volume_id: uuid_format small code shrink

function                                             old     new   delta
volume_id_set_uuid                                   318     300     -18

Signed-off-by: Sven-Göran Bergh <sgb@systemasis.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 9 insertions, 20 deletions

diff --git a/util-linux/volume_id/util.c b/util-linux/volume_id/util.c
index 11ee0d52e..0e2d24be0 100644
--- a/util-linux/volume_id/util.c
+++ b/util-linux/volume_id/util.c
@@ -135,23 +135,8 @@ void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enu
 void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format)
 {
         unsigned i;
-        unsigned count = 0;
+        unsigned count = (format == UUID_DCE_STRING ? VOLUME_ID_UUID_SIZE : 4 << format);
 
-        switch (format) {
-        case UUID_DOS:
-                count = 4;
-                break;
-        case UUID_NTFS:
-                count = 8;
-                break;
-        case UUID_DCE:
-                count = 16;
-                break;
-        case UUID_DCE_STRING:
-                /* 36 is ok, id->uuid has one extra byte for NUL */
-                count = VOLUME_ID_UUID_SIZE;
-                break;
-        }
 //      memcpy(id->uuid_raw, buf, count);
 //      id->uuid_raw_len = count;
 
diff --git a/util-linux/volume_id/volume_id_internal.h b/util-linux/volume_id/volume_id_internal.h
index dd62df399..e26ebaab6 100644
--- a/util-linux/volume_id/volume_id_internal.h
+++ b/util-linux/volume_id/volume_id_internal.h
@@ -136,11 +136,15 @@ void FAST_FUNC free_volume_id(struct volume_id *id);
 #define cpu_to_be32(x) (x)
 #endif
 
+/* volume_id_set_uuid(id,buf,fmt) assumes size of uuid buf
+ * by shifting: 4 << fmt, except for fmt == UUID_DCE_STRING.
+ * The constants below should match sizes.
+ */
 enum uuid_format {
-        UUID_DCE_STRING,
-        UUID_DCE,
-        UUID_DOS,
-        UUID_NTFS,
+        UUID_DOS = 0,           /* 4 bytes */
+        UUID_NTFS = 1,          /* 8 bytes */
+        UUID_DCE = 2,           /* 16 bytes */
+        UUID_DCE_STRING = 3,    /* 36 bytes (VOLUME_ID_UUID_SIZE) */
 };
 
 enum endian {