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⎇ d6b8f18b43c9bd9bf7268e48b61392a2d62bb229 crates/ente-brain/src/engine.rs Rust · 399 líneas · 15.2 KB Historia Quién tocó qué crudo

Pausa: 11 crates del fractal Ente #0 con cerebro completo d6b8f18b4 · Sergio ·

1//! Motor de inferencia. HashMap<EventKindDiscriminant, Vec<Arc<Rule>>> para
2//! lookup O(1) por tipo de evento, luego filter lineal por scope + filtros
3//! del payload (BusInvokeOf, Custom).
4//!
5//! Inmutabilidad fractal: `Arc<Rule>` es el unit de compartición. Clonar una
6//! regla del motor para entregarla al dispatcher es un refcount bump, no copia.
7
8use crate::observer::TimedEvent;
9use crate::rules::{EventKind, EventPattern, Rule, Scope};
10use ente_card::Capability;
11use std::collections::HashMap;
12use std::sync::Arc;
13use std::time::Duration;
14use ulid::Ulid;
15
16/// Discriminante barato de `EventKind` para indexar el HashMap. Sin payload —
17/// el match de payload se hace en una segunda pasada lineal en O(k) donde k
18/// es el número de reglas para ese tag.
19#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
20pub enum EventKindDiscriminant {
21    EnteSpawned,
22    EnteDied,
23    BusAnnounce,
24    BusInvoke,
25    BusInvokeOf,
26    DeviceAdded,
27    DeviceRemoved,
28    Custom,
29}
30
31impl From<&EventKind> for EventKindDiscriminant {
32    fn from(k: &EventKind) -> Self {
33        match k {
34            EventKind::EnteSpawned => Self::EnteSpawned,
35            EventKind::EnteDied => Self::EnteDied,
36            EventKind::BusAnnounce => Self::BusAnnounce,
37            EventKind::BusInvoke => Self::BusInvoke,
38            EventKind::BusInvokeOf(_) => Self::BusInvokeOf,
39            EventKind::DeviceAdded => Self::DeviceAdded,
40            EventKind::DeviceRemoved => Self::DeviceRemoved,
41            EventKind::Custom(_) => Self::Custom,
42        }
43    }
44}
45
46/// Snapshot del Ente que disparó el evento. Necesario para evaluar `Scope`.
47#[derive(Debug, Clone, Default)]
48pub struct SubjectInfo {
49    pub id: Option<Ulid>,
50    pub label: Option<String>,
51    pub capabilities: Vec<Capability>,
52}
53
54pub struct RuleEngine {
55    rules: Vec<Arc<Rule>>,
56    /// Reglas atómicas (Single, Sequence) indexadas por discriminante del
57    /// kind que las dispara. Lookup O(1).
58    by_kind: HashMap<EventKindDiscriminant, Vec<Arc<Rule>>>,
59    /// Reglas compuestas (Either, All): se evalúan contra cada evento.
60    /// Para fractales con N pequeño no afecta perf; con N grande, optimizar
61    /// emitiendo a múltiples buckets en insert (fan-out).
62    compound: Vec<Arc<Rule>>,
63}
64
65impl Default for RuleEngine {
66    fn default() -> Self { Self::empty() }
67}
68
69impl RuleEngine {
70    pub fn empty() -> Self {
71        Self { rules: Vec::new(), by_kind: HashMap::new(), compound: Vec::new() }
72    }
73
74    /// Carga reglas desde JSON (lista de Rule). Usado tras validación KCL.
75    pub fn load_json(json: &str) -> anyhow::Result<Self> {
76        let rules: Vec<Rule> = serde_json::from_str(json)?;
77        let mut engine = Self::empty();
78        for r in rules {
79            r.validate().map_err(|e| anyhow::anyhow!("regla inválida: {e}"))?;
80            engine.insert(r);
81        }
82        Ok(engine)
83    }
84
85    pub fn insert(&mut self, rule: Rule) {
86        let arc = Arc::new(rule);
87        // Atómicas → bucket por discriminante. Compuestas → bucket fallback.
