Record each snapshot's new chunk size when its backup runs (closes #311)

snapshot list worked out NEW CHUNK SIZE from the snapshot's file rows. A
file's row is shared by every snapshot that lists it and rewritten when
the file changes, so a snapshot whose change was a modified file showed
0 B, and older snapshots' figures moved after later backups.

The scanner now totals the size of the chunks it stores that were not
stored before (the chunks chunk_count counts), the backup writes that
total to a new snapshots column, new_chunk_size, and snapshot list reads
it.

Judgement call: the figure is fixed when the backup runs, so removing an
earlier snapshot no longer raises a later snapshot's figure.

Model: opus-5-5

ARCHITECTURE.md

@@ -279,8 +279,8 @@ Key methods:
 - `Scan(ctx, path, snapshotID)` → Main scan operation
 
 Scan phases:
-1. **Phase 1**: Walk directory, identify files needing processing
-2. **Phase 1b**: Count as deleted the files that the previous snapshot of the same name lists and the walk did not find; a file that is excluded, or inside an excluded directory, is not counted
+1. **Phase 0**: Detect deleted files from previous snapshots
+2. **Phase 1**: Walk directory, identify files needing processing
 3. **Phase 2**: Process files (chunk → pack → upload)
 
 #### SnapshotManager
@@ -320,13 +320,13 @@ CreateSnapshot(opts)
     │       │
     │       ├─► scanner.Scan(ctx, path, snapshotID)
     │       │       │
+    │       │       ├─► Phase 0: detectDeletedFiles()
+    │       │       │
     │       │       ├─► Phase 1: scanPhase()
     │       │       │       Walk directory
     │       │       │       Check file metadata changes
     │       │       │       Build list of files to process
     │       │       │
-    │       │       ├─► Phase 1b: detectDeletedFiles()
-    │       │       │
     │       │       └─► Phase 2: processPhase()
     │       │               For each file:
     │       │                   chunker.ChunkReaderStreaming()

README.md

@@ -293,8 +293,8 @@ needed.
 **`snapshot list`**: Show every snapshot known to this host — the union
 of the local index and the backup destination store — with timestamps
 and three sizes per snapshot (compressed remote size; total
-uncompressed chunk size; size of chunks newly referenced by that
-snapshot).
+uncompressed chunk size; size of the chunks that snapshot stored that
+were not stored before, recorded when its backup ran).
 
 Listing the destination store does **not** require the age secret key,
 so it works in vaultik's intended configuration, where the backed-up
@@ -307,8 +307,8 @@ only the hash, so hostname and snapshot name exist solely in the local
 index and in the encrypted per-snapshot database. Snapshots found only
 on the destination store are therefore listed as
 `<remote only:<abbreviated remote key>>` and show `<remote only>` in
-the uncompressed and "new chunk" columns, which can only be computed
-from the local index. Their timestamp and compressed size are real,
+the uncompressed and "new chunk" columns, which come only from the
+local index. Their timestamp and compressed size are real,
 read from the manifest.
 
 Snapshots in the local index with no counterpart on the destination

docs/DATAMODEL.md

@@ -119,6 +119,7 @@ Tracks backup snapshots.
 - `completed_at` (INTEGER) - Completion timestamp (NULL if in progress)
 - `file_count` (INTEGER) - Number of files in snapshot
 - `chunk_count` (INTEGER) - Number of chunks this snapshot stored that were not stored before
+- `new_chunk_size` (INTEGER) - Total size of those chunks before compression; `snapshot list` shows it as NEW CHUNK SIZE
 - `blob_count` (INTEGER) - Number of blobs this snapshot created
 - `total_size` (INTEGER) - Total size of all files
 - `blob_size` (INTEGER) - Total compressed size of all referenced blobs

internal/database/files.go

@@ -277,50 +277,6 @@ func (r *FileRepository) ListUnderPath(
 	return files, rows.Err()
 }
 
-// ListUnderPathInSnapshot returns the files that ListUnderPath returns
-// for path and that the snapshot lists, in no particular order.
-func (r *FileRepository) ListUnderPathInSnapshot(
-	ctx context.Context, path, snapshotID string,
-) ([]*File, error) {
-	path = strings.TrimRight(path, "/")
-	dirPrefix := path + "/"
-
-	query := `
-		SELECT f.id, f.path, f.source_path, f.mtime, f.mtime_nsec, f.size,
-			f.mode, f.uid, f.gid, f.link_target
-		FROM files f
-		JOIN snapshot_files sf ON sf.file_id = f.id
-		WHERE sf.snapshot_id = ?
-		  AND (f.path = ? OR substr(f.path, 1, length(?)) = ?)
-	`
-
-	rows, err := r.db.conn.QueryContext(ctx, query,
-		snapshotID, path, dirPrefix, dirPrefix)
-	if err != nil {
-		return nil, fmt.Errorf("querying files: %w", err)
-	}
-
-	defer func() {
-		err := rows.Close()
-		if err != nil {
-			Fatalf("failed to close rows: %v", err)
-		}
-	}()
-
-	var files []*File
-
-	for rows.Next() {
-		file, err := r.scanFileRows(rows)
-		if err != nil {
-			return nil, fmt.Errorf("scanning file: %w", err)
-		}
-
-		files = append(files, file)
-	}
-
-	return files, rows.Err()
-}
-
 // ListIDsWithChunksNotInUploadedBlobs returns the IDs of the files whose
 // path starts with prefix and that list at least one chunk held by no
 // blob whose upload has completed (uploaded_ts set). A new snapshot

internal/database/files_test.go

@@ -212,65 +212,6 @@ func TestFileRepositoryListUnderPath(t *testing.T) {
 	}
 }
 
-// ListUnderPathInSnapshot leaves out files outside path and files the
-// snapshot does not list, though another snapshot lists them.
-func TestFileRepositoryListUnderPathInSnapshot(t *testing.T) {
-	t.Parallel()
-
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
-
-	ctx := context.Background()
-	files := database.NewFileRepository(db)
-	snapshots := database.NewSnapshotRepository(db)
-
-	listed := map[string][]string{
-		"one": {"/src/a.txt", "/src2/c.txt"},
-		"two": {"/src/b.txt"},
-	}
-
-	for snapshotID, paths := range listed {
-		err := snapshots.Create(ctx, nil, &database.Snapshot{
-			ID:        types.SnapshotID(snapshotID),
-			Hostname:  "host",
-			StartedAt: time.Now(),
-		})
-		if err != nil {
-			t.Fatalf("failed to create snapshot %s: %v", snapshotID, err)
-		}
-
-		for _, path := range paths {
-			err := files.Create(ctx, nil, &database.File{
-				Path:  types.FilePath(path),
-				MTime: time.Now().Truncate(time.Second),
-				Mode:  0644,
-			})
-			if err != nil {
-				t.Fatalf("failed to create %s: %v", path, err)
-			}
-
-			err = snapshots.AddFile(ctx, nil, snapshotID, path)
-			if err != nil {
-				t.Fatalf("failed to add %s to %s: %v", path, snapshotID, err)
-			}
-		}
-	}
-
-	found, err := files.ListUnderPathInSnapshot(ctx, "/src", "one")
-	if err != nil {
-		t.Fatalf("failed to list files: %v", err)
-	}
-
-	got := make([]string, 0, len(found))
-	for _, f := range found {
-		got = append(got, f.Path.String())
-	}
-
-	if !slices.Equal(got, []string{"/src/a.txt"}) {
-		t.Errorf("got %q, want only /src/a.txt", got)
-	}
-}
-
 func TestFileRepositorySymlink(t *testing.T) {
 	t.Parallel()
 

