Implement per-repository cache

archiver.go

@@ -53,7 +53,7 @@ func NewArchiver(s Server) (*Archiver, error) {
 	arch.m = NewMap()
 
 	// init cache
-	arch.c, err = NewCache()
+	arch.c, err = NewCache(s)
 	if err != nil {
 		return nil, err
 	}

cache.go

@@ -7,22 +7,29 @@ import (
 	"path/filepath"
 
 	"github.com/restic/restic/backend"
+	"github.com/restic/restic/debug"
 )
 
-// for testing
-var getCacheDir = GetCacheDir
-
 type Cache struct {
 	base string
 }
 
-func NewCache() (*Cache, error) {
-	dir, err := getCacheDir()
-	if err != nil {
-		return nil, err
+func NewCache(be backend.IDer) (c *Cache, err error) {
+	// try to get explicit cache dir from environment
+	dir := os.Getenv("RESTIC_CACHE")
+
+	// otherwise try OS specific default
+	if dir == "" {
+		dir, err = GetCacheDir()
+		if err != nil {
+			return nil, err
+		}
 	}
 
-	return &Cache{base: dir}, nil
+	basedir := filepath.Join(dir, be.ID().String())
+	debug.Log("Cache.New", "opened cache at %v", basedir)
+
+	return &Cache{base: basedir}, nil
 }
 
 func (c *Cache) Has(t backend.Type, subtype string, id backend.ID) (bool, error) {

cmd/restic/cmd_cache.go

@@ -42,7 +42,7 @@ func (cmd CmdCache) Execute(args []string) error {
 		return err
 	}
 
-	cache, err := restic.NewCache()
+	cache, err := restic.NewCache(s)
 	if err != nil {
 		return err
 	}

cmd/restic/main.go

@@ -79,7 +79,7 @@ func (cmd CmdInit) Execute(args []string) error {
 		os.Exit(1)
 	}
 
-	fmt.Printf("created restic backend at %s\n", opts.Repo)
+	fmt.Printf("created restic backend %v at %s\n", s.ID().Str(), opts.Repo)
 
 	return nil
 }

key_test.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/restic/restic"
@@ -22,7 +23,12 @@ func setupBackend(t testing.TB) restic.Server {
 	tempdir, err := ioutil.TempDir(*testTempDir, "restic-test-")
 	ok(t, err)
 
-	b, err := backend.CreateLocal(tempdir)
+	// create repository below temp dir
+	b, err := backend.CreateLocal(filepath.Join(tempdir, "repo"))
+	ok(t, err)
+
+	// set cache dir
+	err = os.Setenv("RESTIC_CACHE", filepath.Join(tempdir, "cache"))
 	ok(t, err)
 
 	return restic.NewServer(b)