Bound agent result cache

cmd/olliesrv/internal/agent/agent.go

@@ -36,7 +36,7 @@ type Agent struct {
 	closed        atomic.Bool
 	actionMu      sync.Mutex // serializes action registration with shutdown
 	warnedContext bool
-	resultCache   sync.Map
+	resultCache   resultCache
 
 	// Execution state — owned by the agent, protected by stateMu.
 	state          string        // "idle", "thinking", "calling: <tool>"

cmd/olliesrv/internal/agent/loop.go

@@ -43,6 +43,56 @@ type cachedResult struct {
 	Size    int64 // file size at cache time; -1 if no file
 }
 
+const (
+	resultCacheMaxEntries = 256
+	resultCacheMaxBytes   = 32 * 1024 * 1024
+)
+
+type resultCache struct {
+	mu    sync.Mutex
+	items map[string]cachedResult
+	bytes int
+}
+
+func (c *resultCache) Load(key string) (cachedResult, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	v, ok := c.items[key]
+	return v, ok
+}
+
+func (c *resultCache) Delete(key string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if v, ok := c.items[key]; ok {
+		c.bytes -= len(v.Result)
+		delete(c.items, key)
+	}
+}
+
+func (c *resultCache) Store(key string, value cachedResult) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.items == nil {
+		c.items = make(map[string]cachedResult)
+	}
+	if old, ok := c.items[key]; ok {
+		c.bytes -= len(old.Result)
+	}
+	if len(value.Result) > resultCacheMaxBytes {
+		return
+	}
+	c.items[key] = value
+	c.bytes += len(value.Result)
+	for len(c.items) > resultCacheMaxEntries || c.bytes > resultCacheMaxBytes {
+		for k, v := range c.items {
+			delete(c.items, k)
+			c.bytes -= len(v.Result)
+			break
+		}
+	}
+}
+
 // extractFilePath attempts to pull a "path" field from JSON tool args.
 func extractFilePath(args json.RawMessage) string {
 	var m map[string]json.RawMessage
@@ -533,8 +583,7 @@ func (ag *Agent) execOne(ctx context.Context, call backend.ToolCall) (toolResult
 	readSafe := rt.ToolMeta[call.Name].Scope == "read"
 	if readSafe {
 		key := call.Name + "\x00" + string(call.Arguments)
-		if v, ok := resultCache.Load(key); ok {
-			entry := v.(cachedResult)
+		if entry, ok := resultCache.Load(key); ok {
 			if cacheValid(entry, call.Arguments) {
 				ag.emit(Event{Role: "tool", Name: call.Name, Content: entry.Result, OutputFormat: toolOutputFormat(rt, call.Name)})
 				return toolResult{ToolCallID: call.ID, Name: call.Name, Content: entry.Result}, false