internal/database/schema/001.sql

@@ -86,6 +86,7 @@ CREATE TABLE IF NOT EXISTS snapshots (
     completed_at INTEGER,
     file_count INTEGER NOT NULL DEFAULT 0,
     chunk_count INTEGER NOT NULL DEFAULT 0,
+    new_chunk_size INTEGER NOT NULL DEFAULT 0,
     blob_count INTEGER NOT NULL DEFAULT 0,
     total_size INTEGER NOT NULL DEFAULT 0,
     blob_size INTEGER NOT NULL DEFAULT 0,

internal/database/snapshots.go

@@ -129,6 +129,7 @@ func (r *SnapshotRepository) UpdateExtendedStats(
 	compressionLevel int,
 	uploadBytes int64,
 	uploadDurationMs int64,
+	newChunkSize int64,
 ) error {
 	compressionRatio, err := r.extendedCompressionRatio(
 		ctx, tx, snapshotID, blobUncompressedSize,
@@ -143,18 +144,19 @@ func (r *SnapshotRepository) UpdateExtendedStats(
 		    compression_ratio = ?,
 		    compression_level = ?,
 		    upload_bytes = ?,
-		    upload_duration_ms = ?
+		    upload_duration_ms = ?,
+		    new_chunk_size = ?
 		WHERE id = ?
 	`
 
 	if tx != nil {
 		_, err = tx.ExecContext(ctx, query,
 			blobUncompressedSize, compressionRatio, compressionLevel,
-			uploadBytes, uploadDurationMs, snapshotID)
+			uploadBytes, uploadDurationMs, newChunkSize, snapshotID)
 	} else {
 		_, err = r.db.ExecWithLog(ctx, query,
 			blobUncompressedSize, compressionRatio, compressionLevel,
-			uploadBytes, uploadDurationMs, snapshotID)
+			uploadBytes, uploadDurationMs, newChunkSize, snapshotID)
 	}
 
 	if err != nil {
@@ -594,45 +596,24 @@ func (r *SnapshotRepository) GetSnapshotUncompressedChunkSize(
 	return totalSize, nil
 }
 
-// GetSnapshotNewChunkSize returns the sum of plaintext sizes of chunks that are
-// referenced by this snapshot but not by any earlier completed snapshot known to
-// the local database. The result is the marginal uncompressed data this snapshot
-// added to the dedup pool — i.e., the delta from prior snapshots.
+// GetSnapshotNewChunkSize returns the total plaintext size of the chunks the
+// snapshot's backup stored that were not stored before, as the backup
+// recorded it. It is not derived from the snapshot's files: a file's row is
+// shared by every snapshot that lists it and is rewritten when the file
+// changes, so it shows only the file's latest chunks.
 func (r *SnapshotRepository) GetSnapshotNewChunkSize(
 	ctx context.Context, snapshotID string,
 ) (int64, error) {
-	query := `
-		WITH this_snap_chunks AS (
-			SELECT DISTINCT fc.chunk_hash
-			FROM snapshot_files sf
-			JOIN file_chunks fc ON sf.file_id = fc.file_id
-			WHERE sf.snapshot_id = ?
-		),
-		prior_chunks AS (
-			SELECT DISTINCT fc.chunk_hash
-			FROM snapshots s
-			JOIN snapshot_files sf ON sf.snapshot_id = s.id
-			JOIN file_chunks fc ON fc.file_id = sf.file_id
-			WHERE s.completed_at IS NOT NULL
-			  AND s.id != ?
-			  AND s.started_at < (SELECT started_at FROM snapshots WHERE id = ?)
-		)
-		SELECT COALESCE(SUM(c.size), 0)
-		FROM chunks c
-		JOIN this_snap_chunks t ON c.chunk_hash = t.chunk_hash
-		WHERE c.chunk_hash NOT IN (SELECT chunk_hash FROM prior_chunks)
-	`
+	query := `SELECT new_chunk_size FROM snapshots WHERE id = ?`
 
-	var totalSize int64
+	var newChunkSize int64
 
-	err := r.db.conn.QueryRowContext(
-		ctx, query, snapshotID, snapshotID, snapshotID,
-	).Scan(&totalSize)
+	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(&newChunkSize)
 	if err != nil {
 		return 0, fmt.Errorf("querying new chunk size: %w", err)
 	}
 
-	return totalSize, nil
+	return newChunkSize, nil
 }
 
 // GetIncompleteSnapshots returns all snapshots that haven't been completed

internal/log/tty_handler.go

@@ -10,8 +10,6 @@ import (
 	"sync"
 	"time"
 	"unicode"
-
-	"github.com/dustin/go-humanize"
 )
 
 // groupSeparator joins an open group path to an attribute key. This
@@ -306,13 +304,18 @@ func formatDuration(d time.Duration) string {
 	}
 }
 
-// formatBytes formats a byte count with humanize.Bytes, as every command
-// prints one. humanize.Bytes takes no negative count, so one is printed
-// as it is.
+// formatBytes formats bytes in a human-readable way
 func formatBytes(b int64) string {
-	if b < 0 {
+	const unit = 1024
+	if b < unit {
 		return fmt.Sprintf("%d B", b)
 	}
 
-	return humanize.Bytes(uint64(b))
+	div, exp := int64(unit), 0
+	for n := b / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+
+	return fmt.Sprintf("%.1f %cB", float64(b)/float64(div), "KMGTPE"[exp])
 }

internal/log/tty_handler_test.go

@@ -200,8 +200,7 @@ func TestTTYHandlerWithGroupQualifiesKeys(t *testing.T) {
 func TestTTYHandlerByteFormattingSurvivesGrouping(t *testing.T) {
 	t.Parallel()
 
