA1 */
 
                        type = PTR_TYPE_NOTE;
                                goto handle_non_note; /* entry.path is not a SHA1 */
 
                        type = PTR_TYPE_NOTE;


@@ -451,8 +444,7 @@ static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
                                /* internal nodes must be trees */
                                goto handle_non_note;
 
                                /* internal nodes must be trees */
                                goto handle_non_note;
 

-                       if (get_oid_hex_segment(entry.path, 2,
-                                               object_oid.hash + len++))
+                       if (hex_to_bytes(object_oid.hash + len++, entry.path, 1))

                                goto handle_non_note; /* entry.path is not a SHA1 */
 
                        /*
                                goto handle_non_note; /* entry.path is not a SHA1 */
 
                        /*