Add filter by tag and path to stats command

changelog/unreleased/issue-2858

@@ -0,0 +1,9 @@
+Enhancement: Support filtering snapshots by tag and path in the stats command
+
+We've added filtering snapshots by `--tag tagList` and by `--path path` to
+the `stats` command. This includes filtering of only 'latest' snapshots or
+all snapshots in a repository.
+
+https://github.com/restic/restic/issues/2858
+https://github.com/restic/restic/pull/2859
+https://forum.restic.net/t/stats-for-a-host-and-filtered-snapshots/3020

cmd/restic/cmd_stats.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"path/filepath"
 
-	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
 	"github.com/restic/restic/internal/walker"
 
@@ -15,18 +14,19 @@ import (
 )
 
 var cmdStats = &cobra.Command{
-	Use:   "stats [flags] [snapshot-ID]",
+	Use:   "stats [flags] [snapshot ID] [...]",
 	Short: "Scan the repository and show basic statistics",
 	Long: `
-The "stats" command walks one or all snapshots in a repository and
+The "stats" command walks one or multiple snapshots in a repository
-accumulates statistics about the data stored therein. It reports on
+and accumulates statistics about the data stored therein. It reports 
-the number of unique files and their sizes, according to one of
+on the number of unique files and their sizes, according to one of
 the counting modes as given by the --mode flag.
 
-If no snapshot is specified, all snapshots will be considered. Some
+It operates on all snapshots matching the selection criteria or all
-modes make more sense over just a single snapshot, while others
+snapshots if nothing is specified. The special snapshot ID "latest"
-are useful across all snapshots, depending on what you are trying
+is also supported. Some modes make more sense over 
-to calculate.
+just a single snapshot, while others are useful across all snapshots,
+depending on what you are trying to calculate.
 
 The modes are:
 
@@ -50,11 +50,26 @@ Exit status is 0 if the command was successful, and non-zero if there was any er
 	},
 }
 
+// StatsOptions collects all options for the stats command.
+type StatsOptions struct {
+	// the mode of counting to perform (see consts for available modes)
+	countMode string
+
+	// filter snapshots by, if given by user
+	Hosts []string
+	Tags  restic.TagLists
+	Paths []string
+}
+
+var statsOptions StatsOptions
+
 func init() {
 	cmdRoot.AddCommand(cmdStats)
 	f := cmdStats.Flags()
-	f.StringVar(&countMode, "mode", countModeRestoreSize, "counting mode: restore-size (default), files-by-contents, blobs-per-file, or raw-data")
+	f.StringVar(&statsOptions.countMode, "mode", countModeRestoreSize, "counting mode: restore-size (default), files-by-contents, blobs-per-file or raw-data")
-	f.StringArrayVarP(&snapshotByHosts, "host", "H", nil, "filter latest snapshot by this hostname (can be specified multiple times)")
+	f.StringArrayVarP(&statsOptions.Hosts, "host", "H", nil, "only consider snapshots with the given `host` (can be specified multiple times)")
+	f.Var(&statsOptions.Tags, "tag", "only consider snapshots which include this `taglist` in the format `tag[,tag,...]` (can be specified multiple times)")
+	f.StringArrayVar(&statsOptions.Paths, "path", nil, "only consider snapshots which include this (absolute) `path` (can be specified multiple times)")
 }
 
 func runStats(gopts GlobalOptions, args []string) error {
@@ -89,52 +104,25 @@ func runStats(gopts GlobalOptions, args []string) error {
 
 	// create a container for the stats (and other needed state)
 	stats := &statsContainer{
-		uniqueFiles:  make(map[fileID]struct{}),
+		uniqueFiles:    make(map[fileID]struct{}),
-		uniqueInodes: make(map[uint64]struct{}),
+		uniqueInodes:   make(map[uint64]struct{}),
-		fileBlobs:    make(map[string]restic.IDSet),
+		fileBlobs:      make(map[string]restic.IDSet),
-		blobs:        restic.NewBlobSet(),
+		blobs:          restic.NewBlobSet(),
+		snapshotsCount: 0,
 	}
 
