gridfs.server.js

var path = Npm.require('path');
var mongodb = Npm.require('mongodb');
var chunkSize = 262144; // 256k is default GridFS chunk size

/**
 * @public
 * @constructor
 * @param {String} name - The store name
 * @param {Object} options
 * @param {Function} [options.beforeSave] - Function to run before saving a file from the server. The context of the function will be the `FS.File` instance we're saving. The function may alter its properties.
 * @param {Number} [options.maxTries=5] - Max times to attempt saving a file
 * @returns {FS.StorageAdapter} An instance of FS.StorageAdapter.
 *
 * Creates a GridFS store instance on the server. Inherits from FS.StorageAdapter
 * type.
 */
FS.Store.GridFS = function(name, options) {
  var self = this;
  options = options || {};

  if (!(self instanceof FS.Store.GridFS))
    throw new Error('FS.Store.GridFS missing keyword "new"');

  if (!options.db) {
    options.db = process.env.MONGO_URL;
  }

  Meteor.startup(function() {
  }); // EO startup

  return new FS.StorageAdapter(name, options, {

    typeName: 'storage.gridfs',

    get: function(fileKey, callback) {
      var self = this;
      var existing = Meteor._wrapAsync(mongodb.GridStore.exist)(self.db, fileKey, name, {});
      if (!existing) { return callback(null, null); }
      var gs = new mongodb.GridStore(self.db, fileKey, 'r', { root: name });
      gs = Meteor._wrapAsync(gs.open.bind(gs))();
      var result = Meteor._wrapAsync(gs.read.bind(gs))();
      Meteor._wrapAsync(gs.close.bind(gs))();
      callback(null, new Uint8Array(result));
    },

    getBytes: function(fileKey, start, end, callback) {
      var self = this;
      var existing = Meteor._wrapAsync(mongodb.GridStore.exist)(self.db, fileKey, name, {});
      if (!existing) { return callback(null, null); }
      var gs = new mongodb.GridStore(self.db, fileKey, 'r', { root: name });
      gs = Meteor._wrapAsync(gs.open.bind(gs))();
      Meteor._wrapAsync(gs.seek.bind(gs))(start);
      var result = Meteor._wrapAsync(gs.read.bind(gs))(end - start);
      Meteor._wrapAsync(gs.close.bind(gs))();
      callback(null, new Uint8Array(result));
    },

    put: function(fileKey, buffer, options, callback) {

      var self = this;
      options = options || {};
      var existing = Meteor._wrapAsync(mongodb.GridStore.exist)(self.db, fileKey, name, {});

      if (existing && !options.overwrite) {
        // Alter the recommended fileKey until we have one that is unique
        var extension = path.extname(fileKey);
        var fn = fileKey.substr(0, fileKey.length - extension.length);
        var suffix = 0;
        do {
          suffix++;
          fileKey = fn + suffix + extension; //once we exit the loop, this is what will actually be used
        } while (Meteor._wrapAsync(mongodb.GridStore.exist)(self.db, fileKey, name, {}));
      }

      if (EJSON.isBinary(buffer)) {
        buffer = new Buffer(buffer);
      }

      var gridOptions = {
        root: name,
        chunk_size: options.chunk_size || chunkSize,
        metadata: options.metadata || null,
        content_type: options.content_type || 'application/octet-stream'
      };

      var gs = new mongodb.GridStore(self.db, fileKey, 'w', gridOptions);
      gs = Meteor._wrapAsync(gs.open.bind(gs))();
      var result = Meteor._wrapAsync(gs.write.bind(gs))(buffer);
      Meteor._wrapAsync(gs.close.bind(gs))();
      callback(null, fileKey);
    },

    del: function(fileKey, callback) {
      var self = this;
      Meteor._wrapAsync(mongodb.GridStore.unlink)(self.db, fileKey, { root: name });
      callback(null);
    },

    watch: function() {
      throw new Error("GridFS storage adapter does not support the sync option");
    },

    init: function() {
      var self = this;
      self.db = Meteor._wrapAsync(mongodb.MongoClient.connect)(options.db);
    }
  });
};