int __cdecl sub_156E480(int a1, int a2, void *Dst, size_t Size)
{
  int v4; // ebx
  unsigned int v5; // eax
  size_t v6; // ecx
  const void *v7; // eax
  size_t v8; // edi
  signed int v9; // eax

  v4 = 0;
  if ( (unsigned int)a2 >= *(_DWORD *)(a1 + 8264) || !sub_156E520(a1) )
  {
    v5 = *(_DWORD *)(a1 + 8264);
    if ( a2 <= v5 || !sub_156E580(a1, a2 - v5) )
    {
      v6 = Size;
      if ( Size )
      {
        do
        {
          v7 = *(const void **)(a1 + 8268);
          v8 = *(_DWORD *)(a1 + 8272) - (_DWORD)v7;
          if ( v8 >= v6 )
            v8 = v6;
          memmove_0(Dst, v7, v8);
          Dst = (char *)Dst + v8;
          *(_DWORD *)(a1 + 8268) += v8;
          v4 += v8;
          *(_DWORD *)(a1 + 8264) += v8;
          Size -= v8;
          if ( !Size )
            break;
          v9 = sub_156E360((_DWORD *)a1);
          v6 = Size;
        }
        while ( !v9 );
      }
    }
  }
  return v4;
}