support brotli

Author: v1rtl

README.md

@@ -6,8 +6,9 @@ Deno HTTP compression middleware.
 
 ## Features
 
+- `gzip`, `deflate` and `brotli` support
 - Detects supported encodings with `Accept-Encoding` header
-- Supports chaining algorithms (e.g. `gzip` -> `deflate`)
+- Respects encodings order (depending on `Accept-Encoding` value)
 - Creates a `Content-Encoding` header with applied compression
 - Send `409 Not Acceptable` if encoding is not supported
 
@@ -21,14 +22,22 @@ const s = serve({ port: 3000 })
 
 for await (const req of s) {
   await compression({
-    // Path to file
+    // Path to a file
     path: 'README.md',
-    // Apply all algos in a queue
     compression: ['gzip', 'deflate']
   })(req)
 }
 ```
 
+Now try to send a `HEAD` request with `curl`:
+
+```sh
+$ curl localhost:3000 --head -H "Accept-Encoding: br, gzip, deflate" --compressed
+HTTP/1.1 200 OK
+content-length: 550
+content-encoding: br, gzip, deflate
+```
+
 [releases]: https://img.shields.io/github/v/release/deno-libs/compression?style=flat-square
 [docs-badge]: https://img.shields.io/github/v/release/deno-libs/compression?color=yellow&label=Documentation&logo=deno&style=flat-square
 [docs]: https://doc.deno.land/https/deno.land/x/compression/mod.ts

example.ts

@@ -6,6 +6,6 @@ const s = serve({ port: 3000 })
 for await (const req of s) {
   await compression({
     path: 'README.md',
-    compression: ['gzip', 'deflate']
+    compression: ['br', 'gzip', 'deflate']
   })(req)
 }

mod.ts

@@ -1,18 +1,19 @@
-// import { compress as brotli } from 'https://deno.land/x/[email protected]/mod.ts'
+import { compress as brotli } from 'https://deno.land/x/[email protected]/mod.ts'
 import { gzip, deflate } from 'https://deno.land/x/[email protected]/mod.ts'
 import { ServerRequest } from 'https://deno.land/[email protected]/http/server.ts'
 import { Accepts } from 'https://deno.land/x/[email protected]/mod.ts'
+import { readAll } from 'https://deno.land/[email protected]/io/util.ts'
 
 const funcs = {
-  // br: brotli,
+  br: brotli,
   gzip: (body: Uint8Array) => gzip(body, undefined),
   deflate: (body: Uint8Array) => deflate(body, undefined)
 }
 
 /**
  * Supported compression algorithms
  */
-type Compression = 'gzip' | /* 'br' | */ 'deflate'
+type Compression = 'gzip' | 'br' | 'deflate'
 
 export type CompressionOptions = {
   /**
@@ -51,7 +52,7 @@ export const compression = (opts: CompressionOptions) => async (req: ServerReque
 
   const encodings = accepts.encodings()
 
-  const buf = await Deno.readAll(await Deno.open(opts.path))
+  const buf = await readAll(await Deno.open(opts.path))
 
   if (!acceptHeader || acceptHeader === 'identity' || (Array.isArray(encodings) && encodings[0] === 'identity')) {
     return await req.respond({
@@ -77,7 +78,10 @@ export const compression = (opts: CompressionOptions) => async (req: ServerReque
     if (Array.isArray(encodings)) {
       let compressed: Uint8Array = buf
       let encs: string[] = []
-      for (const enc of encodings.filter((x) => x !== 'identity')) {
+
+      for (let enc of encodings.filter((x) => x !== 'identity')) {
+        if (enc === 'brotli') enc = 'br'
+
         if (Object.keys(funcs).includes(enc as string)) {
           compressed = funcs[enc as Compression](compressed)
           encs.push(enc)