all files / modules/middleware/ gzip.js

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const zlib = require("zlib");
const mach = require("../index");
 
mach.extend(
  require("../extensions/acceptEncoding")
);
 
const GZIP_MATCHER = /text|javascript|json/i;
 
function shouldGzipContentType(contentType) {
    if (!contentType || contentType === "text/event-stream") {
        return false;
    }
 
    return GZIP_MATCHER.test(contentType);
}
 
/**
 * A middleware that gzip's the response content (see http://www.gzip.org/).
 * Options may be any of node's zlib options (see http://nodejs.org/api/zlib.html).
 */
function gzip(app, options) {
    return function (conn) {
        return conn.call(app).then(function () {
            const response = conn.response;
            const headers = response.headers;
 
            if (shouldGzipContentType(headers["Content-Type"]) && conn.acceptsEncoding("gzip")) {
                response.content = response.content.pipe(zlib.createGzip(options));
 
                delete headers["Content-Length"];
                headers["Content-Encoding"] = "gzip";
                headers.Vary = "Accept-Encoding";
            }
        });
    };
}
 
module.exports = gzip;