Gridfs

The GridFS wrapper module for Node.js.

var fs = require('fs');
var mongo = require('mongodb');
var Grid = require('gridfs');

mongo.MongoClient.connect(yourMongoURI, function(err, db) {
  var gfs = Grid(db, mongo);

  var source = './example.txt';
  gfs.fromFile({filename: 'hello.txt'}, source, function (err, file) {
    console.log('saved %s to GridFS file %s', source, file._id);
    gfs.readFile({_id: file._id}, function (err, data) {
      console.log('read file %s: %s', file._id, data.toString());
    });
  });

  var contents = 'world';
  var target = './out.txt';
  gfs.writeFile({filename: 'world.txt'}, contents, function (err, file) {
    console.log('wrote "%s" to GridFS file %s', contents, file._id);
    gfs.toFile({_id: file._id}, target, function (err) {
      var fileContents = fs.readFileSync('./out.txt').toString();
      console.log('wrote file %s to %s: %s', file._id, target, fileContents);
    });
  });

  setTimeout(gfs.list.bind(gfs, function (err, filenames) {
    console.log('filenames: ' + filenames); // hello.txt, world.txt
  }), 100);
});

This is a simple extension of the excellent gridfs-stream library, building on its stream interface to provide additional utility methods. As such, huge props to @aheckmann and the rest of the contributors to gridfs-stream.

gridfs can be used as a drop-in replacement for gridfs-stream, as it exports the same object as gridfs-stream, just with additional methods available.

Installation

npm install gridfs

Methods

All options fields are the same as options fields in gridfs-stream; they're just passed along to the stream constructors.

gfs.readFile(options, cb(err, buffer))

Get the contents of the GridFS file specified by options.

gfs.writeFile(options, data, cb(err, file))

Write data to the GridFS file specified by options.

data can be a String or a Buffer.

gfs.toFile(options, target, cb(err))

Read from the GridFS file specified by options and write its contents to target.

target can be a file path or writable stream.

gfs.fromFile(options, source, cb(err, file))

Read from source and write its contents to the GridFS file specified by options.

source can be a file path or readable stream.

Returns the GridFS writeStream used for writing the file.

gfs.list(cb(err, filenames))

Gets the list of files stored in GridFS, using GridStore.list.

Notes on other potentially desirable fs methods

• fs.stat - use gfs.findOne
• fs.unlink - use gfs.remove
• fs.exists - use gfs.exist
• fs.createReadStream - use gfs.createReadStream
• fs.createWriteStream - use gfs.createWriteStream
• fs.appendFile - not currently feasible due to risk of corruption from parallel writes; see MongoDB driver 2.0 notes

Contributing

Pull requests are welcome. Guidelines: make sure npm test passes.

You'll need mocha, eslint, and mongo to run the tests; they use the gridfs-mocha-test database on the local mongo server.