-	// Printed as "1.0 MB", in powers of 1000 like every other byte count.
-	const oneMegabyte = 1_000_000
+	const oneAndAHalfKiB = 1536
 
 	for name, testCase := range map[string]struct {
 		derive func(*slog.Logger) *slog.Logger
@@ -224,13 +223,13 @@ func TestTTYHandlerByteFormattingSurvivesGrouping(t *testing.T) {
 			var buf bytes.Buffer
 
 			logger := slog.New(log.NewTTYHandler(&buf, debugHandlerOptions()))
-			testCase.derive(logger).Info("uploaded", "bytes", oneMegabyte)
+			testCase.derive(logger).Info("uploaded", "bytes", oneAndAHalfKiB)
 
 			line := ansiEscape.ReplaceAllString(buf.String(), "")
 
-			assert.Contains(t, line, testCase.key+"=1.0 MB",
+			assert.Contains(t, line, testCase.key+"=1.5 KB",
 				"a byte count must be human-readable however it is qualified")
-			assert.NotContains(t, line, strconv.Itoa(oneMegabyte),
+			assert.NotContains(t, line, strconv.Itoa(oneAndAHalfKiB),
 				"the raw number must not survive the formatting")
 		})
 	}

internal/snapshot/module.go

@@ -16,9 +16,6 @@ type ScannerParams struct {
 	Fs             afero.Fs
 	Exclude        []string // Exclude patterns (combined global + snapshot-specific)
 	SkipErrors     bool     // Skip file read errors (log loudly but continue)
-	// PreviousSnapshotID is the most recent completed snapshot of the
-	// same name, "" for none.
-	PreviousSnapshotID string
 }
 
 // Module exports backup functionality as an fx module.
@@ -47,18 +44,17 @@ func provideScannerFactory(
 		}
 
 		return NewScanner(ScannerConfig{
-			FS:                 params.Fs,
-			ChunkSize:          cfg.ChunkSize.Int64(),
-			Repositories:       repos,
-			Storage:            storer,
-			MaxBlobSize:        cfg.BlobSizeLimit.Int64(),
-			CompressionLevel:   cfg.CompressionLevel,
-			AgeRecipients:      cfg.AgeRecipients,
-			EnableProgress:     params.EnableProgress,
-			UI:                 params.UI,
-			Exclude:            excludes,
-			SkipErrors:         params.SkipErrors,
-			PreviousSnapshotID: params.PreviousSnapshotID,
+			FS:               params.Fs,
+			ChunkSize:        cfg.ChunkSize.Int64(),
+			Repositories:     repos,
+			Storage:          storer,
+			MaxBlobSize:      cfg.BlobSizeLimit.Int64(),
+			CompressionLevel: cfg.CompressionLevel,
+			AgeRecipients:    cfg.AgeRecipients,
+			EnableProgress:   params.EnableProgress,
+			UI:               params.UI,
+			Exclude:          excludes,
+			SkipErrors:       params.SkipErrors,
 		})
 	}
 }

internal/snapshot/scanner.go

@@ -58,10 +58,6 @@ type Scanner struct {
 	compressionLevel int
 	ageRecipient     string
 	snapshotID       string // Current snapshot being processed
-	// previousSnapshotID is the most recent completed snapshot of the
-	// same name, "" for none. Only a file it lists can be counted as
-	// deleted.
-	previousSnapshotID string
 	// currentSourcePath is the source directory being scanned, stored with
 	// each file record.
 	currentSourcePath string
@@ -133,16 +129,15 @@ type ScannerConfig struct {
 	// SkipErrors skips files that cannot be opened or read (log loudly but
 	// continue); packer, database, encryption, and upload errors still abort.
 	SkipErrors bool
-	// PreviousSnapshotID is the most recent completed snapshot of the
-	// same name, "" for none.
-	PreviousSnapshotID string
 }
 
 // ScanResult contains the results of a scan operation. Files and bytes
 // are counted per file: BytesScanned is the size of the new and changed
 // files, BytesSkipped that of the unchanged ones. FilesFailed counts the
 // new and changed files that phase 2 could not store; FilesScanned
-// includes them and BytesScanned does not.
+// includes them and BytesScanned does not. ChunksCreated counts the
+// chunks that were not already stored, and NewChunkSize is their total
+// size.
 type ScanResult struct {
 	FilesScanned   int
 	FilesSkipped   int
@@ -152,6 +147,7 @@ type ScanResult struct {
 	BytesSkipped   int64
 	BytesDeleted   int64
 	ChunksCreated  int
+	NewChunkSize   int64
 	BlobsCreated   int
 	BlobsUploaded  int
 	BytesUploaded  int64
@@ -211,7 +207,6 @@ func NewScanner(cfg ScannerConfig) *Scanner {
 		compiledExclude:    compiledExclude,
 		progress:           progress,
 		skipErrors:         cfg.SkipErrors,
-		previousSnapshotID: cfg.PreviousSnapshotID,
 		ui:                 uiw,
 		pendingChunkHashes: make(map[string]struct{}),
 	}
@@ -263,9 +258,8 @@ func (s *Scanner) Scan(
 
 	filesToProcess := scanResult.FilesToProcess
 
-	// Phase 1b: Detect deleted files by comparing the previous snapshot
-	// of this name against scanned files
-	err = s.detectDeletedFiles(ctx, path, existingFiles, result)
+	// Phase 1b: Detect deleted files by comparing DB against scanned files
+	err = s.detectDeletedFilesFromMap(ctx, knownFiles, existingFiles, result)
 	if err != nil {
 		return nil, fmt.Errorf("detecting deleted files: %w", err)
 	}
@@ -445,8 +439,9 @@ func (s *Scanner) summarizeScanPhase(
 }
 
 // loadKnownFiles loads the known files at and beneath path from the
-// database into a map for fast lookup. This avoids per-file database
-// queries during the scan phase.
+// database into a map for fast lookup. Every loaded file the scan does
+// not find is counted as deleted. This avoids per-file database queries
+// during the scan phase.
 func (s *Scanner) loadKnownFiles(
 	ctx context.Context, path string,
 ) (map[string]*database.File, error) {
@@ -1874,11 +1869,12 @@ func (s *Scanner) processFileStreaming(
 	return nil
 }
 
-// updateChunkStats counts a chunk that was not already stored. The scan
-// result's file counts, BytesScanned and BytesSkipped are not touched
-// here: the scan phase counts each file once.
+// updateChunkStats counts a chunk that was not already stored, and its
+// size. The scan result's file counts, BytesScanned and BytesSkipped are
+// not touched here: the scan phase counts each file once.
 func (s *Scanner) updateChunkStats(chunkSize int64, result *ScanResult) {
 	result.ChunksCreated++
+	result.NewChunkSize += chunkSize
 
 	if s.progress != nil {
 		s.progress.GetStats().ChunksCreated.Add(1)
@@ -1946,28 +1942,21 @@ func (s *Scanner) queueFileForBatchInsert(
 	})
 }
 
