| 39 | /// `buf` must either be null or point to at least 16 bytes of memory. |
| 40 | #[no_mangle] |
| 41 | pub unsafe extern "C" fn encode_varint(value: u64, buf: *mut u8) -> u8 { |
| 42 | let mut varint: [u8; 16] = [0; 16]; |
| 43 | let mut pos = varint.len() - 1; |
| 44 | |
| 45 | varint[pos] = (value & 127) as u8; |
| 46 | |
| 47 | let mut value = value >> 7; |
| 48 | while value != 0 { |
| 49 | pos -= 1; |
| 50 | value -= 1; |
| 51 | varint[pos] = 128 | (value & 127) as u8; |
| 52 | value >>= 7; |
| 53 | } |
| 54 | |
| 55 | if !buf.is_null() { |
| 56 | std::ptr::copy_nonoverlapping(varint.as_ptr().add(pos), buf, varint.len() - pos); |
| 57 | } |
| 58 | |
| 59 | (varint.len() - pos) as u8 |
| 60 | } |
| 61 | |
| 62 | #[cfg(test)] |
| 63 | mod tests { |