88        if let Some(trigger) = arc.when.trigger_kind() {
89            let disc = EventKindDiscriminant::from(trigger);
90            self.by_kind.entry(disc).or_default().push(arc.clone());
91        } else {
92            self.compound.push(arc.clone());
93        }
94        self.rules.push(arc);
95    }
96
97    pub fn remove(&mut self, id: Ulid) -> bool {
98        let before = self.rules.len();
99        self.rules.retain(|r| r.id != id);
100        for v in self.by_kind.values_mut() {
101            v.retain(|r| r.id != id);
102        }
103        self.compound.retain(|r| r.id != id);
104        before != self.rules.len()
105    }
106
107    pub fn rules(&self) -> impl Iterator<Item = &Arc<Rule>> { self.rules.iter() }
108
109    pub fn len(&self) -> usize { self.rules.len() }
110    pub fn is_empty(&self) -> bool { self.rules.is_empty() }
111
112    /// Despacho determinista. Devuelve reglas que matchean, ordenadas por
113    /// prioridad descendente. Cada Arc<Rule> se clona (refcount) — sin copiar
114    /// los datos.
115    ///
116    /// `history` es el slice de eventos recientes (en orden cronológico,
117    /// más reciente al final) usado para evaluar Sequence patterns.
118    /// Para reglas Single, history se ignora.
119    ///
120    /// Si el evento es `BusInvokeOf(_)`, también consultamos el bucket
121    /// `BusInvoke` (regla genérica que ignora la cap).
122    pub fn dispatch(
123        &self,
124        event: &EventKind,
125        subject: &SubjectInfo,
126        history: &[TimedEvent],
127    ) -> Vec<Arc<Rule>> {
128        let primary = EventKindDiscriminant::from(event);
129        let mut buckets: Vec<&Vec<Arc<Rule>>> = Vec::with_capacity(2);
130        if let Some(v) = self.by_kind.get(&primary) {
131            buckets.push(v);
132        }
133        if matches!(event, EventKind::BusInvokeOf(_)) {
134            if let Some(v) = self.by_kind.get(&EventKindDiscriminant::BusInvoke) {
135                buckets.push(v);
136            }
137        }
138        let mut hits: Vec<Arc<Rule>> = buckets.into_iter()
139            .flat_map(|v| v.iter())
140            .filter(|r| matches_pattern(&r.when, event, history))
141            .filter(|r| matches_scope(&r.scope, subject))
142            .cloned()
143            .collect();
144        // Fallback: reglas compuestas (Either/All) se evalúan siempre.
145        for r in &self.compound {
146            if matches_pattern(&r.when, event, history) && matches_scope(&r.scope, subject) {
147                hits.push(r.clone());
148            }
149        }
150        hits.sort_by(|a, b| b.priority.cmp(&a.priority));
151        hits
152    }
153}
154
155/// Match recursivo del pattern. Atomic patterns evalúan contra el evento
156/// actual + history. Compuestos (Either/All) recursan sobre sus children.
157fn matches_pattern(pattern: &EventPattern, event: &EventKind, history: &[TimedEvent]) -> bool {
158    match pattern {
159        EventPattern::Single { kind } => matches_event_payload(kind, event),
160        EventPattern::Sequence { kinds, within_ms } => {
161            if kinds.is_empty() { return false; }
162            let last_kind = kinds.last().unwrap();
163            if !matches_event_payload(last_kind, event) { return false; }
164            if history.len() < kinds.len() { return false; }
165            let tail = &history[history.len() - kinds.len()..];
166            for (t, k) in tail.iter().zip(kinds) {
167                if !matches_event_payload(k, &t.kind) { return false; }
168            }
169            if *within_ms > 0 {
170                let span = tail.last().unwrap().at.duration_since(tail.first().unwrap().at);
171                if span > Duration::from_millis(*within_ms) { return false; }
172            }
173            true
174        }
175        EventPattern::Either { patterns } => {
176            patterns.iter().any(|p| matches_pattern(p, event, history))
177        }
178        EventPattern::All { patterns } => {
179            patterns.iter().all(|p| matches_pattern(p, event, history))
180        }
181    }
182}
183
184fn matches_event_payload(rule_kind: &EventKind, evt: &EventKind) -> bool {
185    use EventKind::*;
186    match (rule_kind, evt) {
187        (EnteSpawned, EnteSpawned) => true,
188        (EnteDied, EnteDied) => true,
189        (BusAnnounce, BusAnnounce) => true,
190        (BusInvoke, BusInvoke) | (BusInvoke, BusInvokeOf(_)) => true,
