A very inefficient file-based database. For prototyping only.

inefficient-db.coffee

fs = require "fs"

###

A very inefficient file-based database. For prototyping only.

Usage:

  db = new DB()
  # Insert new row
  db.insert { ... }
  # Delete any row matched condition
  db.delete (row) -> condition
  # Find some row
  db.find (row) -> condition
  # Update rows that matched the condition
  db.update (row) -> condition, (row) -> updatedRow

###

DB = () ->
  @data = null;
  # Read and update the internal data model
  @readData = () ->
    data = fs.readFileSync "./data.db", "utf-8"
    try
      @data = JSON.parse data
    catch e
      console.log "DB ERROR:", e
  # Write current data to file
  @writeData = () ->
    content = JSON.stringify @data
    fs.writeFileSync "./data.db", content
  # Get
  @find = (fn) -> @data.filter fn
  # Delete
  @delete = (fn) ->
    @data = @data.filter not fn
    @writeData()
  # Insert
  @insert = (row) ->
    @data = @data.concat row
    @writeData()
  # Update
  @update = (fn, update) ->
    @data = @data.map (row) -> if fn row then update row else row
    @writeData()
  # Main DB implementation
  @readData()
  return this

module.exports = DB