| /* |
| * 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 org.apache.tuweni.kv |
| |
| import kotlinx.coroutines.Dispatchers |
| import org.apache.tuweni.bytes.Bytes |
| import org.fusesource.leveldbjni.JniDBFactory |
| import org.iq80.leveldb.DB |
| import org.iq80.leveldb.DBIterator |
| import org.iq80.leveldb.Options |
| import java.io.IOException |
| import java.nio.file.Files |
| import java.nio.file.Path |
| import java.util.function.Function |
| import kotlin.coroutines.CoroutineContext |
| |
| /** |
| * A key-value store backed by LevelDB. |
| * |
| * @param dbPath The path to the levelDB database. |
| * @param keySerializer the serializer of key objects to bytes |
| * @param valueSerializer the serializer of value objects to bytes |
| * @param keyDeserializer the deserializer of keys from bytes |
| * @param valueDeserializer the deserializer of values from bytes |
| * @param options Options for the levelDB database. |
| * @param coroutineContext The co-routine context for blocking tasks. |
| * @return A key-value store. |
| * @throws IOException If an I/O error occurs. |
| * @constructor Open a LevelDB-backed key-value store. |
| */ |
| class LevelDBKeyValueStore<K, V> |
| @Throws(IOException::class) |
| constructor( |
| dbPath: Path, |
| private val keySerializer: (K) -> Bytes, |
| private val valueSerializer: (V) -> Bytes, |
| private val keyDeserializer: (Bytes) -> K, |
| private val valueDeserializer: (Bytes) -> V, |
| options: Options = Options().createIfMissing(true).cacheSize((100 * 1048576).toLong()), |
| override val coroutineContext: CoroutineContext = Dispatchers.IO |
| ) : KeyValueStore<K, V> { |
| |
| companion object { |
| |
| /** |
| * Open a LevelDB-backed key-value store. |
| * |
| * @param dbPath The path to the levelDB database. |
| * @param keySerializer the serializer of key objects to bytes |
| * @param valueSerializer the serializer of value objects to bytes |
| * @param keyDeserializer the deserializer of keys from bytes |
| * @param valueDeserializer the deserializer of values from bytes |
| * @return A key-value store. |
| * @throws IOException If an I/O error occurs. |
| */ |
| @JvmStatic |
| @Throws(IOException::class) |
| fun <K, V> open( |
| dbPath: Path, |
| keySerializer: Function<K, Bytes>, |
| valueSerializer: Function<V, Bytes>, |
| keyDeserializer: Function<Bytes, K>, |
| valueDeserializer: Function<Bytes, V> |
| ): LevelDBKeyValueStore<K, V> = |
| LevelDBKeyValueStore(dbPath, |
| keySerializer::apply, |
| valueSerializer::apply, |
| keyDeserializer::apply, |
| valueDeserializer::apply) |
| |
| /** |
| * Open a LevelDB-backed key-value store. |
| * |
| * @param dbPath The path to the levelDB database. |
| * @param keySerializer the serializer of key objects to bytes |
| * @param valueSerializer the serializer of value objects to bytes |
| * @param keyDeserializer the deserializer of keys from bytes |
| * @param valueDeserializer the deserializer of values from bytes |
| * @param options Options for the levelDB database. |
| * @return A key-value store. |
| * @throws IOException If an I/O error occurs. |
| */ |
| @JvmStatic |
| @Throws(IOException::class) |
| fun <K, V> open( |
| dbPath: Path, |
| keySerializer: Function<K, Bytes>, |
| valueSerializer: Function<V, Bytes>, |
| keyDeserializer: Function<Bytes, K>, |
| valueDeserializer: Function<Bytes, V>, |
| options: Options |
| ) = |
| LevelDBKeyValueStore(dbPath, |
| keySerializer::apply, |
| valueSerializer::apply, |
| keyDeserializer::apply, |
| valueDeserializer::apply, |
| options) |
| |
| /** |
| * Open a LevelDB-backed key-value store using Bytes keys and values. |
| * |
| * @param dbPath The path to the levelDB database. |
| * @return A key-value store dealing with bytes. |
| * @throws IOException If an I/O error occurs. |
| */ |
| @JvmStatic |
| @Throws(IOException::class) |
| fun open( |
| dbPath: Path |
| ) = |
| LevelDBKeyValueStore<Bytes, Bytes>(dbPath, |
| Function.identity<Bytes>()::apply, |
| Function.identity<Bytes>()::apply, |
| Function.identity<Bytes>()::apply, |
| Function.identity<Bytes>()::apply) |
| } |
| |
| private val db: DB |
| |
| init { |
| Files.createDirectories(dbPath) |
| db = JniDBFactory.factory.open(dbPath.toFile(), options) |
| } |
| |
| override suspend fun get(key: K): V? { |
| val rawValue = db[keySerializer(key).toArrayUnsafe()] |
| return if (rawValue == null) { |
| null |
| } else { |
| valueDeserializer(Bytes.wrap(rawValue)) |
| } |
| } |
| |
| override suspend fun put(key: K, value: V) = db.put(keySerializer(key).toArrayUnsafe(), |
| valueSerializer(value).toArrayUnsafe()) |
| |
| private class KIterator<K>(val iter: DBIterator, val keyDeserializer: (Bytes) -> K) : Iterator<K> { |
| override fun hasNext(): Boolean = iter.hasNext() |
| |
| override fun next(): K = keyDeserializer(Bytes.wrap(iter.next().key)) |
| } |
| |
| override suspend fun keys(): Iterable<K> { |
| val iter = db.iterator() |
| iter.seekToFirst() |
| return Iterable { KIterator(iter, keyDeserializer) } |
| } |
| |
| /** |
| * Closes the underlying LevelDB instance. |
| */ |
| override fun close() = db.close() |
| } |