nexir-mvcc-core 0.1.0

Standalone, deterministic Multi-Version Concurrency Control (MVCC) library for building durable databases
Documentation 
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use nexir_mvcc_core::{
    decode_committed, decode_intent, encode_committed, encode_intent, CommittedVersion, Intent,
    Mutation, Timestamp, TxnId,
};

#[test]
fn test_roundtrip_committed_put() {
    let original = CommittedVersion {
        key: b"testkey".to_vec(),
        commit_ts: Timestamp(42),
        value: Some(b"hello".to_vec()),
    };
    let encoded = encode_committed(&original).unwrap();
    let decoded = decode_committed(&encoded).unwrap();
    assert_eq!(original, decoded);
}

#[test]
fn test_roundtrip_committed_tombstone() {
    let original = CommittedVersion {
        key: b"delkey".to_vec(),
        commit_ts: Timestamp(99),
        value: None,
    };
    let encoded = encode_committed(&original).unwrap();
    let decoded = decode_committed(&encoded).unwrap();
    assert_eq!(original, decoded);
}

#[test]
fn test_roundtrip_intent_put() {
    let original = Intent {
        key: b"mykey".to_vec(),
        txn_id: TxnId(7),
        start_ts: Timestamp(12),
        mutation: Mutation::Put(b"val".to_vec()),
        min_commit_ts: Some(Timestamp(15)),
    };
    let encoded = encode_intent(&original).unwrap();
    let decoded = decode_intent(&encoded).unwrap();
    assert_eq!(original, decoded);
}

#[test]
fn test_roundtrip_intent_delete() {
    let original = Intent {
        key: b"x".to_vec(),
        txn_id: TxnId(1),
        start_ts: Timestamp(2),
        mutation: Mutation::Delete,
        min_commit_ts: None,
    };
    let encoded = encode_intent(&original).unwrap();
    let decoded = decode_intent(&encoded).unwrap();
    assert_eq!(original, decoded);
}

#[test]
fn test_golden_committed_put() {
    let v = CommittedVersion {
        key: b"k".to_vec(),
        commit_ts: Timestamp(1),
        value: Some(b"v".to_vec()),
    };
    let encoded = encode_committed(&v).unwrap();
    // 0x01 = codec version
    // 0x01 = committed record
    // 0x00 00 00 01 = key len, then "k"
    // 0x00 00 00 00 00 00 00 01 = commit_ts=1
    // 0x01 = present flag
    // 0x00 00 00 01 = value len, then "v"
    assert_eq!(
        encoded,
        vec![
            0x01, 0x01, // version, record type
            0x00, 0x00, 0x00, 0x01, b'k', // key
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, // commit_ts
            0x01, // present
            0x00, 0x00, 0x00, 0x01, b'v', // value
        ]
    );
}

#[test]
fn test_golden_committed_tombstone() {
    let v = CommittedVersion {
        key: b"k".to_vec(),
        commit_ts: Timestamp(5),
        value: None,
    };
    let encoded = encode_committed(&v).unwrap();
    assert_eq!(
        encoded,
        vec![
            0x01, 0x01, // version, record type
            0x00, 0x00, 0x00, 0x01, b'k', // key
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, // commit_ts
            0x00, // absent (tombstone)
        ]
    );
}

#[test]
fn test_golden_intent_delete() {
    let intent = Intent {
        key: b"k".to_vec(),
        txn_id: TxnId(10),
        start_ts: Timestamp(20),
        mutation: Mutation::Delete,
        min_commit_ts: None,
    };
    let encoded = encode_intent(&intent).unwrap();
    assert_eq!(
        encoded,
        vec![
            0x01, 0x02, // version, record type
            0x00, 0x00, 0x00, 0x01, b'k', // key
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0A, // txn_id=10
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x14, // start_ts=20
            0x00, // min_commit_ts absent
            0x02, // mutation = Delete
        ]
    );
}

#[test]
fn test_decode_empty_fails() {
    assert!(decode_committed(&[]).is_err());
    assert!(decode_intent(&[]).is_err());
}

#[test]
fn test_decode_bad_version_fails() {
    assert!(decode_committed(&[0xFF]).is_err());
    assert!(decode_intent(&[0xFF]).is_err());
}

#[test]
fn test_decode_wrong_record_type_fails() {
    // valid version, but record type 0xFF is unknown
    let bad = vec![0x01, 0xFF, 0x00, 0x00, 0x00, 0x00];
    assert!(decode_committed(&bad).is_err());
    assert!(decode_intent(&bad).is_err());
}

#[test]
fn test_decode_trailing_garbage_fails() {
    let v = CommittedVersion {
        key: b"k".to_vec(),
        commit_ts: Timestamp(1),
        value: Some(b"v".to_vec()),
    };
    let mut encoded = encode_committed(&v).unwrap();
    encoded.push(0xFF); // trailing garbage
    assert!(decode_committed(&encoded).is_err());

    let intent = Intent {
        key: b"k".to_vec(),
        txn_id: TxnId(10),
        start_ts: Timestamp(20),
        mutation: Mutation::Delete,
        min_commit_ts: None,
    };
    let mut encoded_intent = encode_intent(&intent).unwrap();
    encoded_intent.push(0xFF);
    assert!(decode_intent(&encoded_intent).is_err());
}