Method Scan

agent/agentgit/agentgit.go:151–239

Scan performs a scan of all subscribed repos and computes deltas against the previously emitted snapshots.

(ctx context.Context)

// Scan performs a scan of all subscribed repos and computes deltas
// against the previously emitted snapshots.
func (h *Handler) Scan(ctx context.Context) *codersdk.WorkspaceAgentGitServerMessage {
	if !h.gitAvailable() {
		return nil
	}

	h.mu.Lock()
	roots := make([]string, 0, len(h.repoRoots))
	for r := range h.repoRoots {
		roots = append(roots, r)
	}
	h.mu.Unlock()

	if len(roots) == 0 {
		return nil
	}

	now := h.clock.Now().UTC()
	var repos []codersdk.WorkspaceAgentRepoChanges

	// Perform all I/O outside the lock to avoid blocking
	// AddPaths/GetPaths/Subscribe callers during disk-heavy scans.
	type scanResult struct {
		root    string
		changes codersdk.WorkspaceAgentRepoChanges
		err     error
	}
	results := make([]scanResult, 0, len(roots))
	for _, root := range roots {
		changes, err := getRepoChanges(ctx, h.logger, h.gitBin, root)
		results = append(results, scanResult{root: root, changes: changes, err: err})
	}

	// Re-acquire the lock only to commit snapshot updates.
	h.mu.Lock()
	defer h.mu.Unlock()

	for _, res := range results {
		if res.err != nil {
			if isRepoDeleted(h.gitBin, res.root) {
				// Repo root or .git directory was removed.
				// Emit a removal entry, then evict from watch set.
				removal := codersdk.WorkspaceAgentRepoChanges{
					RepoRoot: res.root,
					Removed:  true,
				}
				delete(h.repoRoots, res.root)
				delete(h.lastSnapshots, res.root)
				repos = append(repos, removal)
			} else {
				// Transient error — log and skip without
				// removing the repo from the watch set.
				h.logger.Warn(ctx, "scan repo failed",
					slog.F("root", res.root),
					slog.Error(res.err),
				)
			}
			continue
		}