Struct SnapshotFsLoader 

pub struct SnapshotFsLoader { /* private fields */ }

A file system backed snapshot loader.

The loader opens a snapshot file and decodes it using the framed binary format written by SnapshotFsWriter:

• 4 bytes version (currently 4)
• 4 bytes length of payload
• 4 bytes CRC-32 of payload
• JSON-serialized Snapshot

Version checking is performed to ensure compatibility between the writer and loader. If the snapshot version does not match the expected version, SnapshotLoaderError::IncompatibleVersion is returned.

If the snapshot file does not exist, load() will return Ok(None) instead of panicking.

Implementations

impl SnapshotFsLoader

pub fn new(path: PathBuf) -> Self

Creates a new snapshot loader from the given path.

Arguments

• path - The filesystem path to the snapshot file

pub fn with_version(path: PathBuf, version: u32) -> Self

Creates a new snapshot loader from the given path with a custom version.

This is useful for testing or when the loader needs to support multiple snapshot versions.

Arguments

• path - The filesystem path to the snapshot file
• version - The expected snapshot version

Trait Implementations

impl SnapshotLoader for SnapshotFsLoader

fn load(&mut self) -> Result<Option<Snapshot>, SnapshotLoaderError>

Load a snapshot from storage.

The loader reads the version frame, validates it against the expected version, then reads the length and payload frames. The payload is decoded from JSON into a Snapshot struct.

If the snapshot file does not exist, returns Ok(None).

Errors

Returns SnapshotLoaderError::IoError if an I/O error occurs. Returns SnapshotLoaderError::IncompatibleVersion if the snapshot version does not match the expected version. Returns SnapshotLoaderError::DecodeError if the snapshot cannot be decoded.