From 3ba47446f06d5b0fbeaeb59d4ffed768b70729d8 Mon Sep 17 00:00:00 2001 From: Michelle Tilley Date: Thu, 26 Feb 2026 14:42:08 -0800 Subject: feat: In-memory search index with atuin daemon (#3201) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ## Summary This PR adds a persistent, in-memory search index to the Atuin daemon, enabling fast fuzzy search without the startup delay of building an index each time the TUI opens. ### Key Changes - **Daemon search service**: A new gRPC service that maintains a Nucleo fuzzy search index in memory - **Real-time index updates**: The daemon listens for history events (new commands, synced records) and updates the index immediately - **Filter mode support**: All existing filter modes work (Global, Host, Session, Directory, Workspace) - **New search engine**: `daemon-fuzzy` search mode that queries the daemon instead of building a local index - **Paged history loading**: Database pagination support for efficient initial index loading - **Configurable logging**: New `[logs]` settings section for daemon and search log configuration - **Component-based daemon architecture**: Refactored daemon internals into a modular, event-driven system - **Fallback to DB search for regex**: Since Nucleo doesn't support regex matching ## Daemon Architecture The daemon has been refactored to use a component-based, event-driven architecture that makes it easier to add new functionality and reason about the system. ### Core Concepts ``` ┌─────────────────────────────────────────────────────────────────────────────┐ │ Atuin Daemon │ │ │ │ ┌─────────────┐ ┌──────────────────────────────────────────────────┐ │ │ │ Daemon │ │ Components │ │ │ │ Handle │────▶│ │ │ │ │ │ │ ┌─────────────┐ ┌─────────────┐ ┌────────────┐ │ │ │ │ • emit() │ │ │ History │ │ Search │ │ Sync │ │ │ │ │ • subscribe │ │ │ Component │ │ Component │ │ Component │ │ │ │ │ • settings │ │ │ │ │ │ │ │ │ │ │ │ • databases │ │ │ gRPC service│ │ gRPC service│ │ background │ │ │ │ └─────────────┘ │ │ WIP history │ │ Nucleo index│ │ sync │ │ │ │ │ │ └─────────────┘ └─────────────┘ └────────────┘ │ │ │ │ └──────────────────────────────────────────────────┘ │ │ │ ▲ │ │ ▼ │ │ │ ┌─────────────────────────────────────┴────────────────────────────────┐ │ │ │ Event Bus (broadcast) │ │ │ │ │ │ │ │ HistoryStarted │ HistoryEnded │ RecordsAdded │ SyncCompleted │ ... │ │ │ └──────────────────────────────────────────────────────────────────────┘ │ │ ▲ │ │ ┌───────────────────────────────────┴──────────────────────────────────┐ │ │ │ Control Service (gRPC) │ │ │ │ External event injection from CLI commands │ │ │ └──────────────────────────────────────────────────────────────────────┘ │ └─────────────────────────────────────────────────────────────────────────────┘ ``` ### DaemonHandle A lightweight, cloneable handle that provides access to shared daemon resources: - **Event emission**: `handle.emit(DaemonEvent::...)` broadcasts to all components - **Event subscription**: `handle.subscribe()` returns a receiver for the event bus - **Settings**: `handle.settings()` for configuration access - **Databases**: `handle.history_db()` and `handle.store()` for data access ### Component Trait Components implement a simple lifecycle: ```rust #[async_trait] trait Component: Send + Sync { fn name(&self) -> &'static str; async fn start(&mut self, handle: DaemonHandle) -> Result<()>; async fn handle_event(&mut self, event: &DaemonEvent) -> Result<()>; async fn stop(&mut self) -> Result<()>; } ``` ### Event-Driven Design Components communicate via events rather than direct coupling: | Event | Emitted By | Consumed By | |-------|-----------|-------------| | `HistoryStarted` | History gRPC | Search (logging) | | `HistoryEnded` | History gRPC | Search (index update) | | `RecordsAdded` | Sync | Search (index update) | | `HistoryPruned` | CLI (via Control) | Search (index