argo-gzip/index.js

Gzip package for Argo

var zlib = require('zlib'),
    argo = require('argo'),
    Stream = require('stream');

var zipPackage = function(argo) {
  return {
    name:"gzip compression",
    install: function() {

      argo
      .use(function(handle){
        handle("request", function(env, next){
          var req = env.request;

          if(req._argoModified) {
            req._gzipModified = "request";
            req._deflatedResponse = false;
            var getRequestBodyFunc = req.getBody;
            req.getBody = function(cb) {      
              var self = this;
              
              getRequestBodyFunc.call(this, function(error, body){
                if(!body) {
                    return cb(null, body)
                }

                if("content-encoding" in self.headers) {
                  var encoding;
                  encoding = self.headers["content-encoding"]
                  
                  if (encoding.indexOf('gzip') !== -1) {
                    zlib.gunzip(body, function(error, result){
                      if(error) {
                        cb(error);
                      } else {
                        req._deflatedResponse = true;
                        cb(null, result);
                      }
                    });
                  } else {
                    cb(null, body);
                  }
                } else {
                  cb(null, body);
                }
              });
            }
          }
          next(env);

        });
        handle("response", {affinity:"hoist"}, function(env, next){
          var res;
          if(env.target.response) {
            res = env.target.response;
          } else {
            res = env.response;
          }

          if(res._argoModified) {
            res._gzipModified = "response";
            res._deflatedResponse = true;
            var getRequestBodyFunc = res.getBody;
            res.getBody = function(cb) {      
              getRequestBodyFunc.call(res, function(error, body){
                res._deflatedResponse = false;
                if(!body) {
                    return cb(null, body)
                }

                if(res.headers && "content-encoding" in res.headers) {
                  var encoding;
                  encoding = res.headers["content-encoding"]
                  if (encoding.indexOf('gzip') !== -1) {
                    if(res._deflatedResponse) {
                      cb(null, body);
                    } else {
                      zlib.gunzip(body, function(error, result){
                        if(error) {
                          cb(error);
                        } else {
                          res._deflatedResponse = true;
                          cb(null, result);
                        }
                      });
                    }
                  } else {
                    cb(null, body);
                  }
                } else {
                  cb(null, body);
                }
              });
            }
          }
          next(env);
        });
      })
      .use(function(handle){ 
        handle("response", {affinity:"sink"}, function(env, next){
          var r;
          if(env.target.response) {
            r = env.target.response;
          } else {
            r = env.response;
          }

          if(!env.response.headers) {
            env.response.headers = {};
          }

          var acceptEncoding = env.request.headers["accept-encoding"];
          if(acceptEncoding && acceptEncoding.indexOf("gzip") !== -1) {
            if (r._deflatedResponse) {
              r.getBody(function(error, body){
                if(error) {
                  r.statusCode = 500;
                  r.body = error;
                  next(env);
                } else {
                  if (body === null || body === undefined) {
                    next(env);
                  } else if (typeof body === 'string') {
                    zlib.gzip(body, function(error, zippedBuffer){
                      if(error) {
                        r.statusCode = 500;
                        r.body = error;
                        next(env);
                      } else {
                        env.response.headers['Content-Encoding'] = 'gzip';
                        env.response.body = zippedBuffer;
                        next(env);
                      }
                    });
                  } else if (body instanceof Stream) {
                    var gzip = zlib.createGzip();
                    gzip
                      .on("finish",function(){
                        env.response.headers['Content-Encoding'] = 'gzip';
                        env.response.body = gzip;
                        next(env);
                      })
                      .on("error",function(error){
                        r.statusCode = 500;
                        r.body = error;
                        next(env);
                      });

                    body.pipe(gzip);
                  } else if (typeof body === 'object') {
                    body = JSON.stringify(body);
                    if(!env.response.getHeader("Content-Type")){
                      env.response.setHeader("Content-Type", "application/json; charset=UTF-8");
                    }
                    zlib.gzip(body, function(error, zippedBuffer){
                      if(error) {
                        r.statusCode = 500;
                        r.body = error;
                        next(env);
                      } else {
                        env.response.headers['Content-Encoding'] = 'gzip';
                        env.response.body = zippedBuffer;
                        next(env);
                      }
                    });
                  } 
                }
              });
            } else {
              next(env);
            }
          } else {
            next(env);
          }
          
        });
      });      
    }
  }
}

module.exports = {package: zipPackage};