-	if snapshotIDString != "" {
+	for sn := range FindFilteredSnapshots(ctx, repo, statsOptions.Hosts, statsOptions.Tags, statsOptions.Paths, args) {
-		// scan just a single snapshot
+		err = statsWalkSnapshot(ctx, sn, repo, stats)
-
-		var sID restic.ID
-		if snapshotIDString == "latest" {
-			sID, err = restic.FindLatestSnapshot(ctx, repo, []string{}, []restic.TagList{}, snapshotByHosts)
-			if err != nil {
-				return errors.Fatalf("latest snapshot for criteria not found: %v", err)
-			}
-		} else {
-			sID, err = restic.FindSnapshot(repo, snapshotIDString)
-			if err != nil {
-				return errors.Fatalf("error loading snapshot: %v", err)
-			}
-		}
-
-		snapshot, err := restic.LoadSnapshot(ctx, repo, sID)
-		if err != nil {
-			return errors.Fatalf("error loading snapshot from repo: %v", err)
-		}
-
-		err = statsWalkSnapshot(ctx, snapshot, repo, stats)
 		if err != nil {
 			return fmt.Errorf("error walking snapshot: %v", err)
 		}
-	} else {
-		// iterate every snapshot in the repo
-		err = repo.List(ctx, restic.SnapshotFile, func(snapshotID restic.ID, size int64) error {
-			snapshot, err := restic.LoadSnapshot(ctx, repo, snapshotID)
-			if err != nil {
-				return fmt.Errorf("Error loading snapshot %s: %v", snapshotID.Str(), err)
-			}
-			return statsWalkSnapshot(ctx, snapshot, repo, stats)
-		})
 	}
+
 	if err != nil {
 		return err
 	}
 
-	if countMode == countModeRawData {
+	if statsOptions.countMode == countModeRawData {
 		// the blob handles have been collected, but not yet counted
 		for blobHandle := range stats.blobs {
 			blobSize, found := repo.LookupBlobSize(blobHandle.ID, blobHandle.Type)
@@ -154,22 +142,16 @@ func runStats(gopts GlobalOptions, args []string) error {
 		return nil
 	}
 
-	// inform the user what was scanned and how it was scanned
+	Printf("Stats in %s mode:\n", statsOptions.countMode)
-	snapshotsScanned := snapshotIDString
+	Printf("Snapshots processed:   %d\n", stats.snapshotsCount)
-	if snapshotsScanned == "latest" {
-		snapshotsScanned = "the latest snapshot"
-	} else if snapshotsScanned == "" {
-		snapshotsScanned = "all snapshots"
-	}
-	Printf("Stats for %s in %s mode:\n", snapshotsScanned, countMode)
 
 	if stats.TotalBlobCount > 0 {
-		Printf("  Total Blob Count:   %d\n", stats.TotalBlobCount)
+		Printf("   Total Blob Count:   %d\n", stats.TotalBlobCount)
 	}
 	if stats.TotalFileCount > 0 {
-		Printf("  Total File Count:   %d\n", stats.TotalFileCount)
+		Printf("   Total File Count:   %d\n", stats.TotalFileCount)
 	}
-	Printf("        Total Size:   %-5s\n", formatBytes(stats.TotalSize))
+	Printf("         Total Size:   %-5s\n", formatBytes(stats.TotalSize))
 
 	return nil
 }
@@ -179,7 +161,9 @@ func statsWalkSnapshot(ctx context.Context, snapshot *restic.Snapshot, repo rest
 		return fmt.Errorf("snapshot %s has nil tree", snapshot.ID().Str())
 	}
 
-	if countMode == countModeRawData {
+	stats.snapshotsCount++
+
+	if statsOptions.countMode == countModeRawData {
 		// count just the sizes of unique blobs; we don't need to walk the tree
 		// ourselves in this case, since a nifty function does it for us
 		return restic.FindUsedBlobs(ctx, repo, *snapshot.Tree, stats.blobs)
@@ -189,6 +173,7 @@ func statsWalkSnapshot(ctx context.Context, snapshot *restic.Snapshot, repo rest
 	if err != nil {
 		return fmt.Errorf("walking tree %s: %v", *snapshot.Tree, err)
 	}
+
 	return nil
 }
 
