Class: Von::Counters::Period

Inherits:
Object
  • Object
show all
Includes:
Commands
Defined in:
lib/von/counters/period.rb

Instance Method Summary collapse

Methods included from Commands

#hdel, #hget, #hgetall, #hincrby, #hset, #llen, #lpop, #lrange, #rpush

Constructor Details

#initialize(field, periods = nil) ⇒ Period

Returns a new instance of Period.



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# File 'lib/von/counters/period.rb', line 6

def initialize(field, periods = nil)
  @field   = field.to_sym
  @periods = periods || []
end

Instance Method Details

#count(time_unit) ⇒ Object

Count the fields for the given time period for this Counter.

Returns an Array of Hashes representing the count



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# File 'lib/von/counters/period.rb', line 44

def count(time_unit)
  return if @periods.empty?

  counts     = []
  this_period = nil
  _period     = @periods.select { |p| p.time_unit == time_unit }.first

  _period.length.times do |i|
    this_period = _period.prev(i)
    counts.unshift(this_period)
  end

  keys = hgetall(hash_key(time_unit))
  counts.map { |date| { :timestamp => date, :count => keys.fetch(date, 0).to_i }}
end

#hash_key(time_unit) ⇒ Object

Returns the Redis hash key used for storing counts for this Period



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# File 'lib/von/counters/period.rb', line 12

def hash_key(time_unit)
  "#{Von.config.namespace}:counters:#{@field}:#{time_unit}"
end

#increment ⇒ Object 



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# File 'lib/von/counters/period.rb', line 21

def increment
  return if @periods.empty?

  @periods.each do |period|
    _hash_key = hash_key(period.time_unit)
    _list_key = list_key(period.time_unit)

    hincrby(_hash_key, period.timestamp, 1)

    unless lrange(_list_key, 0, -1).include?(period.timestamp)
      rpush(_list_key, period.timestamp)
    end

    if llen(_list_key) > period.length
      expired_counter = lpop(_list_key)
      hdel(_hash_key, expired_counter)
    end
  end
end

#list_key(time_unit) ⇒ Object

Returns the Redis list key used for storing current “active” counters



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# File 'lib/von/counters/period.rb', line 17

def list_key(time_unit)
  "#{Von.config.namespace}:lists:#{@field}:#{time_unit}"
end