package restic import ( "context" "encoding/json" "fmt" "io" "math/rand" "testing" "time" "github.com/restic/restic/internal/errors" "github.com/restic/chunker" ) // fakeFile returns a reader which yields deterministic pseudo-random data. func fakeFile(seed, size int64) io.Reader { return io.LimitReader(rand.New(rand.NewSource(seed)), size) } type fakeFileSystem struct { t testing.TB repo Repository duplication float32 buf []byte chunker *chunker.Chunker rand *rand.Rand } // saveFile reads from rd and saves the blobs in the repository. The list of // IDs is returned. func (fs *fakeFileSystem) saveFile(ctx context.Context, rd io.Reader) (blobs IDs) { if fs.buf == nil { fs.buf = make([]byte, chunker.MaxSize) } if fs.chunker == nil { fs.chunker = chunker.New(rd, fs.repo.Config().ChunkerPolynomial) } else { fs.chunker.Reset(rd, fs.repo.Config().ChunkerPolynomial) } blobs = IDs{} for { chunk, err := fs.chunker.Next(fs.buf) if errors.Cause(err) == io.EOF { break } if err != nil { fs.t.Fatalf("unable to save chunk in repo: %v", err) } id := Hash(chunk.Data) if !fs.blobIsKnown(id, DataBlob) { _, _, err := fs.repo.SaveBlob(ctx, DataBlob, chunk.Data, id, true) if err != nil { fs.t.Fatalf("error saving chunk: %v", err) } } blobs = append(blobs, id) } return blobs } const ( maxFileSize = 20000 maxSeed = 32 maxNodes = 15 ) func (fs *fakeFileSystem) treeIsKnown(tree *Tree) (bool, []byte, ID) { data, err := json.Marshal(tree) if err != nil { fs.t.Fatalf("json.Marshal(tree) returned error: %v", err) return false, nil, ID{} } data = append(data, '\n') id := Hash(data) return fs.blobIsKnown(id, TreeBlob), data, id } func (fs *fakeFileSystem) blobIsKnown(id ID, t BlobType) bool { if fs.rand.Float32() < fs.duplication { return false } if fs.repo.Index().Has(id, t) { return true } return false } // saveTree saves a tree of fake files in the repo and returns the ID. func (fs *fakeFileSystem) saveTree(ctx context.Context, seed int64, depth int) ID { rnd := rand.NewSource(seed) numNodes := int(rnd.Int63() % maxNodes) var tree Tree for i := 0; i < numNodes; i++ { // randomly select the type of the node, either tree (p = 1/4) or file (p = 3/4). if depth > 1 && rnd.Int63()%4 == 0 { treeSeed := rnd.Int63() % maxSeed id := fs.saveTree(ctx, treeSeed, depth-1) node := &Node{ Name: fmt.Sprintf("dir-%v", treeSeed), Type: "dir", Mode: 0755, Subtree: &id, } tree.Nodes = append(tree.Nodes, node) continue } fileSeed := rnd.Int63() % maxSeed fileSize := (maxFileSize / maxSeed) * fileSeed node := &Node{ Name: fmt.Sprintf("file-%v", fileSeed), Type: "file", Mode: 0644, Size: uint64(fileSize), } node.Content = fs.saveFile(ctx, fakeFile(fileSeed, fileSize)) tree.Nodes = append(tree.Nodes, node) } known, buf, id := fs.treeIsKnown(&tree) if known { return id } _, _, err := fs.repo.SaveBlob(ctx, TreeBlob, buf, id, false) if err != nil { fs.t.Fatal(err) } return id } // TestCreateSnapshot creates a snapshot filled with fake data. The // fake data is generated deterministically from the timestamp `at`, which is // also used as the snapshot's timestamp. The tree's depth can be specified // with the parameter depth. The parameter duplication is a probability that // the same blob will saved again. func TestCreateSnapshot(t testing.TB, repo Repository, at time.Time, depth int, duplication float32) *Snapshot { seed := at.Unix() t.Logf("create fake snapshot at %s with seed %d", at, seed) fakedir := fmt.Sprintf("fakedir-at-%v", at.Format("2006-01-02 15:04:05")) snapshot, err := NewSnapshot([]string{fakedir}, []string{"test"}, "foo", time.Now()) if err != nil { t.Fatal(err) } snapshot.Time = at fs := fakeFileSystem{ t: t, repo: repo, duplication: duplication, rand: rand.New(rand.NewSource(seed)), } treeID := fs.saveTree(context.TODO(), seed, depth) snapshot.Tree = &treeID id, err := repo.SaveJSONUnpacked(context.TODO(), SnapshotFile, snapshot) if err != nil { t.Fatal(err) } snapshot.id = &id t.Logf("saved snapshot %v", id.Str()) err = repo.Flush(context.Background()) if err != nil { t.Fatal(err) } return snapshot } // TestParseID parses s as a ID and panics if that fails. func TestParseID(s string) ID { id, err := ParseID(s) if err != nil { panic(fmt.Sprintf("unable to parse string %q as ID: %v", s, err)) } return id }