rebuild) | | `HistoryDeleted` | CLI (via Control) | Search (index rebuild) | | `ForceSync` | CLI (via Control) | Sync | | `ShutdownRequested` | Signal handler | All (graceful shutdown) | ### External Event Injection CLI commands can inject events into a running daemon: ```rust // After `atuin history prune` emit_event(DaemonEvent::HistoryPruned).await?; // After deleting specific items emit_event(DaemonEvent::HistoryDeleted { ids }).await?; // Request immediate sync emit_event(DaemonEvent::ForceSync).await?; ``` This ensures the daemon's search index stays in sync with database changes made by CLI commands. ## Search Architecture The search service uses a [forked version of Nucleo](https://github.com/atuinsh/nucleo-ext) that adds filter and scorer callbacks, enabling efficient filtering and frecency-based ranking. ``` ┌────────────────────────────────────────────────────────────────┐ │ Atuin Daemon │ │ │ │ ┌─────────────────┐ ┌──────────────────────────────────┐ │ │ │ Event System │───▶│ Search Component │ │ │ │ │ │ │ │ │ │ • RecordsAdded │ │ ┌────────────────────────────┐ │ │ │ │ • HistoryEnded │ │ │ Deduplicated Index │ │ │ │ │ • HistoryPruned │ │ │ │ │ │ │ └─────────────────┘ │ │ CommandData per command: │ │ │ │ │ │ • Global frecency │ │ │ │ ┌─────────────────┐ │ │ • Filter indexes (sets) │ │ │ │ │ Background Task │ │ │ • Invocation history │ │ │ │ │ │ │ └────────────────────────────┘ │ │ │ │ Rebuilds │ │ │ │ │ │ │ frecency map │ │ ▼ │ │ │ │ every 60s │───▶│ ┌────────────────────────────┐ │ │ │ └─────────────────┘ │ │ Nucleo (forked) │ │ │ │ │ │ │ │ │ │ │ │ • Filter callback │ │ │ │ │ │ • Scorer callback │ │ │ │ │ │ • Fuzzy matching │ │ │ │ │ └────────────────────────────┘ │ │ │ └──────────────────────────────────┘ │ │ │ │ │ │ gRPC (Unix socket) │ └──────────────────────────────────────│─────────────────────────┘ │ ▼ ┌─────────────────────────────────────────────────────────────────┐ │ Search TUI (Client) │ │ │ │ 1. Send query + filter mode + context to daemon │ │ 2. Receive matching history IDs (ranked by frecency) │ │ 3. Hydrate full records from local SQLite database │ │ 4. Display results in TUI │ └─────────────────────────────────────────────────────────────────┘ ``` ### Nucleo Fork The [nucleo-ext fork](https://github.com/atuinsh/nucleo-ext) adds two key features to Nucleo: 1. **Filter callback**: Pre-filter items before fuzzy matching (used for directory/host/session filtering) 2. **Scorer callback**: Compute custom scores after matching (used for frecency ranking) ```rust // Filter: only include commands run in current directory nucleo.set_filter(Some(Arc::new(|cmd: &String| { passing_commands.contains(cmd) }))); // Scorer: combine fuzzy score with frecency nucleo.set_scorer(Some(Arc::new(|cmd: &String, fuzzy_score: u32| { let frecency = frecency_map.get(cmd).unwrap_or(0); fuzzy_score + (frecency * 10) }))); ``` ### Deduplicated Index Commands are stored once per unique command text, with metadata tracking all invocations: ```rust struct CommandData { command: String, invocations: Vec, // All times this command was run global_frecency: FrecencyData, // Precomputed frecency score // O(1) filter indexes directories: HashSet, // All cwds where command was run hosts: HashSet, // All hostnames sessions: HashSet, // All session IDs } ``` This deduplication means: - **Fewer items to match**: ~13K unique commands vs ~62K history entries - **O(1) filter checks**: HashSet lookups instead of scanning invocations - **Single frecency score**: Global frecency computed once, used for all filter modes ### Frecency Scoring Frecency (frequency + recency) scoring prioritizes recently and frequently used commands: ```rust fn compute_frecency(count: u32, last_used: i64, now: i64) -> u32 { let age_hours = (now - last_used) / 3600; // Recency: decays over time (half-life ~24 hours) let recency = (100.0 * (-age_hours as f64 / 24.0).exp()) as