dex4er / js-fs-gzip-blob-storage / #572

/// <reference types="node" />

import {Readable, Writable} from "node:stream"

import zlib from "node:zlib"

import Pumpify from "pumpify"

import {

  FsBlobStorage,

  FsBlobStorageCommitOptions,

  FsBlobStorageOptions,

  FsBlobStorageReadStreamOptions,

  FsBlobStorageRemoveOptions,

  FsBlobStorageWriteStreamOptions,

  DEFAULT_EXT,

} from "fs-blob-storage"

export interface FsGzipBlobStorageOptions extends FsBlobStorageOptions {

  gzipExt?: string

  gzipOptions?: zlib.ZlibOptions

}

export interface FsGzipBlobStorageReadStreamOptions extends FsBlobStorageReadStreamOptions {

  encoding?: never

}

export interface FsGzipBlobStorageWriteStreamOptions extends FsBlobStorageWriteStreamOptions {

  encoding?: never

}

export interface FsGzipBlobStorageCommitOptions extends FsBlobStorageCommitOptions {}

export interface FsGzipBlobStorageRemoveOptions extends FsBlobStorageRemoveOptions {}

export {DEFAULT_EXT, DEFAULT_PART} from "fs-blob-storage"

export const DEFAULT_GZIP_EXT = ".gz"

export class FsGzipBlobStorage {

  private storage: FsBlobStorage

  private ext: string

  private gzipExt: string

  private gzipOptions: zlib.ZlibOptions

  constructor(options: FsGzipBlobStorageOptions = {}) {

    this.storage = new FsBlobStorage(options)

    this.ext = options.ext !== undefined ? options.ext : DEFAULT_EXT

    this.gzipExt = options.gzipExt !== undefined ? options.gzipExt : DEFAULT_GZIP_EXT

    this.gzipOptions = options.gzipOptions || {}

  }

  async createWriteStream(key: string, options: FsGzipBlobStorageWriteStreamOptions = {}): Promise<Writable> {

    const {ext = this.ext} = options

    const gz = this.gzipExt

    const newOptions = Object.assign({}, options, {ext: ext + gz, encoding: null})

    const file = await this.storage.createWriteStream(key, newOptions)

    const gzip = zlib.createGzip(this.gzipOptions)

    return new Pumpify(gzip, file)

  }

  async createReadStream(key: string, options: FsGzipBlobStorageReadStreamOptions = {}): Promise<Readable> {

    const {ext = this.ext} = options

    const gz = this.gzipExt

    const newOptions = Object.assign({}, options, {ext: ext + gz, encoding: null})

    const file = await this.storage.createReadStream(key, newOptions)

    const gunzip = zlib.createGunzip(this.gzipOptions)

    return new Pumpify(file, gunzip)

  }

  commit(key: string, options: FsGzipBlobStorageCommitOptions = {}): Promise<void> {

    const {ext = this.ext} = options

    const gz = this.gzipExt

    const newOptions = Object.assign({}, options, {ext: ext + gz})

    return this.storage.commit(key, newOptions)

  }

  remove(key: string, options: FsGzipBlobStorageRemoveOptions = {}): Promise<void> {

    const {ext = this.ext} = options

    const gz = this.gzipExt

    const newOptions = Object.assign({}, options, {ext: ext + gz})

    return this.storage.remove(key, newOptions)

  }

}

export default FsGzipBlobStorage