response_appender.js

"use strict";

var vsm = require('lrs/virtualServerModule'),
    FIX_HEADER = true;

function ResponseAppender(vsname, appendString, fixContentLength) {

    var self = this;

    self.virtualServer = vsname;
    self.appendString = appendString;

    vsm.on('exist', self.virtualServer, function(vs) {

        vs.on('request', function (servReq, servResp, cliReq) {
            console.log("request received for: " + servReq.url);
            // immediately send request to back end real-server
            servReq.bindHeaders(cliReq);
            servReq.fastPipe(cliReq);
            var body = false,
                total_length = 0;
            cliReq.on('response', function(response) {
                console.log("**HANDLING RESPONSE " + servReq.url + "**");
                // send along response headers un-touched
                response.bindHeaders(servRes);
                if ('Content-Length' in response.headers) {
                    body = []
                }
                response.on('data', function(chunk) {
                    // get a chunk, send a chunk
                    if (body === false) {
                      servResp.write(chunk);  
                    } 
                    else {
                      // collect the chunks
                      body.push(chunk);
                      total_length += Buffer.byteLength(chunk);
                    }
                    console.log("  " + servReq.url + " got " + chunk.length + " bytes of response data");
                });
                response.on('error', function(err) {
                    console.log("#### " + servReq.url + " errored out: "+ err);
                    servRes.end();
                });
                response.on('end', function() {
                    console.log("  ## ENDING ##");
                    // add our additional content
                    if (! body === false) {
                      if (fixContentLength) {
                        servResp.setHeader('Content-Length', total_length + self.appendString.length);
                      }
                      body = Buffer.concat(body, total_length);
                      body += self.appendString;
                      servResp.end(body);
                    }
                    else {
                      servResp.end(self.appendString);
                    }
                });
            });
        });
    });
}

exports.ResponseAppender = ResponseAppender;