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[Qemu-devel] [PATCH 16/22] Add uleb encoding/decoding functions
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PATCH 16/22] Add uleb encoding/decoding functions |
Date: |
Fri, 13 Jul 2012 09:23:38 +0200 |
From: Orit Wasserman <address@hidden>
Implement Unsigned Little Endian Base 128.
Signed-off-by: Orit Wasserman <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
cutils.c | 33 +++++++++++++++++++++++++++++++++
qemu-common.h | 8 ++++++++
2 files changed, 41 insertions(+)
diff --git a/cutils.c b/cutils.c
index b0bdd4b..700f943 100644
--- a/cutils.c
+++ b/cutils.c
@@ -384,3 +384,36 @@ 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;
+ }
+}
diff --git a/qemu-common.h b/qemu-common.h
index 195bab5..3188bdd 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -426,4 +426,12 @@ int64_t pow2floor(int64_t value);
#include "module.h"
+/*
+ * 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);
+int uleb128_decode_small(const uint8_t *in, uint32_t *n);
+
#endif
--
1.7.10.4
- [Qemu-devel] [PATCH 11/22] ram: iterate phase, (continued)
- [Qemu-devel] [PATCH 11/22] ram: iterate phase, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 13/22] Add migration capabilities, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 10/22] ram: save_live_complete() only do one loop, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 14/22] Add XBZRLE documentation, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 17/22] Change ram_save_block to return -1 if there are no more changes, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 18/22] Add xbzrle_encode_buffer and xbzrle_decode_buffer functions, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 19/22] Add XBZRLE to ram_save_block and ram_save_live, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 16/22] Add uleb encoding/decoding functions,
Juan Quintela <=
- [Qemu-devel] [PATCH 15/22] Add cache handling functions, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 21/22] Add XBZRLE statistics, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 20/22] Add migrate_set_cachesize command, Juan Quintela, 2012/07/13
- [Qemu-devel] [PATCH 22/22] ram: save live optimization, Juan Quintela, 2012/07/13