lash_core/
session.rs

1use std::sync::{Arc, OnceLock};
2
3use tokio::sync::mpsc::UnboundedSender;
4
5use crate::PluginMessage;
6use crate::tool_dispatch::ToolDispatchContext;
7use crate::{
8    PromptContribution, RuntimeServices, SandboxMessage, SessionStreamEvent, ToolProvider,
9};
10
11mod execution_context;
12pub(crate) mod process_handles;
13mod tool_execution;
14
15pub use execution_context::RuntimeExecutionContext;
16pub(crate) use execution_context::RuntimeExecutionTracing;
17pub use tool_execution::{ToolInvocation, ToolInvocationReply};
18
19#[derive(Clone, Debug, PartialEq, Eq)]
20struct ToolCatalogCacheKey {
21    include_base_tools: bool,
22    context_overlay_revision: u64,
23    tool_generation: u64,
24    plugin_revision: u64,
25}
26
27#[derive(Debug, Default)]
28struct ToolCatalogDerived {
29    catalog: OnceLock<Arc<Vec<serde_json::Value>>>,
30}
31
32struct ToolCatalogArtifact {
33    tool_catalog: Arc<crate::ToolCatalog>,
34    preamble: Arc<crate::TurnDriverPreamble>,
35    derived: ToolCatalogDerived,
36}
37
38#[derive(Clone)]
39pub(crate) struct ToolCatalogHandle(Arc<ToolCatalogArtifact>);
40
41impl ToolCatalogHandle {
42    fn tool_catalog(&self) -> Arc<crate::ToolCatalog> {
43        Arc::clone(&self.0.tool_catalog)
44    }
45
46    fn preamble(&self) -> Arc<crate::TurnDriverPreamble> {
47        Arc::clone(&self.0.preamble)
48    }
49
50    fn catalog(&self) -> Arc<Vec<serde_json::Value>> {
51        Arc::clone(self.0.derived.catalog.get_or_init(|| {
52            Arc::new(crate::tool_registry::project_tool_catalog(
53                self.0.tool_catalog.tools.iter().cloned(),
54            ))
55        }))
56    }
57}
58
59#[derive(Clone, Debug)]
60pub struct InjectedTurnInput {
61    pub id: Option<String>,
62    pub message: PluginMessage,
63}
64
65#[derive(Debug, thiserror::Error)]
66pub enum SessionError {
67    #[error("I/O error: {0}")]
68    Io(#[from] std::io::Error),
69    #[error("JSON error: {0}")]
70    Json(#[from] serde_json::Error),
71    #[error("code execution is not available in this session")]
72    CodeExecutionUnavailable,
73    #[error("code execution runtime exited unexpectedly")]
74    CodeExecutionRuntimeStopped,
75    #[error(
76        "provider mismatch for session `{session_id}`: persisted provider `{expected}` does not match live provider `{actual}`"
77    )]
78    ProviderMismatch {
79        expected: String,
80        actual: String,
81        session_id: String,
82    },
83    #[error("provider is not configured for session `{session_id}`")]
84    ProviderUnconfigured { session_id: String },
85    #[error("provider `{provider_id}` is not registered for session `{session_id}`")]
86    ProviderUnavailable {
87        provider_id: String,
88        session_id: String,
89    },
90    #[error("protocol error: {0}")]
91    Protocol(String),
92}
93
94#[derive(Clone, Debug)]
95pub struct ExecRequest {
96    pub language: String,
97    pub code: String,
98    pub accept_finish: bool,
99}
100
101pub struct Session {
102    session_id: String,
103    services: RuntimeServices,
104    include_base_tools: bool,
105    context_overlay_revision: u64,
106    context_tools: Vec<Arc<dyn ToolProvider>>,
107    tool_registry: Arc<crate::ToolRegistry>,
108    context_prompt_contributions: Vec<PromptContribution>,
109    message_tx: Option<UnboundedSender<SandboxMessage>>,
110    tool_catalog_cache: std::sync::Mutex<Vec<(ToolCatalogCacheKey, ToolCatalogHandle)>>,
111    /// Memoizes the rendered system prompt across turns. Most consecutive
112    /// turns reuse the same template + context overlay, so the cache hits
113    /// and we skip the section/Vec-join work in
114    /// `lash_sansio::PromptTemplate::render`.
