WIP: trim_entries dedup, context_window rename, compact simplification

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/agent/runner.rs

@@ -909,23 +909,24 @@ impl Agent {
         self.do_compact();
     }
 
-    /// Internal compaction — rebuilds context window from current messages.
-    fn do_compact(&mut self) {
-        let conversation: Vec<Message> = self.context.entries.iter()
-            .map(|e| e.api_message().clone()).collect();
-        let messages = crate::thought::context::trim_conversation(
+    /// Dedup memory entries, trim to fit, reload journal for new time range.
+    fn trim_and_reload(&mut self, entries: &[ConversationEntry]) {
+        self.context.entries = crate::thought::context::trim_entries(
             &self.context,
-            &conversation,
-            &self.client.model,
+            entries,
             &self.tokenizer,
         );
-        self.context.entries = messages.into_iter()
-            .map(ConversationEntry::Message).collect();
+        self.load_startup_journal();
         self.last_prompt_tokens = 0;
-
         self.publish_context_state();
     }
 
+    /// Internal compaction — dedup memory entries and trim to fit.
+    fn do_compact(&mut self) {
+        let entries = self.context.entries.clone();
+        self.trim_and_reload(&entries);
+    }
+
     /// Emergency compaction using stored config — called on context overflow.
     fn emergency_compact(&mut self) {
         self.do_compact();
@@ -964,32 +965,14 @@ impl Agent {
             }
         };
 
-        // Filter out system messages, keep everything else (including Memory entries)
+        // Filter out system messages, dedup memory, trim to fit
         let entries: Vec<ConversationEntry> = entries
             .into_iter()
             .filter(|e| e.message().role != Role::System)
             .collect();
-
-        // Trim to fit context budget
-        let n = entries.len();
-        let conversation: Vec<Message> = entries.iter()
-            .map(|e| e.api_message().clone()).collect();
-        let trimmed = crate::thought::context::trim_conversation(
-            &self.context,
-            &conversation,
-            &self.client.model,
-            &self.tokenizer,
-        );
-        // Keep only the entries that survived trimming (by count from the end)
-        let keep = trimmed.len();
-        self.context.entries = entries.into_iter()
-            .skip(n.saturating_sub(keep))
-            .collect();
-
+        self.trim_and_reload(&entries);
         dbglog!("[restore] {} entries, journal: {} entries",
             self.context.entries.len(), self.context.journal.len());
-        self.last_prompt_tokens = 0;
-        self.publish_context_state();
         true
     }
 

src/bin/poc-agent.rs

@@ -40,14 +40,14 @@ use poc_memory::agent::ui_channel::{ContextInfo, StatusInfo, StreamTarget, UiMes
 
 /// Hard compaction threshold — context is rebuilt immediately.
 /// Uses config percentage of model context window.
-fn compaction_threshold(model: &str, app: &AppConfig) -> u32 {
-    (poc_memory::thought::context::model_context_window(model) as u32) * app.compaction.hard_threshold_pct / 100
+fn compaction_threshold(app: &AppConfig) -> u32 {
+    (poc_memory::thought::context::context_window() as u32) * app.compaction.hard_threshold_pct / 100
 }
 
 /// Soft threshold — nudge the model to journal before compaction.
 /// Fires once; the hard threshold handles the actual rebuild.
-fn pre_compaction_threshold(model: &str, app: &AppConfig) -> u32 {
-    (poc_memory::thought::context::model_context_window(model) as u32) * app.compaction.soft_threshold_pct / 100
+fn pre_compaction_threshold(app: &AppConfig) -> u32 {
+    (poc_memory::thought::context::context_window() as u32) * app.compaction.soft_threshold_pct / 100
 }
 
