-> drives/sync (#438)

drives/sync/synchronizer.go

@@ -0,0 +1,59 @@
+package sync
+
+import (
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"os"
+)
+
+func Synchronize(src, dst Target) error {
+	srcTree, err := src.Inventory()
+	if err != nil {
+		return errors.Wrap(err, "error creating source inventory")
+	}
+
+	dstTree, err := dst.Inventory()
+	if err != nil {
+		return errors.Wrap(err, "error creating destination inventory")
+	}
+
+	dstIndex := make(map[string]*Object)
+	for _, f := range dstTree {
+		dstIndex[f.Path] = f
+	}
+
+	var copyList []*Object
+	for _, srcF := range srcTree {
+		if dstF, found := dstIndex[srcF.Path]; found {
+			if !srcF.IsDir && (dstF.Size != srcF.Size || dstF.Modified.Unix() != srcF.Modified.Unix()) {
+				logrus.Debugf("%v <- dstF.Size = '%d', srcF.Size = '%d', dstF.Modified.UTC = '%d', srcF.Modified.UTC = '%d'", srcF.Path, dstF.Size, srcF.Size, dstF.Modified.Unix(), srcF.Modified.Unix())
+				copyList = append(copyList, srcF)
+			}
+		} else {
+			logrus.Debugf("%v <- !found", srcF.Path)
+			copyList = append(copyList, srcF)
+		}
+	}
+
+	for _, copyPath := range copyList {
+		if copyPath.IsDir {
+			if err := dst.Mkdir(copyPath.Path); err != nil {
+				return err
+			}
+		} else {
+			ss, err := src.ReadStream(copyPath.Path)
+			if err != nil {
+				return err
+			}
+			if err := dst.WriteStream(copyPath.Path, ss, os.ModePerm); err != nil {
+				return err
+			}
+			if err := dst.SetModificationTime(copyPath.Path, copyPath.Modified); err != nil {
+				return err
+			}
+		}
+		logrus.Infof("=> %v", copyPath.Path)
+	}
+
+	return nil
+}