115    prompt_cache: Arc<lash_sansio::PromptCache>,
116}
117
118impl Session {
119    pub async fn new(services: RuntimeServices, session_id: &str) -> Result<Self, SessionError> {
120        let tool_registry = services.plugins.tool_registry();
121        let mut session = Self {
122            session_id: session_id.to_string(),
123            services,
124            include_base_tools: true,
125            context_overlay_revision: 0,
126            context_tools: Vec::new(),
127            tool_registry,
128            context_prompt_contributions: Vec::new(),
129            message_tx: None,
130            tool_catalog_cache: std::sync::Mutex::new(Vec::new()),
131            prompt_cache: Arc::new(lash_sansio::PromptCache::new()),
132        };
133
134        let protocol_session = Arc::clone(session.plugins().protocol_session());
135        protocol_session
136            .initialize_session(crate::plugin::ProtocolSessionContext::new(
137                &mut session,
138                session_id,
139            ))
140            .await?;
141
142        Ok(session)
143    }
144
145    pub fn session_id(&self) -> &str {
146        &self.session_id
147    }
148
149    pub(crate) fn protocol_extra_prompt_contributions(&self) -> Vec<PromptContribution> {
150        // Protocol-specific prompt contributions are owned by the protocol
151        // plugins via their
152        // `reg.prompt().contribute(...)` hooks. Nothing to add here.
153        Vec::new()
154    }
155
156    pub fn tools(&self) -> Arc<dyn ToolProvider> {
157        Arc::clone(&self.tool_registry) as Arc<dyn ToolProvider>
158    }
159
160    pub fn plugins(&self) -> &Arc<crate::PluginSession> {
161        &self.services.plugins
162    }
163
164    pub fn set_context_overlay(
165        &mut self,
166        tool_providers: Vec<Arc<dyn ToolProvider>>,
167        prompt_contributions: Vec<PromptContribution>,
168        include_base_tools: bool,
169    ) -> Result<(), crate::PluginError> {
170        let tool_providers_unchanged = self.context_tools.len() == tool_providers.len()
171            && self
172                .context_tools
173                .iter()
174                .zip(&tool_providers)
175                .all(|(current, next)| Arc::ptr_eq(current, next));
176        let overlay_unchanged = self.include_base_tools == include_base_tools
177            && self.context_prompt_contributions == prompt_contributions
178            && tool_providers_unchanged;
179        let registry = self
180            .services
181            .plugins
182            .tool_registry()
183            .compose_session_catalog(include_base_tools, tool_providers.clone())
184            .map(Arc::new)
185            .map_err(|err| {
186                crate::PluginError::Session(format!("failed to build session tool registry: {err}"))
187            })?;
188        self.include_base_tools = include_base_tools;
189        if !overlay_unchanged {
190            self.context_overlay_revision = self.context_overlay_revision.wrapping_add(1);
191        }
192        self.context_tools = tool_providers;
193        self.tool_registry = registry;
194        self.context_prompt_contributions = prompt_contributions;
195        self.tool_catalog_cache
196            .lock()
197            .expect("tool catalog cache lock")
198            .clear();
199        Ok(())
200    }
201
202    pub fn prompt_cache(&self) -> Arc<lash_sansio::PromptCache> {
203        Arc::clone(&self.prompt_cache)
204    }
205
206    pub fn context_prompt_contributions(&self) -> &[PromptContribution] {
207        &self.context_prompt_contributions
208    }
209
210    pub fn history_store(&self) -> Option<Arc<dyn crate::store::RuntimePersistence>> {
211        self.services.store.clone()
212    }
213
214    fn tool_catalog_cache_key(&self) -> ToolCatalogCacheKey {
