Fish Brain

A pure javascript in-memory database with support to save into file system.
This database is designed only for SMALL quantities of data (say 20mb = 2,621,440 characters).
Database files are just JSON files.

Install

npm i -S fishbrain

Instance

const Fishbrain = require('fishbrain')

To create a small fish with memory-only database (will forget everything when restart)

const smallFish = new Fishbrain('memory')

To create a big fish with file-system database (will persist)

const bigFish = new FishBrain('path_to_your_dbfile')

Your dbfile can be anything, no extension required and inside its just a plain JSON text file.

To keep a low memory footprint you can pass an optional shallow value when creating your brain

const bigFish = new FishBrain('path_to_your_dbfile', false)

your DB in filesystem will still have all data, but your copy in memory will only have reserved values

Create and Update

set(object)

If no _id is provided in the object when setting the record, a new record will be created and a new id will be returned.
If an existing _id is provided, it will replace matching keys and insert new ones.
If an un-existing _id is provided, it will create a new record with that _id.
If the existing record has value _protected, it will not be updated.

Read

get(query[, projection])  

When calling get with a query object, will return all items that match.
When calling get with an empty object, will return all items in the database.
When setting a projection, only the specified fields will be returned.

Delete

del(query)

When called with no query or empty query, will return with no action done. When called with a query object, all items matching that query will be removed from the DB

flush

flush()

Will delete all records from DB

Reserved keys

_id is used to create or update records
_ttl is used to set a time to live (see examples)
_protected is used to protect a value from being updated, but you still can delete it

Examples

const Fishbrain = require('fishbrain')
const fish = new Fishbrain('memory')

const id = fish.set({mykey: 'my value'})
const row1 = fish.get({_id: id})
// row1 = [{_id:<some uuid>, mykey: 'my value'}]

fish.set({_id: id, otherValue: 'yay'})
const row2 = fish.get({_id: id})
// row2 = [{_id:<some uuid>, mykey: 'my value', otherValue: 'yay'}]

fish.set({_id:'customText', bar:'foo'})
const row3 = fish.get({_id: `customText`})
// row3 = [{_id:'customText', bar:'foo'}]

const allRows = fish.get({})
// allRows = [
// 	{_id:<some uuid>, mykey: 'my value', otherValue: 'yay'},
// 	{_id:'customText', bar:'foo'}
// ]

const allRowsProjected = fish.get({},['bar'])
// allRowsProjected = [
// 	{bar: undefined},
// 	{bar: 'foo'}
// ]

const threeSecondsFromNow = new Date().getTime() / 1000 + 3
const dory = fish.set({
  _ttl: threeSecondsFromNow,
  nemo: 'P. Sherman 42 Wallaby Way, Sydney'
})
const result = fish.get({_id: dory},['nemo'])
// result = [{nemo: 'P. Sherman 42 Wallaby Way, Sydney'}]

setTimeout(() => {
  const result2 = fish.get({_id: dory},['nemo'])
  // result2 = []
},5000)

fish.del({bar:'foo'}) // all records with bar: 'foo' gone
fish.flush() // all gone