Class: Rollup::Aggregator

Inherits:
Object
  • Object
show all
Defined in:
lib/rollup/aggregator.rb

Instance Method Summary collapse

Constructor Details

#initialize(klass) ⇒ Aggregator

Returns a new instance of Aggregator.



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# File 'lib/rollup/aggregator.rb', line 3

def initialize(klass)
  @klass = klass # or relation
end

Instance Method Details

#determine_dimension_name(group) ⇒ Object 



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# File 'lib/rollup/aggregator.rb', line 116

def determine_dimension_name(group)
  # split by ., ->>, and -> and remove whitespace
  value = group.to_s.split(/\s*((\.)|(->>)|(->))\s*/).last

  # removing starting and ending quotes
  # for simplicity, they don't need to be the same
  value = value[1..-2] if value.match(/\A["'`].+["'`]\z/)

  unless value.match(/\A\w+\z/)
    raise "Cannot determine dimension name: #{group}. Use the dimension_names option"
  end

  value
end

#maybe_clear(clear, name, interval) ⇒ Object 



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# File 'lib/rollup/aggregator.rb', line 176

def maybe_clear(clear, name, interval)
  if clear
    Rollup.transaction do
      Rollup.unscoped.where(name: name, interval: interval).delete_all
      yield
    end
  else
    yield
  end
end

#perform_calculation(relation, &block) ⇒ Object

calculation can mutate relation, but that’s fine



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# File 'lib/rollup/aggregator.rb', line 132

def perform_calculation(relation, &block)
  if block_given?
    yield(relation)
  else
    relation.count
  end
end

#perform_group(name, column:, interval:, time_zone:, current:, last:, clear:, range:) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/rollup/aggregator.rb', line 39

def perform_group(name, column:, interval:, time_zone:, current:, last:, clear:, range:)
  raise ArgumentError, "Cannot use last and range together" if last && range
  raise ArgumentError, "Cannot use last and clear together" if last && clear
  raise ArgumentError, "Cannot use range and clear together" if range && clear
  raise ArgumentError, "Cannot use range and current together" if range && !current.nil?

  current = true if current.nil?
  time_zone = Rollup.time_zone if time_zone.nil?

  gd_options = {
    current: current
  }

  # make sure Groupdate global options aren't applied
  gd_options[:time_zone] = time_zone
  gd_options[:week_start] = Rollup.week_start if interval.to_s == "week"
  gd_options[:day_start] = 0 if Utils.date_interval?(interval)

  if last
    gd_options[:last] = last
  elsif range
    gd_options[:range] = range
    gd_options[:expand_range] = true
    gd_options.delete(:current)
  elsif !clear
    # if no rollups, compute all intervals
    # if rollups, recompute last interval
    max_time = Rollup.unscoped.where(name: name, interval: interval).maximum(Utils.time_sql(interval))
    if max_time
      # for MySQL on Ubuntu 18.04 (and likely other platforms)
      if max_time.is_a?(String)
        utc = ActiveSupport::TimeZone["Etc/UTC"]
        max_time =
          if Utils.date_interval?(interval)
            max_time.to_date
          else
            t = utc.parse(max_time)
            t = t.in_time_zone(time_zone) if time_zone
            t
          end
      end

      # aligns perfectly if time zone doesn't change
      # if time zone does change, there are other problems besides this
      gd_options[:range] = max_time..
    end
  end

  # intervals are stored as given
  # we don't normalize intervals (i.e. change 60s -> 1m)
  case interval.to_s
  when "hour", "day", "week", "month", "quarter", "year"
    @klass.group_by_period(interval, column, **gd_options)
  when /\A\d+s\z/
    @klass.group_by_second(column, n: interval.to_i, **gd_options)
  when /\A\d+m\z/
    @klass.group_by_minute(column, n: interval.to_i, **gd_options)
  else
    raise ArgumentError, "Invalid interval: #{interval}"
  end
end

