| // 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. |
| |
| #ifndef EXTERNAL_STORE_H |
| #define EXTERNAL_STORE_H |
| |
| #include <memory> |
| #include <string> |
| #include <unordered_map> |
| #include <vector> |
| |
| #include "plasma/client.h" |
| |
| namespace plasma { |
| |
| // ==== The external store ==== |
| // |
| // This file contains declaration for all functions that need to be implemented |
| // for an external storage service so that objects evicted from Plasma store |
| // can be written to it. |
| |
| class ExternalStore { |
| public: |
| /// Default constructor. |
| ExternalStore() = default; |
| |
| /// Virtual destructor. |
| virtual ~ExternalStore() = default; |
| |
| /// Connect to the local plasma store. Return the resulting connection. |
| /// |
| /// \param endpoint The name of the endpoint to connect to the external |
| /// storage service. While the formatting of the endpoint name is |
| /// specific to the implementation of the external store, it always |
| /// starts with {store-name}://, where {store-name} is the name of the |
| /// external store. |
| /// |
| /// \return The return status. |
| virtual Status Connect(const std::string& endpoint) = 0; |
| |
| /// This method will be called whenever an object in the Plasma store needs |
| /// to be evicted to the external store. |
| /// |
| /// This API is experimental and might change in the future. |
| /// |
| /// \param ids The IDs of the objects to put. |
| /// \param data The object data to put. |
| /// \return The return status. |
| virtual Status Put(const std::vector<ObjectID>& ids, |
| const std::vector<std::shared_ptr<Buffer>>& data) = 0; |
| |
| /// This method will be called whenever an evicted object in the external |
| /// store store needs to be accessed. |
| /// |
| /// This API is experimental and might change in the future. |
| /// |
| /// \param ids The IDs of the objects to get. |
| /// \param buffers List of buffers the data should be written to. |
| /// \return The return status. |
| virtual Status Get(const std::vector<ObjectID>& ids, |
| std::vector<std::shared_ptr<Buffer>> buffers) = 0; |
| }; |
| |
| class ExternalStores { |
| public: |
| typedef std::unordered_map<std::string, std::shared_ptr<ExternalStore>> StoreMap; |
| /// Extracts the external store name from the external store endpoint. |
| /// |
| /// \param endpoint The endpoint for the external store. |
| /// \param[out] store_name The name of the external store. |
| /// \return The return status. |
| static Status ExtractStoreName(const std::string& endpoint, std::string* store_name); |
| |
| /// Register a new external store. |
| /// |
| /// \param store_name Name of the new external store. |
| /// \param store The new external store object. |
| static void RegisterStore(const std::string& store_name, |
| std::shared_ptr<ExternalStore> store); |
| |
| /// Remove an external store from the registry. |
| /// |
| /// \param store_name Name of the external store to remove. |
| static void DeregisterStore(const std::string& store_name); |
| |
| /// Obtain the external store given its name. |
| /// |
| /// \param store_name Name of the external store. |
| /// \return The external store object. |
| static std::shared_ptr<ExternalStore> GetStore(const std::string& store_name); |
| |
| private: |
| /// Obtain mapping between external store names and store instances. |
| /// |
| /// \return Mapping between external store names and store instances. |
| static StoreMap& Stores(); |
| }; |
| |
| #define REGISTER_EXTERNAL_STORE(name, store) \ |
| class store##Class { \ |
| public: \ |
| store##Class() { ExternalStores::RegisterStore(name, std::make_shared<store>()); } \ |
| ~store##Class() { ExternalStores::DeregisterStore(name); } \ |
| }; \ |
| store##Class singleton_##store = store##Class() |
| |
| } // namespace plasma |
| |
| #endif // EXTERNAL_STORE_H |