-// detectDeletedFiles counts as deleted each file at or beneath path that
-// the previous snapshot of this name lists and the walk did not find.
-// A file that is excluded, or inside an excluded directory, is not
-// counted: the walk skips it whether or not it is still on disk.
-func (s *Scanner) detectDeletedFiles(
+// detectDeletedFilesFromMap finds files that existed in previous snapshots
+// but no longer exist. Uses pre-loaded maps to avoid any filesystem or
+// database access.
+func (s *Scanner) detectDeletedFilesFromMap(
 	ctx context.Context,
-	path string,
+	knownFiles map[string]*database.File,
 	existingFiles map[string]struct{},
 	result *ScanResult,
 ) error {
-	if s.previousSnapshotID == "" {
+	if len(knownFiles) == 0 {
 		return nil
 	}
 
-	previousFiles, err := s.repos.Files.ListUnderPathInSnapshot(
-		ctx, path, s.previousSnapshotID)
-	if err != nil {
-		return fmt.Errorf("listing files of snapshot %s: %w",
-			s.previousSnapshotID, err)
-	}
-
-	for _, file := range previousFiles {
+	// Check each known file against the enumerated set (no filesystem access needed)
+	for path, file := range knownFiles {
 		// Check context cancellation periodically
 		select {
 		case <-ctx.Done():
@@ -1975,16 +1964,13 @@ func (s *Scanner) detectDeletedFiles(
 		default:
 		}
 
-		filePath := file.Path.String()
-
-		_, exists := existingFiles[filePath]
-		if exists || s.excludedOrInExcludedDir(filePath, path) {
-			continue
+		// Check if the file exists in our enumerated set
+		if _, exists := existingFiles[path]; !exists {
+			// File has been deleted
+			result.FilesDeleted++
+			result.BytesDeleted += file.Size
+			log.Debug("Detected deleted file", "path", path, "size", file.Size)
 		}
-
-		result.FilesDeleted++
-		result.BytesDeleted += file.Size
-		log.Debug("Detected deleted file", "path", filePath, "size", file.Size)
 	}
 
 	if result.FilesDeleted > 0 {
@@ -1995,20 +1981,6 @@ func (s *Scanner) detectDeletedFiles(
 	return nil
 }
 
-// excludedOrInExcludedDir reports whether filePath, which is at or
-// beneath rootPath, or any directory between rootPath and it, matches an
-// exclude pattern. A pattern such as */.local/share/Trash matches the
-// directory but not the files inside it, which the walk skips too.
-func (s *Scanner) excludedOrInExcludedDir(filePath, rootPath string) bool {
-	for p := filePath; len(p) > len(rootPath); p = filepath.Dir(p) {
-		if s.shouldExclude(p, rootPath) {
-			return true
-		}
-	}
-
-	return false
-}
-
 // wrapPermissionError augments permission errors with platform-specific
 // remediation instructions. On macOS, TCC-protected directories (Calendars,
 // Reminders, Photos, etc.) return EPERM unless the running application has

internal/snapshot/snapshot.go

@@ -199,6 +199,7 @@ func (sm *SnapshotManager) UpdateSnapshotStatsExtended(
 			stats.CompressionLevel,
 			stats.BytesUploaded,
 			stats.UploadDurationMs,
+			stats.NewChunkSize,
 		)
 	})
 }
@@ -906,6 +907,7 @@ type ExtendedBackupStats struct {
 	BlobUncompressedSize int64 // Total uncompressed size of all referenced blobs
 	CompressionLevel     int   // Compression level used for this snapshot
 	UploadDurationMs     int64 // Total milliseconds spent uploading to S3
+	NewChunkSize         int64 // Total size of the chunks counted in ChunksCreated
 }
 
 // deleteOtherSnapshots deletes all snapshots except the current one

internal/vaultik/blob_fetch.go

@@ -103,8 +103,6 @@ func (v *Vaultik) FetchAndDecryptBlob(
 }
 
 // FetchBlob downloads a blob and returns a reader for the encrypted data.
-// The reader is closed as soon as ctx is cancelled, which ends a read
-// blocked inside it.
 func (v *Vaultik) FetchBlob(
 	ctx context.Context, blobHash string,
 ) (io.ReadCloser, error) {
@@ -122,47 +120,5 @@ func (v *Vaultik) FetchBlob(
 		return nil, fmt.Errorf("downloading blob %s: %w", shortHash(blobHash), err)
 	}
 
-	return newCloseOnCancelReader(ctx, rc), nil
-}
-
-// closeOnCancelReader closes the reader it wraps when ctx is cancelled.
-// Not every backend's reader stops on cancel by itself (the file
-// backend's does not), and a read stalled on a slow or hung source would
-// otherwise outlast the shutdown timeout, so the process would exit
-// before restore or deep verify removed its decrypted temporary files.
-type closeOnCancelReader struct {
-	io.ReadCloser
-
-	ctx  context.Context //nolint:containedctx // Read reports its error
-	stop func() bool
-}
-
-func newCloseOnCancelReader(
-	ctx context.Context, rc io.ReadCloser,
-) *closeOnCancelReader {
-	return &closeOnCancelReader{
-		ReadCloser: rc,
-		ctx:        ctx,
-		stop:       context.AfterFunc(ctx, func() { _ = rc.Close() }),
-	}
-}
-
-// Read returns the context's error, not the closed reader's, once ctx
-// has been cancelled.
-func (r *closeOnCancelReader) Read(p []byte) (int, error) {
-	n, err := r.ReadCloser.Read(p)
-	if err != nil && r.ctx.Err() != nil {
-		return n, r.ctx.Err()
-	}
-
-	return n, err
-}
-
-// Close closes the wrapped reader, unless the cancel already closed it.
-func (r *closeOnCancelReader) Close() error {
-	if !r.stop() {
-		return nil
-	}
-
-	return r.ReadCloser.Close()
+	return rc, nil
 }

