feat: ServeStaticQuick

chokidar is now a production dependency

please read the comments in ServeStaticQuick.js for a description of
what the class does

public and dist directories are now served with that class by default

before starting hyper-express on the listen port, await for all
ServeLiveDirectory and ServeStaticQuick instances

controllers/middlewares/ServeLiveDirectory.js

@@ -95,6 +95,11 @@ class ServeLiveDirectory {
     return res.send(file.buffer)
   }
 
+  ready () {
+    // Returns a promise which resolves to true once LiveDirectory instance is ready
+    return this.instance.ready()
+  }
+
   #middleware (req, res, next) {
     // Only process GET and HEAD requests
     if (req.method !== 'GET' && req.method !== 'HEAD') {

controllers/middlewares/ServeStaticQuick.js

@@ -0,0 +1,276 @@
+/*
+ * ServeStaticQuick.
+ *
+ * This is intended as a compromise between ServeStatic handler and
+ * ServeLiveDirectory middleware.
+ *
+ * This monitors and caches the configured directory's file tree for quick lookups,
+ * thus allowing multiple instances of this middleware to be used together, if needed.
+ *
+ * When matches are found, it will then simply spawn ReadStream to the physical files.
+ * Due to the fact that it does not have to pre-cache the whole files into memory,
+ * this is likely the better choice to serve generic assets
+ * in an environment where memory space is a premium.
+ *
+ * This class also has Conditional GETs support,
+ * which involves handling cache-related headers such as
+ * If-Match, If-Unmodified-Since, ETag, etc.
+ * And partial bytes fetch by handling Content-Range header,
+ * which is useful for streaming, among other things.
+ */
+
+const chokidar = require('chokidar')
+const etag = require('etag')
+const fs = require('fs')
+const parseRange = require('range-parser')
+const serveUtils = require('./../utils/serveUtils')
+const logger = require('./../../logger')
+
+class ServeStaticQuick {
+  directory
+  files
+  watcher
+
+  #options
+  #readyPromise
+  #readyResolve
+
+  constructor (directory, options = {}) {
+    if (!directory || typeof directory !== 'string') {
+      throw new TypeError('Root directory must be set')
+    }
+
+    this.directory = serveUtils.forwardSlashes(directory)
+
+    // Ensure does not end with a forward slash
+    if (this.directory.endsWith('/')) {
+      this.directory = this.directory.slice(0, -1)
+    }
+
+    if (options.acceptRanges === undefined) {
+      options.acceptRanges = true
+    }
+
+    if (options.etag === undefined) {
+      options.etag = true
+    }
+
+    if (options.lastModified === undefined) {
+      options.lastModified = true
+    }
+
+    if (options.setHeaders && typeof options.setHeaders !== 'function') {
+      throw new TypeError('Middleware option setHeaders must be a function')
+    }
+
+    this.files = new Map()
+
+    this.watcher = chokidar.watch(this.directory, {
+      alwaysStat: true,
+      awaitWriteFinish: {
+        pollInterval: 100,
+        stabilityThreshold: 500
+      }
+    })
+
+    this.#bindWatchHandlers()
+
+    this.#options = options
+  }
+
+  /*
+   * Based on https://github.com/pillarjs/send/blob/0.18.0/index.js
+   * Copyright(c) 2012 TJ Holowaychuk
+   * Copyright(c) 2014-2022 Douglas Christopher Wilson
+   * MIT Licensed
+   */
+
+  handler (req, res, stat) {
+    // ReadStream options
+    let len = stat.size
+    const opts = {}
+    let ranges = req.headers.range
+    let offset = 0
+
+    // set content-type
+    res.type(req.path)
+
+    // set header fields
+    this.#setHeaders(req, res, stat)
+
+    // conditional GET support
+    if (serveUtils.isConditionalGET(req)) {
+      if (serveUtils.isPreconditionFailure(req, res)) {
+        return res.status(412).end()
+      }
+
+      if (serveUtils.isFresh(req, res)) {
+        return res.status(304).end()
+      }
+    }
+
+    // adjust len to start/end options
+    len = Math.max(0, len - offset)
+    if (opts.end !== undefined) {
+      const bytes = opts.end - offset + 1
+      if (len > bytes) len = bytes
+    }
+
+    // Range support
+    if (this.#options.acceptRanges && serveUtils.BYTES_RANGE_REGEXP.test(ranges)) {
