| 1 | use serde::{Deserialize, Serialize}; |
| 2 | use serde_json::Value; |
| 3 | use sha2::{Digest, Sha256}; |
| 4 | |
| 5 | use super::RUNTIME_CONTRACT_SCHEMA_VERSION; |
| 6 | |
| 7 | #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)] |
| 8 | #[serde(rename_all = "snake_case")] |
| 9 | pub enum RuntimeEventKind { |
| 10 | UserMessage, |
| 11 | AssistantMessage, |
| 12 | ToolStarted, |
| 13 | ToolCompleted, |
| 14 | ApprovalRequested, |
| 15 | ApprovalResolved, |
| 16 | SteeringQueued, |
| 17 | SteeringDelivered, |
| 18 | ResourcesLoaded, |
| 19 | Condensation, |
| 20 | Work, |
| 21 | Child, |
| 22 | Usage, |
| 23 | Retry, |
| 24 | Termination, |
| 25 | } |
| 26 | |
| 27 | #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)] |
| 28 | pub struct RuntimeEventEnvelope { |
| 29 | pub schema_version: u32, |
| 30 | pub sequence: u64, |
| 31 | pub event_id: String, |
| 32 | pub kind: RuntimeEventKind, |
| 33 | #[serde(default, skip_serializing_if = "Option::is_none")] |
| 34 | pub parent_event_id: Option<String>, |
| 35 | #[serde(default, skip_serializing_if = "Option::is_none")] |
| 36 | pub causal_event_id: Option<String>, |
| 37 | pub recorded_at_ms: u64, |
| 38 | pub payload: Value, |
| 39 | pub checksum: String, |
| 40 | } |
| 41 | |
| 42 | impl RuntimeEventEnvelope { |
| 43 | #[must_use] |
| 44 | pub fn new( |
| 45 | sequence: u64, |
| 46 | event_id: impl Into<String>, |
| 47 | kind: RuntimeEventKind, |
| 48 | recorded_at_ms: u64, |
| 49 | payload: Value, |
| 50 | ) -> Self { |
| 51 | let mut event = Self { |
| 52 | schema_version: RUNTIME_CONTRACT_SCHEMA_VERSION, |
| 53 | sequence, |
| 54 | event_id: event_id.into(), |
| 55 | kind, |
| 56 | parent_event_id: None, |
| 57 | causal_event_id: None, |
| 58 | recorded_at_ms, |
| 59 | payload, |
| 60 | checksum: String::new(), |
| 61 | }; |
| 62 | event.checksum = event.expected_checksum(); |
| 63 | event |
| 64 | } |
| 65 | |
| 66 | #[must_use] |
| 67 | pub fn expected_checksum(&self) -> String { |
| 68 | let canonical = serde_json::json!({ |
| 69 | "schema_version": self.schema_version, |
| 70 | "sequence": self.sequence, |
| 71 | "event_id": self.event_id, |
| 72 | "kind": self.kind, |
| 73 | "parent_event_id": self.parent_event_id, |
| 74 | "causal_event_id": self.causal_event_id, |
| 75 | "recorded_at_ms": self.recorded_at_ms, |
| 76 | "payload": self.payload, |
| 77 | }); |
| 78 | let bytes = serde_json::to_vec(&canonical).expect("runtime event JSON is serializable"); |
| 79 | let digest = Sha256::digest(bytes); |
| 80 | digest.iter().map(|byte| format!("{byte:02x}")).collect() |
| 81 | } |
| 82 | |
| 83 | pub fn validate(&self) -> Result<(), String> { |
| 84 | if self.schema_version != RUNTIME_CONTRACT_SCHEMA_VERSION { |
| 85 | return Err(format!( |
| 86 | "unsupported runtime event schema {}", |
| 87 | self.schema_version |
| 88 | )); |
| 89 | } |
| 90 | if self.event_id.trim().is_empty() { |
| 91 | return Err("runtime event ID cannot be empty".to_string()); |
| 92 | } |
| 93 | let expected = self.expected_checksum(); |
| 94 | if self.checksum != expected { |
| 95 | return Err(format!("runtime event {} checksum mismatch", self.event_id)); |