u32; // Frequency: logarithmic scaling let frequency = (count.ln() * 20.0).min(100.0) as u32; recency + frequency } ``` The frecency map is: - **Precomputed by background task** every 60 seconds - **Never computed inline** during search (no latency impact) - **Graceful fallback**: If unavailable, search works without frecency ranking ### Filter Mode Implementation | Filter Mode | Implementation | |-------------|----------------| | Global | No filter (all commands) | | Directory | `command.directories.contains(cwd)` | | Workspace | `command.directories.any(\|d\| d.starts_with(git_root))` | | Host | `command.hosts.contains(hostname)` | | Session | `command.sessions.contains(session_id)` | Filters are pre-computed into a HashSet before the search, making the filter callback O(1). ### Search Flow 1. **Daemon startup**: Loads history from SQLite in pages, builds deduplicated index 2. **Frecency precompute**: Background task builds frecency map after history loads 3. **Search request**: Client sends query with filter mode and context 4. **Filter**: Pre-computed HashSet determines which commands pass the filter 5. **Match**: Nucleo fuzzy matches the query against command text 6. **Score**: Frecency scorer ranks results (fuzzy score + frecency * 10) 7. **Response**: Returns history IDs for the most recent invocation of each matching command 8. **Hydration**: Client fetches full records from local SQLite ### Configuration ```toml # Enable daemon + autostart [daemon] enabled = true autostart = true # Enable daemon-based fuzzy search [search] search_mode = "daemon-fuzzy" ``` ## Performance Performance varies based on several factors, but in most initial testing with the new architecture shows improvement: * **Nucleo performs searches up to 4.5x faster**: direct DB search averages 18.07ms, but the daemon completes the same queries in 3.99ms. * **IPC overhead is significant, but acceptable**: a significant amount of wall-time is taken up by the transfer of data over IPC (via UDS in this case). This averages to about ~7.8ms and accounts for 66% of client-side wall time. * **Tail latency improves at every layer**: p99 times correspond to initial requests, worst-case query patterns, etc. but the average p99 daemon-based response time is 3.6x better than the associated DB-based search p99 time * **Query complexity no longer impacts performance**: the Nucleo-based search shows consistent 2-7ms times regardless of query pattern. The DB-based search had a 17x variance (3.59ms to 62.46ms). Interestingly, @ellie - who has a larger history store than I do - gets even better performance on the IPC layer. This could use a lot more testing in various edge cases and on various hardware, but seems promising. ### Regular DB search ``` Individual calls for: db_search -------------------------------------------------------------------------------------------------------------- # Wall Busy Idle Fields -------------------------------------------------------------------------------------------------------------- 1 32.25ms 32.20ms 47.70µs {"mode":"Fuzzy","query":"^"} 2 19.48ms 19.40ms 84.20µs {"mode":"Fuzzy","query":"^c"} 3 20.40ms 20.10ms 297.00µs {"mode":"Fuzzy","query":"^ca"} 4 13.07ms 13.00ms 69.90µs {"mode":"Fuzzy","query":"^car"} 5 12.17ms 12.10ms 67.10µs {"mode":"Fuzzy","query":"^carg"} 6 20.78ms 20.70ms 76.60µs {"mode":"Fuzzy","query":"^cargo"} 7 9.15ms 9.10ms 53.20µs {"mode":"Fuzzy","query":"^cargo "} 8 10.24ms 10.00ms 237.00µs {"mode":"Fuzzy","query":"^cargo b"} 9 10.01ms 9.68ms 325.00µs {"mode":"Fuzzy","query":"^cargo bu"} 10 5.89ms 5.83ms 57.20µs {"mode":"Fuzzy","query":"^cargo bui"} 11 8.85ms 8.28ms 568.00µs {"mode":"Fuzzy","query":"^cargo buil"} 12 7.70ms 7.49ms 212.00µs {"mode":"Fuzzy","query":"^cargo build"} 13 3.59ms 3.53ms 57.00µs {"mode":"Fuzzy","query":"^cargo build$"} 14 6.50ms 6.44ms 63.60µs {"mode":"Fuzzy","query":"^cargo "} 15 6.48ms 6.38ms 100.00µs {"mode":"Fuzzy","query":"!"