215        ToolCatalogCacheKey {
216            include_base_tools: self.include_base_tools,
217            context_overlay_revision: self.context_overlay_revision,
218            tool_generation: self.tool_registry.generation(),
219            plugin_revision: self.plugins().snapshot_revision_fingerprint(),
220        }
221    }
222
223    fn build_tool_catalog_entry(
224        &self,
225        session_id: &str,
226    ) -> Result<ToolCatalogHandle, crate::PluginError> {
227        let provider = self.tools();
228        let tools = provider.tool_manifests();
229        let contract_provider = Arc::clone(&provider);
230        let resolve_contract: lash_sansio::ToolContractResolver =
231            Arc::new(move |name: &str| contract_provider.resolve_contract(name));
232        let tool_catalog = Arc::new(self.plugins().resolve_tool_catalog(
233            crate::plugin::ToolCatalogContext {
234                session_id: session_id.to_string(),
235                tools,
236                resolve_contract: Some(Arc::clone(&resolve_contract)),
237                tool_access: self.plugins().tool_access().clone(),
238                subagent: self.plugins().subagent_context().cloned(),
239                extensions: self.plugins().extensions().clone(),
240            },
241        )?);
242        let input = crate::ProtocolBuildInput {
243            tool_catalog: Arc::clone(&tool_catalog),
244            plugin_extensions: self.plugins().extensions().clone(),
245            trigger_events: self.plugins().triggers().clone(),
246            extra_prompt_contributions: self.protocol_extra_prompt_contributions(),
247        };
248        let driver = self.plugins().protocol_driver();
249        let preamble = driver.build_preamble(input);
250        Ok(ToolCatalogHandle(Arc::new(ToolCatalogArtifact {
251            tool_catalog,
252            preamble: Arc::new(preamble),
253            derived: ToolCatalogDerived::default(),
254        })))
255    }
256
257    fn tool_catalog_cache_entry(
258        &self,
259        session_id: &str,
260    ) -> Result<ToolCatalogHandle, crate::PluginError> {
261        let key = self.tool_catalog_cache_key();
262        let mut cache = self
263            .tool_catalog_cache
264            .lock()
265            .expect("tool catalog cache lock");
266        if let Some((_, entry)) = cache.iter().find(|(entry_key, _)| *entry_key == key) {
267            return Ok(entry.clone());
268        }
269        let entry = self.build_tool_catalog_entry(session_id)?;
270        cache.push((key, entry.clone()));
271        Ok(entry)
272    }
273
274    pub fn resolved_tool_catalog(
275        &self,
276        session_id: &str,
277    ) -> Result<Arc<crate::ToolCatalog>, crate::PluginError> {
278        Ok(self.tool_catalog_cache_entry(session_id)?.tool_catalog())
279    }
280
281    pub(crate) fn turn_driver_preamble(
282        &self,
283        session_id: &str,
284    ) -> Result<Arc<crate::TurnDriverPreamble>, crate::PluginError> {
285        Ok(self.tool_catalog_cache_entry(session_id)?.preamble())
286    }
287
288    pub(crate) fn shared_tool_catalog(
289        &self,
290        session_id: &str,
291    ) -> Result<Arc<Vec<serde_json::Value>>, crate::PluginError> {
292        Ok(self.tool_catalog_cache_entry(session_id)?.catalog())
293    }
294
295    pub fn tool_catalog(
296        &self,
297        session_id: &str,
298    ) -> Result<Vec<serde_json::Value>, crate::PluginError> {
299        Ok(self.shared_tool_catalog(session_id)?.as_ref().clone())
300    }
301
302    #[allow(
303        clippy::too_many_arguments,
304        reason = "code execution bridge carries explicit per-turn runtime dependencies"
305    )]
306    pub(crate) fn code_execution_context<'run>(
307        &self,
308        session_id: &str,