internal/vaultik/fault_injection_test.go

@@ -661,18 +661,17 @@ func faultScannerFactory(
 ) snapshot.ScannerFactory {
 	return func(params snapshot.ScannerParams) *snapshot.Scanner {
 		return snapshot.NewScanner(snapshot.ScannerConfig{
-			FS:                 params.Fs,
-			Storage:            storer,
-			ChunkSize:          faultChunkSize,
-			MaxBlobSize:        faultMaxBlobSize,
-			CompressionLevel:   cfg.CompressionLevel,
-			AgeRecipients:      cfg.AgeRecipients,
-			Repositories:       repos,
-			EnableProgress:     params.EnableProgress,
-			UI:                 params.UI,
-			Exclude:            params.Exclude,
-			SkipErrors:         params.SkipErrors,
-			PreviousSnapshotID: params.PreviousSnapshotID,
+			FS:               params.Fs,
+			Storage:          storer,
+			ChunkSize:        faultChunkSize,
+			MaxBlobSize:      faultMaxBlobSize,
+			CompressionLevel: cfg.CompressionLevel,
+			AgeRecipients:    cfg.AgeRecipients,
+			Repositories:     repos,
+			EnableProgress:   params.EnableProgress,
+			UI:               params.UI,
+			Exclude:          params.Exclude,
+			SkipErrors:       params.SkipErrors,
 		})
 	}
 }

internal/vaultik/helpers.go

@@ -89,6 +89,22 @@ type SnapshotInfo struct {
 	RemotePresent    *bool            `json:"remote_present"`
 }
 
+// formatBytes formats bytes in a human-readable format
+func formatBytes(bytes int64) string {
+	const unit = 1024
+	if bytes < unit {
+		return fmt.Sprintf("%d B", bytes)
+	}
+
+	div, exp := int64(unit), 0
+	for n := bytes / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+
+	return fmt.Sprintf("%.1f %cB", float64(bytes)/float64(div), "KMGTPE"[exp])
+}
+
 // parseSnapshotTimestamp extracts the timestamp from a snapshot ID
 // Format: hostname_snapshotname_2026-01-12T14:41:15Z
 func parseSnapshotTimestamp(snapshotID string) (time.Time, error) {

internal/vaultik/new_chunk_size_test.go

@@ -0,0 +1,133 @@
+package vaultik_test
+
+import (
+	"bytes"
+	"context"
+	"maps"
+	"path/filepath"
+	"testing"
+
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/chunker"
+	"sneak.berlin/go/vaultik/internal/database"
+	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/storage"
+	"sneak.berlin/go/vaultik/internal/vaultik"
+)
+
+// TestNewChunkSizeOfChangedFileStaysFixed covers
+// https://git.eeqj.de/sneak/vaultik/issues/311. A backup whose only change
+// is a modified file lists the size of the chunks that change added as its
+// NEW CHUNK SIZE, and a later backup that changes the file again leaves
+// every earlier snapshot's figure as it was. The file's row in the local
+// index is shared by all three snapshots and rewritten by each backup.
+func TestNewChunkSizeOfChangedFileStaysFixed(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	fs := afero.NewOsFs()
+	tempDir := t.TempDir()
+	dataDir := filepath.Join(tempDir, "src")
+	dbPath := filepath.Join(tempDir, "index.sqlite")
+	changedPath := filepath.Join(dataDir, "changed.bin")
+
+	ctx := context.Background()
+	files := writeFaultSourceTree(t, fs, dataDir)
+	cfg := changedFileConfig(dataDir, dbPath)
+
+	appendRandomBytes(t, fs, files, changedPath, appendedFileSize)
+
+	store, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
+	require.NoError(t, err)
+
+	db, err := database.New(ctx, dbPath)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = db.Close() })
+
+	repos := database.NewRepositories(db)
+	v := newBackupVaultik(ctx, cfg, store, repos, db, fs)
+
+	require.NoError(t, backUp(v, "first"))
+
+	firstFiles := maps.Clone(files)
+	firstID := localSnapshotID(ctx, t, repos, "first")
+
+	appendRandomBytes(t, fs, files, changedPath, faultChunkSize)
+	require.NoError(t, backUp(v, "second"))
+
+	secondID := localSnapshotID(ctx, t, repos, "second")
+	secondAdded := sizeOfNewChunks(t, files, firstFiles)
+	require.Positive(t, secondAdded)
+	assert.Equal(t, secondAdded, listedNewChunkSizes(t, v)[secondID],
+		"the second snapshot must count the chunks the change added")
+
+	appendRandomBytes(t, fs, files, changedPath, faultChunkSize)
+	require.NoError(t, backUp(v, "third"))
+
+	sizes := listedNewChunkSizes(t, v)
+	assert.Equal(t, sizeOfNewChunks(t, firstFiles, nil), sizes[firstID],
+		"a later backup must not change the first snapshot's figure")
+	assert.Equal(t, secondAdded, sizes[secondID],
+		"a later backup must not change the second snapshot's figure")
+}
+
+// sizeOfNewChunks returns the total size of the distinct chunks of the
+// files in after that no file in before has, cut the way the backup cuts
+// them.
+func sizeOfNewChunks(t *testing.T, after, before map[string][]byte) int64 {
+	t.Helper()
+
+	known := make(map[string]bool)
+	for _, chunk := range chunksOf(t, before) {
+		known[chunk.Hash] = true
+	}
+
+	var total int64
+
+	for _, chunk := range chunksOf(t, after) {
+		if !known[chunk.Hash] {
+			known[chunk.Hash] = true
+			total += chunk.Size
+		}
+	}
+
+	return total
+}
+
+// chunksOf returns the chunks of every file in files.
+func chunksOf(t *testing.T, files map[string][]byte) []chunker.Chunk {
+	t.Helper()
+
+	c := chunker.NewChunker(faultChunkSize)
+
+	var all []chunker.Chunk
+
+	for _, content := range files {
+		chunks, err := c.ChunkReader(bytes.NewReader(content))
+		require.NoError(t, err)
+
+		all = append(all, chunks...)
+	}
+
+	return all
+}
+
+// listedNewChunkSizes runs `snapshot list --json` and returns each listed
+// snapshot's new_chunk_size by snapshot ID.
+func listedNewChunkSizes(t *testing.T, v *vaultik.Vaultik) map[string]int64 {
+	t.Helper()
+
+	var out bytes.Buffer
+
+	v.Stdout = &out
+	require.NoError(t, v.ListSnapshots(true))
+
+	sizes := make(map[string]int64)
+	for _, row := range decodeListJSON(t, out.String()) {
+		sizes[row.ID] = row.NewChunkSize
+	}
+
+	return sizes
+}

internal/vaultik/restore_interrupt_test.go

@@ -142,14 +142,14 @@ func TestRestoreCleansTempDirOnInterrupt(t *testing.T) {
 }
 