#prepare_result(result, name, dimension_names, interval) ⇒ Object 



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# File 'lib/rollup/aggregator.rb', line 140

def prepare_result(result, name, dimension_names, interval)
  raise "Expected calculation to return Hash, not #{result.class.name}" unless result.is_a?(Hash)

  time_class = Utils.date_interval?(interval) ? Date : Time
  dimensions_supported = Utils.dimensions_supported?
  expected_key_size = dimension_names.size + 1

  result.map do |key, value|
    dimensions = {}
    if dimensions_supported && dimension_names.any?
      unless key.is_a?(Array) && key.size == expected_key_size
        raise "Expected result key to be Array with size #{expected_key_size}"
      end
      time = key[-1]
      # may be able to support dimensions in SQLite by sorting dimension names
      dimension_names.each_with_index do |dn, i|
        dimensions[dn] = key[i]
      end
    else
      time = key
    end

    raise "Expected time to be #{time_class.name}, not #{time.class.name}" unless time.is_a?(time_class)
    raise "Expected value to be Numeric or nil, not #{value.class.name}" unless value.is_a?(Numeric) || value.nil?

    record = {
      name: name,
      interval: interval,
      time: time,
      value: value
    }
    record[:dimensions] = dimensions if dimensions_supported
    record
  end
end

#rollup(name, column: nil, interval: "day", dimension_names: nil, time_zone: nil, current: nil, last: nil, clear: false, range: nil, &block) ⇒ Object 



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# File 'lib/rollup/aggregator.rb', line 7

def rollup(name, column: nil, interval: "day", dimension_names: nil, time_zone: nil, current: nil, last: nil, clear: false, range: nil, &block)
  raise "Name can't be blank" if name.blank?

  column ||= @klass.rollup_column || :created_at
  # Groupdate 6+ validates, but keep this for now for additional safety
  # no need to quote/resolve column here, as Groupdate handles it
  column = validate_column(column)

  relation = perform_group(name, column: column, interval: interval, time_zone: time_zone, current: current, last: last, clear: clear, range: range)
  result = perform_calculation(relation, &block)

  dimension_names = set_dimension_names(dimension_names, relation)
  records = prepare_result(result, name, dimension_names, interval)

  maybe_clear(clear, name, interval) do
    save_records(records) if records.any?
  end
end

#save_records(records) ⇒ Object 



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# File 'lib/rollup/aggregator.rb', line 187

def save_records(records)
  # order must match unique index
  # consider using index name instead
  conflict_target = [:name, :interval, :time]
  conflict_target << :dimensions if Utils.dimensions_supported?

  options = Utils.mysql? ? {} : {unique_by: conflict_target}
  Rollup.unscoped.upsert_all(records, **options)
end

#set_dimension_names(dimension_names, relation) ⇒ Object 



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# File 'lib/rollup/aggregator.rb', line 101

def set_dimension_names(dimension_names, relation)
  groups = relation.group_values[0..-2]

  if dimension_names
    Utils.check_dimensions
    if dimension_names.size != groups.size
      raise ArgumentError, "Expected dimension_names to be size #{groups.size}, not #{dimension_names.size}"
    end
    dimension_names
  else
    Utils.check_dimensions if groups.any?
    groups.map { |group| determine_dimension_name(group) }
  end
end

#validate_column(column) ⇒ Object

basic version of Active Record disallow_raw_sql! symbol = column (safe), Arel node = SQL (safe), other = untrusted matches table.column and column



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# File 'lib/rollup/aggregator.rb', line 29

def validate_column(column)
  unless column.is_a?(Symbol) || column.is_a?(Arel::Nodes::SqlLiteral)
    column = column.to_s
    unless /\A\w+(\.\w+)?\z/i.match(column)
      raise ActiveRecord::UnknownAttributeReference, "Query method called with non-attribute argument(s): #{column.inspect}. Use Arel.sql() for known-safe values."
    end
  end
  column
end