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
/// Helper to calculate the number of bytes used when encoding a
/// given set of values.a
#[derive(Default, Debug, Clone, Eq, PartialEq, Hash, Ord, PartialOrd)]
pub struct WireLenCalc {
/// Number of bytes needed to encode the provided values.
pub len: usize,
}
impl WireLenCalc {
pub fn new() -> WireLenCalc {
WireLenCalc { len: 0 }
}
/// Add the needed len to encode the given [`u32`] as VARINT to the overall `len`.
pub fn add_var_uint32(&mut self, value: u32) {
// determine needed byte length
if value < (1 << 7) {
self.len += 1;
} else if value < (1 << (7 * 2)) {
self.len += 2;
} else if value < (1 << (7 * 3)) {
self.len += 3;
} else if value < (1 << (7 * 4)) {
self.len += 4;
} else {
self.len += 5;
}
}
/// Add the needed len to encode the given [`u64`] as VARINT to the overall `len`.
pub fn add_var_uint64(&mut self, value: u64) {
// determine needed byte length
if value < (1 << 7) {
self.len += 1;
} else if value < (1 << (7 * 2)) {
self.len += 2;
} else if value < (1 << (7 * 3)) {
self.len += 3;
} else if value < (1 << (7 * 4)) {
self.len += 4;
} else if value < (1 << (7 * 5)) {
self.len += 5;
} else if value < (1 << (7 * 6)) {
self.len += 6;
} else if value < (1 << (7 * 7)) {
self.len += 7;
} else if value < (1 << (7 * 8)) {
self.len += 8;
} else if value < (1 << (7 * 9)) {
self.len += 9;
} else {
self.len += 10;
}
}
/// Add the needed len to encode a fixed32 to the overall `len`.
pub fn add_fixed32(&mut self) {
self.len += 4;
}
/// Add the needed len to encode a fixed64 to the overall `len`.
pub fn add_fixed64(&mut self) {
self.len += 8;
}
/// Add the needed len to encode a float to the overall `len`.
pub fn add_float(&mut self) {
self.len += 4;
}
/// Add the needed len to encode a double to the overall `len`.
pub fn add_double(&mut self) {
self.len += 8;
}
/// Add the length needed to encode bytes of the given length.
pub fn add_bytes(&mut self, len: usize) {
self.len += len;
}
}