 // scratchEntries returns the vaultik blob-cache and snapshot-database
-// scratch entries (restore's and deep verify's) currently present in dir.
+// scratch entries currently present in dir.
 func scratchEntries(t *testing.T, dir string) []string {
 	t.Helper()
 
 	var matches []string
 
 	for _, pattern := range []string{
-		"vaultik-blobcache-*", "vaultik-restore-*", "vaultik-verify-*",
+		"vaultik-blobcache-*", "vaultik-restore-*",
 	} {
 		found, err := filepath.Glob(filepath.Join(dir, pattern))
 		require.NoError(t, err)
@@ -206,119 +206,3 @@ func TestRestoreSkipErrorsCancelDuringBlobDownload(t *testing.T) {
 	assert.NotContains(t, out.String(), srcPath,
 		"the cancel was reported as a failed file")
 }
-
-// stallingBlobStorer wraps a Storer so that every blob download hands
-// over the first half of the blob and then stalls, ignoring the context,
-// as a file:// blob on a hung USB stick or network share does. Only
-// closing the returned reader ends the stall.
-type stallingBlobStorer struct {
-	storage.Storer
-
-	once    sync.Once
-	stalled chan struct{}
-}
-
-func newStallingBlobStorer(inner storage.Storer) *stallingBlobStorer {
-	return &stallingBlobStorer{Storer: inner, stalled: make(chan struct{})}
-}
-
-func (s *stallingBlobStorer) Get(
-	ctx context.Context, key string,
-) (io.ReadCloser, error) {
-	rc, err := s.Storer.Get(ctx, key)
-	if err != nil || !strings.HasPrefix(key, "blobs/") {
-		return rc, err
-	}
-
-	blob, err := io.ReadAll(rc)
-	_ = rc.Close()
-
-	if err != nil {
-		return nil, err
-	}
-
-	// The writer is never closed, so once the first half has been read
-	// the next Read blocks until the reader is closed.
-	pr, pw := io.Pipe()
-
-	go func() {
-		_, _ = pw.Write(blob[:len(blob)/2])
-
-		s.once.Do(func() { close(s.stalled) })
-	}()
-
-	return pr, nil
-}
-
-// TestInterruptDuringStalledBlobReadCleansTempDir stops a restore and a
-// deep verify while a blob read is stalled on a source that ignores the
-// context. Stopping must end that read, so the operation unwinds and
-// removes its decrypted scratch files well within the shutdown timeout
-// (issue #325).
-//
-// Not parallel: it points TMPDIR at a private directory (via t.Setenv)
-// so it can assert on exactly the scratch files the operation created.
-func TestInterruptDuringStalledBlobReadCleansTempDir(t *testing.T) {
-	log.Initialize(log.Config{})
-
-	operations := map[string]func(v *Vaultik, snapshotID, targetDir string) error{
-		"restore": func(v *Vaultik, snapshotID, targetDir string) error {
-			return v.Restore(&RestoreOptions{
-				SnapshotID: snapshotID,
-				TargetDir:  targetDir,
-			})
-		},
-		"deep verify": func(v *Vaultik, snapshotID, _ string) error {
-			return v.RunDeepVerify(snapshotID, &VerifyOptions{Deep: true})
-		},
-	}
-
-	for name, op := range operations {
-		t.Run(name, func(t *testing.T) {
-			fs := afero.NewOsFs()
-			root := t.TempDir()
-
-			// Random content, so the blob stays large enough to stall
-			// part-way through its compressed, encrypted body.
-			cfg, storer, snapshotID, _ := backupOneFile(context.Background(),
-				t, fs, root, "a.bin", randomBytes(t, 256*1024), 0o644)
-
-			scratch := filepath.Join(root, "scratch")
-			require.NoError(t, fs.MkdirAll(scratch, 0o755))
-			t.Setenv("TMPDIR", scratch)
-
-			stalling := newStallingBlobStorer(storer)
-
-			ctx, cancel := context.WithCancel(context.Background())
-			defer cancel()
-
-			v := newRestoreVaultik(ctx, cfg, stalling, fs)
-			v.cancel = cancel
-
-			var opErr error
-
-			stop := v.StartOperation(func() {
-				opErr = op(v, snapshotID, filepath.Join(root, "restored"))
-			})
-
-			select {
-			case <-stalling.stalled:
-			case <-time.After(30 * time.Second):
-				t.Fatal("the operation never reached a blob read")
-			}
-
-			require.NotEmpty(t, scratchEntries(t, scratch),
-				"expected decrypted scratch files to exist mid-read")
-
-			stopCtx, stopCancel := context.WithTimeout(
-				context.Background(), 10*time.Second)
-			defer stopCancel()
-
-			require.True(t, stop(stopCtx),
-				"stop timed out; the stalled blob read was not interrupted")
-			require.ErrorIs(t, opErr, context.Canceled)
-			require.Empty(t, scratchEntries(t, scratch),
-				"decrypted scratch files remained after the interrupt")
-		})
-	}
-}

internal/vaultik/snapshot.go

@@ -209,6 +209,7 @@ type snapshotStats struct {
 	totalFiles         int
 	totalBytes         int64
 	totalChunks        int
+	newChunkSize       int64
 	totalBlobs         int
 	totalBytesSkipped  int64
 	totalFilesSkipped  int
@@ -240,18 +241,12 @@ func (v *Vaultik) createNamedSnapshot(
 		return err
 	}
 
-	previousSnapshotID, err := v.previousSnapshotID(snapName)
-	if err != nil {
-		return err
-	}
-
 	scanner := v.ScannerFactory(snapshot.ScannerParams{
-		EnableProgress:     !opts.Cron,
-		UI:                 v.UI,
-		Fs:                 v.Fs,
-		Exclude:            v.Config.GetExcludes(snapName),
-		SkipErrors:         opts.SkipErrors,
-		PreviousSnapshotID: previousSnapshotID,
+		EnableProgress: !opts.Cron,
+		UI:             v.UI,
+		Fs:             v.Fs,
+		Exclude:        v.Config.GetExcludes(snapName),
+		SkipErrors:     opts.SkipErrors,
 	})
 
 	snapshotID, err := v.SnapshotManager.CreateSnapshotWithName(
@@ -286,24 +281,6 @@ func (v *Vaultik) createNamedSnapshot(
 	return nil
 }
 
