Method Acquire

cli/agent/lsp/pool.go:103–159

Acquire returns a ready Session for absPath: the pooled client for the file's project root and language server (spawned and initialized on first use), with the document opened or re-synchronized when its content changed since the last call. Callers must pass an absolute, cleaned path.

(ctx context.Context, absPath string)

// use), with the document opened or re-synchronized when its content changed
// since the last call. Callers must pass an absolute, cleaned path.
func (p *Pool) Acquire(ctx context.Context, absPath string) (*Session, error) {
	spec, ok := ServerForFile(absPath)
	if !ok {
		return nil, fmt.Errorf("no language server configured for %q files (supported: %s)",
			filepath.Ext(absPath), strings.Join(SupportedExtensions(), " "))
	}

	data, err := os.ReadFile(absPath) //#nosec G304 -- agent-requested source file, same trust boundary as @read
	if err != nil {
		return nil, err
	}
	if len(data) > maxDocumentBytes {
		return nil, fmt.Errorf("file too large for language-server analysis (%d bytes, limit %d)", len(data), maxDocumentBytes)
	}

	root := findProjectRoot(absPath)
	key := root + "\x00" + strings.Join(spec.Command, " ")

	p.mu.Lock()
	defer p.mu.Unlock()
	p.reapIdleLocked()

	entry, ok := p.entries[key]
	if !ok {
		// The server must OUTLIVE this call: exec.CommandContext ties the
		// subprocess lifetime to its context, so spawning with the request
		// ctx (or any ctx we cancel) kills the server the moment we return —
		// the E2E symptom is an instant "broken pipe" on initialize. The pool
		// owns the lifetime (idle reap + Close); only inherit values.
		client, spawnErr := p.spawn(context.WithoutCancel(ctx), spec, p.logger)
		if spawnErr != nil {
			return nil, fmt.Errorf("start %s: %w (install it or override via %s)", spec.Command[0], spawnErr, spec.EnvKey)
		}
		rootURI := "file://" + root
		if initErr := client.Initialize(rootURI); initErr != nil {
			client.Shutdown()
			return nil, fmt.Errorf("initialize %s: %w", spec.Command[0], initErr)
		}
		entry = &poolEntry{
			client:  client,
			docs:    map[string]docState{},
			rootURI: rootURI,
			spec:    spec,
			poolKey: key,
		}
		p.entries[key] = entry
		p.logger.Info("lsp: language server started",
			zap.String("server", spec.Command[0]), zap.String("root", root))
	}
	entry.lastUse = p.now()

	uri := "file://" + absPath
	if syncErr := entry.syncDocument(uri, spec.LanguageID, string(data)); syncErr != nil {
		return nil, syncErr
	}
	return &Session{Client: entry.client, URI: uri, Root: root}, nil
}