Support Brotli

Closes koajs#77

Author: ryota-ka

README.md

@@ -50,6 +50,8 @@ app.use(staticCache(path.join(__dirname, 'public'), {
 - `options.buffer` (bool) - store the files in memory instead of streaming from the filesystem on each request.
 - `options.gzip` (bool) - when request's accept-encoding include gzip, files will compressed by gzip.
 - `options.usePrecompiledGzip` (bool) - try use gzip files, loaded from disk, like nginx gzip_static
+- `options.brotli` (bool) - when request's accept-encoding include br, files will compressed by brotli.
+- `options.usePrecompiledBrotli` (bool) - try use brotli files, loaded from disk
 - `options.alias` (obj) - object map of aliases. See below.
 - `options.prefix` (str) - the url prefix you wish to add, default to `''`.
 - `options.dynamic` (bool) - dynamic load file which not cached on initialization.

index.js

@@ -6,6 +6,7 @@ var mime = require('mime-types')
 var compressible = require('compressible')
 var readDir = require('fs-readdir-recursive')
 var debug = require('debug')('koa-static-cache')
+var util = require('util');
 
 module.exports = function staticCache(dir, options, files) {
   if (typeof dir === 'object') {
@@ -20,6 +21,7 @@ module.exports = function staticCache(dir, options, files) {
   files = new FileManager(files || options.files)
   dir = dir || options.dir || process.cwd()
   dir = path.normalize(dir)
+  var enableBrotli = !!options.brotli
   var enableGzip = !!options.gzip
   var filePrefix = path.normalize(options.prefix.replace(/^\//, ''))
 
@@ -79,7 +81,7 @@ module.exports = function staticCache(dir, options, files) {
 
     ctx.status = 200
 
-    if (enableGzip) ctx.vary('Accept-Encoding')
+    if (enableBrotli || enableGzip) ctx.vary('Accept-Encoding')
 
     if (!file.buffer) {
       var stats = await fs.stat(file.path)
@@ -102,10 +104,14 @@ module.exports = function staticCache(dir, options, files) {
 
     if (ctx.method === 'HEAD') return
 
+    var acceptBrotli = ctx.acceptsEncodings('br') === 'br'
     var acceptGzip = ctx.acceptsEncodings('gzip') === 'gzip'
 
     if (file.zipBuffer) {
-      if (acceptGzip) {
+      if (acceptBrotli) {
+        ctx.set('content-encoding', 'br')
+        ctx.body = file.brBuffer
+      } else if (acceptGzip) {
         ctx.set('content-encoding', 'gzip')
         ctx.body = file.zipBuffer
       } else {
@@ -114,13 +120,27 @@ module.exports = function staticCache(dir, options, files) {
       return
     }
 
+    var shouldBrotli = enableBrotli
+      && file.length > 1024
+      && acceptBrotli
+      && compressible(file.type)
     var shouldGzip = enableGzip
       && file.length > 1024
       && acceptGzip
       && compressible(file.type)
 
     if (file.buffer) {
-      if (shouldGzip) {
+      if (shouldBrotli) {
+
+        var brFile = files.get(filename + '.br')
+        if (options.usePrecompiledBrotli && brFile && brFile.buffer) { // if .br file already read from disk
+          file.brBuffer = brFile.buffer
+        } else {
+          file.brBuffer = await util.promisify(zlib.brotliCompress)(file.buffer)
+        }
+        ctx.set('content-encoding', 'br')
+        ctx.body = file.brBuffer
+      } else if (shouldGzip) {
 
         var gzFile = files.get(filename + '.gz')
         if (options.usePrecompiledGzip && gzFile && gzFile.buffer) { // if .gz file already read from disk
@@ -148,8 +168,12 @@ module.exports = function staticCache(dir, options, files) {
     }
 
     ctx.body = stream
-    // enable gzip will remove content length
-    if (shouldGzip) {
+    // enable brotli/gzip will remove content length
+    if (shouldBrotli) {
+      ctx.remove('content-length')
+      ctx.set('content-encoding', 'br')
+      ctx.body = stream.pipe(zlib.createBrotliCompress())
+    } else if (shouldGzip) {
       ctx.remove('content-length')
       ctx.set('content-encoding', 'gzip')
       ctx.body = stream.pipe(zlib.createGzip())

test/index.js

@@ -63,6 +63,26 @@ app5.use(staticCache({
 }))
 var server5 = http.createServer(app5.callback())
 
