extra-disk-store
A disk-based persistent store.
Install
npm install --save extra-disk-store
# or
yarn add extra-disk-storeLimitations
This library uses lmdb as the storage layer for performance reasons. Unfortunately, lmdb only supports keys of limited size (1978 bytes), so make sure you only use this library for scenarios with limited key size.
Usage
import { DiskStore } from 'extra-disk-store'
const store = new DiskStore('/tmp/store')
await store.set('key', Buffer.from('value'))
const value = store.get('key')API
DiskStore
class DiskStore {
constructor(dirname: string)
close(): Promise<void>
has(key: string): boolean
get(key: string): Buffer | undefined
set(key: string, value: Buffer): Promise<void>
delete(key: string): Promise<void>
clear(): Promise<void>
keys(): IterableIterator<string>
}DiskStoreWithCache
interface ICache {
set(key: string, value: Buffer | false): void
get(key: string): Buffer | false | undefined
delete(key: string): void
clear(): void
}
class DiskStoreWithCache {
constructor(
store: DiskStore
, cache: ICache
)
close(): Promise<void>
has(key: string): boolean
get(key: string): Buffer | undefined
set(key: string, value: Buffer): Promise<void>
delete(key: string): Promise<void>
clear(): Promise<void>
keys(): IterableIterator<string>
}DiskStoreView
interface IKeyConverter<T> {
toString: (value: T) => Awaitable<string>
fromString: (value: string) => Awaitable<T | undefined>
}
interface IValueConverter<T> {
toBuffer: (value: T) => Awaitable<Buffer>
fromBuffer: (value: Buffer) => Awaitable<T>
}
class DiskStoreView<K, V> {
constructor(
store: DiskStore | DiskStoreWithCache
, keyConverter: IKeyConverter<K>
, valueConverter: IValueConverter<V>
) {}
has(key: K): Promise<boolean>
get(key: K): Promise<V | undefined>
set(key: K, value: V): Promise<void>
delete(key: K): Promise<void>
clear(): Promise<void>
keys(): IterableIterator<K>
}Converters
IndexKeyConverter
class IndexKeyConverter implements IKeyConverter<number>JSONKeyConverter
class JSONKeyConverter<T> implements IKeyConverter<T>JSONValueConverter
class JSONValueConverter<T> implements IValueConverter<T> {
constructor(encoding: BufferEncoding = 'utf-8')
}PassthroughKeyConverter
class PassthroughKeyConverter implements IKeyConverter<string>PassthroughValueConverter
class PassthroughValueConverter implements IValueConverter<Buffer>PrefixKeyConverter
class PrefixKeyConverter<T> implements IKeyConverter<T> {
constructor(keyConverter: IKeyConverter<T>, prefix: string)
}LZ4ValueConverter
class LZ4ValueConverter<T> implements IValueConverter<T> {
constructor(valueConverter: IValueConverter<T>)
}ZstandardValueConverter
class ZstandardValueConverter<T> implements IValueConverter<T> {
constructor(
valueConverter: IValueConverter<T>
, level: number
)
}