 #[tokio::main]
@@ -280,8 +280,8 @@ impl Session {
     async fn check_compaction(&mut self) {
         let mut agent_guard = self.agent.lock().await;
         let tokens = agent_guard.last_prompt_tokens();
-        let hard = compaction_threshold(agent_guard.model(), &self.config.app);
-        let soft = pre_compaction_threshold(agent_guard.model(), &self.config.app);
+        let hard = compaction_threshold(&self.config.app);
+        let soft = pre_compaction_threshold(&self.config.app);
 
         if tokens > hard {
             let _ = self.ui_tx.send(UiMessage::Info(format!(
@@ -452,7 +452,7 @@ impl Session {
                     let total_chars: usize =
                         msgs.iter().map(|e| e.message().content_text().len()).sum();
                     let prompt_tokens = agent.last_prompt_tokens();
-                    let threshold = compaction_threshold(agent.model(), &self.config.app);
+                    let threshold = compaction_threshold(&self.config.app);
                     let _ = self.ui_tx.send(UiMessage::Info(format!(
                         "  {} messages, ~{} chars",
                         msgs.len(),

src/thought/context.rs

@@ -15,27 +15,49 @@ pub struct JournalEntry {
     pub content: String,
 }
 
-/// Look up a model's context window size in tokens.
-pub fn model_context_window(_model: &str) -> usize {
+/// Context window size in tokens (from config).
+pub fn context_window() -> usize {
     crate::config::get().api_context_window
 }
 
 /// Context budget in tokens: 60% of the model's context window.
-fn context_budget_tokens(model: &str) -> usize {
-    model_context_window(model) * 60 / 100
+fn context_budget_tokens() -> usize {
+    context_window() * 60 / 100
 }
 
-/// Trim conversation to fit within the context budget.
-/// Returns the trimmed conversation messages (oldest dropped first).
-pub fn trim_conversation(
+/// Dedup and trim conversation entries to fit within the context budget.
+///
+/// 1. Dedup: if the same memory key appears multiple times, keep only
+///    the latest render (drop the earlier Memory entry and its
+///    corresponding assistant tool_call message).
+/// 2. Trim: drop oldest entries until the conversation fits, snapping
+///    to user message boundaries.
+pub fn trim_entries(
     context: &ContextState,
-    conversation: &[Message],
-    model: &str,
+    entries: &[ConversationEntry],
     tokenizer: &CoreBPE,
-) -> Vec<Message> {
+) -> Vec<ConversationEntry> {
     let count = |s: &str| tokenizer.encode_with_special_tokens(s).len();
-    let max_tokens = context_budget_tokens(model);
 
+    // --- Phase 1: dedup memory entries by key (keep last) ---
+    let mut seen_keys: std::collections::HashMap<&str, usize> = std::collections::HashMap::new();
+    let mut drop_indices: std::collections::HashSet<usize> = std::collections::HashSet::new();
+
+    for (i, entry) in entries.iter().enumerate() {
+        if let ConversationEntry::Memory { key, .. } = entry {
+            if let Some(prev) = seen_keys.insert(key.as_str(), i) {
+                drop_indices.insert(prev);
+            }
+        }
+    }
+
+    let deduped: Vec<ConversationEntry> = entries.iter().enumerate()
+        .filter(|(i, _)| !drop_indices.contains(i))
+        .map(|(_, e)| e.clone())
+        .collect();
+
+    // --- Phase 2: trim to fit context budget ---
+    let max_tokens = context_budget_tokens();
     let identity_cost = count(&context.system_prompt)
         + context.personality.iter().map(|(_, c)| count(c)).sum::<usize>();
     let journal_cost: usize = context.journal.iter().map(|e| count(&e.content)).sum();
@@ -45,23 +67,23 @@ pub fn trim_conversation(
         .saturating_sub(journal_cost)
         .saturating_sub(reserve);
 
-    let msg_costs: Vec<usize> = conversation.iter()
-        .map(|m| msg_token_count(tokenizer, m)).collect();
+    let msg_costs: Vec<usize> = deduped.iter()
+        .map(|e| msg_token_count(tokenizer, e.message())).collect();
     let total: usize = msg_costs.iter().sum();
 
     let mut skip = 0;
     let mut trimmed = total;
-    while trimmed > available && skip < conversation.len() {
+    while trimmed > available && skip < deduped.len() {
         trimmed -= msg_costs[skip];
         skip += 1;
     }
 
     // Walk forward to user message boundary
-    while skip < conversation.len() && conversation[skip].role != Role::User {
+    while skip < deduped.len() && deduped[skip].message().role != Role::User {
         skip += 1;
     }
 
-    conversation[skip..].to_vec()
+    deduped[skip..].to_vec()
 }
 
 /// Count the token footprint of a message using BPE tokenization.