+      // parse
+      ranges = parseRange(len, ranges, {
+        combine: true
+      })
+
+      // If-Range support
+      if (!serveUtils.isRangeFresh(req, res)) {
+        // range stale
+        ranges = -2
+      }
+
+      // unsatisfiable
+      if (ranges === -1) {
+        // Content-Range
+        res.header('Content-Range', serveUtils.contentRange('bytes', len))
+
+        // 416 Requested Range Not Satisfiable
+        return res.status(416).end()
+      }
+
+      // valid (syntactically invalid/multiple ranges are treated as a regular response)
+      if (ranges !== -2 && ranges.length === 1) {
+        // Content-Range
+        res.status(206)
+        res.header('Content-Range', serveUtils.contentRange('bytes', len, ranges[0]))
+
+        // adjust for requested range
+        offset += ranges[0].start
+        len = ranges[0].end - ranges[0].start + 1
+      }
+    }
+
+    // set read options
+    opts.start = offset
+    opts.end = Math.max(offset, offset + len - 1)
+
+    // HEAD support
+    if (req.method === 'HEAD') {
+      // If HEAD, also set Content-Length (must be string)
+      res.header('Content-Length', String(len))
+      return res.end()
+    }
+
+    if (len === 0) {
+      res.end()
+    }
+
+    return this.#stream(req, res, stat, opts, len)
+  }
+
+  // Returns a promise which resolves to true once ServeStaticQuick is ready
+  ready () {
+    // Resolve with true if ready is not a promise
+    if (this.#readyPromise === true) return Promise.resolve(true)
+
+    // Create a promise if one does not exist for ready event
+    if (this.#readyPromise === undefined) { this.#readyPromise = new Promise((resolve) => (this.#readyResolve = resolve)) }
+
+    return this.#readyPromise
+  }
+
+  #bindWatchHandlers () {
+    this.watcher.on('all', (event, path, stat) => {
+      const relPath = serveUtils.relativePath(this.directory, path)
+
+      if (!relPath) return // skips root directory
+
+      switch (event) {
+        case 'add':
+        case 'addDir':
+        case 'change':
+          this.files.set(relPath, stat)
+          break
+        case 'unlink':
+        case 'unlinkDir':
+          this.files.delete(relPath)
+          break
+      }
+    })
+
+    // Bind 'ready' for when all files have been loaded
+    this.watcher.once('ready', () => {
+      // Resolve pending promise if one exists
+      if (typeof this.#readyResolve === 'function') {
+        this.#readyResolve()
+        this.#readyResolve = null
+      }
+
+      // Mark instance as ready
+      this.#readyPromise = true
+    })
+  }
+
+  #get (path) {
+    const stat = this.files.get(path)
+
+    if (!stat || stat.isDirectory()) return
+
+    return stat
+  }
+
+  #middleware (req, res, next) {
+    // Only process GET and HEAD requests
+    if (req.method !== 'GET' && req.method !== 'HEAD') {
+      return next()
+    }
+
+    const stat = this.#get(req.path)
+    if (stat === undefined) {
+      return next()
+    }
+
+    return this.handler(req, res, stat)
+  }
+
+  #setHeaders (req, res, stat) {
+    // Always do external setHeaders function first,
+    // in case it will overwrite the following default headers anyways
+    if (this.#options.setHeaders) {
+      this.#options.setHeaders(req, res)
+    }
+
+    if (this.#options.acceptRanges && !res.get('Accept-Ranges')) {
+      res.header('Accept-Ranges', 'bytes')
+    }
+
+    if (this.#options.lastModified && !res.get('Last-Modified')) {
+      const modified = stat.mtime.toUTCString()
+      res.header('Last-Modified', modified)
+    }
+
+    if (this.#options.etag && !res.get('ETag')) {
+      const val = etag(stat)
+      res.header('ETag', val)
+    }
+  }
+
+  #stream (req, res, stat, opts, len) {
+    const fullPath = this.directory + req.path
+    const readStream = fs.createReadStream(fullPath, opts)
+
+    readStream.on('error', error => {
+      readStream.destroy()
+      logger.error(error)
+    })
+
+    // 2nd param will be set as Content-Length header (must be number)
+    return res.stream(readStream, len)
+  }
+
+  get middleware () {
+    return this.#middleware.bind(this)
+  }
+}
+
+module.exports = ServeStaticQuick