| 96 | } |
| 97 | Ok(()) |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | #[derive(Debug, Default, Clone)] |
| 102 | pub struct AppendOnlyRuntimeLedger { |
| 103 | events: Vec<RuntimeEventEnvelope>, |
| 104 | } |
| 105 | |
| 106 | impl AppendOnlyRuntimeLedger { |
| 107 | pub fn append(&mut self, event: RuntimeEventEnvelope) -> Result<(), String> { |
| 108 | event.validate()?; |
| 109 | let expected_sequence = self.events.last().map_or(0, |last| last.sequence + 1); |
| 110 | if event.sequence != expected_sequence { |
| 111 | return Err(format!( |
| 112 | "runtime event sequence {} does not follow {}", |
| 113 | event.sequence, expected_sequence |
| 114 | )); |
| 115 | } |
| 116 | if self |
| 117 | .events |
| 118 | .iter() |
| 119 | .any(|item| item.event_id == event.event_id) |
| 120 | { |
| 121 | return Err(format!("duplicate runtime event ID `{}`", event.event_id)); |
| 122 | } |
| 123 | self.events.push(event); |
| 124 | Ok(()) |
| 125 | } |
| 126 | |
| 127 | #[must_use] |
| 128 | pub fn events(&self) -> &[RuntimeEventEnvelope] { |
| 129 | &self.events |
| 130 | } |
| 131 | |
| 132 | #[must_use] |
| 133 | pub fn range(&self, start: u64, end_inclusive: u64) -> Vec<&RuntimeEventEnvelope> { |
| 134 | self.events |
| 135 | .iter() |
| 136 | .filter(|event| (start..=end_inclusive).contains(&event.sequence)) |
| 137 | .collect() |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | #[cfg(test)] |
| 142 | mod tests { |
| 143 | use super::*; |
| 144 | |
| 145 | #[test] |
| 146 | fn ledger_rejects_corruption_and_sequence_gaps() { |
| 147 | let mut ledger = AppendOnlyRuntimeLedger::default(); |
| 148 | ledger |
| 149 | .append(RuntimeEventEnvelope::new( |
| 150 | 0, |
| 151 | "event-0", |
| 152 | RuntimeEventKind::UserMessage, |
| 153 | 1, |
| 154 | serde_json::json!({"text": "hello"}), |
| 155 | )) |
| 156 | .unwrap(); |
| 157 | |
| 158 | let gap = RuntimeEventEnvelope::new( |
| 159 | 2, |
| 160 | "event-2", |
| 161 | RuntimeEventKind::Termination, |
| 162 | 2, |
| 163 | serde_json::json!({}), |
| 164 | ); |
| 165 | assert!(ledger.append(gap).unwrap_err().contains("does not follow")); |
| 166 | |
| 167 | let mut corrupt = RuntimeEventEnvelope::new( |
| 168 | 1, |
| 169 | "event-1", |
| 170 | RuntimeEventKind::ToolCompleted, |
| 171 | 2, |
| 172 | serde_json::json!({"ok": true}), |
| 173 | ); |
| 174 | corrupt.payload = serde_json::json!({"ok": false}); |
| 175 | assert!( |
| 176 | corrupt |
| 177 | .validate() |
| 178 | .unwrap_err() |
| 179 | .contains("checksum mismatch") |
| 180 | ); |
| 181 | } |
| 182 | |
| 183 | #[test] |
| 184 | fn derived_range_does_not_remove_original_events() { |
| 185 | let mut ledger = AppendOnlyRuntimeLedger::default(); |
| 186 | for sequence in 0..3 { |
| 187 | ledger |
| 188 | .append(RuntimeEventEnvelope::new( |
| 189 | sequence, |
| 190 | format!("event-{sequence}"), |
| 191 | RuntimeEventKind::AssistantMessage, |
| 192 | sequence, |
| 193 | serde_json::json!({"sequence": sequence}), |
| 194 | )) |
| 195 | .unwrap(); |
| 196 | } |
| 197 | assert_eq!(ledger.range(1, 2).len(), 2); |
| 198 | assert_eq!(ledger.events().len(), 3); |
| 199 | } |
| 200 | } |
| 201 |