+var app6 = new Koa()
+app6.use(staticCache(path.join(__dirname, '..'), {
+  buffer: true,
+  brotli: true,
+  filter(file) {
+    return !file.includes('node_modules')
+  }
+}))
+var server6 = http.createServer(app6.callback())
+
+var app7 = new Koa()
+var files7 = {}
+app7.use(staticCache(path.join(__dirname, '..'), {
+  brotli: true,
+  filter(file) {
+    return !file.includes('node_modules')
+  }
+}, files7))
+var server7 = http.createServer(app7.callback())
+
 describe('Static Cache', function () {
 
   it('should dir priority than options.dir', function (done) {
@@ -601,4 +621,85 @@ describe('Static Cache', function () {
       .expect(404)
       .end(done)
   })
+
+  it('should serve files with brotli buffer', function (done) {
+    var index = fs.readFileSync('index.js')
+    zlib.brotliCompress(index, function (err, content) {
+      request(server6)
+      .get('/index.js')
+      .set('Accept-Encoding', 'br')
+      .responseType('arraybuffer')
+      .expect(200)
+      .expect('Cache-Control', 'public, max-age=0')
+      .expect('Content-Encoding', 'br')
+      .expect('Content-Type', /javascript/)
+      .expect('Content-Length', String(content.length))
+      .expect('Vary', 'Accept-Encoding')
+      .expect(function (res) {
+        return res.body.toString('hex') === content.toString('hex')
+      })
+      .end(function (err, res) {
+        if (err)
+          return done(err)
+        res.should.have.header('Content-Length')
+        res.should.have.header('Last-Modified')
+        res.should.have.header('ETag')
+
+        etag = res.headers.etag
+
+        done()
+      })
+    })
+  })
+
+  it('should not serve files with brotli buffer when accept encoding not include br',
+  function (done) {
+    var index = fs.readFileSync('index.js')
+    request(server6)
+    .get('/index.js')
+    .set('Accept-Encoding', '')
+    .expect(200)
+    .expect('Cache-Control', 'public, max-age=0')
+    .expect('Content-Type', /javascript/)
+    .expect('Content-Length', String(index.length))
+    .expect('Vary', 'Accept-Encoding')
+    .expect(index.toString())
+    .end(function (err, res) {
+      if (err)
+        return done(err)
+      res.should.not.have.header('Content-Encoding')
+      res.should.have.header('Content-Length')
+      res.should.have.header('Last-Modified')
+      res.should.have.header('ETag')
+      done()
+    })
+  })
+
+  it('should serve files with brotli stream', function (done) {
+    var index = fs.readFileSync('index.js')
+    zlib.brotliCompress(index, function (err, content) {
+      request(server7)
+      .get('/index.js')
+      .set('Accept-Encoding', 'br')
+      .expect(200)
+      .expect('Cache-Control', 'public, max-age=0')
+      .expect('Content-Encoding', 'br')
+      .expect('Content-Type', /javascript/)
+      .expect('Vary', 'Accept-Encoding')
+      .expect(function (res) {
+        return res.body.toString('hex') === content.toString('hex')
+      })
+      .end(function (err, res) {
+        if (err)
+          return done(err)
+        res.should.not.have.header('Content-Length')
+        res.should.have.header('Last-Modified')
+        res.should.have.header('ETag')
+
+        etag = res.headers.etag
+
+        done()
+      })
+    })
+  })
 })