191        (BusInvokeOf(want), BusInvokeOf(got)) => want == got,
192        (DeviceAdded, DeviceAdded) => true,
193        (DeviceRemoved, DeviceRemoved) => true,
194        (Custom(want), Custom(got)) => want == got,
195        _ => false,
196    }
197}
198
199fn matches_scope(scope: &Scope, subj: &SubjectInfo) -> bool {
200    if scope.is_wildcard() { return true; }
201    if let Some(id) = scope.subject_id {
202        if subj.id != Some(id) { return false; }
203    }
204    if let Some(lbl) = &scope.subject_label {
205        if subj.label.as_ref() != Some(lbl) { return false; }
206    }
207    if let Some(cap) = &scope.subject_has_cap {
208        if !subj.capabilities.contains(cap) { return false; }
209    }
210    true
211}
212
213#[cfg(test)]
214mod tests {
215    use super::*;
216    use crate::rules::{Action, EventPattern, LogLevel};
217    use std::time::{Duration, Instant};
218
219    fn rule_single(id_str: &str, kind: EventKind, prio: u8) -> Rule {
220        Rule {
221            id: id_str.parse().unwrap(),
222            priority: prio,
223            when: EventPattern::Single { kind },
224            then: vec![Action::Log {
225                level: LogLevel::Info,
226                message: id_str.into(),
227            }],
228            scope: Scope::default(),
229        }
230    }
231
232    fn empty_history() -> Vec<TimedEvent> { Vec::new() }
233
234    #[test]
235    fn dispatch_picks_only_matching_kind() {
236        let mut e = RuleEngine::empty();
237        e.insert(rule_single("01KQQ100000000000000000001", EventKind::EnteSpawned, 5));
238        e.insert(rule_single("01KQQ100000000000000000002", EventKind::EnteDied, 5));
239        let hits = e.dispatch(&EventKind::EnteSpawned, &SubjectInfo::default(), &empty_history());
240        assert_eq!(hits.len(), 1);
241    }
242
243    #[test]
244    fn priority_orders_descending() {
245        let mut e = RuleEngine::empty();
246        e.insert(rule_single("01KQQ100000000000000000003", EventKind::EnteSpawned, 1));
247        e.insert(rule_single("01KQQ100000000000000000004", EventKind::EnteSpawned, 9));
248        let hits = e.dispatch(&EventKind::EnteSpawned, &SubjectInfo::default(), &empty_history());
249        assert_eq!(hits[0].priority, 9);
250        assert_eq!(hits[1].priority, 1);
251    }
252
253    #[test]
254    fn scope_filters_by_label() {
255        let mut e = RuleEngine::empty();
256        let mut r = rule_single("01KQQ100000000000000000005", EventKind::EnteSpawned, 5);
257        r.scope = Scope { subject_label: Some("foo".into()), ..Default::default() };
258        e.insert(r);
259        let foo = SubjectInfo { label: Some("foo".into()), ..Default::default() };
260        let bar = SubjectInfo { label: Some("bar".into()), ..Default::default() };
261        assert_eq!(e.dispatch(&EventKind::EnteSpawned, &foo, &empty_history()).len(), 1);
262        assert_eq!(e.dispatch(&EventKind::EnteSpawned, &bar, &empty_history()).len(), 0);
263    }
264
265    #[test]
266    fn bus_invoke_generic_matches_specific() {
267        let mut e = RuleEngine::empty();
268        e.insert(rule_single("01KQQ100000000000000000006", EventKind::BusInvoke, 5));
269        let hits = e.dispatch(
270            &EventKind::BusInvokeOf(Capability::LegacyLogind),
271            &SubjectInfo::default(),
272            &empty_history(),
273        );
274        assert_eq!(hits.len(), 1);
275    }
276
277    #[test]
278    fn sequence_pattern_matches_with_history() {
279        let mut e = RuleEngine::empty();
280        let r = Rule {
281            id: "01KQQ100000000000000000007".parse().unwrap(),
282            priority: 5,
283            when: EventPattern::Sequence {
284                kinds: vec![EventKind::EnteSpawned, EventKind::BusAnnounce],
285                within_ms: 1000,
286            },
287            then: vec![Action::Log { level: LogLevel::Info, message: "seq".into() }],
288            scope: Scope::default(),
289        };
290        e.insert(r);
291
292        let now = Instant::now();
293        let history = vec![
294            TimedEvent { kind: EventKind::EnteSpawned, at: now },
295            TimedEvent { kind: EventKind::BusAnnounce, at: now + Duration::from_millis(50) },
296        ];
297        let hits = e.dispatch(&EventKind::BusAnnounce, &SubjectInfo::default(), &history);
298        assert_eq!(hits.len(), 1, "esperaba match secuencia, got {}", hits.len());
299    }
300
301    #[test]
302    fn sequence_rejects_outside_time_window() {
