Re: [Qemu-devel] [PATCH v9 02/10] Add uleb encoding/decoding functions

[Anthony Liguori]

On 04/11/2012 01:49 PM, Orit Wasserman wrote:
> Implement Unsigned Little Endian Base 128.
>
> Signed-off-by: Orit Wasserman<address@hidden>
> ---
>   migration.h |    4 ++++
>   savevm.c    |   28 ++++++++++++++++++++++++++++
>   2 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/migration.h b/migration.h
> index 691b367..d798fac 100644
> --- a/migration.h
> +++ b/migration.h
> @@ -92,4 +92,8 @@ 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);

Please stick this in cutils.h and add documentation for the functions.

> +
>   #endif
> diff --git a/savevm.c b/savevm.c
> index 12fb209..0b2fe38 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -2368,3 +2368,31 @@ 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);

g_assert

Regards,

Anthony Liguori

> +    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;
> +    }
> +}
> +