vantadb 0.1.4

VantaDB: An embedded persistent memory and vector retrieval engine for local-first AI applications.
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
150
151
152
153

//! Memory Telemetry Contract Harness
//!
//! Validates that VantaDB reports process-scoped memory with explicit units
//! and that controlled scenarios can be compared without pretending those
//! numbers represent full engine footprint or mmap residency.

#[path = "common/mod.rs"]
mod common;

use common::{TerminalReporter, VantaHarness};
use std::fs;
use std::path::Path;
use tempfile::tempdir;
use vantadb::config::VantaConfig;
use vantadb::node::{NodeFlags, UnifiedNode, VectorRepresentations};
use vantadb::storage::{BackendKind, StorageEngine};

fn open_fjall(path: &str) -> StorageEngine {
    let config = VantaConfig {
        backend_kind: BackendKind::Fjall,
        ..Default::default()
    };
    StorageEngine::open_with_config(path, Some(config)).expect("Failed to open Fjall engine")
}

fn dir_size_bytes(path: &Path) -> u64 {
    if !path.exists() {
        return 0;
    }

    let mut total = 0u64;
    let mut stack = vec![path.to_path_buf()];
    while let Some(current) = stack.pop() {
        if let Ok(entries) = fs::read_dir(&current) {
            for entry in entries.flatten() {
                let entry_path = entry.path();
                if entry_path.is_dir() {
                    stack.push(entry_path);
                } else if let Ok(metadata) = entry.metadata() {
                    total += metadata.len();
                }
            }
        }
    }
    total
}

fn make_node(id: u64) -> UnifiedNode {
    let mut node = UnifiedNode::new(id);
    node.vector = VectorRepresentations::Full(vec![id as f32, 1.0, 2.0, 3.0]);
    node.flags.set(NodeFlags::HAS_VECTOR);
    node.set_field("category", vantadb::FieldValue::String("telemetry".into()));
    node
}

#[test]
fn memory_telemetry_contract() {
    TerminalReporter::suite_banner("MEMORY TELEMETRY CONTRACT", 4);
    let mut harness = VantaHarness::new("OBSERVABILITY (MEMORY CONTRACT)");

    let dir = tempdir().expect("Failed to create temp dir");
    let db_path = dir.path().to_str().unwrap();
    let data_dir = dir.path().join("data");

    harness.execute("Cold Start: Empty Engine", || {
        let _engine = open_fjall(db_path);
        let bytes = dir_size_bytes(&data_dir);
        TerminalReporter::info(&format!(
            "Process telemetry is process-scoped only; on-disk bytes after cold start = {}",
            bytes
        ));
        assert!(
            data_dir.exists(),
            "Fjall data directory must exist after open"
        );
    });

    harness.execute("Moderate Ingest: 1K vectors + flush", || {
        let engine = open_fjall(db_path);
        for id in 1..=1_000u64 {
            engine.insert(&make_node(id)).unwrap();
        }
        engine.flush().unwrap();

        let total_bytes = dir_size_bytes(&data_dir);
        let vector_store = data_dir.join("vector_store.vanta");
        let ann_index = data_dir.join("vector_index.bin");

        TerminalReporter::info(&format!(
            "Disk bytes after flush: total={}, vantafile={}, ann={}",
            total_bytes,
            fs::metadata(&vector_store).map(|m| m.len()).unwrap_or(0),
            fs::metadata(&ann_index).map(|m| m.len()).unwrap_or(0)
        ));

        assert!(
            vector_store.exists(),
            "vector_store.vanta must exist after flush"
        );
        assert!(
            ann_index.exists(),
            "vector_index.bin must exist after flush"
        );

        let metrics = vantadb::metrics::operational_metrics_snapshot();
        assert!(metrics.memory.process_rss_bytes > 0);
        assert!(metrics.memory.hnsw_nodes_count >= 1_000);
        assert!(metrics.memory.hnsw_logical_bytes > 0);
        #[cfg(any(unix, target_os = "windows"))]
        assert!(metrics.memory.mmap_resident_bytes.is_some());
    });

    harness.execute("WAL Replay: write without flush then reopen", || {
        {
            let engine = open_fjall(db_path);
            for id in 1_001..=1_100u64 {
                engine.insert(&make_node(id)).unwrap();
            }
        }

        let reopened = open_fjall(db_path);
        for id in 1_001..=1_100u64 {
            assert!(
                reopened.get(id).unwrap().is_some(),
                "Recovered node {} must be visible after WAL replay",
                id
            );
        }

        let wal_path = data_dir.join("vanta.wal");
        TerminalReporter::info(&format!(
            "WAL bytes after replay path: {}",
            fs::metadata(&wal_path).map(|m| m.len()).unwrap_or(0)
        ));
    });

    harness.execute("Restart: Index reload remains queryable", || {
        let reopened = open_fjall(db_path);
        let results = reopened.hnsw.load().search_nearest(
            &[1.0, 1.0, 2.0, 3.0],
            None,
            None,
            0,
            5,
            Some(&reopened.vector_store.read()),
        );

        assert!(!results.is_empty(), "Reopened index must remain queryable");
        TerminalReporter::success(
            "Telemetry contract kept separate from reload/query correctness checks.",
        );
    });
}