git/stats: Report on multi-pack-indices

We'll soon start writing multi-pack-indices in our repository
maintenance. Start exposing information about multi-pack-indices so that
we can monitor the progress of that change. Please refer to the
gitformat-pack(5) man page for further details on these data structures.

2 files changed, 42 insertions, 4 deletions

diff --git a/internal/git/stats/repository_info.go b/internal/git/stats/repository_info.go
index d14cbc3a2..363b267bd 100644
--- a/internal/git/stats/repository_info.go
+++ b/internal/git/stats/repository_info.go
@@ -240,6 +240,10 @@ type PackfilesInfo struct {
 	GarbageSize uint64 `json:"garbage_size"`
 	// HasBitmap indicates whether the packfiles have a bitmap.
 	HasBitmap bool `json:"has_bitmap"`
+	// HasMultiPackIndex indicates whether there is a multi-pack-index.
+	HasMultiPackIndex bool `json:"has_multi_pack_index"`
+	// HasMultiPackIndexBitmap indicates whether the multi-pack-index has a bitmap.
+	HasMultiPackIndexBitmap bool `json:"has_multi_pack_index_bitmap"`
 }
 
 // PackfilesInfoForRepository derives various information about packfiles for the given repository.
@@ -286,6 +290,10 @@ func PackfilesInfoForRepository(repo *localrepo.Repo) (PackfilesInfo, error) {
 			case strings.HasSuffix(entryName, ".bitmap"):
 				info.HasBitmap = true
 			}
+		case entryName == "multi-pack-index":
+			info.HasMultiPackIndex = true
+		case strings.HasPrefix(entryName, "multi-pack-index-") && strings.HasSuffix(entryName, ".bitmap"):
+			info.HasMultiPackIndexBitmap = true
 		default:
 			info.GarbageCount++
 			if entryInfo.Size() > 0 {
diff --git a/internal/git/stats/repository_info_test.go b/internal/git/stats/repository_info_test.go
index 8fa25c6fe..1c2be2ead 100644
--- a/internal/git/stats/repository_info_test.go
+++ b/internal/git/stats/repository_info_test.go
@@ -737,6 +737,32 @@ func TestPackfileInfoForRepository(t *testing.T) {
 		})
 	})
 
+	t.Run("multi-pack-index", func(t *testing.T) {
+		repo, repoPath := createRepo(t)
+
+		packfileDir := filepath.Join(repoPath, "objects", "pack")
+		require.NoError(t, os.MkdirAll(packfileDir, 0o755))
+		require.NoError(t, os.WriteFile(filepath.Join(packfileDir, "multi-pack-index"), nil, 0o644))
+
+		requirePackfilesInfo(t, repo, PackfilesInfo{
+			HasMultiPackIndex: true,
+		})
+	})
+
+	t.Run("multi-pack-index with bitmap", func(t *testing.T) {
+		repo, repoPath := createRepo(t)
+
+		packfileDir := filepath.Join(repoPath, "objects", "pack")
+		require.NoError(t, os.MkdirAll(packfileDir, 0o755))
+		require.NoError(t, os.WriteFile(filepath.Join(packfileDir, "multi-pack-index"), nil, 0o644))
+		require.NoError(t, os.WriteFile(filepath.Join(packfileDir, "multi-pack-index-c0363841cc7e5783a996c72f0a4a7ae4440aaa40.bitmap"), nil, 0o644))
+
+		requirePackfilesInfo(t, repo, PackfilesInfo{
+			HasMultiPackIndex:       true,
+			HasMultiPackIndexBitmap: true,
+		})
+	})
+
 	t.Run("multiple packfiles with other data structures", func(t *testing.T) {
 		repo, repoPath := createRepo(t)
 
@@ -750,15 +776,19 @@ func TestPackfileInfoForRepository(t *testing.T) {
 			"pack-foo.pack",
 			"pack-foo.idx",
 			"garbage",
+			"multi-pack-index",
+			"multi-pack-index-c0363841cc7e5783a996c72f0a4a7ae4440aaa40.bitmap",
 		} {
 			require.NoError(t, os.WriteFile(filepath.Join(packfileDir, file), []byte("1"), 0o644))
 		}
 
 		requirePackfilesInfo(t, repo, PackfilesInfo{
-			Count:        2,
-			Size:         2,
-			GarbageCount: 1,
-			GarbageSize:  1,
+			Count:                   2,
+			Size:                    2,
+			GarbageCount:            1,
+			GarbageSize:             1,
+			HasMultiPackIndex:       true,
+			HasMultiPackIndexBitmap: true,
 		})
 	})
 }