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.
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.
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.
// 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);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)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.
Apache License, Version 2.0