| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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 statefun |
| |
| import ( |
| "fmt" |
| "github.com/apache/flink-statefun/statefun-sdk-go/v3/pkg/statefun/internal" |
| "github.com/apache/flink-statefun/statefun-sdk-go/v3/pkg/statefun/internal/protocol" |
| "sync" |
| ) |
| |
| // An AddressScopedStorage is used for reading and writing persistent |
| // values that are managed by the Stateful Functions runtime for |
| // fault-tolerance and consistency. |
| // |
| // All access to the storage is scoped to the current function instance, |
| // identified by the instance's Address. This means that within an |
| // invocation, function instances may only access its own persisted |
| // values through this storage. |
| type AddressScopedStorage interface { |
| |
| // Get returnss the values of the provided ValueSpec, scoped to the |
| // current invoked Address and stores the result in the value |
| // pointed to by receiver. The method will return false |
| // if there is no value for the spec in storage |
| // so callers can differentiate between missing and |
| // the types zero value. |
| Get(spec ValueSpec, receiver interface{}) (exists bool) |
| |
| // Set updates the value for the provided ValueSpec, scoped |
| // to the current invoked Address. |
| Set(spec ValueSpec, value interface{}) |
| |
| // Remove deletes the prior value set for the the provided |
| // ValueSpec, scoped to the current invoked Address. |
| // |
| // After removing the value, calling Get for the same |
| // spec under the same Address will return false. |
| Remove(spec ValueSpec) |
| } |
| |
| type storage struct { |
| mutex sync.RWMutex |
| cells map[string]*internal.Cell |
| } |
| |
| type storageFactory interface { |
| getStorage() *storage |
| |
| getMissingSpecs() []*protocol.FromFunction_PersistedValueSpec |
| } |
| |
| func newStorageFactory( |
| batch *protocol.ToFunction_InvocationBatchRequest, |
| specs map[string]*protocol.FromFunction_PersistedValueSpec, |
| ) storageFactory { |
| storage := &storage{ |
| cells: make(map[string]*internal.Cell, len(specs)), |
| } |
| |
| states := make(map[string]*protocol.FromFunction_PersistedValueSpec, len(specs)) |
| for k, v := range specs { |
| states[k] = v |
| } |
| |
| if batch.State != nil { |
| for _, state := range batch.State { |
| spec, exists := states[state.StateName] |
| if !exists { |
| continue |
| } |
| |
| delete(states, state.StateName) |
| |
| storage.cells[state.StateName] = internal.NewCell(state, spec.TypeTypename) |
| } |
| } |
| |
| if len(states) > 0 { |
| var missing = make([]*protocol.FromFunction_PersistedValueSpec, 0, len(states)) |
| for _, spec := range states { |
| missing = append(missing, spec) |
| } |
| |
| return MissingSpecs(missing) |
| } else { |
| return storage |
| } |
| } |
| |
| func (s *storage) getStorage() *storage { |
| return s |
| } |
| |
| func (s *storage) getMissingSpecs() []*protocol.FromFunction_PersistedValueSpec { |
| return nil |
| } |
| |
| func (s *storage) Get(spec ValueSpec, receiver interface{}) bool { |
| s.mutex.RLock() |
| defer s.mutex.RUnlock() |
| |
| cell, ok := s.cells[spec.Name] |
| if !ok { |
| panic(fmt.Errorf("unregistered ValueSpec %s", spec.Name)) |
| } |
| |
| if !cell.HasValue() { |
| return false |
| } |
| |
| cell.SeekToBeginning() |
| if err := spec.ValueType.Deserialize(cell, receiver); err != nil { |
| panic(fmt.Errorf("failed to deserialize persisted value `%s`: %w", spec.Name, err)) |
| } |
| |
| return true |
| } |
| |
| func (s *storage) Set(spec ValueSpec, value interface{}) { |
| s.mutex.Lock() |
| defer s.mutex.Unlock() |
| |
| cell, ok := s.cells[spec.Name] |
| if !ok { |
| panic(fmt.Errorf("unregistered ValueSpec %s", spec.Name)) |
| } |
| |
| err := spec.ValueType.Serialize(cell, value) |
| if err != nil { |
| panic(fmt.Errorf("failed to serialize %s: %w", spec.Name, err)) |
| } |
| } |
| |
| func (s *storage) Remove(spec ValueSpec) { |
| s.mutex.Lock() |
| defer s.mutex.Unlock() |
| |
| cell, ok := s.cells[spec.Name] |
| if !ok { |
| panic(fmt.Errorf("unregistered ValueSpec %s", spec.Name)) |
| } |
| |
| cell.Delete() |
| } |
| |
| func (s *storage) getStateMutations() []*protocol.FromFunction_PersistedValueMutation { |
| mutations := make([]*protocol.FromFunction_PersistedValueMutation, 0, len(s.cells)) |
| for name, cell := range s.cells { |
| if mutation := cell.GetStateMutation(name); mutation != nil { |
| mutations = append(mutations, mutation) |
| } |
| } |
| |
| return mutations |
| } |
| |
| type MissingSpecs []*protocol.FromFunction_PersistedValueSpec |
| |
| func (m MissingSpecs) getStorage() *storage { |
| return nil |
| } |
| |
| func (m MissingSpecs) getMissingSpecs() []*protocol.FromFunction_PersistedValueSpec { |
| return m |
| } |