ajs/lib/cache.js

Asynchronous templating in Node.js

'use strict';

// [« Back to Index](index.html)

var fs = require('fs');

// A very simple singleton memory cache to store compiled template functions for
// extremely fast retrieval. We use a file's mtime (modified time) to determine
// when the cache is stale and needs to be refreshed.
module.exports = new function () {
  this._store = {};

  this.get = function (filename, callback) {
    var cached = this._store[filename];
    if (!cached) return callback(null, null);

    fs.stat(filename, function (err, stat) {
      if (err) return callback(err);
      if (cached.mtime.toString() != stat.mtime.toString()) callback(null, null);else callback(null, cached.template);
    });
  };

  this.getSync = function (filename) {
    var cached = this._store[filename];
    if (!cached) return null;

    var stat = fs.statSync(filename);
    if (cached.mtime.toString() != stat.mtime.toString()) return null;else return cached.template;
  };

  this.set = function (filename, template) {
    var self = this;
    fs.stat(filename, function (err, stat) {
      if (stat) {
        self._store[filename] = {
          template: template,
          mtime: stat.mtime
        };
      };
    });
  };
}();