Patchwork [v7,02/11] Add uleb encoding/decoding functions

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Submitter Orit Wasserman
Date Jan. 26, 2012, 2:24 p.m.
Message ID <1327587897-31192-3-git-send-email-owasserm@redhat.com>
Download mbox | patch
Permalink /patch/137954/
State New
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Comments

Orit Wasserman - Jan. 26, 2012, 2:24 p.m.
Implement Unsigned Little Endian Base 128.

Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
 migration.h |    4 ++++
 savevm.c    |   28 ++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 0 deletions(-)

Patch

diff --git a/migration.h b/migration.h
index 372b066..50dec18 100644
--- a/migration.h
+++ b/migration.h
@@ -95,4 +95,8 @@  void migrate_add_blocker(Error *reason);
  */
 void migrate_del_blocker(Error *reason);
 
+/* ULEB128 */
+int uleb128_encode_small(uint8_t *out, uint32_t n);
+int uleb128_decode_small(const uint8 *in, uint32_t *n);
+
 #endif
diff --git a/savevm.c b/savevm.c
index 80be1ff..74c674f 100644
--- a/savevm.c
+++ b/savevm.c
@@ -2297,3 +2297,31 @@  void vmstate_register_ram_global(MemoryRegion *mr)
 {
     vmstate_register_ram(mr, NULL);
 }
+
+/* ULEB128 */
+int uleb128_encode_small(uint8_t *out, uint32_t n)
+{
+    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 *in, uint32_t *n)
+{
+    if (!(*in & 0x80)) {
+        *n = *in++;
+        return 1;
+    } else {
+        *n = *in++ & 0x7f;
+        assert(!(*in & 0x80));
+        *n |= *in++ << 7;
+        return 2;
+    }
+}
+