vantage-faker

Synthetic, optionally-live datasource for Vantage. Generates realistic rows and — for live effects — keeps mutating them, pushing genuine change-events so a subscribed Dio animates inserts and expiries. For testing and demos, without a real backend.

Incubating: API may change.

Effects

• static — generate rows once; never change.
• fifo — insert one row at a time (newest-first), expire each after a random retention.
• PulseSim — a config-driven live aggregate feed driving three coupled tables.
• LiveFolderSim — a synthetic, constantly-mutating multi-layer log tree.

LiveFolderSim

Models a "live" log folder structure that grows in real time, all in memory:

• {date}/access_logs_{HH}/chunk_{NN}.log — high-volume access log. The active chunk bumps every second by requests_per_sec × bytes_per_request bytes; when it crosses chunk_threshold, a new chunk starts (the old stays).
• {date}/error_logs/{HH:MM:SS}-errors.log — rare; one file per error occurrence, gated by error_pct_per_sec.
• {date}/events/{event_type}.log — ten event types each with its own 1–10% per-second probability of bumping its file by 2000–4000 bytes.

Each folder and file carries created/modified; modifying a file touches its parent folder (and ancestors up to the root) so a parent reflects its newest child. backfill replays the algorithm at full speed from now − backfill to now on construction before real-time ticks begin.

Two Vistas come out of one shared run loop:

• Listing (listing_vista(path)): one row per child of a path — {name, kind, size, created, modified}. Patched in place on each tick via ChangeEvents so a subscribed Dio doesn't re-list.
• Folder size (size_vista()): {path, size, file_count} — get-only, no list. Fetched with 100ms–1s latency scaled by file count, the exact slow-get shape viewport debounce tests need.

cargo run --example live_folder_cli

Example

use std::time::Duration;
use vantage_faker::{FakerColumn, FakerTable, FifoEffect};

let columns = vec![
    FakerColumn { name: "id".into(),    ty: "string".into(),  flags: vec!["id".into()] },
    FakerColumn { name: "email".into(), ty: "string".into(),  flags: vec![] },
    FakerColumn { name: "amount".into(), ty: "decimal".into(), flags: vec![] },
];

let table = FakerTable::build(
    "events",
    columns,
    "id",
    Box::new(FifoEffect {
        interval: Duration::from_secs(1),
        retention_lo: Duration::from_secs(30),
        retention_hi: Duration::from_secs(60),
    }),
);

// `table.vista` lists the current rows; `table.events.subscribe()` streams live deltas.

Values are drawn from the fake crate: the column name is matched first (email, name, phone, city, …), then the declared type.

License

MIT OR Apache-2.0