simlate_pgdump.rb

require 'sinatra'
require 'json'

class Pgdump
	attr_reader :name

	def initialize
		@name = "dump-#{rand(99999)}"
		@step = 0
	end

	def self.create
		dump = new
		@@pgdumps ||= {}
		@@pgdumps[dump.name] = dump
	end

	def self.find(name)
		return nil if !defined?(@@pgdumps)
		@@pgdumps[name]
	end

	def to_h
		{
			'name' => name,
			'state' => state,
			'progress' => progress,
			'size' => 123456
		}
	end

	def to_json
		to_h.to_json
	end

	def advance_progress
		@step += 1 if @step < highest_step
	end

	def progress
		case @step
			when 0: [ ]
			when 1: [ ['dump','0.3MB my_table1'] ]
			when 2: [ ['dump','1.7MB other_table'] ]
			when 3: [ ['dump','2.8MB the_last_table'] ]
			when 4: [ ['dump','3.1MB'], ['gzip','1.2MB'] ]
			when 5: [ ['dump','3.1MB'], ['gzip','2.0MB'] ]
			when 6: [ ['dump','3.1MB'], ['gzip','2.0MB'], ['store','0.4MB'] ]
			when 7: [ ['dump','3.1MB'], ['gzip','2.0MB'], ['store','1.8MB'] ]
			when 8: [ ['dump','3.1MB'], ['gzip','2.0MB'], ['store','2.0MB'] ]
		end
	end

	def highest_step
		8
	end

	def state
		return 'underway' if @step < highest_step
		'complete'
	end
end

post '/apps/:app/pgdumps' do
	Pgdump.create.to_json
end

get '/apps/:app/pgdumps/:name' do
	pgdump = Pgdump.find(params[:name])
	pgdump.advance_progress
	pgdump.to_json
end