Class: Hanover::GCounter

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ GCounter

Returns a new instance of GCounter.



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# File 'lib/hanover/g_counter.rb', line 4

def initialize
  self.counts = Hash.new{0}
end

Instance Attribute Details

#counts ⇒ Object

Returns the value of attribute counts.



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# File 'lib/hanover/g_counter.rb', line 3

def counts
  @counts
end

Class Method Details

.from_json(json) ⇒ Object 



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# File 'lib/hanover/g_counter.rb', line 15

def self.from_json(json)
  # don't symbolize keys
  h = JSON.parse json
  raise ArgumentError.new 'unexpected type field in JSON' unless h['type'] == 'GCounter'

  gc = new
  gc.counts = h['c']
  return gc
end

Instance Method Details

#increment ⇒ Object 



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# File 'lib/hanover/g_counter.rb', line 25

def increment
  counts[tag] += 1
end

#merge(other) ⇒ Object 



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# File 'lib/hanover/g_counter.rb', line 33

def merge(other)
  new_keys = Set.new
  new_keys.merge counts.keys
  new_keys.merge other.counts.keys
  
  new_keys.each do |k|
    counts[k] = [counts[k], other.counts[k]].max
  end
end

#tag ⇒ Object 



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# File 'lib/hanover/g_counter.rb', line 43

def tag
  radix = 36
  [
    object_id.to_s(radix),
    Process.uid.to_s(radix), 
    Process.gid.to_s(radix), 
    Process.pid.to_s(radix), 
    `hostname`.strip
    ].join
end

#to_json ⇒ Object 



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# File 'lib/hanover/g_counter.rb', line 8

def to_json
  {
    type: 'GCounter',
    c: counts
    }.to_json
end

#value ⇒ Object 



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# File 'lib/hanover/g_counter.rb', line 29

def value
  counts.values.inject(0, &:+)
end