1// Copyright 2018 Google LLC 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package datastore 16 17import ( 18 "fmt" 19 20 pb "google.golang.org/genproto/googleapis/datastore/v1" 21) 22 23// A Mutation represents a change to a Datastore entity. 24type Mutation struct { 25 key *Key // needed for transaction PendingKeys and to dedup deletions 26 mut *pb.Mutation 27 err error 28} 29 30func (m *Mutation) isDelete() bool { 31 _, ok := m.mut.Operation.(*pb.Mutation_Delete) 32 return ok 33} 34 35// NewInsert creates a mutation that will save the entity src into the datastore with 36// key k, returning an error if k already exists. 37// See Client.Put for valid values of src. 38func NewInsert(k *Key, src interface{}) *Mutation { 39 if !k.valid() { 40 return &Mutation{err: ErrInvalidKey} 41 } 42 p, err := saveEntity(k, src) 43 if err != nil { 44 return &Mutation{err: err} 45 } 46 return &Mutation{ 47 key: k, 48 mut: &pb.Mutation{Operation: &pb.Mutation_Insert{Insert: p}}, 49 } 50} 51 52// NewUpsert creates a mutation that saves the entity src into the datastore with key 53// k, whether or not k exists. See Client.Put for valid values of src. 54func NewUpsert(k *Key, src interface{}) *Mutation { 55 if !k.valid() { 56 return &Mutation{err: ErrInvalidKey} 57 } 58 p, err := saveEntity(k, src) 59 if err != nil { 60 return &Mutation{err: err} 61 } 62 return &Mutation{ 63 key: k, 64 mut: &pb.Mutation{Operation: &pb.Mutation_Upsert{Upsert: p}}, 65 } 66} 67 68// NewUpdate creates a mutation that replaces the entity in the datastore with key k, 69// returning an error if k does not exist. See Client.Put for valid values of src. 70func NewUpdate(k *Key, src interface{}) *Mutation { 71 if !k.valid() { 72 return &Mutation{err: ErrInvalidKey} 73 } 74 if k.Incomplete() { 75 return &Mutation{err: fmt.Errorf("datastore: can't update the incomplete key: %v", k)} 76 } 77 p, err := saveEntity(k, src) 78 if err != nil { 79 return &Mutation{err: err} 80 } 81 return &Mutation{ 82 key: k, 83 mut: &pb.Mutation{Operation: &pb.Mutation_Update{Update: p}}, 84 } 85} 86 87// NewDelete creates a mutation that deletes the entity with key k. 88func NewDelete(k *Key) *Mutation { 89 if !k.valid() { 90 return &Mutation{err: ErrInvalidKey} 91 } 92 if k.Incomplete() { 93 return &Mutation{err: fmt.Errorf("datastore: can't delete the incomplete key: %v", k)} 94 } 95 return &Mutation{ 96 key: k, 97 mut: &pb.Mutation{Operation: &pb.Mutation_Delete{Delete: keyToProto(k)}}, 98 } 99} 100 101func mutationProtos(muts []*Mutation) ([]*pb.Mutation, error) { 102 // If any of the mutations have errors, collect and return them. 103 var merr MultiError 104 for i, m := range muts { 105 if m.err != nil { 106 if merr == nil { 107 merr = make(MultiError, len(muts)) 108 } 109 merr[i] = m.err 110 } 111 } 112 if merr != nil { 113 return nil, merr 114 } 115 var protos []*pb.Mutation 116 // Collect protos. Remove duplicate deletions (see deleteMutations). 117 seen := map[string]bool{} 118 for _, m := range muts { 119 if m.isDelete() { 120 ks := m.key.String() 121 if seen[ks] { 122 continue 123 } 124 seen[ks] = true 125 } 126 protos = append(protos, m.mut) 127 } 128 return protos, nil 129} 130