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authorOrit Wasserman <owasserm@redhat.com>2012-08-06 21:42:51 +0300
committerJuan Quintela <quintela@redhat.com>2012-08-08 13:51:12 +0200
commite6546bb938f5326269b6669d6cbb44d72458caa4 (patch)
tree814808b641a518d7ed721705cc28a99b99ba9ca8 /cutils.c
parent9fb26641ab497eda9138f9af75cbeb02ed59b5ae (diff)
Add uleb encoding/decoding functions
Implement Unsigned Little Endian Base 128. Signed-off-by: Orit Wasserman <owasserm@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'cutils.c')
-rw-r--r--cutils.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/cutils.c b/cutils.c
index 35e2e2bf44..ee4614d378 100644
--- a/cutils.c
+++ b/cutils.c
@@ -391,3 +391,36 @@ int64_t pow2floor(int64_t value)
}
return value;
}
+
+/*
+ * Implementation of ULEB128 (http://en.wikipedia.org/wiki/LEB128)
+ * Input is limited to 14-bit numbers
+ */
+int uleb128_encode_small(uint8_t *out, uint32_t n)
+{
+ g_assert(n <= 0x3fff);
+ if (n < 0x80) {
+ *out++ = n;
+ return 1;
+ } else {
+ *out++ = (n & 0x7f) | 0x80;
+ *out++ = n >> 7;
+ return 2;
+ }
+}
+
+int uleb128_decode_small(const uint8_t *in, uint32_t *n)
+{
+ if (!(*in & 0x80)) {
+ *n = *in++;
+ return 1;
+ } else {
+ *n = *in++ & 0x7f;
+ /* we exceed 14 bit number */
+ if (*in & 0x80) {
+ return -1;
+ }
+ *n |= *in++ << 7;
+ return 2;
+ }
+}