Class: MetricSystem::Database

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/metric_system/database.rb

Constant Summary collapse

PERIODS = 
[
  [ :year,   31536000, "strftime('%Y-01-01',          starts_at, 'unixepoch')" ],
  [ :month,   2592000, "strftime('%Y-%m-01',          starts_at, 'unixepoch')" ],
  [ :week,     604800, "strftime('%Y-%m-%d',          starts_at, 'unixepoch',  'weekday 1', '-7 days')" ],
  [ :day,       86400, "strftime('%Y-%m-%d',          starts_at, 'unixepoch')" ],
  [ :hour,       3600, "strftime('%Y-%m-%d %H:00:00', starts_at, 'unixepoch')" ],
  [ :minute,       60, "strftime('%Y-%m-%d %H:%M:00', starts_at, 'unixepoch')" ],
  # [ :second,        1, "strftime('%Y-%m-%d %H:%M:%S', starts_at, 'unixepoch')" ],
]
PERIODS_BY_KEY = 
PERIODS.by(&:first)

Instance Method Summary collapse

Constructor Details

#initialize(path, readonly = false) ⇒ Database

Returns a new instance of Database.



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# File 'lib/metric_system/database.rb', line 2

def initialize(path, readonly = false)
  require_relative "./sqlite3_extensions"
  open path

  exec "PRAGMA query_only = 1" if readonly # This might or might not work.
  @db.readonly = !!readonly
end

Instance Method Details

#add_event(table, name, value, starts_at) ⇒ Object 



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# File 'lib/metric_system/database.rb', line 72

def add_event(table, name, value, starts_at)
  # get names of all related events. An event "a.b.c" is actually
  # 3 events: "a", "a.b", "a.b.c"
  names = begin
    parts = name.split(".")
    parts.length.downto(1).map do |cnt|
      parts[0,cnt].join(".")
    end
  end

  if starts_at
    starts_at = Time.parse(starts_at) if starts_at.is_a?(String)

    names.each do |name|
      run "INSERT INTO #{table}(name, value, starts_at) VALUES(?, ?, ?)", name, value, starts_at.to_i
    end
  else
    names.each do |name|
      run "INSERT INTO #{table}(name, value) VALUES(?, ?)", name, value
    end
  end
rescue
  STDERR.puts "#{$!}: #{table} #{name.inspect}, #{value.inspect}"
end

#aggregate(*keys) ⇒ Object 



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# File 'lib/metric_system/database.rb', line 99

def aggregate(*keys)
  if keys.empty?
    keys = PERIODS.map(&:first)
  end

  transaction do
    keys.each do |period|
      aggregate_for_period :period => period, :source => :counters, :dest => :aggregated_counters, :aggregate => "sum"
    end

    exec "DELETE FROM counters"
  end

  transaction do
    keys.each do |period|
      aggregate_for_period :period => period, :source => :gauges, :dest => :aggregated_gauges, :aggregate => "CAST(sum AS FLOAT) / count"
    end

    exec "DELETE FROM gauges"
  end
end