harmos-storage 0.1.7

Harmos storage: durable journals, snapshots and Arrow-backed stream storage.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149

/* ***
 *
 * Harmos
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * ***
 */

// Verify Durable Typed Replay And Exclusive JSON Root Ownership.

/* === Modules === */

/* === Re-Exports === */

/* === Imports === */

// Standard Library Imports
use std::{
    num::{NonZeroU32, NonZeroUsize},
    path::Path,
};

// Third Party Imports

// Local Imports
use harmos_storage::{query::RecordSelection, *};

/* === Constants === */

/* === Macros === */

/* === Type Aliases === */

/* === Structs === */

/* === Enums === */

/* === Traits === */

/* === Implementations === */

/* === Public Functions === */

/* === Private Functions === */

fn backend(root: &Path) -> JsonStorage {
    let history = StoreHistory {
        store: Identifier::new("json-test").unwrap(),
        epoch: Identifier::new("first").unwrap(),
    };
    let settings = JsonStorageSettings {
        root: root.to_owned(),
        max_entry_bytes: NonZeroUsize::new(4096).unwrap(),
    };
    JsonStorage::new(settings, history)
}

fn record(history: &StoreHistory, sequence: u64) -> StoredRecord {
    let schema = SchemaKey {
        id: Identifier::new("record").unwrap(),
        version: NonZeroU32::new(1).unwrap(),
        payload_encoding: PayloadEncoding::PostcardV1,
    };
    StoredRecord {
        position: StorageCursor { history: history.clone(), sequence },
        schema,
        scope: None,
        item: Identifier::new("item").unwrap(),
        source: None,
        source_time: None,
        payload: vec![sequence as u8],
    }
}

/* === Tests === */

#[tokio::test]
async fn typed_replay() {
    let directory = tempfile::tempdir().unwrap();
    let storage = backend(directory.path());
    assert_eq!(storage.open().await.unwrap().sequence, 0);
    let first = record(storage.history(), 1);
    let batch = StorageBatch::new(vec![first.clone()]);
    assert_eq!(storage.write_records(batch.clone()).await.unwrap(), first.position);
    assert_eq!(storage.write_records(batch).await.unwrap(), first.position);

    let mut conflict = first.clone();
    conflict.payload = vec![99];
    assert!(storage.write_records(StorageBatch::new(vec![conflict])).await.is_err());
    let skipped = record(storage.history(), 3);
    assert!(storage.write_records(StorageBatch::new(vec![skipped])).await.is_err());
    storage.close().await.unwrap();

    let pending = directory.path().join("data").join("uncommitted.pending");
    std::fs::write(pending, b"interrupted write").unwrap();

    let reopened = backend(directory.path());
    assert_eq!(reopened.open().await.unwrap(), first.position);
    let snapshot = reopened.open_snapshot(&first.position).await.unwrap();
    let selection = RecordSelection {
        schema: first.schema.clone(),
        scope: None,
        item: None,
        source_start: None,
        source_end: None,
    };
    let page = ScanPage {
        after: 0,
        rows: NonZeroUsize::new(1).unwrap(),
        bytes: NonZeroUsize::new(4096).unwrap(),
    };
    assert_eq!(reopened.read_records(&snapshot, &selection, page).await.unwrap(), vec![first]);
    reopened.release_snapshot(&snapshot).await.unwrap();
    assert!(reopened.read_records(&snapshot, &selection, page).await.is_err());
    reopened.close().await.unwrap();
}

#[tokio::test]
async fn root_lease() {
    let directory = tempfile::tempdir().unwrap();
    let first = backend(directory.path());
    let second = backend(directory.path());
    first.open().await.unwrap();
    assert!(second.open().await.is_err());
    first.close().await.unwrap();
    assert_eq!(second.open().await.unwrap().sequence, 0);
    second.close().await.unwrap();
}

#[tokio::test]
async fn truncated_commit() {
    let directory = tempfile::tempdir().unwrap();
    let storage = backend(directory.path());
    storage.open().await.unwrap();
    let row = record(storage.history(), 1);
    storage.write_records(StorageBatch::new(vec![row])).await.unwrap();
    storage.close().await.unwrap();

    let data = directory.path().join("data");
    let entry = std::fs::read_dir(data).unwrap().next().unwrap().unwrap();
    let file = std::fs::OpenOptions::new().write(true).open(entry.path()).unwrap();
    let length = file.metadata().unwrap().len();
    file.set_len(length - 1).unwrap();
    drop(file);

    let reopened = backend(directory.path());
    assert!(reopened.open().await.is_err());
}