protobuf/
cached_size.rs

1use std::hash::Hash;
2use std::hash::Hasher;
3use std::sync::atomic::AtomicUsize;
4use std::sync::atomic::Ordering;
5
6/// Cached size field used in generated code.
7///
8/// It is always equal to itself to simplify generated code.
9/// (Generated code can use `#[derive(Eq)]`).
10///
11/// This type should rarely be used directly.
12#[derive(Debug, Default)]
13pub struct CachedSize {
14    size: AtomicUsize,
15}
16
17impl CachedSize {
18    /// Create a new `CachedSize` object.
19    pub const fn new() -> CachedSize {
20        CachedSize {
21            size: AtomicUsize::new(0),
22        }
23    }
24
25    /// Get cached size
26    pub fn get(&self) -> u32 {
27        self.size.load(Ordering::Relaxed) as u32
28    }
29
30    /// Set cached size
31    pub fn set(&self, size: u32) {
32        self.size.store(size as usize, Ordering::Relaxed)
33    }
34}
35
36impl Clone for CachedSize {
37    fn clone(&self) -> CachedSize {
38        CachedSize {
39            size: AtomicUsize::new(self.size.load(Ordering::Relaxed)),
40        }
41    }
42}
43
44impl PartialEq<CachedSize> for CachedSize {
45    fn eq(&self, _other: &CachedSize) -> bool {
46        true
47    }
48}
49
50impl Eq for CachedSize {}
51
52impl Hash for CachedSize {
53    fn hash<H: Hasher>(&self, _state: &mut H) {
54        // ignore cached size in cache computation
55    }
56}