dorkbox.storage.Storage.kt Maven / Gradle / Ivy
/*
* Copyright 2021 dorkbox, llc
*
* Licensed 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 dorkbox.storage
import com.esotericsoftware.kryo.Kryo
import dorkbox.storage.types.MemoryStore
import dorkbox.storage.types.PropertyStore
import mu.KLogger
import mu.KotlinLogging
import org.slf4j.helpers.NOPLogger
import java.io.File
typealias AccessFunc = ((key: Any, value: Any, load: (key: Any, value: Any) -> Unit) -> Unit)
abstract class Storage(val logger: KLogger) : AutoCloseable {
companion object {
/**
* Gets the version number.
*/
const val version = "1.2"
init {
// Add this project to the updates system, which verifies this class + UUID + version information
dorkbox.updates.Updates.add(Storage::class.java, "c1281a7c576c4a9db0823763ff2fe811", version)
}
const val versionTag = "__VERSION__"
}
fun init(initMessage: String) {
// always initialize the version tag information
if (getVersion() == -1L) {
setVersion(0L)
}
KotlinLogging.logger("Storage").info(initMessage)
}
/**
* @return the version of data stored in the database
*/
fun getVersion(): Long {
return get(versionTag) ?: -1L
}
/**
* Sets the version of data stored in the database
*/
abstract fun setVersion(version: Long)
/**
* @return the file that backs this storage
*/
abstract fun file(): File?
/**
* Returns the number of objects in the database.
*/
abstract fun size(): Int
/**
* Checks if there is a object corresponding to the given key.
*/
abstract operator fun contains(key: Any): Boolean
/**
* Reads an object using the specific key, and casts it to the expected class
*/
abstract operator fun get(key: Any): V?
/**
* Returns the saved data for the specified key.
*
* @param key The key used to check if data already exists.
* @param data This is the default value, and if there is no value with the key in the DB this default value will be returned AND saved.
*/
operator fun get(key: Any, data: V): V {
val current = get(key) as Any?
if (current == null) {
set(key, data)
return data
}
@Suppress("UNCHECKED_CAST")
return current as V
}
/**
* Saves the given data to storage with the associated key.
*
* Setting to NULL removes the value
*/
abstract operator fun set(key: Any, data: Any?)
/**
* Deletes an object from storage.
*/
fun delete(key: Any) {
set(key, null)
}
/**
* Deletes all contents of this storage, and if applicable, it's location on disk.
*/
abstract fun deleteAll()
/**
* Closes this storage system
*/
abstract override fun close()
interface Builder {
/** true if the backing storage type uses strings for everything, or false if it uses something else */
val isStringBased: Boolean
/**
* Builds the storage using the specified configuration
*/
fun build(): Storage
/**
* Allows for this storage type to be shared among [build] invocations. The first [build] will create the object used by all other [build] invocations (instead of creating a new one each time)
*/
fun shared(): Builder
/**
* Allows for custom load actions when keys/values need to be transformed before loading them from storage
*
* @param onLoad action to load data when the key/value pairs are read from storage
*/
fun onLoad(onLoad: AccessFunc): Builder
/**
* Allows for custom save actions when key/values need to be translated before saving them to storage\
*
* @param onSave action to save data when the key/value pairs are saved to storage.
*/
fun onSave(onSave: AccessFunc): Builder
/**
* Specify how to configure the kryo instance for serialization. This instance of kryo will be used to serialize the key/value data, which is subsequently saved to disk
*/
fun onNewSerializer(onNewKryo: Kryo.() -> Unit): Builder
/**
* Assigns a logger to use for the storage system. The default is a No Operation (NOP) logger which will ignore everything.
*/
fun logger(logger: KLogger): Builder
}
@Suppress("UNCHECKED_CAST")
abstract class FileBuilder: Builder {
var onLoad: AccessFunc? = null
var onSave: AccessFunc? = null
var onNewKryo: Kryo.() -> Unit = { }
var shared = false
@Volatile var sharedBuild: Storage? = null
var logger: KLogger = KotlinLogging.logger(NOPLogger.NOP_LOGGER)
var file = File("storage.db")
var readOnly = false
var readOnlyViolent = false
override val isStringBased = false
internal fun manageShared(buildFun: () -> Storage): Storage {
return if (shared) {
if (sharedBuild == null) {
sharedBuild = buildFun()
}
sharedBuild!!