} 16 31.68ms 31.60ms 75.90µs {"mode":"Fuzzy","query":"!g"} 17 62.46ms 62.40ms 58.90µs {"mode":"Fuzzy","query":"!gi"} 18 30.35ms 30.30ms 46.90µs {"mode":"Fuzzy","query":"!git"} 19 53.84ms 53.80ms 40.80µs {"mode":"Fuzzy","query":"!git "} 20 19.24ms 19.20ms 39.70µs {"mode":"Fuzzy","query":"!git c"} 21 22.03ms 22.00ms 34.70µs {"mode":"Fuzzy","query":"!git co"} 22 17.13ms 17.00ms 133.00µs {"mode":"Fuzzy","query":"!git com"} 23 16.14ms 15.90ms 242.00µs {"mode":"Fuzzy","query":"!git comm"} 24 5.11ms 5.08ms 28.60µs {"mode":"Fuzzy","query":"!git commi"} 25 7.31ms 7.26ms 52.70µs {"mode":"Fuzzy","query":"!git commit"} Summary: 25 calls Wall: avg=18.07ms, min=3.59ms, max=62.46ms, p50=13.07ms, p99=62.46ms Busy: avg=17.95ms, min=3.53ms, max=62.40ms, p50=13.00ms, p99=62.40ms ``` ### Daemon-based search **Client** ``` Individual calls for: daemon_search -------------------------------------------------------------------------------------------------------------- # Wall Busy Idle Fields -------------------------------------------------------------------------------------------------------------- 1 13.05ms 2.55ms 10.50ms {"query":"^"} 2 10.65ms 1.40ms 9.25ms {"query":"^c"} 3 10.72ms 1.18ms 9.54ms {"query":"^ca"} 4 5.54ms 485.00µs 5.06ms {"query":"^car"} 5 15.02ms 1.02ms 14.00ms {"query":"^carg"} 6 9.49ms 840.00µs 8.65ms {"query":"^cargo"} 7 5.53ms 555.00µs 4.97ms {"query":"^cargo "} 8 8.56ms 717.00µs 7.84ms {"query":"^cargo b"} 9 12.34ms 1.24ms 11.10ms {"query":"^cargo bu"} 10 8.38ms 650.00µs 7.73ms {"query":"^cargo bui"} 11 13.07ms 770.00µs 12.30ms {"query":"^cargo buil"} 12 17.11ms 709.00µs 16.40ms {"query":"^cargo build"} 13 15.41ms 907.00µs 14.50ms {"query":"^cargo build$"} 14 8.19ms 665.00µs 7.52ms {"query":"^cargo "} 15 7.98ms 1.72ms 6.26ms {"query":"!"} 16 13.56ms 856.00µs 12.70ms {"query":"!g"} 17 8.11ms 624.00µs 7.49ms {"query":"!gi"} 18 14.57ms 775.00µs 13.80ms {"query":"!git"} 19 14.18ms 779.00µs 13.40ms {"query":"!git "} 20 9.62ms 802.00µs 8.82ms {"query":"!git c"} 21 15.50ms 1.50ms 14.00ms {"query":"!git co"} 22 11.58ms 1.48ms 10.10ms {"query":"!git com"} 23 13.82ms 2.12ms 11.70ms {"query":"!git comm"} 24 17.48ms 2.18ms 15.30ms {"query":"!git commi"} 25 14.81ms 1.71ms 13.10ms {"query":"!git commit"} Summary: 25 calls Wall: avg=11.77ms, min=5.53ms, max=17.48ms, p50=12.34ms, p99=17.48ms Busy: avg=1.13ms, min=485.00µs, max=2.55ms, p50=856.00µs, p99=2.55ms ``` **Daemon** ``` Individual calls for: daemon_search_query -------------------------------------------------------------------------------------------------------------- # Wall Busy Idle Fields -------------------------------------------------------------------------------------------------------------- 1 1.75ms 250ns 1.75ms {"query":"^","query_id":1} 2 4.58ms 125ns 4.58ms {"query":"^c","query_id":2} 3 4.39ms 250ns 4.39ms {"query":"^ca","query_id":3} 4 2.52ms 125ns 2.52ms {"query":"^car","query_id":4} 5 4.44ms 250ns 4.44ms {"query":"^carg","query_id":5} 6 3.66ms 167ns 3.66ms {"query":"^cargo","query_id":6} 7 2.38ms 84ns 2.38ms {"query":"^cargo ","query_id":7} 8 4.13ms 84ns 4.13ms {"query":"^cargo b","query_id":8} 9 4.40ms 167ns 4.40ms {"query":"^cargo bu","query_id":9} 10 3.87ms 125ns 3.87ms {"query":"^cargo bui","query_id":10} 11 4.36ms 84ns 4.36ms {"query":"^cargo buil","query_id":11} 12 3.96ms 333ns 3.96ms {"query":"^cargo build","query_id":12} 13 4.61ms 167ns 4.61ms {"query":"^cargo build$","query_id":13} 14 4.20ms 209ns 4.20ms {"query":"^cargo ","query_id":14} 15 238.17µs 167ns 238.00µs {"query":"!","query_id":15} 16 4.44ms 125ns 4.44ms {"query":"!g","query_id":16} 17 3.47ms 83ns 3.47ms {"query":"!gi","query_id":17} 18 4.57ms 125ns 4.57ms {"query":"!git","query_id":18} 19 7.15ms 167ns 7.15ms {"query":"!git ","query_id":19} 20 4.27ms 250ns 4.27ms {"query":"!git c","query_id":20} 21 5.19ms 292ns 5.19ms {"query":"!git