Class: ClusterId::V1::Generator

Inherits:
Object
  • Object
show all
Defined in:
lib/clusterid/v1/generator.rb

Overview

Create instances of Value objects based on time, random data, and serializable values for data centre, environment, and type IDs.

Since:

  • 1.0.0

Instance Method Summary collapse

Constructor Details

#initialize(serializer: NullSerializer.new, deserializer: NullDeserializer.new, byte_generator: SecureRandom, clock: Clock) ⇒ Generator

Note:

It is the caller's responsibility to ensure the serializer and deserializer follow the expected bit lengths for custom types. No overflow checks are done. Overflow will either be discarded or overwrite other bits. See the Value class for allowed bit lengths.

Returns a new instance of Generator.

Parameters:

  • serializer (Serializer) (defaults to: NullSerializer.new) —

    an object which serializes Value attributes

  • deserializer (Deserializer) (defaults to: NullDeserializer.new) —

    an object which deserializes Value attributes

  • byte_generator (#bytes(n)) (defaults to: SecureRandom) —

    an object which provides random bytes

  • clock (#now_ms) (defaults to: Clock) —

    an object which provides millisecond timestamps

Since:

  • 1.0.0



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# File 'lib/clusterid/v1/generator.rb', line 19

def initialize(serializer: NullSerializer.new, deserializer: NullDeserializer.new, byte_generator: SecureRandom, clock: Clock)
  @serializer = serializer
  @deserializer = deserializer
  @byte_generator = byte_generator
  @clock = clock
end

Instance Method Details

#from_byte_string(s) ⇒ Value

Returns the Value represented by s.

Returns:

Since:

  • 1.0.0



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# File 'lib/clusterid/v1/generator.rb', line 51

def from_byte_string(s)
  Value.new(s, @deserializer)
end

#generate(data_centre: nil, environment: nil, type_id: nil) ⇒ Value

Generate a Value for a given data centre, environment, and type ID.

Parameters:

  • data_centre (D) (defaults to: nil) —

    a serializable value representing the data centre the Value is generated within

  • environment (E) (defaults to: nil) —

    a serializable value representing the environment the Value is generated within

  • type_id (T) (defaults to: nil) —

    a serializable value representing the type of entity for a generated Value

Returns:

  • (Value) —

    a time-based, partially random value to identify an entity

Since:

  • 1.0.0



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# File 'lib/clusterid/v1/generator.rb', line 32

def generate(data_centre: nil, environment: nil, type_id: nil)
  raw_data = +""
  # Nonce
  raw_data += @byte_generator.bytes(5)
  # Type ID
  raw_data += [@serializer.from_type_id(type_id)].pack("S")
  # Details (Version, Data Centre, Environment)
  raw_data += [
    (FORMAT_VERSION << 5) +
      (@serializer.from_data_centre(data_centre) << 2) +
      @serializer.from_environment(environment)
  ].pack("C")
  # Timestamp
  raw_data += [@clock.now_ms].pack("Q")

  Value.new(raw_data.freeze, @deserializer)
end