refactor(ext/compress): make extension lighter

ext/compress.ts

@@ -1,57 +1,82 @@
 // Copyright 2023 Samuel Kopp. All rights reserved. Apache-2.0 license.
-import * as brotli from 'https://deno.land/x/brotli@0.1.7/mod.ts'
-import { deflate, gzip } from 'https://deno.land/x/foras@2.0.8/src/deno/mod.ts'
+import { compress as brotli } from 'https://deno.land/x/brotli@0.1.7/mod.ts'
+import {
+ deflate,
+ gzip,
+ initBundledOnce,
+ InitOutput,
+} from 'https://deno.land/x/foras@2.0.8/src/deno/mod.ts'
 import { createExtension } from '../mod.ts'
 
+type CompressionAlgorithm = {
+ format: 'br' | 'deflate' | 'gzip'
+ compress: (input: Uint8Array) => Uint8Array | Promise<Uint8Array>
+}
+
+let FORAS: InitOutput | undefined
+
+export const BROTLI: CompressionAlgorithm = {
+ format: 'br',
+ compress: brotli,
+}
+
+export const DEFLATE: CompressionAlgorithm = {
+ format: 'deflate',
+ async compress(input) {
+ if (!FORAS) {
+ FORAS = await initBundledOnce()
+ }
+
+ return deflate(input)
+ },
+}
+
+export const GZIP: CompressionAlgorithm = {
+ format: 'gzip',
+ async compress(input) {
+ if (!FORAS) {
+ FORAS = await initBundledOnce()
+ }
+
+ return gzip(input)
+ },
+}
+
 /**
- * An extension to compress the body of the response with [Brotli](https://github.com/google/brotli), [gzip](https://www.gzip.org), or [deflate](https://www.ietf.org/rfc/rfc1951.txt), based on the `Accept-Encoding` header of the incoming request.
+ * An extension to compress the body of the response with [brotli](https://github.com/google/brotli), [gzip](https://www.gzip.org), or [deflate](https://www.ietf.org/rfc/rfc1951.txt), based on the `Accept-Encoding` header of the incoming request.
  *
  * @since v1.0
  */
-export const compress = createExtension({
- onResponse({ c }) {
+export const compress = createExtension<{
+ algorithm: CompressionAlgorithm | CompressionAlgorithm[]
+}>({
+ async onResponse({ c, _ }) {
+ const alg = _.algorithm instanceof Array ? _.algorithm : [_.algorithm]
+
  const header = c.req.headers['accept-encoding']
 
  if (c.res.body === null || !header || header === 'identity') {
  return
  }
 
- if (header.includes('br')) {
- c.res.body = c.res.body instanceof Uint8Array
- ? brotli.compress(c.res.body)
- : c.res.body instanceof ArrayBuffer
- ? brotli.compress(new Uint8Array(c.res.body))
- : typeof c.res.body === 'string'
- ? brotli.compress(new TextEncoder().encode(c.res.body))
- : c.res.body
-
- if (c.res.body instanceof Uint8Array) {
- c.res.header('content-encoding', 'br')
+ for (let i = 0; i < alg.length; ++i) {
+ if (!header.includes(alg[i].format)) {
+ continue
  }
- } else if (header.includes('gzip')) {
- c.res.body = c.res.body instanceof Uint8Array
- ? gzip(c.res.body)
- : c.res.body instanceof ArrayBuffer
- ? gzip(new Uint8Array(c.res.body))
- : typeof c.res.body === 'string'
- ? gzip(new TextEncoder().encode(c.res.body))
- : c.res.body
 
- if (c.res.body instanceof Uint8Array) {
- c.res.header('content-encoding', 'gzip')
- }
- } else if (header.includes('deflate')) {
  c.res.body = c.res.body instanceof Uint8Array
- ? deflate(c.res.body)
+ ? await alg[i].compress(c.res.body)
  : c.res.body instanceof ArrayBuffer
- ? deflate(new Uint8Array(c.res.body))
+ ? await alg[i].compress(new Uint8Array(c.res.body))
  : typeof c.res.body === 'string'
- ? deflate(new TextEncoder().encode(c.res.body))
+ ? await alg[i].compress(new TextEncoder().encode(c.res.body))
  : c.res.body
 
  if (c.res.body instanceof Uint8Array) {
- c.res.header('content-encoding', 'deflate')
+ c.res.header('content-encoding', alg[i].format)
  }
+
+ break
  }
  },
 })