small key value store

server.rb

require 'sinatra'
require 'json'

class Value
  attr_accessor :type, :value

  def initialize(value)
    @value = value

    if ['true', 'false'].include? value.downcase
      @type = 'boolean'
    elsif value.match(/^(\d)+$/) # integer or double
      value = value.to_i
      if value >= -2147483648 && value <= 2147483647
        @type = 'integer'
      else
        @type = 'double'
      end
    else
      @type = 'string'
    end
  end
end

class SecondaryValue
  attr_accessor :type, :primary_keys

  def initialize()
    @type = nil
    @primary_keys = Set.new
  end

  def check_value(value)
    return @type.nil? || @type == value.type
  end

  def insert_primary_key(key, type)
    @type = type
    
    primary_keys << key
  end
end

db = Hash.new
secondary_db = Hash.new
lock = Mutex.new

get '/' do
  'Hello world!'
end

post '/store' do
  params = JSON.parse(request.body.read)

  puts "params #{params}"

  key = params['key']
  values = params["values"]

  if db[key].nil?
    db[key] = Hash.new
  end

  puts "key: #{key}"
  puts "values: #{values}"


  values.each do |value|
    puts "debug: #{value}"
    secondary_key = value["attribute_name"]
    val = Value.new(value["attribute_value"])

    seondary_value = secondary_db[secondary_key]
    if seondary_value.nil?
      secondary_db[secondary_key] = SecondaryValue.new
      seondary_value = secondary_db[secondary_key]
    end

    if !seondary_value.check_value(val)
      status 403
      body "attribute: #{secondary_key} must be of type #{seondary_value.type}"
      return
    end

    lock.synchronize do
      db[key][secondary_key] = val
      seondary_value.insert_primary_key(key, val.type)
    end
  end

  'Success'
end

get '/fetch' do
  key = params["key"]

  puts "fetching key #{key}"

  values = db[key]
  if values.nil?
    status 404
    body "no values set for #{key}"
    return
  end

  results = []

  puts "values #{values.class} #{values}"
  values.each do |key, value|
    puts "key #{key}"
    puts "value #{value}"
    puts "value.value #{value.value}"

    results << {
      attribute_name: key,
      attribute_value: value.value,
    }
  end

  puts "values #{results}"
  results.to_json
end

get '/delete' do
  key = params["key"]

  values = db[key]
  if values.nil?
    status 404
    body "no values set for #{key}"
    return
  end

  results = []

  lock.synchronize do
    values.each do |skey, value|
      secondary_db[skey].primary_keys.delete key
      
      if secondary_db[skey].primary_keys.size == 0 # optional?
        secondary_db[skey].type = nil
      end
    end

    db.delete key
  end

  'OK'
end

get '/stretch' do
  secondary_key = params["attribute_name"]
  search_value = Value.new params["attribute_value"]

  results = []

  secondary_value = secondary_db[secondary_key]
  
  if secondary_value && secondary_value.type == search_value.type
    secondary_value.primary_keys.each do |key|
      if db[key][secondary_key].value == search_value.value
        results << key
      end
    end
  end

  status results.size == 0 ? 404 : 200
  results.to_json
end

get '/debug' do
  "db #{db} \n secondary_db #{secondary_db}\n"
end