From 51974e8c2e540f159b50f8563ad6690d7c10b314 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers@mozilla.com>
Date: Fri, 3 Jan 2014 15:56:11 -0500
Subject: [PATCH] look up metadata once then start server Fixes #33

---
 app.js          | 12 ++++++++----
 lib/filemap.js  | 46 +++++++++++++++++++++++++++++-----------------
 routes/index.js | 38 +++++---------------------------------
 3 files changed, 42 insertions(+), 54 deletions(-)

diff --git a/app.js b/app.js
index f7f271b..e23011f 100644
--- a/app.js
+++ b/app.js
@@ -2,6 +2,7 @@ var express = require('express');
 var http = require('http');
 var routes = require('./routes');
 var config = require('./config/config');
+var FileMap = require('./lib/filemap');
 var app = express();
 
 app.configure(function () {
@@ -17,10 +18,13 @@ app.configure(function () {
   app.use(express.static(__dirname + '/public'));
 });
 
-app.get('/list', routes.list);
-app.get('/transcode/:extension/:fileID', routes.transcode);
+FileMap.update(function () {
+  routes.FileMap = FileMap;
+  app.get('/list', routes.list);
+  app.get('/transcode/:extension/:fileID', routes.transcode);
 
-http.createServer(app).listen(app.get('port'), function () {
-  console.log('Express server listening on port ' + app.get('port'));
+  http.createServer(app).listen(app.get('port'), function () {
+    console.log('Express server listening on port ' + app.get('port'));
+  });
 });
 
diff --git a/lib/filemap.js b/lib/filemap.js
index 1f0a524..6ec63a8 100644
--- a/lib/filemap.js
+++ b/lib/filemap.js
@@ -1,35 +1,47 @@
 var shell = require('shelljs');
 var fs = require('fs');
+var Metalib = require('fluent-ffmpeg').Metadata;
 var music_folders = require('../config/config.json').music_folders
                                                     .map(escapejson);
 var supported_extension_re = /\.(mp3|ogg|wav|m4a|flac)$/;
 var file_dict = {};
+var file_metadata = [];
 
-function escapejson (filename) {
-  return filename.replace(/\\/g, '');
-};
+function escapejson (filename) { return filename.replace(/\\/g, ''); };
 
-var FileMap = {
-  retrieve: function (id) {
-    return file_dict[id];
-  },
-  retrieveAll: function () {
-    return file_dict;
-  },
+module.exports = {
+  retrieve: function (id) { return file_dict[id]; },
+  retrieveAll: function () { return file_metadata; },
   previously_transcoded: function (file_path) {
     var lib_file_path = 'library/' + file_path;
     return fs.existsSync(lib_file_path) ? lib_file_path : '';
   },
-  update: function () {
+  update: function (cb) {
+    var counter = file_metadata.length = 0;
     shell.find(music_folders).filter(function (file_path) {
       return supported_extension_re.test(file_path) && fs.existsSync(file_path);
-    }).forEach(function (file_path) {
-      file_dict[fs.statSync(file_path).ino] = file_path;
+    }).forEach(function (file_path, i, all_songs) {
+      if (i === 0) console.log('Parsing ' + all_songs.length + ' songs.');
+      var songID = fs.statSync(file_path).ino;
+      file_dict[songID] = file_path;
+      new Metalib(file_path, function (metadata, err) {
+        if (err) return console.error(err);
+        file_metadata.push({
+          songID: songID,
+          ext: file_path.replace(/.+\./, ''),
+          title: metadata.title || file_path.replace(/.+\//, ''),
+          artist: metadata.artist,
+          album: metadata.album,
+          year: metadata.date,
+          track: metadata.track,
+          duration: metadata.durationraw,
+        });
+        if (++counter === all_songs.length && typeof cb === 'function') {
+          console.log('Done parsing.');
+          cb();
+        }
+      });
     });
   }
 };
 
-FileMap.update();
-
-exports.FileMap = FileMap;
-
diff --git a/routes/index.js b/routes/index.js
index 6013a66..869da37 100644
--- a/routes/index.js
+++ b/routes/index.js
@@ -1,41 +1,13 @@
 var fs = require('fs');
-var Metalib = require('fluent-ffmpeg').Metadata;
-var FileMap = require('../lib/filemap').FileMap;
 var convert = require('../lib/convert');
 
-exports.list = function (req, res){
-  var filemap = FileMap.retrieveAll();
-  var filemapKeys = Object.keys(filemap);
-  var files = [];
-
-  filemapKeys.forEach(function (id) {
-    var filename = filemap[id];
-    new Metalib(filename, function (metadata, err) {
-      if (err) return console.error(err);
-      files.push({
-        songID: id,
-        ext: filename.replace(/.+\./, ''),
-        title: metadata.title || filename.replace(/.+\//, ''),
-        artist: metadata.artist,
-        album: metadata.album,
-        year: metadata.date,
-        track: metadata.track,
-        duration: metadata.durationraw,
-      });
-
-      // On the last file
-      if (files.length === filemapKeys.length) {
-        res.send(files);
-      }
-    });
-  });
-};
-
+exports.FileMap = null;
+exports.list = function (req, res) { res.send(exports.FileMap.retrieveAll()); };
 exports.transcode = function (req, res) {
   // Check if original file ext is in filemap
-  var file_path = FileMap.retrieve(req.params.fileID);
+  var file_path = exports.FileMap.retrieve(req.params.fileID);
   if (!file_path) {
-    console.log('original file was not in filemap');
+    console.log('Original file was not in filemap');
     return res.send(404);
   }
 
@@ -49,7 +21,7 @@ exports.transcode = function (req, res) {
 
   // Was the requested extension previously encoded?
   var previous_file_name = req.params.fileID + '.' + requested_extension;
-  var previous_file_path = FileMap.previously_transcoded(previous_file_name);
+  var previous_file_path = exports.FileMap.previously_transcoded(previous_file_name);
   if (previous_file_path) {
     console.log('Found previously encoded version in library/');
     return res.sendfile(previous_file_path);