-// previousSnapshotID returns the ID of the most recent completed snapshot
-// named snapName in the local index, or "" when there is none.
-func (v *Vaultik) previousSnapshotID(snapName string) (string, error) {
-	snapshots, err := v.Repositories.Snapshots.ListRecent(v.ctx, listRecentLimit)
-	if err != nil {
-		return "", fmt.Errorf("listing snapshots: %w", err)
-	}
-
-	for _, s := range snapshots {
-		if s.CompletedAt != nil &&
-			parseSnapshotName(s.ID.String(), s.Hostname.String()) == snapName {
-			return s.ID.String(), nil
-		}
-	}
-
-	return "", nil
-}
-
 // resolveSnapshotPaths resolves source directories to absolute paths
 // with symlink resolution.
 func (v *Vaultik) resolveSnapshotPaths(snapName string) ([]string, error) {
@@ -365,6 +342,7 @@ func (v *Vaultik) scanAllDirectories(
 		stats.totalFiles += result.FilesScanned
 		stats.totalBytes += result.BytesScanned
 		stats.totalChunks += result.ChunksCreated
+		stats.newChunkSize += result.NewChunkSize
 		stats.totalBlobs += result.BlobsCreated
 		stats.totalFilesSkipped += result.FilesSkipped
 		stats.totalFilesFailed += result.FilesFailed
@@ -427,6 +405,7 @@ func (v *Vaultik) finalizeSnapshotMetadata(
 		BlobUncompressedSize: stats.blobUncompressedSize,
 		CompressionLevel:     v.Config.CompressionLevel,
 		UploadDurationMs:     stats.uploadDuration.Milliseconds(),
+		NewChunkSize:         stats.newChunkSize,
 	}
 
 	err = v.SnapshotManager.UpdateSnapshotStatsExtended(v.ctx, snapshotID, extStats)
@@ -657,7 +636,7 @@ func (v *Vaultik) confirmAndExecutePurge(
 			v.stdoutf("  %s (%s, %s)\n",
 				snap.ID,
 				snap.Timestamp.Format("2006-01-02 15:04:05"),
-				ubytes(snap.CompressedSize))
+				formatBytes(snap.CompressedSize))
 		}
 	}
 

internal/vaultik/snapshot_deleted_count_test.go

@@ -1,196 +0,0 @@
-package vaultik_test
-
-import (
-	"bytes"
-	"context"
-	"fmt"
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/spf13/afero"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"sneak.berlin/go/vaultik/internal/config"
-	"sneak.berlin/go/vaultik/internal/database"
-	"sneak.berlin/go/vaultik/internal/log"
-	"sneak.berlin/go/vaultik/internal/storage"
-	"sneak.berlin/go/vaultik/internal/ui"
-	"sneak.berlin/go/vaultik/internal/vaultik"
-)
-
-// These tests cover https://git.eeqj.de/sneak/vaultik/issues/304: a
-// backup counts a file as deleted only when the previous snapshot of
-// the same name had it and it is gone, and never counts an excluded
-// file.
-
-// deletedCountEnv is a backup setup over the source directory src whose
-// user-facing output is kept in out. Each test configures its snapshots
-// with setSnapshot.
-type deletedCountEnv struct {
-	v   *vaultik.Vaultik
-	out *bytes.Buffer
-	src string
-}
-
-// newDeletedCountEnv writes files, keyed by path relative to src.
-func newDeletedCountEnv(t *testing.T, files map[string][]byte) *deletedCountEnv {
-	t.Helper()
-
-	ctx := context.Background()
-	fs := afero.NewOsFs()
-	tempDir := t.TempDir()
-	srcDir := filepath.Join(tempDir, "src")
-
-	for rel, content := range files {
-		path := filepath.Join(srcDir, rel)
-		require.NoError(t, fs.MkdirAll(filepath.Dir(path), 0o755))
-		require.NoError(t, afero.WriteFile(fs, path, content, 0o644))
-	}
-
-	cfg := faultTestConfig()
-	cfg.IndexPath = filepath.Join(tempDir, "index.sqlite")
-	cfg.Snapshots = map[string]config.SnapshotConfig{}
-
-	store, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
-	require.NoError(t, err)
-
-	db, err := database.New(ctx, cfg.IndexPath)
-	require.NoError(t, err)
-	t.Cleanup(func() { _ = db.Close() })
-
-	repos := database.NewRepositories(db)
-	out := &bytes.Buffer{}
-	v := newBackupVaultik(ctx, cfg, store, repos, db, fs)
-	v.UI = ui.NewWithColor(out, false)
-
-	return &deletedCountEnv{v: v, out: out, src: srcDir}
-}
-
-// setSnapshot configures the snapshot name to back up the path rel
-// beneath src, with the given excludes.
-func (e *deletedCountEnv) setSnapshot(name, rel string, exclude ...string) {
-	e.v.Config.Snapshots[name] = config.SnapshotConfig{
-		Paths:   []string{filepath.Join(e.src, rel)},
-		Exclude: exclude,
-	}
-}
-
-// backUp runs a backup of the named snapshot and returns its output.
-func (e *deletedCountEnv) backUp(t *testing.T, name string) string {
-	t.Helper()
-
-	e.out.Reset()
-	require.NoError(t, e.v.CreateSnapshot(&vaultik.SnapshotCreateOptions{
-		Snapshots: []string{name},
-	}))
-
-	return e.out.String()
-}
-
-// A file this snapshot excludes is not counted as deleted: neither one
-// that another snapshot backs up, nor one that the previous snapshot of
-// this name had before the exclude was added.
-func TestBackupDoesNotCountExcludedFileAsDeleted(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	env := newDeletedCountEnv(t, map[string][]byte{
-		"top.txt":       []byte("top"),
-		"cache/tmp.bin": []byte("cache"),
-		"photos/a.jpg":  []byte("photo a"),
-		"photos/b.jpg":  []byte("photo b"),
-		"photos/c.jpg":  []byte("photo c"),
-	})
-	env.setSnapshot("photos", "photos")
-	env.setSnapshot("home", "", "/photos")
-
-	env.backUp(t, "photos")
-	assert.Contains(t, env.backUp(t, "home"), filesLine(2, 2, 0))
-
-	env.setSnapshot("home", "", "/photos", "/cache")
-	assert.Contains(t, env.backUp(t, "home"), filesLine(1, 0, 1))
-}
-
-// A file inside a directory that an exclude added after a backup
-// matches is not counted as deleted, though the pattern matches only the
-// directory.
-func TestBackupDoesNotCountFileInExcludedDirectoryAsDeleted(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	env := newDeletedCountEnv(t, map[string][]byte{
-		"top.txt":                         []byte("top"),
-		"user/.local/share/Trash/old.txt": []byte("old"),
-	})
-	env.setSnapshot("home", "")
-
-	assert.Contains(t, env.backUp(t, "home"), filesLine(2, 2, 0))
-
-	env.setSnapshot("home", "", "*/.local/share/Trash")
-	assert.Contains(t, env.backUp(t, "home"), filesLine(1, 0, 1))
-}
-
-// A backup counts only files that the previous snapshot of its own name
-// had, not one that a later snapshot of another name over the same path
-// had and that is since removed.
-func TestBackupIgnoresSnapshotOfAnotherName(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	env := newDeletedCountEnv(t, map[string][]byte{
-		"kept.txt": []byte("kept"),
-	})
-	env.setSnapshot("home", "")
-	env.setSnapshot("other", "")
-
-	env.backUp(t, "home")
-
-	// Snapshot start times are kept in whole seconds: wait so that other's
-	// snapshot is strictly the most recent.
-	time.Sleep(time.Second)
-
-	extra := filepath.Join(env.src, "extra.txt")
-	require.NoError(t, os.WriteFile(extra, []byte("extra"), 0o600))
-	env.backUp(t, "other")
-	require.NoError(t, os.Remove(extra))
-
-	assert.Contains(t, env.backUp(t, "home"), filesLine(1, 0, 1))
-}
-
-// A file removed from disk is counted as deleted by the next backup of
-// the snapshot that had it, and not by any later backup of that
-// snapshot, nor by the first backup of another name over the same path.
-func TestBackupCountsDeletedFileOnce(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	aContent := bytes.Repeat([]byte("a"), 1000)
-	bContent := bytes.Repeat([]byte("b"), 2000)
-	keptContent := bytes.Repeat([]byte("k"), 500)
-
-	env := newDeletedCountEnv(t, map[string][]byte{
-		"a.txt":    aContent,
-		"b.txt":    bContent,
-		"kept.txt": keptContent,
-	})
-	env.setSnapshot("home", "")
-	env.setSnapshot("other", "")
-
-	assert.Contains(t, env.backUp(t, "home"), filesLine(3, 3, 0))
-
-	require.NoError(t, os.Remove(filepath.Join(env.src, "a.txt")))
-	require.NoError(t, os.Remove(filepath.Join(env.src, "b.txt")))
-
-	summary := env.backUp(t, "home")
-	assert.Contains(t, summary,
-		"Files: 1 examined, 0 backed up, 1 unchanged, 2 deleted.")
-	assert.Contains(t, summary,
-		fmt.Sprintf("Data: %s total (%s backed up), %s deleted.",
-			env.v.UI.Size(int64(len(keptContent))), env.v.UI.Size(0),
-			env.v.UI.Size(int64(len(aContent)+len(bContent)))))
-
-	assert.Contains(t, env.backUp(t, "home"), filesLine(1, 0, 1))
-	assert.Contains(t, env.backUp(t, "other"), filesLine(1, 0, 1))
-}