co","query_id":21} 22 4.29ms 417ns 4.29ms {"query":"!git com","query_id":22} 23 4.08ms 125ns 4.08ms {"query":"!git comm","query_id":23} 24 4.50ms 167ns 4.50ms {"query":"!git commi","query_id":24} 25 4.35ms 208ns 4.35ms {"query":"!git commit","query_id":25} Summary: 25 calls Wall: avg=3.99ms, min=238.17µs, max=7.15ms, p50=4.29ms, p99=7.15ms Busy: avg=182ns, min=83ns, max=417ns, p50=167ns, p99=417ns ``` **Nucleo matching time (in daemon)** ``` Individual calls for: nucleo_match -------------------------------------------------------------------------------------------------------------- # Wall Busy Idle Fields -------------------------------------------------------------------------------------------------------------- 1 1.73ms 125ns 1.73ms {"query":"^","query_id":1} 2 4.57ms 167ns 4.57ms {"query":"^c","query_id":2} 3 4.37ms 125ns 4.37ms {"query":"^ca","query_id":3} 4 2.51ms 84ns 2.51ms {"query":"^car","query_id":4} 5 4.43ms 125ns 4.43ms {"query":"^carg","query_id":5} 6 3.64ms 125ns 3.64ms {"query":"^cargo","query_id":6} 7 2.37ms 84ns 2.37ms {"query":"^cargo ","query_id":7} 8 4.11ms 125ns 4.11ms {"query":"^cargo b","query_id":8} 9 4.36ms 208ns 4.36ms {"query":"^cargo bu","query_id":9} 10 3.85ms 125ns 3.85ms {"query":"^cargo bui","query_id":10} 11 4.35ms 125ns 4.35ms {"query":"^cargo buil","query_id":11} 12 3.94ms 250ns 3.94ms {"query":"^cargo build","query_id":12} 13 4.59ms 125ns 4.59ms {"query":"^cargo build$","query_id":13} 14 4.18ms 84ns 4.18ms {"query":"^cargo ","query_id":14} 15 220.13µs 125ns 220.00µs {"query":"!","query_id":15} 16 4.43ms 125ns 4.43ms {"query":"!g","query_id":16} 17 3.45ms 125ns 3.45ms {"query":"!gi","query_id":17} 18 4.55ms 125ns 4.55ms {"query":"!git","query_id":18} 19 7.12ms 209ns 7.12ms {"query":"!git ","query_id":19} 20 4.25ms 166ns 4.25ms {"query":"!git c","query_id":20} 21 5.18ms 125ns 5.18ms {"query":"!git co","query_id":21} 22 4.27ms 125ns 4.27ms {"query":"!git com","query_id":22} 23 4.06ms 292ns 4.06ms {"query":"!git comm","query_id":23} 24 4.46ms 166ns 4.46ms {"query":"!git commi","query_id":24} 25 4.31ms 208ns 4.31ms {"query":"!git commit","query_id":25} Summary: 25 calls Wall: avg=3.97ms, min=220.13µs, max=7.12ms, p50=4.27ms, p99=7.12ms Busy: avg=147ns, min=84ns, max=292ns, p50=125ns, p99=292ns ``` --- crates/atuin-daemon/src/daemon.rs | 450 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 450 insertions(+) create mode 100644 crates/atuin-daemon/src/daemon.rs (limited to 'crates/atuin-daemon/src/daemon.rs') diff --git a/crates/atuin-daemon/src/daemon.rs b/crates/atuin-daemon/src/daemon.rs new file mode 100644 index 00000000..ec0b7b68 --- /dev/null +++ b/crates/atuin-daemon/src/daemon.rs @@ -0,0 +1,450 @@ +//! Core daemon infrastructure. +//! +//! This module provides the foundational types for building the atuin daemon: +//! +//! - [`DaemonState`]: Shared state owned by the daemon +//! - [`DaemonHandle`]: A lightweight, cloneable handle for accessing daemon state +//! - [`Component`]: A trait for implementing daemon components +//! - [`Daemon`]: The main daemon orchestrator +//! - [`DaemonBuilder`]: Builder for constructing and configuring the daemon + +use std::sync::Arc; + +use atuin_client::{ + database::Sqlite as HistoryDatabase, encryption, record::sqlite_store::SqliteStore, + settings::Settings, +}; +use eyre::{Context, Result}; +use tokio::sync::{RwLock, broadcast}; + +use crate::events::DaemonEvent; + +// ============================================================================ +// DaemonState +// ============================================================================ + +/// Shared state owned by the daemon. +/// +/// This contains all the resources that components and services need access to. +/// The state is wrapped in an `Arc` and accessed via [`DaemonHandle`]. +pub struct DaemonState { + // Event bus + event_tx: broadcast::Sender, + + // Configuration (mutable - can be