309        agent_frame_id: &str,
310        sessions: Arc<dyn crate::plugin::SessionStateService>,
311        session_lifecycle: Arc<dyn crate::plugin::SessionLifecycleService>,
312        session_graph: Arc<dyn crate::plugin::SessionGraphService>,
313        processes: Arc<dyn crate::ProcessService>,
314        process_cancel_ability: Arc<dyn crate::ProcessCancelAbility>,
315        effect_controller: crate::runtime::RuntimeEffectControllerHandle<'run>,
316        direct_completions: crate::DirectCompletionClient<'run>,
317        trigger_router: Option<crate::TriggerRouter>,
318        event_tx: tokio::sync::mpsc::Sender<SessionStreamEvent>,
319        chronological_projection: Arc<crate::ChronologicalProjection>,
320        protocol_extension: Option<crate::ProtocolTurnExtensionHandle>,
321        turn_context: crate::TurnContext,
322        execution_env_spec: crate::ProcessExecutionEnvSpec,
323        checkpoint_messages: crate::tool_dispatch::CheckpointMessageBuffer,
324    ) -> Result<RuntimeExecutionContext<'run>, crate::PluginError> {
325        let dispatch = Arc::new(ToolDispatchContext {
326            plugins: Arc::clone(self.plugins()),
327            tools: self.tools(),
328            tool_catalog: self.resolved_tool_catalog(session_id)?,
329            sessions,
330            session_lifecycle,
331            session_graph,
332            processes,
333            process_cancel_ability,
334            trigger_router,
335            effect_controller,
336            direct_completions: direct_completions.clone(),
337            parent_invocation: None,
338            execution_env_spec: execution_env_spec.clone(),
339            session_id: session_id.to_string(),
340            agent_frame_id: agent_frame_id.to_string(),
341            event_tx,
342            checkpoint_messages,
343            trigger_outcomes: crate::tool_dispatch::ToolTriggerOutcomeBuffer::default(),
344            attachment_store: Arc::clone(&self.services.attachment_store),
345            turn_context: turn_context.clone(),
346            clock: Arc::clone(&self.services.clock),
347        });
348        Ok(RuntimeExecutionContext::new(
349            session_id.to_string(),
350            dispatch,
351            Arc::clone(&self.services.process_env_store),
352            Arc::clone(&self.services.attachment_store),
353            chronological_projection,
354            protocol_extension,
355            turn_context,
356        ))
357        .map(|context| context.with_execution_env_spec(execution_env_spec))
358    }
359
360    /// Set the message sender for streaming messages during execution.
361    pub fn set_message_sender(&mut self, tx: UnboundedSender<SandboxMessage>) {
362        self.message_tx = Some(tx);
363    }
364
365    /// Clear the message sender (drops the sender, causing receivers to terminate).
366    pub fn clear_message_sender(&mut self) {
367        self.message_tx = None;
368    }
369
370    pub fn invalidate_runtime_caches(&self) {
371        self.tool_catalog_cache
372            .lock()
373            .expect("tool catalog cache lock")
374            .clear();
375        self.prompt_cache.clear();
376    }
377
378    pub async fn refresh_tool_catalog(&mut self) -> Result<(), SessionError> {
379        self.tool_registry = self
380            .services
381            .plugins
382            .tool_registry()
383            .compose_session_catalog(self.include_base_tools, self.context_tools.clone())
384            .map(Arc::new)
385            .map_err(|err| SessionError::Protocol(format!("tool reconfigure failed: {err}")))?;
386        self.tool_catalog_cache
387            .lock()
388            .expect("tool catalog cache lock")
389            .clear();
390        Ok(())
391    }
392}
lash_core/session.rs

lash_core/
session.rs