lolisafe.js

@@ -47,6 +47,7 @@ const ExpressCompat = require('./controllers/middlewares/ExpressCompat')
 const NunjucksRenderer = require('./controllers/middlewares/NunjucksRenderer')
 const RateLimiter = require('./controllers/middlewares/RateLimiter')
 const ServeLiveDirectory = require('./controllers/middlewares/ServeLiveDirectory')
+const ServeStaticQuick = require('./controllers/middlewares/ServeStaticQuick')
 
 // Handlers
 const ServeStatic = require('./controllers/handlers/ServeStatic')
@@ -190,17 +191,17 @@ if (config.cacheControl) {
   })
 }
 
-// Init LiveDirectory middlewares for static assets
+// Init ServeStaticQuick middlewares for static assets
 // Static assets in /public directory
-const serveLiveDirectoryPublicInstance = new ServeLiveDirectory(paths.public, {
+const serveStaticQuickPublicInstance = new ServeStaticQuick(paths.public, {
   setHeaders: setHeadersForStaticAssets
 })
-safe.use(serveLiveDirectoryPublicInstance.middleware)
+safe.use(serveStaticQuickPublicInstance.middleware)
 // Static assets in /dist directory
-const serveLiveDirectoryDistInstance = new ServeLiveDirectory(paths.dist, {
+const serveStaticQuickDistInstance = new ServeStaticQuick(paths.dist, {
   setHeaders: setHeadersForStaticAssets
 })
-safe.use(serveLiveDirectoryDistInstance.middleware)
+safe.use(serveStaticQuickDistInstance.middleware)
 
 // Routes
 safe.use(album)
@@ -310,6 +311,13 @@ safe.use('/api', api)
       logger.log(`Connection established with ${utils.scan.version}`)
     }
 
+    // Await all ServeLiveDirectory and ServeStaticQuick instances
+    await Promise.all([
+      serveStaticQuickDistInstance.ready(),
+      serveStaticQuickPublicInstance.ready(),
+      serveLiveDirectoryCustomPagesInstance.ready()
+    ])
+
     // Binds Express to port
     await safe.listen(utils.conf.port)
     logger.log(`lolisafe started on port ${utils.conf.port}`)

package.json

@@ -37,6 +37,7 @@
     "bcrypt": "~5.0.1",
     "better-sqlite3": "~7.6.2",
     "blake3": "~2.1.7",
+    "chokidar": "~3.5.3",
     "clamscan": "~2.1.2",
     "content-disposition": "~0.5.4",
     "etag": "~1.8.1",
@@ -62,7 +63,6 @@
     "@ronilaukkarinen/gulp-stylelint": "~14.0.6",
     "browserslist": "~4.21.3",
     "bulma": "~0.9.4",
-    "chokidar": "~3.5.3",
     "cssnano": "~5.1.12",
     "del": "~6.1.1",
     "eslint": "~8.20.0",