reloaded) + settings: RwLock, + + // Encryption key (immutable - derived at startup) + encryption_key: [u8; 32], + + // Database handles + history_db: HistoryDatabase, + store: SqliteStore, +} + +// ============================================================================ +// DaemonHandle +// ============================================================================ + +/// A lightweight handle to the daemon's shared state. +/// +/// This is the primary way for components, gRPC services, and spawned tasks to +/// interact with the daemon. It provides access to: +/// +/// - Event emission and subscription +/// - Configuration (settings, encryption key) +/// - Database handles +/// +/// The handle is cheaply cloneable (wraps an `Arc`) and can be freely passed +/// around to any code that needs daemon access. +/// +/// # Example +/// +/// ```ignore +/// // Emit an event +/// handle.emit(DaemonEvent::HistoryPruned); +/// +/// // Access settings +/// let settings = handle.settings().await; +/// let sync_freq = settings.daemon.sync_frequency; +/// +/// // Access database +/// let history = handle.history_db().load(id).await?; +/// ``` +#[derive(Clone)] +pub struct DaemonHandle { + state: Arc, +} + +impl DaemonHandle { + // ---- Events ---- + + /// Emit an event to the daemon's event bus. + /// + /// This is fire-and-forget - if no receivers are listening (which shouldn't + /// happen in normal operation), the event is dropped silently. + pub fn emit(&self, event: DaemonEvent) { + if let Err(e) = self.state.event_tx.send(event) { + tracing::warn!("failed to emit event (no receivers?): {e}"); + } + } + + /// Subscribe to the event bus. + /// + /// Returns a receiver that will receive all events emitted after this call. + /// Useful for components that need to listen for events outside of the + /// normal `handle_event` callback flow. + pub fn subscribe(&self) -> broadcast::Receiver { + self.state.event_tx.subscribe() + } + + /// Request graceful shutdown of the daemon. + pub fn shutdown(&self) { + self.emit(DaemonEvent::ShutdownRequested); + } + + // ---- Configuration ---- + + /// Get the current settings. + /// + /// This acquires a read lock on the settings. For most use cases, clone + /// the settings if you need to hold onto them. + pub async fn settings(&self) -> tokio::sync::RwLockReadGuard<'_, Settings> { + self.state.settings.read().await + } + + /// Reload settings from disk and emit a SettingsReloaded event. + /// + /// Components listening for `SettingsReloaded` can then re-read settings + /// via `handle.settings()` to pick up the changes. + pub async fn reload_settings(&self) -> Result<()> { + let new_settings = Settings::new()?; + *self.state.settings.write().await = new_settings; + self.emit(DaemonEvent::SettingsReloaded); + tracing::info!("settings reloaded"); + Ok(()) + } + + /// Get the encryption key. + pub fn encryption_key(&self) -> &[u8; 32] { + &self.state.encryption_key + } + + // ---- Database ---- + + /// Get a reference to the history database. + pub fn history_db(&self) -> &HistoryDatabase { + &self.state.history_db + } + + /// Get a reference to the record store. + pub fn store(&self) -> &SqliteStore { + &self.state.store + } +} + +impl std::fmt::Debug for DaemonHandle { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + f.debug_struct("DaemonHandle").finish_non_exhaustive() + } +} + +// ============================================================================ +// Component Trait +// ============================================================================ + +/// A daemon component that handles a specific domain. +/// +/// Components are the building blocks of the daemon. Each component: +/// +/// - Has a unique name for logging and debugging +/// - Can optionally expose gRPC services +/// - Receives a [`DaemonHandle`] on startup for accessing daemon resources +/// - Handles events