Handling nested PStore transactions (IRC example)

store.rb

require 'pstore'

class Store
  def initialize(relative_path: '.data.pstore')
    @store = PStore.new(relative_path, true)
    @store.ultra_safe = true
    @store.transaction(true) { }
    @in_transaction = false
    @store
  end

  def transaction(read_only = false)
    return yield @store if @in_transaction

    @in_transaction = true
    @store.transaction read_only do
      yield @store
    end
  ensure
    @in_transaction = false
  end
end

store = Store.new

store.transaction do
  store.transaction do |data|
    data[:meaning] = 42
  end
end

store.transaction { |hash| hash[:meaning] }
#=> 42