JSON DB FS

README

JSON FileSystem Database is a JSON Document database, such as MongoDB. All methods are asynchronous and accessing / filtering is executed in parallel using async. Currently supports 2 types of data drivers: Memory and Disk. Memory driver is very performant. It is possible to flush data to disk (configurable). Disk driver is less performant. Holds all data in disk, and reads/writes everytime you interact with the collection. Is implemented with Pessimistic Transaction Locking approach. Based on Jalalhejazi, jsonfs.

Dependencies

Internal unique ids generated with node-uuid. Object utilities with underscore. Methods implemented using asynchronous and parallel strategies with async. Pessimistic transaction locking is performed using lockfile. Criteria queries on JSON objects Mongo style json-criteria.

API

  var JSONDBFSDriver = require('jsondbfs');
  var database;

  // receives an array containing the collections you want to create / use ['Users', 'Others']
  // existing collections will be attached
  JSONDBFSDriver.connect(['Users'], {path: '/path/to/store/collections', driver: 'memory'}, function(err, db){
    database = db;
  });

  // now the collection can be accessed in the database object: 'database['Users'].insert' or 'database.Users.insert'

  database.Users.insert({name: 'Manuel', roles: ['Admin', 'Super']}, function(err, document){
    // inserts the document and returns it representation in the database (including the internal id)
    ...
  });

  database.Users.count(function(err, count){
    // returns the length of the collection
    ...
  });

  database.Users.count({name: 'Manuel'}, function(err, count){
    // returns the number of documents matching that criteria
    ...
  });

  database.Users.update({name: 'Manuel'}, {name: 'Manuel Martins', token: 'xsf32S123ss'}, function(err, result){
    // updates a specified document based on a criteria
    // result is { nMatched: 1, nModified: 1, nUpserted: 0 }
    ...
  });

  database.Users.findAndModify({name: 'Manuel Martins'}, {name: 'Manuel Martins', token: 'f32S123'}, {retObj: true}, function(err, result){
    // updates a specified document based on a criteria
    // result is the updated document
    // withou retObj info on updated / insert { nMatched: 1, nModified: 1, nUpserted: 0 } is returned
    ...
  });

  database.Users.find(function(err, documents){
    // returns everything since there is no criteria specified
    ...
  });

  database.Users.find({name: 'John'},function(err, documents){
    // returns an array with the elements that match the criteria
    ...
  });

  database.Users.findOne({name: 'John'},function(err, document){
    // returns the first document that matches the criteria
    ...
  });

  database.Users.remove({name: 'Manuel'}, function(err, success){
    // returns true if records were removed
    ...
  });

Support for Query and Projection Operators:

    database.Users.findOne({
      identities: {
        $elemMatch: {
          id: identity.id,
          provider: identity.provider
        }
      }
    }, function (err, document) {
      // returns the first document that matches the criteria inside an array of identities
      ...
    });

    database.Collection.find({
      quantity: { $gt: 25 }
    }, function (err, documents) {
      // returns the documents that matches the criteria
      ...
    });

    ...

Support provided using json-criteria.

Options

// Driver options
var JSONDBFSDriver = require('jsondbfs');
var database;

// driver options
var driverOptions = {
 path: '/path/to/store/collections',
 driver: 'memory',
 memory: {
    flush: true,
    flushInterval: 10000
  }
 };
JSONDBFSDriver.connect(['Collection'], driverOptions, callback);
...

// Collection options
database.Collection.update(criteria, updateCriteria, {upsert: false, multi: true, retObj: true}, callback);
database.Collection.findAndModify(criteria, updateCriteria, {upsert: false, multi: true, retObj: true}, callback);
database.Collection.find(criteria, {multi: false}, callback);
database.Collection.remove(criteria, {multi: false}, callback);

Driver options

When initializing the Driver you can pass 4 options:

options.path - The path to store the db collection files. Defaults to '/tmp/'.
options.driver - One of ['memory', 'disk'], defaults to 'disk'.
options.memory.flush - If you want to flush the memory to disk. Only used if driver is 'memory'. Defaults to 'false'.
options.memory.flushInterval - Time interval to flush memory to disk. Only used if driver is 'memory'. Defaults to '10000'ms. (10s)

Collections options

When updating a record you can pass 3 options:

options.upsert - If record is not found and this options is set to true, a new record will be created. Accepts a boolean 'true' or 'false'. Defaults to 'false'.
options.multi - Should update multiple records if they match. Accepts a boolean 'true' or 'false'. Defaults to 'true'.
options.retObj - Set to true if you want to return the updated object, otherwise a stats object is returned with info on updated records (as with MongoDB).

When removing or finding you can pass 1 option:

options.multi - Should update multiple records if they match. Accepts a boolean 'true' or 'false'. Defaults to 'true'.

Please check the tests for more details.

License

Apache License, Version 2.0