cu29_unifiedlog/
noop.rs

1use crate::{
2    SECTION_HEADER_COMPACT_SIZE, SECTION_MAGIC, SectionHandle, SectionHeader, SectionStorage,
3    UnifiedLogStatus, UnifiedLogWrite,
4};
5use bincode::Encode;
6use bincode::config::standard;
7use bincode::enc::EncoderImpl;
8use bincode::enc::write::SizeWriter;
9use bincode::error::EncodeError;
10use cu29_traits::{CuResult, UnifiedLogType};
11
12#[derive(Debug, Default)]
13pub struct NoopSectionStorage {
14    bytes_written: usize,
15}
16
17impl SectionStorage for NoopSectionStorage {
18    fn initialize<E: Encode>(&mut self, header: &E) -> Result<usize, EncodeError> {
19        let header_size = encoded_size(header)?;
20        self.bytes_written = header_size;
21        Ok(header_size)
22    }
23
24    fn post_update_header<E: Encode>(&mut self, header: &E) -> Result<usize, EncodeError> {
25        encoded_size(header)
26    }
27
28    fn append<E: Encode>(&mut self, entry: &E) -> Result<usize, EncodeError> {
29        let size = encoded_size(entry)?;
30        self.bytes_written = self.bytes_written.saturating_add(size);
31        Ok(size)
32    }
33
34    fn flush(&mut self) -> CuResult<usize> {
35        Ok(self.bytes_written)
36    }
37}
38
39#[derive(Debug, Default)]
40pub struct NoopLogger {
41    total_used_space: usize,
42    total_allocated_space: usize,
43}
44
45impl NoopLogger {
46    pub fn new() -> Self {
47        Self::default()
48    }
49}
50
51impl UnifiedLogWrite<NoopSectionStorage> for NoopLogger {
52    fn add_section(
53        &mut self,
54        entry_type: UnifiedLogType,
55        requested_section_size: usize,
56    ) -> CuResult<SectionHandle<NoopSectionStorage>> {
57        let allocated_size = requested_section_size.max(SECTION_HEADER_COMPACT_SIZE as usize);
58        let section_header = SectionHeader {
59            magic: SECTION_MAGIC,
60            block_size: SECTION_HEADER_COMPACT_SIZE,
61            entry_type,
62            offset_to_next_section: allocated_size.min(u32::MAX as usize) as u32,
63            used: 0,
64            is_open: true,
65        };
66
67        self.total_allocated_space = self.total_allocated_space.saturating_add(allocated_size);
68        SectionHandle::create(section_header, NoopSectionStorage::default())
69    }
70
71    fn flush_section(&mut self, section: &mut SectionHandle<NoopSectionStorage>) {
72        section.mark_closed();
73        let _ = section.post_update_header();
74        if let Ok(used) = section.get_storage_mut().flush() {
75            self.total_used_space = self.total_used_space.saturating_add(used);
76        }
77    }
78
79    fn status(&self) -> UnifiedLogStatus {
80        UnifiedLogStatus {
81            total_used_space: self.total_used_space,
82            total_allocated_space: self.total_allocated_space,
83        }
84    }
85}
86
87fn encoded_size<E: Encode>(value: &E) -> Result<usize, EncodeError> {
88    let mut encoder = EncoderImpl::<_, _>::new(SizeWriter::default(), standard());
89    value.encode(&mut encoder)?;
90    Ok(encoder.into_writer().bytes_written)
91}
cu29_unifiedlog/noop.rs

cu29_unifiedlog/
noop.rs
