Class: LaunchDarkly::Impl::Migrations::Migrator Private

Inherits:
Object
  • Object
show all
Includes:
LaunchDarkly::Interfaces::Migrations::Migrator
Defined in:
lib/ldclient-rb/impl/migrations/migrator.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

An implementation of the [LaunchDarkly::Interfaces::Migrations::Migrator] interface, capable of supporting feature-flag backed technology migrations.

Since:

  • 5.5.0

Instance Method Summary collapse

Constructor Details

#initialize(client, read_execution_order, read_config, write_config, measure_latency, measure_errors) ⇒ Migrator

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of Migrator.

Parameters:

Since:

  • 5.5.0



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# File 'lib/ldclient-rb/impl/migrations/migrator.rb', line 68

def initialize(client, read_execution_order, read_config, write_config, measure_latency, measure_errors)
  @client = client
  @read_execution_order = read_execution_order
  @read_config = read_config
  @write_config = write_config
  @measure_latency = measure_latency
  @measure_errors = measure_errors
  @sampler = LaunchDarkly::Impl::Sampler.new(Random.new)
end

Instance Method Details

#read(key, context, default_stage, payload = nil) ⇒ LaunchDarkly::Migrations::OperationResult

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Perform the configured read operations against the appropriate old and/or new origins.

Parameters:

  • key (String) —

    The migration-based flag key to use for determining migration stages

  • context (LaunchDarkly::LDContext) —

    The context to use for evaluating the migration flag

  • default_stage (Symbol) —

    The stage to fallback to if one could not be determined for the requested flag

  • payload (String) (defaults to: nil) —

    An optional payload to pass through to the configured read operations.

Returns:

Since:

  • 5.5.0



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# File 'lib/ldclient-rb/impl/migrations/migrator.rb', line 88

def read(key, context, default_stage, payload = nil)
  stage, tracker = @client.migration_variation(key, context, default_stage)
  tracker.operation(LaunchDarkly::Migrations::OP_READ)

  old = Executor.new(@client.logger, LaunchDarkly::Migrations::ORIGIN_OLD, @read_config.old, tracker, @measure_latency, @measure_errors, payload)
  new = Executor.new(@client.logger, LaunchDarkly::Migrations::ORIGIN_NEW, @read_config.new, tracker, @measure_latency, @measure_errors, payload)

  case stage
  when LaunchDarkly::Migrations::STAGE_OFF
    result = old.run
  when LaunchDarkly::Migrations::STAGE_DUALWRITE
    result = old.run
  when LaunchDarkly::Migrations::STAGE_SHADOW
    result = read_both(old, new, @read_config.comparison, @read_execution_order, tracker)
  when LaunchDarkly::Migrations::STAGE_LIVE
    result = read_both(new, old, @read_config.comparison, @read_execution_order, tracker)
  when LaunchDarkly::Migrations::STAGE_RAMPDOWN
    result = new.run
  when LaunchDarkly::Migrations::STAGE_COMPLETE
    result = new.run
  else
    result = LaunchDarkly::Migrations::OperationResult.new(
      LaunchDarkly::Migrations::ORIGIN_OLD,
      LaunchDarkly::Result.fail("invalid stage #{stage}; cannot execute read")
    )
  end

  @client.track_migration_op(tracker)

  result
end

#write(key, context, default_stage, payload = nil) ⇒ LaunchDarkly::Migrations::WriteResult

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Perform the configured write operations against the appropriate old and/or new origins.

Parameters:

  • key (String) —

    The migration-based flag key to use for determining migration stages

  • context (LaunchDarkly::LDContext) —

    The context to use for evaluating the migration flag

  • default_stage (Symbol) —

    The stage to fallback to if one could not be determined for the requested flag

  • payload (String) (defaults to: nil) —

    An optional payload to pass through to the configured write operations.

Returns:

Since:

  • 5.5.0



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# File 'lib/ldclient-rb/impl/migrations/migrator.rb', line 130

def write(key, context, default_stage, payload = nil)
  stage, tracker = @client.migration_variation(key, context, default_stage)
  tracker.operation(LaunchDarkly::Migrations::OP_WRITE)

  old = Executor.new(@client.logger, LaunchDarkly::Migrations::ORIGIN_OLD, @write_config.old, tracker, @measure_latency, @measure_errors, payload)
  new = Executor.new(@client.logger, LaunchDarkly::Migrations::ORIGIN_NEW, @write_config.new, tracker, @measure_latency, @measure_errors, payload)

  case stage
  when LaunchDarkly::Migrations::STAGE_OFF
    result = old.run()
    write_result = LaunchDarkly::Migrations::WriteResult.new(result)
  when LaunchDarkly::Migrations::STAGE_DUALWRITE
    authoritative_result, nonauthoritative_result = write_both(old, new, tracker)
    write_result = LaunchDarkly::Migrations::WriteResult.new(authoritative_result, nonauthoritative_result)
  when LaunchDarkly::Migrations::STAGE_SHADOW
    authoritative_result, nonauthoritative_result = write_both(old, new, tracker)
    write_result = LaunchDarkly::Migrations::WriteResult.new(authoritative_result, nonauthoritative_result)
  when LaunchDarkly::Migrations::STAGE_LIVE
    authoritative_result, nonauthoritative_result = write_both(new, old, tracker)
    write_result = LaunchDarkly::Migrations::WriteResult.new(authoritative_result, nonauthoritative_result)
  when LaunchDarkly::Migrations::STAGE_RAMPDOWN
    authoritative_result, nonauthoritative_result = write_both(new, old, tracker)
    write_result = LaunchDarkly::Migrations::WriteResult.new(authoritative_result, nonauthoritative_result)
  when LaunchDarkly::Migrations::STAGE_COMPLETE
    result = new.run()
    write_result = LaunchDarkly::Migrations::WriteResult.new(result)
  else
    result = LaunchDarkly::Migrations::OperationResult.fail(
      LaunchDarkly::Migrations::ORIGIN_OLD,
      LaunchDarkly::Result.fail("invalid stage #{stage}; cannot execute write")
    )
    write_result = LaunchDarkly::Migrations::WriteResult.new(result)
  end

  @client.track_migration_op(tracker)

  write_result
end