Add internal debug bundle collaborators

internal/core/debugbundle/bundle.go

@@ -0,0 +1,89 @@
+// Package debugbundle owns explicitly requested per-run debug bundles.
+package debugbundle
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+const maxCreateAttempts = 16
+
+var utcNow = func() time.Time { return time.Now().UTC() }
+
+type Bundle struct {
+	path, summaryRoot, traceRoot string
+	createdAt                    time.Time
+}
+
+func Allocate(parent string) (*Bundle, error) {
+	parent = strings.TrimSpace(parent)
+	if parent == "" {
+		return nil, fmt.Errorf("debug parent must not be empty")
+	}
+	if err := os.MkdirAll(parent, 0o700); err != nil {
+		return nil, fmt.Errorf("create debug parent %q: %w", parent, err)
+	}
+	var last string
+	for attempt := 0; attempt < maxCreateAttempts; attempt++ {
+		createdAt := utcNow()
+		runID := fmt.Sprintf("run-%d", createdAt.UnixNano())
+		path := filepath.Join(parent, runID)
+		last = path
+		if err := os.Mkdir(path, 0o700); err != nil {
+			if os.IsExist(err) {
+				continue
+			}
+			return nil, fmt.Errorf("create debug bundle %q: %w", path, err)
+		}
+		summary, trace := filepath.Join(path, "summary"), filepath.Join(path, "trace")
+		if err := os.Mkdir(summary, 0o700); err != nil {
+			_ = os.Remove(path)
+			return nil, fmt.Errorf("create debug summary %q: %w", summary, err)
+		}
+		if err := os.Mkdir(trace, 0o700); err != nil {
+			_ = os.RemoveAll(path)
+			return nil, fmt.Errorf("create debug trace %q: %w", trace, err)
+		}
+		return &Bundle{path: path, summaryRoot: summary, traceRoot: trace, createdAt: createdAt}, nil
+	}
+	return nil, fmt.Errorf("create debug bundle %q: exhausted unique run ID attempts", last)
+}
+func (b *Bundle) Path() string {
+	if b == nil {
+		return ""
+	}
+	return b.path
+}
+func (b *Bundle) SummaryRoot() string {
+	if b == nil {
+		return ""
+	}
+	return b.summaryRoot
+}
+func (b *Bundle) TraceRoot() string {
+	if b == nil {
+		return ""
+	}
+	return b.traceRoot
+}
+func (b *Bundle) RunID() string {
+	if b == nil {
+		return ""
+	}
+	return filepath.Base(b.path)
+}
+func (b *Bundle) CreatedAt() time.Time {
+	if b == nil {
+		return time.Time{}
+	}
+	return b.createdAt
+}
+func (b *Bundle) Summary() *SummaryWriter {
+	if b == nil {
+		return nil
+	}
+	return &SummaryWriter{root: b.summaryRoot, runID: b.RunID(), createdAt: b.createdAt}
+}