from the event bus +/// - Performs cleanup on shutdown +/// +/// # Lifecycle +/// +/// 1. **Construction**: Component is created (usually via `new()`) +/// 2. **Start**: `start()` is called with a [`DaemonHandle`] +/// 3. **Running**: `handle_event()` is called for each event on the bus +/// 4. **Shutdown**: `stop()` is called for cleanup +/// +/// # Example +/// +/// ```ignore +/// pub struct MyComponent { +/// handle: Option, +/// } +/// +/// #[async_trait] +/// impl Component for MyComponent { +/// fn name(&self) -> &'static str { "my-component" } +/// +/// async fn start(&mut self, handle: DaemonHandle) -> Result<()> { +/// self.handle = Some(handle); +/// Ok(()) +/// } +/// +/// async fn handle_event(&mut self, event: &DaemonEvent) -> Result<()> { +/// match event { +/// DaemonEvent::SomeEvent => { +/// // Handle the event +/// if let Some(handle) = &self.handle { +/// handle.emit(DaemonEvent::ResponseEvent); +/// } +/// } +/// _ => {} +/// } +/// Ok(()) +/// } +/// +/// async fn stop(&mut self) -> Result<()> { +/// Ok(()) +/// } +/// } +/// ``` +#[tonic::async_trait] +pub trait Component: Send + Sync { + /// Human-readable name for logging and debugging. + fn name(&self) -> &'static str; + + /// Called once at startup. + /// + /// Store the handle if you need to emit events or access daemon resources + /// later. The handle is cheaply cloneable, so feel free to clone it for + /// spawned tasks. + async fn start(&mut self, handle: DaemonHandle) -> Result<()>; + + /// Handle an incoming event. + /// + /// Called for every event on the bus. To emit new events in response, + /// use the handle stored during `start()`. Events emitted here will be + /// processed in subsequent event loop iterations. + async fn handle_event(&mut self, event: &DaemonEvent) -> Result<()>; + + /// Called on graceful shutdown. + /// + /// Use this to clean up resources, abort spawned tasks, etc. + async fn stop(&mut self) -> Result<()>; +} + +// ============================================================================ +// Daemon +// ============================================================================ + +/// The main daemon orchestrator. +/// +/// The daemon manages components, runs the event loop, and coordinates startup +/// and shutdown. It is constructed via [`DaemonBuilder`]. +/// +/// # Event Loop +/// +/// The daemon runs a simple event loop: +/// +/// 1. Wait for an event on the bus +/// 2. Dispatch the event to all components (in registration order) +/// 3. Components may emit new events in response +/// 4. Repeat until `ShutdownRequested` is received +/// +/// Events emitted during handling are queued and processed in subsequent +/// iterations, ensuring the loop eventually drains. +pub struct Daemon { + components: Vec>, + handle: DaemonHandle, +} + +impl Daemon { + /// Create a new daemon builder. + pub fn builder(settings: Settings) -> DaemonBuilder { + DaemonBuilder::new(settings) + } + + /// Get a clone of the daemon handle. + /// + /// The handle can be used to emit events, access settings, etc. + pub fn handle(&self) -> DaemonHandle { + self.handle.clone() + } + + /// Start all components. + /// + /// This must be called before `run_event_loop()`. It initializes all + /// registered components with the daemon handle. + pub async fn start_components(&mut self) -> Result<()> { + for component in &mut self.components { + tracing::info!(component = component.name(), "starting component"); + component + .start(self.handle.clone()) + .await + .with_context(|| format!("failed to start component: {}", component.name()))?; + } + Ok(()) + } + + /// Run the daemon event loop. + /// + /// This processes events until a ShutdownRequested event is received. + /// Components must be started first via `start_components()`. + pub async fn run_event_loop(&mut self) -> Result<()> { + let mut event_rx = self.handle.subscribe(); + loop { + match event_rx.recv().await { + Ok(DaemonEvent::ShutdownRequested) => { + tracing::info!