Bailing if .mo files don't exist. Caching fs exists and readFile calls.

lib/i18n.js

@@ -22,6 +22,8 @@ var logger = require('./logging.js').logger,
 
 const BIDI_RTL_LANGS = ['ar', 'db-LB', 'fa', 'he'];
 
+var mo_cache = {};
+
 /**
  * Connect middleware which is i18n aware.
  *
@@ -40,18 +42,44 @@ exports.abide = function (options) {
   if (! options.ngettext_alias)      options.ngettext_alias = 'ngettext';
   if (! options.supported_languages) options.supported_languages = ['en-US'];
   if (! options.default_lang)        options.default_lang = 'en-US';
+  if (! options.debug_lang)          options.debug_lang = 'it-CH';
   if (! options.locale_directory)    options.locale_directory = 'locale';
 
+  var mo_file_path = function (locale) {
+    return path.resolve(
+             path.join(__dirname, '..'),
+                       options.locale_directory,
+                       path.join(locale, 'LC_MESSAGES', 'messages.mo'));
+  };
+
+  options.supported_languages.forEach(function (lang, i) {
+    var l = localeFrom(lang);
+
+    mo_cache[l] = {
+      exists: path.existsSync(mo_file_path(l)),
+      gt: null
+    };
+
+    if (! mo_cache[l].exists && l !== 'it_CH') {
+      var msg = util.format('Bad locale=[%s] mo file does not exist: [%s]. See locale/README', l, mo_file_path(l));
+      if (l == 'en_US') {
+        logger.warn(msg);
+      } else {
+        logger.error(msg);
+        throw msg;
+      }
+    }
+  });
+
   return function(req, resp, next) {
     var langs = parseAcceptLanguage(req.headers['accept-language']),
         lang_dir,
         lang = bestLanguage(langs, options.supported_languages,
                             options.default_lang),
+        debug_lang = options.debug_lang.toLowerCase(),
         locale;
 
-    // TODO(aok): Check if we're not in production mode before switching eo to db-LB
-    // Must fix before Esperanto could ship.
-    if (lang && lang.toLowerCase && lang.toLowerCase() == 'it-ch') {
+    if (lang && lang.toLowerCase && lang.toLowerCase() == debug_lang) {
         lang = 'db-LB'; // What? http://www.youtube.com/watch?v=rJLnGjhPT1Q
     }
 
@@ -63,35 +91,28 @@ exports.abide = function (options) {
     req.lang = lang;
 
     locale = localeFrom(lang);
+
     resp.local('locale', locale);
     req.locale = locale;
 
-    // Thread saftey, app startup or per request?
-    gt = new Gettext();
-
-    // Figure out where the mofile should live, and support absolute or
-    // relative paths
-    mo_path = path.resolve(
-      path.join(__dirname, '..'),
-		  options.locale_directory,
-		  path.join(locale, 'LC_MESSAGES', 'messages.mo'));
-
     resp.local('format', format);
     req.format = format;
 
-    if (path.existsSync(mo_path)) {
-      gt.addTextdomain(locale, fs.readFileSync(mo_path));
-
-      // Per request ???
-      gt.textdomain(locale);
+    if (mo_cache[locale].exists) {
+      if (mo_cache[locale].gt === null) {
+        mo_cache[locale].gt = new Gettext();
+        mo_path = mo_file_path(locale);
+        mo_cache[locale].gt.addTextdomain(locale,
+                                           fs.readFileSync(mo_path));
+        mo_cache[locale].gt.textdomain(locale);
+      }
+      var gt = mo_cache[locale].gt;
       resp.local(options.gettext_alias, gt.gettext.bind(gt));
       req.gettext = gt.gettext.bind(gt);
       resp.local(options.ngettext_alias, gt.ngettext.bind(gt));
       req.ngettext = gt.ngettext.bind(gt);
    } else {
-      // TODO if in development mode, warn, test ignore and production error
-      /* logger.error('Bad language=' + lang + ' or locale=' + locale +
-                   ' mo file does not exist. [' + mo_path + ']'); */
+      // en-US in a non gettext environment... fake it
       var identity = function (a, b) { return a; };
       resp.local(options.gettext_alias, identity);
       req.gettext = identity;