agentic_codebase/format/
mmap.rs

1//! Memory-mapped file access for `.acb` files.
2//!
3//! Provides zero-copy access to `.acb` data using OS-level memory mapping.
4//! This is the preferred access method for large files.
5
6use std::path::Path;
7
8use crate::graph::CodeGraph;
9use crate::types::{AcbError, AcbResult};
10
11use super::reader::AcbReader;
12
13/// A memory-mapped view of an `.acb` file.
14///
15/// This wraps the mmap and provides access to the graph data
16/// without loading the entire file into heap memory.
17pub struct MappedCodeGraph {
18    _mmap: memmap2::Mmap,
19    graph: CodeGraph,
20}
21
22impl MappedCodeGraph {
23    /// Open and memory-map an `.acb` file.
24    ///
25    /// The file is mapped read-only. The graph is parsed from the mapped data.
26    ///
27    /// # Safety
28    ///
29    /// This uses `unsafe` internally for mmap. The file must not be modified
30    /// while the mapping is active.
31    pub fn open(path: &Path) -> AcbResult<Self> {
32        if !path.exists() {
33            return Err(AcbError::PathNotFound(path.to_path_buf()));
34        }
35
36        let file = std::fs::File::open(path)?;
37        // SAFETY: We only map read-only, and we don't expose the raw mapping.
38        // The caller must ensure the file is not modified while mapped.
39        let mmap = unsafe { memmap2::Mmap::map(&file)? };
40
41        let graph = AcbReader::read_from_data(&mmap)?;
42
43        Ok(Self { _mmap: mmap, graph })
44    }
45
46    /// Get a reference to the parsed code graph.
47    pub fn graph(&self) -> &CodeGraph {
48        &self.graph
49    }
50
51    /// Consume and return the parsed graph (drops the mmap).
52    pub fn into_graph(self) -> CodeGraph {
53        self.graph
54    }
55}
agentic_codebase/format/mmap.rs

agentic_codebase/format/
mmap.rs
