Allow multiple entries in the index

src/restic/repository/index.go

@@ -18,7 +18,7 @@ import (
 // Index holds a lookup table for id -> pack.
 type Index struct {
 	m    sync.Mutex
-	pack map[backend.ID]indexEntry
+	pack map[backend.ID][]indexEntry
 
 	final      bool       // set to true for all indexes read from the backend ("finalized")
 	id         backend.ID // set to the ID of the index when it's finalized
@@ -36,18 +36,19 @@ type indexEntry struct {
 // NewIndex returns a new index.
 func NewIndex() *Index {
 	return &Index{
-		pack:    make(map[backend.ID]indexEntry),
+		pack:    make(map[backend.ID][]indexEntry),
 		created: time.Now(),
 	}
 }
 
 func (idx *Index) store(blob PackedBlob) {
-	idx.pack[blob.ID] = indexEntry{
+	list := idx.pack[blob.ID]
+	idx.pack[blob.ID] = append(list, indexEntry{
 		tpe:    blob.Type,
 		packID: blob.PackID,
 		offset: blob.Offset,
 		length: blob.Length,
-	}
+	})
 }
 
 // Final returns true iff the index is already written to the repository, it is
@@ -131,7 +132,8 @@ func (idx *Index) Lookup(id backend.ID) (pb PackedBlob, err error) {
 	idx.m.Lock()
 	defer idx.m.Unlock()
 
-	if p, ok := idx.pack[id]; ok {
+	if packs, ok := idx.pack[id]; ok {
+		p := packs[0]
 		debug.Log("Index.Lookup", "id %v found in pack %v at %d, length %d",
 			id.Str(), p.packID.Str(), p.offset, p.length)
 
@@ -154,7 +156,8 @@ func (idx *Index) ListPack(id backend.ID) (list []PackedBlob) {
 	idx.m.Lock()
 	defer idx.m.Unlock()
 
-	for blobID, entry := range idx.pack {
+	for blobID, packList := range idx.pack {
+		for _, entry := range packList {
 			if entry.packID == id {
 				list = append(list, PackedBlob{
 					ID:     blobID,
@@ -165,6 +168,7 @@ func (idx *Index) ListPack(id backend.ID) (list []PackedBlob) {
 				})
 			}
 		}
+	}
 
 	return list
 }
@@ -257,7 +261,8 @@ func (idx *Index) Each(done chan struct{}) <-chan PackedBlob {
 			close(ch)
 		}()
 
-		for id, blob := range idx.pack {
+		for id, packs := range idx.pack {
+			for _, blob := range packs {
 				select {
 				case <-done:
 					return
@@ -270,6 +275,7 @@ func (idx *Index) Each(done chan struct{}) <-chan PackedBlob {
 				}:
 				}
 			}
+		}
 	}()
 
 	return ch
@@ -281,9 +287,11 @@ func (idx *Index) Packs() backend.IDSet {
 	defer idx.m.Unlock()
 
 	packs := backend.NewIDSet()
-	for _, entry := range idx.pack {
+	for _, list := range idx.pack {
+		for _, entry := range list {
 			packs.Insert(entry.packID)
 		}
+	}
 
 	return packs
 }
@@ -294,12 +302,14 @@ func (idx *Index) Count(t pack.BlobType) (n uint) {
 	idx.m.Lock()
 	defer idx.m.Unlock()
 
-	for id, blob := range idx.pack {
+	for id, list := range idx.pack {
+		for _, blob := range list {
 			if blob.tpe == t {
 				n++
 				debug.Log("Index.Count", "  blob %v counted: %v", id.Str(), blob)
 			}
 		}
+	}
 
 	return
 }
@@ -330,7 +340,8 @@ func (idx *Index) generatePackList() ([]*packJSON, error) {
 	list := []*packJSON{}
 	packs := make(map[backend.ID]*packJSON)
 
-	for id, blob := range idx.pack {
+	for id, packedBlobs := range idx.pack {
+		for _, blob := range packedBlobs {
 			if blob.packID.IsNull() {
 				panic("null pack id")
 			}
@@ -362,6 +373,7 @@ func (idx *Index) generatePackList() ([]*packJSON, error) {
 				Length: blob.length,
 			})
 		}
+	}
 
 	debug.Log("Index.generatePackList", "done")