jdeng · July 25, 2020 04:27 · Jul 25, 2020
diff --git a/test.go b/test.go
@@ -0,0 +1,166 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"flag"
+	"fmt"
+
+	// "os"
+	"path"
+	"path/filepath"
+	"time"
+
+	restic "github.com/restic/restic/cmd/global"
+)
+
+func splitPath(p string) []string {
+	d, f := path.Split(p)
+	if d == "" || d == "/" {
+		return []string{f}
+	}
+	s := splitPath(path.Clean(d))
+	return append(s, f)
+}
+
+func getFileBytesFromNode(ctx context.Context, repo restic.Repository, node *restic.Node) ([]byte, error) {
+	var out bytes.Buffer
+	var buf []byte
+	for _, id := range node.Content {
+		size, found := repo.LookupBlobSize(id, restic.DataBlob)
+		if !found {
+			return nil, fmt.Errorf("id %v not found in repository", id)
+		}
+
+		buf = buf[:cap(buf)]
+		if len(buf) < restic.CiphertextLength(int(size)) {
+			buf = restic.NewBlobBuffer(int(size))
+		}
+
+		n, err := repo.LoadBlob(ctx, restic.DataBlob, id, buf)
+		if err != nil {
+			return nil, err
+		}
+		buf = n
+
+		_, err = out.Write(buf)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return out.Bytes(), nil
+}
+
+func getFileBytes(ctx context.Context, tree *restic.Tree, repo restic.Repository, prefix string, pathComponents []string) ([]byte, error) {
+	if tree == nil {
+		return nil, fmt.Errorf("called with a nil tree")
+	}
+	if repo == nil {
+		return nil, fmt.Errorf("called with a nil repository")
+	}
+	l := len(pathComponents)
+	if l == 0 {
+		return nil, fmt.Errorf("empty path components")
+	}
+	item := filepath.Join(prefix, pathComponents[0])
+	for _, node := range tree.Nodes {
+		if node.Name == pathComponents[0] {
+			switch {
+			case l == 1 && node.Type == "file":
+				return getFileBytesFromNode(ctx, repo, node)
+			case l > 1 && node.Type == "dir":
+				subtree, err := repo.LoadTree(ctx, *node.Subtree)
+				if err != nil {
+					return nil, err
+				}
+				return getFileBytes(ctx, subtree, repo, item, pathComponents[1:])
+			case l > 1:
+				return nil, fmt.Errorf("%q should be a dir, but s a %q", item, node.Type)
+			case node.Type != "file":
+				return nil, fmt.Errorf("%q should be a file, but is a %q", item, node.Type)
+			}
+		}
+	}
+	return nil, fmt.Errorf("path %q not found in snapshot", item)
+}
+
+func LoadRepository(ctx context.Context, repository, password, rootPath string) (repo restic.Repository, tree *restic.Tree, err error) {
+	opts := restic.GlobalOptions{Repo: repository, Ctx: ctx}
+	repo, err = OpenRepository(opts, password)
+	if err != nil {
+		return
+	}
+
+	err = repo.LoadIndex(ctx)
+	if err != nil {
+		return
+	}
+
+	id, err := restic.FindLatestSnapshot(ctx, repo, []string{rootPath}, []restic.TagList{}, []string{})
+	if err != nil {
+		return
+	}
+
+	sn, err := restic.LoadSnapshot(ctx, repo, id)
+	if err != nil {
+		return
+	}
+
+	tree, err = repo.LoadTree(ctx, *sn.Tree)
+	return
+}
+
+func elapsed(what string) func() {
+	start := time.Now()
+	return func() {
+		fmt.Printf("%s took %v\n", what, time.Since(start))
+	}
+}
+
+func GetFileBytes(ctx context.Context, repo restic.Repository, tree *restic.Tree, p string) ([]byte, error) {
+	defer elapsed("GetFileBytes: " + p)()
+
+	prefix := ""
+	splittedPath := splitPath(p)
+	return getFileBytes(ctx, tree, repo, prefix, splittedPath)
+}
+
+const maxKeys = 20
+
+// OpenRepository reads the password and opens the repository.
+func OpenRepository(opts restic.GlobalOptions, password string) (restic.Repository, error) {
+	be, err := restic.Open(opts, restic.Options{})
+	if err != nil {
+		return nil, err
+	}
+
+	s := restic.NewRepository(be)
+
+	err = s.SearchKey(opts.Ctx, password, maxKeys, opts.KeyHint)
+	if err != nil {
+		return nil, err
+	}
+
+	c, err := restic.NewCache(s.Config().ID, opts.CacheDir)
+	if err != nil {
+		fmt.Printf("unable to open cache: %v\n", err)
+		return s, nil
+	}
+
+	// start using the cache
+	s.UseCache(c)
+	return s, nil
+}
+
+var (
+	repo     = flag.String("repo", "", "repository address")
+	password = flag.String("password", "", "password")
+	root     = flag.String("root", "", "root path")
+)
+
+func main() {
+	flag.Parse()
+	r, tree, err := LoadRepository(context.Background(), *repo, *password, *root)
+	fmt.Printf("repo: %v, tree: %v, err: %v\n", r, tree, err)
+}