cs_string_rw/
write_7_bit_encoded_i32.rs

1use std::io;
2
3pub trait Write7BitEncodedI32Ext {
4	fn write_7_bit_encoded_i32(&mut self, n: i32) -> io::Result<()>;
5}
6
7impl<T: io::Write> Write7BitEncodedI32Ext for T {
8	fn write_7_bit_encoded_i32(&mut self, n: i32) -> io::Result<()> {
9		let mut n = n as u32;
10		let mut byte: u8;
11		let mut buff = Vec::<u8>::with_capacity(4);
12		loop {
13			byte = (n & 127) as u8;
14			if n < 128 {
15				break;
16			}
17
18			byte |= 128;
19			n >>= 7;
20			buff.push(byte);
21		}
22
23		buff.push(byte);
24		self.write_all(&buff)
25	}
26}
27
28#[cfg(test)]
29mod tests {
30	use super::*;
31	use crate::write_byte_vec::WriteByteVec;
32	#[test]
33	fn writing_ints() {
34		let mut out = Vec::<u8>::with_capacity(40);
35		let mut writer = WriteByteVec::new(&mut out);
36		writer.write_7_bit_encoded_i32(-1).unwrap();
37		writer.write_7_bit_encoded_i32(-2147483648).unwrap();
38		writer.write_7_bit_encoded_i32(1).unwrap();
39		writer.write_7_bit_encoded_i32(2147483647).unwrap();
40		writer.write_7_bit_encoded_i32(0).unwrap();
41		writer.write_7_bit_encoded_i32(2).unwrap();
42		writer.write_7_bit_encoded_i32(5).unwrap();
43		writer.write_7_bit_encoded_i32(8000000).unwrap();
44		writer.write_7_bit_encoded_i32(160000000).unwrap();
45		writer.write_7_bit_encoded_i32(30000).unwrap();
46		writer.write_7_bit_encoded_i32(-2323232).unwrap();
47		writer.write_7_bit_encoded_i32(-23232).unwrap();
48		assert_eq!(
49			out,
50			[
51				0xff, 0xff, 0xff, 0xff, 0x0f, 0x80, 0x80, 0x80, 0x80, 0x08, 0x01, 0xff, 0xff, 0xff,
52				0xff, 0x07, 0x00, 0x02, 0x05, 0x80, 0xa4, 0xe8, 0x03, 0x80, 0xd0, 0xa5, 0x4c, 0xb0,
53				0xea, 0x01, 0xe0, 0x99, 0xf2, 0xfe, 0x0f, 0xc0, 0xca, 0xfe, 0xff, 0x0f,
54			]
55		);
56	}
57}
cs_string_rw/write_7_bit_encoded_i32.rs

cs_string_rw/
write_7_bit_encoded_i32.rs
