#include "axl_vlq.h"

u32 axl_vlq_encode(u32 num, u8* out)
{
    u8 buf[5];
    int pos = 0;

    if(num == 0)
    {
        out[0] = 0;
        return 1;
    }

    while(num > 0)
    {
        buf[pos] = num & 0x7F;
        num >>= 7;
        pos++;
    }

    for(int j = pos - 1; j > 0; j--)
    {
        buf[j] |= 0x80;
    }
    
    for(int j = pos - 1; j >= 0; j--) 
    {
        *out++ = buf[j];
    }
    
    return pos;
}

u32 axl_vlq_decode(const u8* in, u32* num) 
{
    *num = 0;
    u32 pos = 0;

    while(pos < AXL_VLQ_MAX_LEN) 
    {
        u8 b = in[pos++];
    
        *num = (*num << 7) | (b & 0x7F);
        
        if(!(b & 0x80)) 
        {
            return pos;
        }
        
        if(*num > (U32_MAX >> 7)) 
        {  
            return 0;
        }
    }

    return 0;
}