internal/vaultik/snapshot_list.go

@@ -553,8 +553,8 @@ func (v *Vaultik) printSnapshotTable(snapshots []SnapshotInfo) error {
 
 		if snap.LocallyTracked {
 			id = snap.ID.String()
-			uncompressed = ubytes(snap.UncompressedSize)
-			newChunks = ubytes(snap.NewChunkSize)
+			uncompressed = formatBytes(snap.UncompressedSize)
+			newChunks = formatBytes(snap.NewChunkSize)
 		} else {
 			id = formatRemoteOnlyID(snap.RemoteKey)
 			uncompressed = remoteOnlyCell
@@ -564,7 +564,7 @@ func (v *Vaultik) printSnapshotTable(snapshots []SnapshotInfo) error {
 		_, err = fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n",
 			id,
 			snap.Timestamp.Format("2006-01-02 15:04:05"),
-			ubytes(snap.CompressedSize),
+			formatBytes(snap.CompressedSize),
 			uncompressed,
 			newChunks)
 		if err != nil {

internal/vaultik/snapshot_list_test.go

@@ -212,8 +212,8 @@ const (
 	listConfiguredName = "home"
 	listLocalID        = "testhost_home_2026-03-01T10:00:00Z"
 	listRemoteID       = "otherhost_media_2026-03-02T11:22:33Z"
-	// fiveMegabytes is printed as "5.0 MB" by every command.
-	fiveMegabytes = 5_000_000
+	// fiveMegabytes formats as "5.0 MB" through formatBytes.
+	fiveMegabytes = 5 * 1024 * 1024
 )
 
 // TestListSnapshots_RemoteWithoutSecretKey is the regression guard for
@@ -306,48 +306,6 @@ func TestListSnapshots_RemoteOnlyRowRendering(t *testing.T) {
 		"are not in the local index")
 }
 
-// TestSnapshotListAndPurgePrintSizesLikeRemoteInfo checks that the
-// `snapshot list` table and the purge listing print a byte count the way
-// `remote info` does: in powers of 1000, as the MB label says.
-func TestSnapshotListAndPurgePrintSizesLikeRemoteInfo(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	const wantSize = "5.0 MB" // fiveMegabytes
-
-	env := newListEnv(t)
-
-	// A remote-only snapshot: `snapshot list` and `remote info` both take
-	// its size from the manifest.
-	remoteKey := env.addRemote(t, listRemoteID,
-		time.Date(2026, 3, 2, 11, 22, 33, 0, time.UTC))
-
-	// A locally tracked snapshot of the same size for the purge to list.
-	// The purge prints the snapshot's blob size, the last argument here.
-	start := time.Date(2026, 3, 1, 10, 0, 0, 0, time.UTC)
-	env.addLocal(t, listLocalID, start)
-	env.addRemote(t, listLocalID, start)
-	require.NoError(t, env.v.Repositories.Snapshots.UpdateCounts(
-		context.Background(), nil, listLocalID, 0, 0, 0, 0, fiveMegabytes))
-
-	require.NoError(t, env.v.RemoteInfo(false))
-	assert.Contains(t, findTableRow(t, env.stdout.String(), remoteKey[:16]),
-		wantSize, "remote info")
-
-	env.stdout.Reset()
-	require.NoError(t, env.v.ListSnapshots(false))
-	assert.Contains(t, findTableRow(t, env.stdout.String(),
-		"<remote only:"+remoteKey[:12]+">"), wantSize, "snapshot list")
-
-	// Without --force and with nothing on stdin the purge lists what it
-	// would delete, reads no confirmation, and deletes nothing.
-	env.stdout.Reset()
-	require.NoError(t, env.v.PurgeSnapshotsWithOptions(
-		&vaultik.SnapshotPurgeOptions{OlderThan: "1d"}))
-	assert.Contains(t, findTableRow(t, env.stdout.String(), listLocalID),
-		wantSize, "snapshot purge")
-}
-
 // findTableRow returns the single output line containing needle.
 func findTableRow(t *testing.T, out, needle string) string {
 	t.Helper()
@@ -487,6 +445,7 @@ type listJSONRow struct {
 	RemoteKey      string `json:"remote_key"`
 	Timestamp      string `json:"timestamp"`
 	CompressedSize int64  `json:"compressed_size"`
+	NewChunkSize   int64  `json:"new_chunk_size"`
 	LocallyTracked bool   `json:"locally_tracked"`
 	RemotePresent  *bool  `json:"remote_present"`
 }