Commit e6546bb9 authored by Orit Wasserman's avatar Orit Wasserman Committed by Juan Quintela
Browse files

Add uleb encoding/decoding functions 



Implement Unsigned Little Endian Base 128.

Signed-off-by: default avatarOrit Wasserman <owasserm@redhat.com>

Reviewed-by: default avatarLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
parent 9fb26641

cutils.c

+33 −0
Original line number Diff line number Diff line
@@ -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;

    }

}

qemu-common.h

+8 −0
Original line number Diff line number Diff line
@@ -443,4 +443,12 @@ 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