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import { readAll } from 'https://deno.land/std@0.181.0/streams/read_all.ts'import { compress as brotli } from 'https://deno.land/x/brotli@0.1.7/mod.ts'import { Foras } from 'https://deno.land/x/foras@2.0.8/src/deno/mod.ts'import { Accepts } from 'https://deno.land/x/accepts@2.1.1/mod.ts'
await Foras.initBundledOnce()
const funcs = {  br: brotli,  gzip: (body: Uint8Array) => Foras.gzip(body, undefined),  deflate: (body: Uint8Array) => Foras.deflate(body, undefined),}
/** * Supported compression algorithms */type Compression = 'gzip' | 'br' | 'deflate'
export type CompressionOptions = Partial<{  /**   * Path to file   */  path: string
  /**   * Body as a byte array (as returned from Deno.readFile methods)   */  bodyBinary: Uint8Array
  /**   * Body as a string (as returned from Deno.readTextFile)   */  bodyText: string}>
/** * HTTP Compression middleware. * @param {CompressionOptions} opts * * @example * ```tsimport { compression } from 'https://deno.land/x/http_compression/mod.ts'import { Server } from 'https://deno.land/std@0.181.0/http/server.ts'
new Server({  handler: async (req) => {    return await compression({ path, compression: ['br', 'gzip', 'deflate'] })(req)  }, port: 3000}).listenAndServe() * ``` */export const compression =  (opts: CompressionOptions) => async (req: Request): Promise<Response> => {    const acceptHeader = req.headers.get('Accept-Encoding')
    const accepts = new Accepts(req.headers)
    const encodings = accepts.encodings()
    let buf: Uint8Array    if (opts.bodyBinary) {      buf = opts.bodyBinary    } else if (opts.bodyText) {      const encoder = new TextEncoder()      buf = encoder.encode(opts.bodyText)    } else if (opts.path) {      const file = await Deno.open(opts.path)      buf = await readAll(file)      file.close()    } else {      throw Error('Must specify either bodyBinary, bodyText, or path.')    }
    if (      !acceptHeader || acceptHeader === 'identity' ||      (Array.isArray(encodings) && encodings[0] === 'identity')    ) {      return new Response(buf, {        status: 200,        headers: new Headers({          'Content-Encoding': 'identity',        }),      })    } else if (acceptHeader === '*') {      const compressed = funcs.gzip(buf)
      return new Response(compressed, {        headers: new Headers({          'Content-Encoding': 'gzip',        }),      })    } else {      if (Array.isArray(encodings)) {        let compressed: Uint8Array = buf        const encs: string[] = []
        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)          }        }
        return new Response(compressed, {          headers: new Headers({            'Content-Encoding': encs.join(', '),          }),        })      } else {        return Object.keys(funcs).includes(encodings as string)          ? new Response(funcs[encodings as Compression](buf), {            headers: new Headers({              'Content-Encoding': encodings as string,            }),          })          : new Response('Not Acceptable', {            status: 406,          })      }    }  }