Fix font compositing (close #32)

src/serve_font.js

@@ -1,12 +1,9 @@
 'use strict';
 
-var async = require('async'),
-    path = require('path'),
-    fs = require('fs');
-
 var clone = require('clone'),
     express = require('express');
 
+var utils = require('./utils');
 
 module.exports = function(options, allowedFonts) {
   var app = express().disable('x-powered-by');
@@ -15,41 +12,14 @@ module.exports = function(options, allowedFonts) {
 
   var fontPath = options.paths.fonts;
 
-  var getFontPbf = function(name, range, callback) {
-    // if some of the files failed to load (does not exist or not allowed),
-    // return empty buffer so the other fonts can still work
-    if (allowedFonts[name]) {
-      var filename = path.join(fontPath, name, range + '.pbf');
-      return fs.readFile(filename, function(err, data) {
-        if (err) {
-          console.log('Font load error:', filename);
-          return callback(null, new Buffer([]));
-        } else {
-          return callback(null, data);
-        }
-      });
-    } else {
-      return callback(null, new Buffer([]));
-    }
-  };
-
   app.get('/:fontstack/:range([\\d]+-[\\d]+).pbf',
       function(req, res, next) {
     var fontstack = decodeURI(req.params.fontstack);
     var range = req.params.range;
 
-    var fonts = fontstack.split(',');
-
-    var queue = [];
-    fonts.forEach(function(font) {
-      queue.push(function(callback) {
-        getFontPbf(font, range, callback);
-      });
-    });
-
-    return async.parallel(queue, function(err, results) {
-      var concated = Buffer.concat(results);
-      if (err || concated.length == 0) {
+    return utils.getFontsPbf(allowedFonts, fontPath, fontstack, range,
+        function(err, concated) {
+      if (err || concated.length === 0) {
         return res.status(400).send('');
       } else {
         res.header('Content-type', 'application/x-protobuf');