} else {
buildFun()
}
}
override fun shared(): B {
shared = true
return this as B
}
override fun onLoad(onLoad: AccessFunc): Builder {
this.onLoad = onLoad
return this
}
override fun onSave(onSave: AccessFunc): Builder {
this.onSave = onSave
return this
}
override fun onNewSerializer(onNewKryo: Kryo.() -> Unit): Builder {
this.onNewKryo = onNewKryo
return this
}
override fun logger(logger: KLogger): B {
this.logger = logger
return this as B
}
/**
* Specify the file to write to on disk when saving objects
*/
fun file(file: File): B {
this.file = file
return this as B
}
/**
* Specify the file to write to on disk when saving objects
*/
fun file(file: String): B {
return file(File(file))
}
/**
* Mark this storage system as read only (silently drop `set` operations)
*/
fun readOnly(): B{
readOnly = true
readOnlyViolent = false
return this as B
}
/**
* Mark this storage system as read only (throw an IOException for `set` operations)
*/
fun readOnlyThrowExceptions(): B {
readOnly = true
readOnlyViolent = true
return this as B
}
}
/**
* An in-memory only storage system.
*
* This storage system DOES NOT care about serializing data, so `register` has no effect.
*/
class Memory : Builder {
private var logger: KLogger = KotlinLogging.logger(NOPLogger.NOP_LOGGER)
private var shared = false
@Volatile private var sharedBuild: Storage? = null
override val isStringBased = true
override fun build(): Storage {
return if (shared) {
if (sharedBuild == null) {
sharedBuild = MemoryStore(logger)
}
sharedBuild!!
} else {
MemoryStore(logger)
}
}
override fun shared(): Memory {
shared = true
return this
}
override fun onLoad(onLoad: AccessFunc): Builder {
return this
}
override fun onSave(onSave: AccessFunc): Builder {
return this
}
override fun onNewSerializer(onNewKryo: Kryo.() -> Unit): Builder {
return this
}
/**
* Assigns a logger to use for the storage system. If null, then only errors will be logged to the error console.
*/
override fun logger(logger: KLogger): Builder {
this.logger = logger
return this
}
}
/**
* Java property file storage system
*/
class Property : FileBuilder() {
private var autoLoad = false
override val isStringBased = true
/**
* Builds the storage system
*/
override fun build(): Storage {
return manageShared {
PropertyStore(file.absoluteFile, autoLoad, readOnly, readOnlyViolent, logger, onNewKryo,
onLoad, onSave)
}
}
/**
* Allow auto-loading any changes made to disk
*/
fun autoLoadChanges(): Property {
autoLoad = true
return this
}
}
// /**
// * JSON file storage system
// */
// class Json : Storage.FileBuilder() {
// private var autoLoad = false
//
// override fun build(): Storage {
// return manageShared {
// JsonStore(file.absoluteFile, autoLoad, readOnly, readOnlyViolent, logger,
// onLoad, onSave)
// }
// }
//
// /**
// * Allow auto-loading any changes made to disk
// */
// fun autoLoadChanges(): Json {
// autoLoad = true
// return this
// }
// }
// /**
// * Lightning Memory Database
// *
// * https://github.com/lmdbjava/lmdbjava
// */
// class Lmdb : SimpleBuilder, K>() {
// private var file = File("storage.db")
// private var readOnly = false
//
// /**
// * Builds the storage system
// */
// override fun build(): Storage {
// return manageShared { LmdbStore(file.absoluteFile, readOnly, serializationManager, logger,
// onLoadKey, onSaveKey, onLoadValue, onSaveValue) }
// }
//
// /**
// * Specify the file to write to on disk when saving objects
// */
// fun file(file: File): Lmdb {
// this.file = file
// return this
// }
//
// /**
// * Specify the file to write to on disk when saving objects
// */
// fun file(file: String): Lmdb {
// return file(File(file))
// }
//
// /**
// * Mark this storage system as read only
// */
// fun readOnly(): Lmdb {
// readOnly = true
// return this
// }
// }
}
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