Class: StrokeDB::LamportTimestamp

Inherits:
Object
  • Object
show all
Defined in:
lib/strokedb/sync/lamport_timestamp.rb

Defined Under Namespace

Classes: CounterOverflow

Constant Summary collapse

MAX_COUNTER = 
2**64
BASE = 
16
BASE_LENGTH = 
16

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(c = 0, __uuid = Util.random_uuid) ⇒ LamportTimestamp

Returns a new instance of LamportTimestamp.



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 9

def initialize(c = 0, __uuid = Util.random_uuid)
  if c > MAX_COUNTER
    raise CounterOverflow.new, "Max counter value is 2**64"
  end
  @counter = c
  @uuid    = __uuid 
end

Instance Attribute Details

#counter ⇒ Object (readonly)

Returns the value of attribute counter.



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 7

def counter
  @counter
end

#uuid ⇒ Object (readonly)

Returns the value of attribute uuid.



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 7

def uuid
  @uuid
end

Class Method Details

.from_raw(raw_string) ⇒ Object

Raw format



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 40

def self.from_raw(raw_string)
  new.marshal_load(raw_string)
end

.zero(__uuid = Util.random_uuid) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 69

def self.zero(__uuid = Util.random_uuid)
  ts = new(0)
  ts.instance_variable_set(:@uuid, __uuid)
  ts
end

.zero_string ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 74

def self.zero_string
  "0"*BASE_LENGTH + NIL_UUID
end

Instance Method Details

#<(other) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 57

def <(other)
  (self <=> other) < 0
end

#<=(other) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 60

def <=(other)
  (self <=> other) <= 0
end

#<=>(other) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 50

def <=>(other)
  primary = (@counter <=> other.counter)
  primary == 0 ? (@uuid <=> other.uuid) : primary
end

#==(other) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 54

def ==(other)
  @counter == other.counter && @uuid == other.uuid
end

#>(other) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 63

def >(other)
  (self <=> other) > 0
end

#>=(other) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 66

def >=(other)
  (self <=> other) >= 0
end

#dup ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 23

def dup
  LamportTimestamp.new(@counter, @uuid)
end

#marshal_dump ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 26

def marshal_dump
  @counter.to_s(BASE).rjust(BASE_LENGTH, '0') + @uuid
end

#marshal_load(dumped) ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 29

def marshal_load(dumped)
  @counter = dumped[0, BASE_LENGTH].to_i(BASE)
  @uuid    = dumped[BASE_LENGTH, 36]
  self
end

#next ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 16

def next
  LamportTimestamp.new(@counter + 1, @uuid)
end

#next! ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 19

def next!
  @counter += 1
  self
end

#to_json ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 35

def to_json
  marshal_dump.to_json
end

#to_raw ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 43

def to_raw
  marshal_dump
end

#to_s ⇒ Object 



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# File 'lib/strokedb/sync/lamport_timestamp.rb', line 47

def to_s
  marshal_dump
end