File: leb128.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg3-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental, sid, trixie
  • size: 893,396 kB
  • sloc: xml: 158,127; python: 35,830; javascript: 19,497; cpp: 19,002; sh: 17,245; ansic: 13,127; asm: 4,376; makefile: 1,051; perl: 29; lisp: 29; ruby: 19; sql: 11
file content (95 lines) | stat: -rw-r--r-- 3,713 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
use rustc_serialize::Decoder;
use rustc_serialize::leb128::*;
use rustc_serialize::opaque::{MAGIC_END_BYTES, MemDecoder};

macro_rules! impl_test_unsigned_leb128 {
    ($test_name:ident, $write_fn_name:ident, $read_fn_name:ident, $int_ty:ident) => {
        #[test]
        fn $test_name() {
            // Test 256 evenly spaced values of integer range,
            // integer max value, and some "random" numbers.
            let mut values = Vec::new();

            let increment = (1 as $int_ty) << ($int_ty::BITS - 8);
            values.extend((0..256).map(|i| $int_ty::MIN + i * increment));

            values.push($int_ty::MAX);

            values.extend(
                (-500..500).map(|i| (i as $int_ty).wrapping_mul(0x12345789ABCDEFu64 as $int_ty)),
            );

            let mut stream = Vec::new();

            let mut buf = Default::default();
            for &x in &values {
                let n = $write_fn_name(&mut buf, x);
                stream.extend(&buf[..n]);
            }
            let stream_end = stream.len();
            stream.extend(MAGIC_END_BYTES);

            let mut decoder = MemDecoder::new(&stream, 0).unwrap();
            for &expected in &values {
                let actual = $read_fn_name(&mut decoder);
                assert_eq!(expected, actual);
            }
            assert_eq!(stream_end, decoder.position());
        }
    };
}

impl_test_unsigned_leb128!(test_u16_leb128, write_u16_leb128, read_u16_leb128, u16);
impl_test_unsigned_leb128!(test_u32_leb128, write_u32_leb128, read_u32_leb128, u32);
impl_test_unsigned_leb128!(test_u64_leb128, write_u64_leb128, read_u64_leb128, u64);
impl_test_unsigned_leb128!(test_u128_leb128, write_u128_leb128, read_u128_leb128, u128);
impl_test_unsigned_leb128!(test_usize_leb128, write_usize_leb128, read_usize_leb128, usize);

macro_rules! impl_test_signed_leb128 {
    ($test_name:ident, $write_fn_name:ident, $read_fn_name:ident, $int_ty:ident) => {
        #[test]
        fn $test_name() {
            // Test 256 evenly spaced values of integer range,
            // integer max value, and some "random" numbers.
            let mut values = Vec::new();

            let mut value = $int_ty::MIN;
            let increment = (1 as $int_ty) << ($int_ty::BITS - 8);

            for _ in 0..256 {
                values.push(value);
                // The addition in the last loop iteration overflows.
                value = value.wrapping_add(increment);
            }

            values.push($int_ty::MAX);

            values.extend(
                (-500..500).map(|i| (i as $int_ty).wrapping_mul(0x12345789ABCDEFi64 as $int_ty)),
            );

            let mut stream = Vec::new();

            let mut buf = Default::default();
            for &x in &values {
                let n = $write_fn_name(&mut buf, x);
                stream.extend(&buf[..n]);
            }
            let stream_end = stream.len();
            stream.extend(MAGIC_END_BYTES);

            let mut decoder = MemDecoder::new(&stream, 0).unwrap();
            for &expected in &values {
                let actual = $read_fn_name(&mut decoder);
                assert_eq!(expected, actual);
            }
            assert_eq!(stream_end, decoder.position());
        }
    };
}

impl_test_signed_leb128!(test_i16_leb128, write_i16_leb128, read_i16_leb128, i16);
impl_test_signed_leb128!(test_i32_leb128, write_i32_leb128, read_i32_leb128, i32);
impl_test_signed_leb128!(test_i64_leb128, write_i64_leb128, read_i64_leb128, i64);
impl_test_signed_leb128!(test_i128_leb128, write_i128_leb128, read_i128_leb128, i128);
impl_test_signed_leb128!(test_isize_leb128, write_isize_leb128, read_isize_leb128, isize);