Mountain/ApplicationState/Internal/Persistence/MementoLoader/
LoadInitialMementoFromDisk.rs

1//! Best-effort synchronous memento loader for `ApplicationState`'s
2//! `default()` path. Failures don't propagate - corrupted files are
3//! backed up, missing directories are created, and an empty map is
4//! returned so initialisation always succeeds.
5
6use std::{collections::HashMap, fs, path::Path};
7
8use serde_json::Value;
9
10use crate::{ApplicationState::Internal::Persistence::MementoLoader::AttemptMementoRecovery, dev_log};
11
12pub fn Fn(StorageFilePath:&Path) -> HashMap<String, Value> {
13	if !StorageFilePath.exists() {
14		dev_log!(
15			"storage",
16			"[MementoLoader] Memento file does not exist: {}",
17			StorageFilePath.display()
18		);
19
20		return HashMap::new();
21	}
22
23	match fs::read_to_string(StorageFilePath) {
24		Ok(Content) => {
25			serde_json::from_str(&Content).unwrap_or_else(|Error| {
26				dev_log!(
27					"storage",
28					"error: [MementoLoader] Failed to parse JSON from '{}': {}. Attempting recovery.",
29					StorageFilePath.display(),
30					Error
31				);
32
33				AttemptMementoRecovery::Fn(StorageFilePath, &Content);
34
35				HashMap::new()
36			})
37		},
38
39		Err(Error) => {
40			dev_log!(
41				"storage",
42				"error: [MementoLoader] Failed to read '{}': {}. Attempting recovery.",
43				StorageFilePath.display(),
44				Error
45			);
46
47			if let Some(Parent) = StorageFilePath.parent()
48				&& !Parent.exists()
49				&& let Err(DirError) = fs::create_dir_all(Parent)
50			{
51				dev_log!(
52					"storage",
53					"warn: [MementoLoader] Failed to create directory '{}': {}",
54					Parent.display(),
55					DirError
56				);
57			}
58
59			HashMap::new()
60		},
61	}
62}

Mountain/ApplicationState/Internal/Persistence/MementoLoader/LoadInitialMementoFromDisk.rs

Mountain/ApplicationState/Internal/Persistence/MementoLoader/
LoadInitialMementoFromDisk.rs