@@ -201,19 +186,19 @@ func statsWalkTree(repo restic.Repository, stats *statsContainer) walker.WalkFun
 			return true, nil
 		}
 
-		if countMode == countModeUniqueFilesByContents || countMode == countModeBlobsPerFile {
+		if statsOptions.countMode == countModeUniqueFilesByContents || statsOptions.countMode == countModeBlobsPerFile {
 			// only count this file if we haven't visited it before
 			fid := makeFileIDByContents(node)
 			if _, ok := stats.uniqueFiles[fid]; !ok {
 				// mark the file as visited
 				stats.uniqueFiles[fid] = struct{}{}
 
-				if countMode == countModeUniqueFilesByContents {
+				if statsOptions.countMode == countModeUniqueFilesByContents {
 					// simply count the size of each unique file (unique by contents only)
 					stats.TotalSize += node.Size
 					stats.TotalFileCount++
 				}
-				if countMode == countModeBlobsPerFile {
+				if statsOptions.countMode == countModeBlobsPerFile {
 					// count the size of each unique blob reference, which is
 					// by unique file (unique by contents and file path)
 					for _, blobID := range node.Content {
@@ -243,7 +228,7 @@ func statsWalkTree(repo restic.Repository, stats *statsContainer) walker.WalkFun
 			}
 		}
 
-		if countMode == countModeRestoreSize {
+		if statsOptions.countMode == countModeRestoreSize {
 			// as this is a file in the snapshot, we can simply count its
 			// size without worrying about uniqueness, since duplicate files
 			// will still be restored
@@ -275,23 +260,13 @@ func makeFileIDByContents(node *restic.Node) fileID {
 
 func verifyStatsInput(gopts GlobalOptions, args []string) error {
 	// require a recognized counting mode
-	switch countMode {
+	switch statsOptions.countMode {
 	case countModeRestoreSize:
 	case countModeUniqueFilesByContents:
 	case countModeBlobsPerFile:
 	case countModeRawData:
 	default:
-		return fmt.Errorf("unknown counting mode: %s (use the -h flag to get a list of supported modes)", countMode)
+		return fmt.Errorf("unknown counting mode: %s (use the -h flag to get a list of supported modes)", statsOptions.countMode)
-	}
-
-	// ensure at most one snapshot was specified
-	if len(args) > 1 {
-		return fmt.Errorf("only one snapshot may be specified")
-	}
-
-	// if a snapshot was specified, mark it as the one to scan
-	if len(args) == 1 {
-		snapshotIDString = args[0]
 	}
 
 	return nil
@@ -320,23 +295,14 @@ type statsContainer struct {
 	// blobs is used to count individual unique blobs,
 	// independent of references to files
 	blobs restic.BlobSet
+
+	// holds count of all considered snapshots
+	snapshotsCount int
 }
 
 // fileID is a 256-bit hash that distinguishes unique files.
 type fileID [32]byte
 
-var (
-	// the mode of counting to perform
-	countMode string
-
-	// the snapshot to scan, as given by the user
-	snapshotIDString string
-
-	// snapshotByHost is the host to filter latest
-	// snapshot by, if given by user
-	snapshotByHosts []string
-)
-
 const (
 	countModeRestoreSize           = "restore-size"
 	countModeUniqueFilesByContents = "files-by-contents"

doc/manual_rest.rst

@@ -306,6 +306,10 @@ host by using the ``--host`` flag:
 There we see that it would take 482 GiB of disk space to restore the latest
 snapshot from "myserver".
 
+In case you have multiple backups running from the same host so can also use
+``--tag`` and ``--path`` to be more specific about which snapshots you
+are looking for.
+
 But how much space does that snapshot take on disk? In other words, how much
 has restic's deduplication helped? We can check: