signinum_core/
context.rs

1// SPDX-License-Identifier: Apache-2.0
2
3/// Cache hit/miss counters reported by codec contexts.
4#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
5pub struct CacheStats {
6    /// Number of cache lookups that reused existing state.
7    pub hits: u64,
8    /// Number of cache lookups that had to build new state.
9    pub misses: u64,
10    /// Number of currently occupied cache slots.
11    pub occupied_slots: u64,
12    /// Number of cache entries evicted by later insertions.
13    pub evictions: u64,
14}
15
16impl CacheStats {
17    /// Construct cache statistics from explicit counters.
18    pub const fn new(hits: u64, misses: u64) -> Self {
19        Self {
20            hits,
21            misses,
22            occupied_slots: 0,
23            evictions: 0,
24        }
25    }
26
27    /// Construct cache statistics from full counters.
28    pub const fn with_slots(hits: u64, misses: u64, occupied_slots: u64, evictions: u64) -> Self {
29        Self {
30            hits,
31            misses,
32            occupied_slots,
33            evictions,
34        }
35    }
36}
37
38/// Reusable codec state cached across decode calls.
39pub trait CodecContext: Default + Send {
40    /// Drop cached state while keeping the context reusable.
41    fn clear(&mut self);
42
43    /// Return current cache counters, when the codec tracks them.
44    fn cache_stats(&self) -> CacheStats {
45        CacheStats::default()
46    }
47}
48
49/// Wrapper that owns codec context state for repeated decode calls.
50#[derive(Debug, Default)]
51pub struct DecoderContext<C: CodecContext> {
52    codec: C,
53}
54
55impl<C: CodecContext> DecoderContext<C> {
56    /// Construct an empty decoder context.
57    pub fn new() -> Self {
58        Self {
59            codec: C::default(),
60        }
61    }
62
63    /// Borrow the codec-specific context.
64    pub fn codec(&self) -> &C {
65        &self.codec
66    }
67
68    /// Mutably borrow the codec-specific context.
69    pub fn codec_mut(&mut self) -> &mut C {
70        &mut self.codec
71    }
72
73    /// Clear cached codec state.
74    pub fn clear(&mut self) {
75        self.codec.clear();
76    }
77
78    /// Return cache counters from the codec-specific context.
79    pub fn cache_stats(&self) -> CacheStats {
80        self.codec.cache_stats()
81    }
82
83    /// Consume the wrapper and return the codec-specific context.
84    pub fn into_inner(self) -> C {
85        self.codec
86    }
87}
signinum_core/context.rs

signinum_core/
context.rs
