| // Copyright 2019 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package datastore |
| |
| import ( |
| "encoding/base64" |
| "strings" |
| |
| "cloud.google.com/go/datastore/internal/gaepb" |
| "github.com/golang/protobuf/proto" |
| ) |
| |
| // decodeGAEKey attempts to decode the given encoded key generated by the |
| // GAE Datastore package (google.golang.org/appengine/datastore), returning nil |
| // if the key couldn't be decoded. |
| func decodeGAEKey(encoded string) *Key { |
| // Re-add padding. |
| if m := len(encoded) % 4; m != 0 { |
| encoded += strings.Repeat("=", 4-m) |
| } |
| |
| b, err := base64.URLEncoding.DecodeString(encoded) |
| if err != nil { |
| return nil |
| } |
| ref := new(gaepb.Reference) |
| if err := proto.Unmarshal(b, ref); err != nil { |
| return nil |
| } |
| return gaeProtoToKey(ref) |
| } |
| |
| // gaeProtoToKey accepts a GAE Datastore key and converts it to a Cloud Datastore key. |
| // This is adapted from the "protoToKey" function in the appengine/datastore package. |
| // |
| // NOTE(cbro): this is a lossy operation, as GAE Datastore keys include the project/app ID, |
| // but Cloud Datastore keys do not. |
| func gaeProtoToKey(r *gaepb.Reference) *Key { |
| namespace := r.GetNameSpace() |
| var k *Key |
| for _, e := range r.Path.Element { |
| k = &Key{ |
| Kind: e.GetType(), |
| Name: e.GetName(), |
| ID: e.GetId(), |
| Parent: k, |
| Namespace: namespace, |
| } |
| } |
| if !k.valid() { |
| return nil |
| } |
| return k |
| } |