("shutdown requested, stopping daemon"); + break; + } + Ok(event) => { + tracing::debug!(?event, "processing event"); + self.dispatch_event(&event).await; + } + Err(broadcast::error::RecvError::Lagged(n)) => { + tracing::warn!( + skipped = n, + "event receiver lagged, some events were dropped" + ); + } + Err(broadcast::error::RecvError::Closed) => { + tracing::info!("event bus closed, stopping daemon"); + break; + } + } + } + Ok(()) + } + + /// Stop all components. + /// + /// This performs graceful shutdown of all components. + pub async fn stop_components(&mut self) { + for component in &mut self.components { + tracing::info!(component = component.name(), "stopping component"); + if let Err(e) = component.stop().await { + tracing::error!( + component = component.name(), + error = ?e, + "error stopping component" + ); + } + } + tracing::info!("all components stopped"); + } + + /// Run the daemon. + /// + /// This is a convenience method that starts components, runs the event loop, + /// and handles shutdown. It does not return until the daemon is shut down. + pub async fn run(mut self) -> Result<()> { + self.start_components().await?; + self.run_event_loop().await?; + self.stop_components().await; + tracing::info!("daemon stopped"); + Ok(()) + } + + async fn dispatch_event(&mut self, event: &DaemonEvent) { + for component in &mut self.components { + if let Err(e) = component.handle_event(event).await { + tracing::error!( + component = component.name(), + error = ?e, + "error handling event" + ); + } + } + } +} + +// ============================================================================ +// DaemonBuilder +// ============================================================================ + +/// Builder for constructing a [`Daemon`]. +/// +/// # Example +/// +/// ```ignore +/// let daemon = Daemon::builder(settings) +/// .store(store) +/// .history_db(history_db) +/// .component(HistoryComponent::new()) +/// .component(SearchComponent::new()) +/// .component(SyncComponent::new()) +/// .build() +/// .await?; +/// +/// daemon.run().await?; +/// ``` +pub struct DaemonBuilder { + settings: Settings, + store: Option, + history_db: Option, + components: Vec>, +} + +impl DaemonBuilder { + /// Create a new daemon builder with the given settings. + pub fn new(settings: Settings) -> Self { + Self { + settings, + store: None, + history_db: None, + components: Vec::new(), + } + } + + /// Set the record store. + pub fn store(mut self, store: SqliteStore) -> Self { + self.store = Some(store); + self + } + + /// Set the history database. + pub fn history_db(mut self, db: HistoryDatabase) -> Self { + self.history_db = Some(db); + self + } + + /// Register a component. + /// + /// Components are started in registration order and stopped in reverse order. + pub fn component(mut self, component: impl Component + 'static) -> Self { + self.components.push(Box::new(component)); + self + } + + /// Build the daemon. + /// + /// This loads the encryption key and creates the daemon state. + pub async fn build(self) -> Result { + let store = self.store.ok_or_else(|| eyre::eyre!("store is required"))?; + let history_db = self + .history_db + .ok_or_else(|| eyre::eyre!("history_db is required"))?; + + // Load encryption key + let encryption_key: [u8; 32] = encryption::load_key(&self.settings) + .context("could not load encryption key")? + .into(); + + // Create the event bus + let (event_tx, _) = broadcast::channel(64); + + // Create the shared state + let state = Arc::new(DaemonState { + event_tx, + settings: RwLock::new(self.settings), + encryption_key, + history_db, + store, + }); + + // Create the handle (just a reference to the state) + let handle = DaemonHandle { state }; + + Ok(Daemon { + components: self.components, + handle, + }) + } +} -- cgit v1.3.1