check cross device rename error

weed/filer/filer_rename.go

@@ -0,0 +1,30 @@
+package filer
+
+import (
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"strings"
+)
+
+func (f *Filer) CanRename(source, target util.FullPath) error {
+	sourceBucket := f.DetectBucket(source)
+	targetBucket := f.DetectBucket(target)
+	if sourceBucket != targetBucket {
+		return fmt.Errorf("can not move across collection %s => %s", sourceBucket, targetBucket)
+	}
+	return nil
+}
+
+func (f *Filer) DetectBucket(source util.FullPath) (bucket string) {
+	if strings.HasPrefix(string(source), f.DirBucketsPath+"/") {
+		bucketAndObjectKey := string(source)[len(f.DirBucketsPath)+1:]
+		t := strings.Index(bucketAndObjectKey, "/")
+		if t < 0 {
+			bucket = bucketAndObjectKey
+		}
+		if t > 0 {
+			bucket = bucketAndObjectKey[:t]
+		}
+	}
+	return bucket
+}