android13/external/rust/crates/protobuf/src/varint.rs

40 lines
1.0 KiB
Rust

use std::mem::MaybeUninit;
use crate::misc::maybe_uninit_write;
/// Encode u64 as varint.
/// Panics if buffer length is less than 10.
#[inline]
pub fn encode_varint64(mut value: u64, buf: &mut [MaybeUninit<u8>]) -> usize {
assert!(buf.len() >= 10);
unsafe {
let mut i = 0;
while (value & !0x7F) > 0 {
maybe_uninit_write(buf.get_unchecked_mut(i), ((value & 0x7F) | 0x80) as u8);
value >>= 7;
i += 1;
}
maybe_uninit_write(buf.get_unchecked_mut(i), value as u8);
i + 1
}
}
/// Encode u32 value as varint.
/// Panics if buffer length is less than 5.
#[inline]
pub fn encode_varint32(mut value: u32, buf: &mut [MaybeUninit<u8>]) -> usize {
assert!(buf.len() >= 5);
unsafe {
let mut i = 0;
while (value & !0x7F) > 0 {
maybe_uninit_write(buf.get_unchecked_mut(i), ((value & 0x7F) | 0x80) as u8);
value >>= 7;
i += 1;
}
maybe_uninit_write(buf.get_unchecked_mut(i), value as u8);
i + 1
}
}