ptdb

Plain Text DB

This is a lame little plugin that allows you to use a javascript object as a database. You can save/load objects to file.

Saving is not guaranteed

This is not meant to be a high-write db, this is meant to be something you can use when your app doesn't need an actual db.

Install PTDB

npm install ptdb

Usage

You must require the PTDB object

var PTDB = require('ptdb');

Loading

To load/create a new DB, simply create a new instance and give it a name.

You can specify the following config options:

• syncInterval: the number of milleseconds between syncs to disk

var mydb = new PTDB('mydb'); // creates/loads a new mydb.ptdb in local path
mydb.load(function() {
  // DB has loaded, do some stuff
});

var anotherdb = new PTDB('db/anotherdb', {syncInterval: 1000});  // creates/loads from db/anotherdb.ptdb, and sets the write interval to 1s

Reading

To read an item from the db:

mydb.load(function() {
  // Read an item from the db
  mydb.read('path.to.item', function(err, item) {
    if (!err) console.log(item);
  });

  // Read from the top/head (.)
  mydb.read('.', function(err, item) {
    if (!err) console.log(item);
  });

  // pop an item off an array in the db
  mydb.pop('path.to.array', function(err, item) {
    if (!err) console.log(item);
  });

  // shift an item off an array in the db
  mydb.shift('path.to.array', function(err, item) {
    if (!err) console.log(item);
  });
});

Writing

You have a few options for writing, based on the type of item you are writing too. If the item or path doesn't exist, it will create it.

mydb.load(function() {
  mydb.write('path.to.item', item, function(err) {
    if (!err) console.log('Item written');
  });

  mydb.push('path.to.array', item, function(err) {
    if (!err) console.log('Item pushed to array');
  });

  mydb.unshift('path.to.array', item, function(err) {
    if (!err) console.log('Item unshifted to array');
  });
});

Deleting

You can delete items from the db as well.

mydb.unset('path.to.item', function(err) {
  if (!err) console.log('Item deleted');
});

// You can truncate the whole db by unsetting head (.)
mydb.unset('.', function(err) {
  if (!err) console.log('Item deleted');
});

Closing

You can close your db when you are done with it: This will break the lock and free the memory.

mydb.close();

You can always reopen the db by loading again!

Events

PTDB has the following events:

• load: This is emitted when the db is loaded
• save: This is emitted when the db is saved
• close: This is emitted when the db is closed

Watchers

Watchers are functions that watch parts of the db and are called when changes occur. You can register more than one watcher for a given path.

Note: Watchers are only triggered on saves and will always be called once.

// Register a watcher
mydb.watch('path.to.watch', function(newVal, oldVal, path) {
  // run a mapreduce or something
});

// Remove all watchers for a path
mydb.unwatch('path.to.unwatch');

Testing

Run tests via

npm run test