rocks4j

KV Store for Java backed by RocksDB.

Getting Started

Maven

<dependency>
  <groupId>com.github.aleksandarskrbic</groupId>
  <artifactId>rocks4j</artifactId>
  <version>1.0.0</version>
</dependency>

Gradle

compile "com.github.aleksandarskrbic:rocks4j:1.0.0"

Introduction

The goal of this project is to provide KV store backed by RocksDB with simple Java API. Allow developers to quickly integrate RocksDB into the existing Java/Scala project. It can be used as a local caching mechanism in microservices or just to replace huge in-memory data structures.

API

There are five available operations against KV repository:

• save(K key, V value)
• findByKey(K key)
• findAll()
• deleteByKey(K key)
• deleteAll()

Examples

Suppose you have a Java class:

public class Item {
    private Long id;
    private String desc;
    
    // constructors, getters and setters
}

To create KV repository for Item class, firstly you need to create a configuration class that accepts a path to file (where RocksDB files will be) and the name of the repository:

final RocksDBConfiguration configuration = new RocksDBConfiguration("/path/to/rocksdb", "item");

After configuration class is created, you are able to instantiate the Item Repository:

public class ItemRepository extends RocksDBKeyValueRepository<Long, Item> {

  public ItemRepository(final RocksDBConfiguration configuration) {
    super(configuration);
  }
  
}

final ItemRepository itemRepository = new ItemRepository(configuration);

final Item item = new Item(1L, "Desc")

itemRepository.save(item.getId(), item);
final Optional<Item> itemOptional = itemRepository.findByKey(item.getId());
final Collection<Item> all = itemRepository.findAll();
itemRepository.deleteByKey(item.getId());
itemRepository.deleteAll();

Note

In order to maintain flexibility, when exception related to RocksDB or Serialization/Deserialization in RocksDBKeyValueRepository, exceptions are just propagated, so it's a client's responsibility to deal with it. Best practice would be to override methods from RocksDBKeyValueRepository and handle those exceptions and handle those exceptions into your repository class. Another solution would be to handle it every time you invoke methods provided by RocksDBKeyValueRepository which is not recommended.

Example

public static class ItemRepository extends RocksDBKeyValueRepository<Long, Item> {

    public ItemRepository(final RocksDBConfiguration configuration) {
        super(configuration);
    }

    @Override
    public void save(final Long key, final Item value) {
        try {
            super.save(key, value);
        } catch (final SerializationException e) {
            // log or handle
        } catch (final SaveFailedException e) {
            // log or handle
        }
    }

    // other methods
}

Credits

Special thanks to @jovicaandric and @vajda.