require 'saulabs/reportable/reporting_period' require 'saulabs/reportable/result_set' require 'active_record' module Saulabs module Reportable # The +ReportCache+ class is a regular +ActiveRecord+ model and represents cached results for single {Saulabs::Reportable::ReportingPeriod}s. # +ReportCache+ instances are identified by the combination of +model_name+, +report_name+, +grouping+, +aggregation+ and +reporting_period+. # class ReportCache < ActiveRecord::Base self.table_name = :reportable_cache validates_presence_of :model_name validates_presence_of :report_name validates_presence_of :grouping validates_presence_of :aggregation validates_presence_of :value validates_presence_of :reporting_period # attr_accessible :model_name, :report_name, :grouping, :aggregation, :value, :reporting_period, :conditions self.skip_time_zone_conversion_for_attributes = [:reporting_period] # Clears the cache for the specified +klass+ and +report+ # # @param [Class] klass # the model the report to clear the cache for works on # @param [Symbol] report # the name of the report to clear the cache for # # @example Clearing the cache for a report # # class User < ActiveRecord::Base # reportable :registrations # end # # Saulabs::Reportable::ReportCache.clear_for(User, :registrations) # def self.clear_for(klass, report) self.where(model_name: klass.name, report_name: report.to_s).delete_all end # Processes the report using the respective cache. # # @param [Saulabe::Reportable::Report] report # the report to process # @param [Hash] options # options for the report # # @option options [Symbol] :grouping (:day) # the period records are grouped in (+:hour+, +:day+, +:week+, +:month+); Beware that reportable treats weeks as starting on monday! # @option options [Fixnum] :limit (100) # the number of reporting periods to get (see +:grouping+) # @option options [Hash] :conditions ({}) # conditions like in +ActiveRecord::Base#find+; only records that match these conditions are reported; # @option options [Boolean] :live_data (false) # specifies whether data for the current reporting period is to be read; if +:live_data+ is +true+, you will experience a performance hit since the request cannot be satisfied from the cache alone # @option options [DateTime, Boolean] :end_date (false) # when specified, the report will only include data for the +:limit+ reporting periods until this date. # # @return [ResultSet>] # the result of the report as pairs of {DateTime}s and {Float}s # def self.process(report, options, &block) raise ArgumentError.new('A block must be given') unless block_given? # If end_date is in the middle of the current reporting period it means it requests live_data. # Update the options hash to reflect reality. current_reporting_period = ReportingPeriod.new(options[:grouping]) if options[:end_date] && options[:end_date] > current_reporting_period.date_time options[:live_data] = true options.delete(:end_date) end self.transaction do cached_data = read_cached_data(report, options) new_data = read_new_data(cached_data, options, &block) prepare_result(new_data, cached_data, report, options) end end private def self.prepare_result(new_data, cached_data, report, options) new_data = new_data.to_a.map { |data| [ReportingPeriod.from_db_string(options[:grouping], data[0]), data[1]] } cached_data.to_a.map! { |cached| [ReportingPeriod.new(options[:grouping], cached.reporting_period), cached.value] } current_reporting_period = ReportingPeriod.new(options[:grouping]) reporting_period = get_first_reporting_period(options) result = [] while reporting_period < (options[:end_date] ? ReportingPeriod.new(options[:grouping], options[:end_date]).next : current_reporting_period) if cached = cached_data.find { |cached| reporting_period == cached[0] } result << [cached[0].date_time, cached[1]] else new_cached = build_cached_data(report, options[:grouping], options[:conditions], reporting_period, find_value(new_data, reporting_period)) new_cached.save! result << [reporting_period.date_time, new_cached.value] end reporting_period = reporting_period.next end if options[:live_data] result << [current_reporting_period.date_time, find_value(new_data, current_reporting_period)] end Saulabs::Reportable::ResultSet.new(result, report.klass.name, report.name) end def self.find_value(data, reporting_period) data = data.detect { |d| d[0] == reporting_period } data ? data[1] : 0.0 end def self.build_cached_data(report, grouping, conditions, reporting_period, value) self.new( :model_name => report.klass.to_s, :report_name => report.name.to_s, :grouping => grouping.identifier.to_s, :aggregation => report.aggregation.to_s, :conditions => serialize_conditions(conditions), :reporting_period => reporting_period.date_time, :value => value ) end def self.serialize_conditions(conditions) if conditions.is_a?(Array) && conditions.any? conditions.join elsif conditions.is_a?(Hash) && conditions.any? conditions.map.sort{|x,y|x.to_s<=>y.to_s}.flatten.join else conditions.empty? ? '' : conditions.to_s end end def self.read_cached_data(report, options) conditions = build_conditions_for_reading_cached_data(report, options) conditions.limit(options[:limit]).order('reporting_period ASC') end def self.build_conditions_for_reading_cached_data(report, options) start_date = get_first_reporting_period(options).date_time conditions = where('reporting_period >= ?', start_date).where( model_name: report.klass.to_s, report_name: report.name.to_s, grouping: options[:grouping].identifier.to_s, aggregation: report.aggregation.to_s, conditions: serialize_conditions(options[:conditions] || []) ) if options[:end_date] end_date = ReportingPeriod.new(options[:grouping], options[:end_date]).date_time conditions.where('reporting_period <= ?', end_date) else conditions end end def self.read_new_data(cached_data, options, &block) return [] if !options[:live_data] && cached_data.size == options[:limit] first_reporting_period_to_read = get_first_reporting_period_to_read(cached_data, options) last_reporting_period_to_read = options[:end_date] ? ReportingPeriod.new(options[:grouping], options[:end_date]).last_date_time : nil yield(first_reporting_period_to_read.date_time, last_reporting_period_to_read) end def self.get_first_reporting_period_to_read(cached_data, options) return get_first_reporting_period(options) if cached_data.empty? last_cached_reporting_period = ReportingPeriod.new(options[:grouping], cached_data.last.reporting_period) missing_reporting_periods = options[:limit] - cached_data.length last_reporting_period = if !options[:live_data] && options[:end_date] ReportingPeriod.new(options[:grouping], options[:end_date]) else ReportingPeriod.new(options[:grouping]).previous end if missing_reporting_periods == 0 || last_cached_reporting_period.offset(missing_reporting_periods) == last_reporting_period # cache only has missing data contiguously at the end last_cached_reporting_period.next else get_first_reporting_period(options) end end def self.get_first_reporting_period(options) if options[:end_date] ReportingPeriod.first(options[:grouping], options[:limit] - 1, options[:end_date]) else ReportingPeriod.first(options[:grouping], options[:limit]) end end end end end