happner
Version:
distributed application engine with evented storage and mesh services
238 lines (187 loc) • 7.1 kB
JavaScript
// TODO: This is expensive... minifies and gzips a set of scripts !! at every startup...
// to provide single /client/api script to browser.
// Better if this was cached to disk (when in production mode)
// BUG: more than one meshnode in same process and packager does not apply
// post-start changes to script package into all mesh nodes.
// A preliminary work toward asset packaging (minify, gzip, etag, etc.)
// The ideal would be a per component widget assembly line.
// Allows for serving individual scripts development.
// This one packages only the core /client/api script from ./api.js and it's dependancies
// Make it not do all this on every startup.
module.exports = Packager;
var fs = require('fs')
, zlib = require('zlib')
, md5 = require('md5')
, Promise = require('bluebird')
, minifyJS = require('uglify-js').minify
, normalize = require('path').normalize
, dirname = require('path').dirname
, sep = require('path').sep
, happnProtocol
;
var watchedFiles = {}; // Properly support only one packager per process!
function Packager(mesh) {
this.log = mesh.log.createLogger('Packager');
mesh.tools.packages = this.packages = {};
var script1 = dirname(dirname(require.resolve('bluebird'))) + sep + 'browser' + sep + 'bluebird.js';
var script2 = normalize(mesh._mesh.datalayer.server.services.pubsub.script);
var script3 = dirname(require.resolve('happn')) + sep + 'client' + sep + 'base.js';
happnProtocol = require(require.resolve('happn').replace(sep + 'lib' + sep + 'index.js', '') + sep + 'package.json').protocol;
var script4 = normalize(__dirname + sep + 'shared' + sep + 'logger.js');
var script5 = normalize(__dirname + sep + 'shared' + sep + 'promisify.js');
var script6 = normalize(__dirname + sep + 'shared' + sep + 'mesh-error.js');
var script7 = normalize(__dirname + sep + 'shared' + sep + 'messenger.js');
var script8 = normalize(__dirname + sep + 'shared' + sep + 'internals.js');
var script9 = normalize(__dirname + sep + 'shared' + sep + 'mesh-client.js');
this.scripts = [
{watch: false, min: false, file: script1},
{watch: false, min: false, file: script2},
{watch: true, min: false, file: script3},
{watch: true, min: false, file: script4},
{watch: true, min: false, file: script5},
{watch: true, min: false, file: script6},
{watch: true, min: false, file: script7},
{watch: true, min: false, file: script8},
{watch: true, min: false, file: script9}
//
// When not running NODE_ENV=production the package is re-assembled
// when this file changes.
]
this.merged = {}; // final product, merges scripts
}
Packager.prototype.initialize = function (callback) {
this.log.$$DEBUG('Building /api/client package');
var readFilePromise = Promise.promisify(fs.readFile);
var lstatPromise = Promise.promisify(fs.lstat);
var _this = this;
return Promise.all(
_this.scripts.map(function (script) {
return new Promise(function (resolve, reject) {
// handle each script object
if (process.env.NODE_ENV == 'production' && !script.min) {
var gotMinFile = script.file.replace(/\.js$/, '.min.js');
// Production
return lstatPromise(gotMinFile)
.then(function () {
script.file = gotMinFile;
script.min = true;
resolve(script);
})
.catch(function () {
script.min = false;
resolve(script);
});
}
// Not production
return resolve(script);
});
})
)
// Read the files
.then(function (scripts) {
return Promise.all(
scripts.map(function (script) {
_this.log.$$DEBUG('reading script %s', script.file);
return readFilePromise(script.file);
})
);
})
// Load the buffer data onto the scripts array
.then(function (buffers) {
buffers.forEach(function (buf, i) {
_this.scripts[i].buf = buf;
});
})
// TODO: Watch where necessary...
// In non production mode, it would
// be ideal if changes to the component scripts
// were detected, averting the need to restart the
// server to get the updated script to the browser.
// Minifi if production
.then(function () {
_this.scripts.forEach(function (script) {
if (process.env.NODE_ENV == 'production' && !script.min) {
_this.log.$$DEBUG('minify script %s', script.file);
script.buf = minifyJS(script.buf.toString(), {fromString: true}).code;
}
});
})
// Set watchers
.then(function () {
_this.scripts.forEach(function (script) {
if (!script.watch) return;
if (process.env.NODE_ENV == 'production') return;
_this.log.$$DEBUG('(non-production) watching %s', script.file);
if (watchedFiles[script.file]) {
return
}
;
watchedFiles[script.file] = 1; // prevent too many listeners on file
// for systems that run many mesh nodes
// in one process
fs.watchFile(script.file, {interval: 100}, function (curr, prev) {
if (!(prev.mtime < curr.mtime)) {
return;
}
_this.log.warn('changed %s', script.file);
readFilePromise(script.file)
.then(function (buf) {
script.buf = buf;
return _this.assemble()
})
.then(function () {
_this.log.warn('reload done');
})
.catch(function (e) {
_this.log.error('reload failed', e);
});
});
});
})
// Assemble the package.
.then(function () {
return _this.assemble();
})
.then(function () {
callback(null);
})
.catch(callback)
};
Packager.prototype.assemble = function () {
var _this = this;
var gzip = Promise.promisify(zlib.gzip);
return new Promise(function (resolve, reject) {
_this.merged.script = '';
_this.scripts.forEach(function (script) {
var scriptStr = script.buf.toString();
if (script.file.indexOf('client' + sep + 'base.js') > -1) scriptStr = scriptStr.replace('{{protocol}}', happnProtocol);
_this.merged.script += scriptStr + '\n';
});
_this.merged.md5 = md5(_this.merged.script);
_this.log.$$DEBUG('gzip package');
gzip(_this.merged.script)
.then(function (zipped) {
_this.merged.data = zipped;
_this.merged.gzip = true;
resolve();
})
.catch(function () {
_this.merged.data = _this.merged.script
_this.merged.gzip = false;
resolve();
})
})
.then(function () {
return new Promise(function (resolve, reject) {
Object.defineProperty(_this.packages, 'api', {
get: function () {
return _this.merged;
},
enumerable: true,
configurable: true,
});
_this.log.$$DEBUG('done');
resolve();
});
});
}