Class: PeriodicCounter

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

Constant Summary collapse

WEEKDAYS = 
%w(sunday monday tuesday wednesday thursday friday saturday)

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(environment, root) ⇒ PeriodicCounter

Returns a new instance of PeriodicCounter.



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# File 'lib/periodic_counter.rb', line 8

def initialize(environment, root)
  @db, @log, @mail = ActiveWrapper.setup(
    :base => root,
    :env => environment
  )
  @db.establish_connection
  
  @tables = ActiveRecord::Base.connection.tables.inject({}) do |hash, table|
    hash[table] = ActiveRecord::Base.connection.columns(table).collect(&:name)
    hash
  end
  
  if File.exists?(counters_yml = "#{root}/config/counters.yml")
    @counters = YAML::load(File.open(counters_yml))
  else
    raise "#{counters_yml} not found"
  end
  
  @counters.each do |table, counters|
    columns = @tables[table]
    if columns
      columns.each do |column|
        if counters.include?(column)
          # Find period columns
          period = columns.select do |col|
            col =~ /^#{column}/ &&
            (col =~ /_last_/ || col =~ /_ago$/)
          end
          # Grab all records
          select_columns = [ 'id', column, "#{column}_data" ]
          select_columns += period
          records = ActiveRecord::Base.connection.select_all <<-SQL
            SELECT #{select_columns.join(', ')}
            FROM #{table}
          SQL
          records.each do |record|
            id = record.delete('id')
            data = YAML::load(record["#{column}_data"] || '') || {}
            count = record.delete(column).to_i
            # Set period counters
            period.each do |col|
              if WEEKDAYS.include?(weekday = col.split('_last_')[1])
                data["#{col}_before_today"] ||= 0
                if self.class.weekday(weekday)
                  record[col] = count - data["#{col}_before_today"]
                else
                  data["#{col}_before_today"] = count
                end
              else
                computed_at = data["#{col}_at"]
                last_time =
                  if col.include?('minute')
                    self.class.this_minute
                  elsif col.include?('hour')
                    self.class.this_hour
                  elsif col.include?('day')
                    self.class.today
                  elsif col.include?('week')
                    self.class.last_monday
                  elsif col.include?('month')
                    self.class.first_of_the_month
                  end
                if col =~ /_ago$/
                  duration = column_to_period_integer(col, -3, -2)
                  if !computed_at || last_time == computed_at
                    data[col] = count
                    data["#{col}_at"] = last_time
                  end
                  if computed_at && (Time.now.utc - computed_at - duration) >= 0
                    record[col] = data[col]
                    data[col] = count
                    data["#{col}_at"] = last_time
                  end
                else
                  duration = column_to_period_integer(col, -2, -1)
                  if !computed_at || (Time.now.utc - computed_at - duration) >= 0
                    data[col] = count
                    data["#{col}_at"] = last_time
                  else
                    data[col] ||= count
                    data["#{col}_at"] ||= last_time
                  end
                  record[col] = count - data[col].to_i
                end
              end
            end
            # Update record
            record["#{column}_data"] = "'#{YAML::dump(data)}'"
            set = record.collect { |col, value| "#{col} = #{value || 0}" }
            ActiveRecord::Base.connection.update <<-SQL
              UPDATE #{table}
              SET #{set.join(', ')}
              WHERE id = #{id}
            SQL
          end
        end
      end
    end
  end
end

Class Method Details

.first_of_the_month(now = Time.now.utc.to_date) ⇒ Object 



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# File 'lib/periodic_counter.rb', line 120

def first_of_the_month(now=Time.now.utc.to_date)
  Date.new(now.year, now.month, 1).to_time(:utc)
end

.last_monday(now = Time.now.utc.to_date) ⇒ Object 



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# File 'lib/periodic_counter.rb', line 124

def last_monday(now=Time.now.utc.to_date)
  wday = now.wday
  if wday == 0
    -6
  else
    diff = 1 - wday
  end
  Date.new(now.year, now.month, now.day + diff).to_time(:utc)
end

.this_hour(now = Time.now.utc) ⇒ Object 



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# File 'lib/periodic_counter.rb', line 134

def this_hour(now=Time.now.utc)
  now - (now.min * 60) - now.sec
end

.this_minute(now = Time.now.utc) ⇒ Object 



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# File 'lib/periodic_counter.rb', line 138

def this_minute(now=Time.now.utc)
  now - now.sec
end

.today(now = Time.now.utc.to_date) ⇒ Object 



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# File 'lib/periodic_counter.rb', line 142

def today(now=Time.now.utc.to_date)
  Date.new(now.year, now.month, now.day).to_time(:utc)
end

.weekday(day) ⇒ Object 



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# File 'lib/periodic_counter.rb', line 146

def weekday(day)
  Time.now.utc.to_date.wday == WEEKDAYS.index(day)
end

Instance Method Details

#column_to_period_integer(column, from, to) ⇒ Object 



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# File 'lib/periodic_counter.rb', line 109

def column_to_period_integer(column, from, to)
  column = column.split('_')[from..to]
  column[0] = column[0].to_i
  if column[0] == 0
    column[0] = 1
  end
  eval(column.join('.'))
end