303        let mut e = RuleEngine::empty();
304        let r = Rule {
305            id: "01KQQ100000000000000000008".parse().unwrap(),
306            priority: 5,
307            when: EventPattern::Sequence {
308                kinds: vec![EventKind::EnteSpawned, EventKind::BusAnnounce],
309                within_ms: 100,
310            },
311            then: vec![Action::Log { level: LogLevel::Info, message: "seq".into() }],
312            scope: Scope::default(),
313        };
314        e.insert(r);
315        let now = Instant::now();
316        let history = vec![
317            TimedEvent { kind: EventKind::EnteSpawned, at: now },
318            TimedEvent { kind: EventKind::BusAnnounce, at: now + Duration::from_millis(500) },
319        ];
320        let hits = e.dispatch(&EventKind::BusAnnounce, &SubjectInfo::default(), &history);
321        assert!(hits.is_empty(), "no debería matchear fuera de la ventana");
322    }
323
324    #[test]
325    fn either_matches_any_branch() {
326        let mut e = RuleEngine::empty();
327        let r = Rule {
328            id: "01KQQ100000000000000000010".parse().unwrap(),
329            priority: 5,
330            when: EventPattern::Either { patterns: vec![
331                EventPattern::Single { kind: EventKind::EnteSpawned },
332                EventPattern::Single { kind: EventKind::EnteDied },
333            ]},
334            then: vec![Action::Log { level: LogLevel::Info, message: "either".into() }],
335            scope: Scope::default(),
336        };
337        e.insert(r);
338        assert_eq!(e.dispatch(&EventKind::EnteSpawned, &SubjectInfo::default(), &[]).len(), 1);
339        assert_eq!(e.dispatch(&EventKind::EnteDied, &SubjectInfo::default(), &[]).len(), 1);
340        assert_eq!(e.dispatch(&EventKind::BusAnnounce, &SubjectInfo::default(), &[]).len(), 0);
341    }
342
343    #[test]
344    fn all_requires_every_branch() {
345        let mut e = RuleEngine::empty();
346        // All: matchear sólo si el evento actual es BusAnnounce Y la
347        // secuencia EnteSpawned→BusAnnounce ocurrió en history.
348        let r = Rule {
349            id: "01KQQ100000000000000000011".parse().unwrap(),
350            priority: 5,
351            when: EventPattern::All { patterns: vec![
352                EventPattern::Single { kind: EventKind::BusAnnounce },
353                EventPattern::Sequence {
354                    kinds: vec![EventKind::EnteSpawned, EventKind::BusAnnounce],
355                    within_ms: 0,
356                },
357            ]},
358            then: vec![Action::Log { level: LogLevel::Info, message: "all".into() }],
359            scope: Scope::default(),
360        };
361        e.insert(r);
362
363        let now = Instant::now();
364        let history = vec![
365            TimedEvent { kind: EventKind::EnteSpawned, at: now },
366            TimedEvent { kind: EventKind::BusAnnounce, at: now + Duration::from_millis(10) },
367        ];
368        // Single y Sequence ambos matchean → All matches.
369        assert_eq!(e.dispatch(&EventKind::BusAnnounce, &SubjectInfo::default(), &history).len(), 1);
370        // Sólo Single matchea (history vacío) → All no matches.
371        assert!(e.dispatch(&EventKind::BusAnnounce, &SubjectInfo::default(), &[]).is_empty());
372    }
373
374    #[test]
375    fn sequence_requires_correct_order() {
376        let mut e = RuleEngine::empty();
377        let r = Rule {
378            id: "01KQQ100000000000000000009".parse().unwrap(),
379            priority: 5,
380            when: EventPattern::Sequence {
381                kinds: vec![EventKind::EnteSpawned, EventKind::BusAnnounce],
382                within_ms: 0,
383            },
384            then: vec![Action::Log { level: LogLevel::Info, message: "seq".into() }],
385            scope: Scope::default(),
386        };
387        e.insert(r);
388        let now = Instant::now();
389        // Orden invertido en el history.
390        let history = vec![
391            TimedEvent { kind: EventKind::BusAnnounce, at: now },
392            TimedEvent { kind: EventKind::EnteSpawned, at: now + Duration::from_millis(10) },
393        ];
394        // El evento actual es EnteSpawned, pero el último de la secuencia
395        // requerida es BusAnnounce — no debería matchear.
396        let hits = e.dispatch(&EventKind::EnteSpawned, &SubjectInfo::default(), &history);
397        assert!(hits.is_empty());
398    }
399}