Add MasterIndex.PackSize()

internal/repository/master_index.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 
 	"github.com/restic/restic/internal/debug"
+	"github.com/restic/restic/internal/pack"
 	"github.com/restic/restic/internal/restic"
 	"github.com/restic/restic/internal/ui/progress"
 	"golang.org/x/sync/errgroup"
@@ -111,6 +112,27 @@ func (mi *MasterIndex) Packs() restic.IDSet {
 	return packs
 }
 
+// PackSize returns the size of all packs computed by index information.
+// If onlyHdr is set to true, only the size of the header is returned
+// Note that this function only gives correct sizes, if there are no
+// duplicates in the index.
+func (mi *MasterIndex) PackSize(ctx context.Context, onlyHdr bool) map[restic.ID]int64 {
+	packSize := make(map[restic.ID]int64)
+
+	for blob := range mi.Each(ctx) {
+		size, ok := packSize[blob.PackID]
+		if !ok {
+			size = pack.HeaderSize
+		}
+		if !onlyHdr {
+			size += int64(blob.Length)
+		}
+		packSize[blob.PackID] = size + int64(pack.EntrySize)
+	}
+
+	return packSize
+}
+
 // Count returns the number of blobs of type t in the index.
 func (mi *MasterIndex) Count(t restic.BlobType) (n uint) {
 	mi.idxMutex.RLock()