Class: Lyra::DualView

Inherits:
Object
  • Object
show all
Defined in:
lib/lyra/dual_view.rb

Overview

Provides dual view comparison between CRUD state and Event-sourced state

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(model_class, model_id) ⇒ DualView

Returns a new instance of DualView.



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# File 'lib/lyra/dual_view.rb', line 6

def initialize(model_class, model_id)
  @model_class = model_class
  @model_id = model_id
end

Instance Attribute Details

#model_class ⇒ Object (readonly)

Returns the value of attribute model_class.



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# File 'lib/lyra/dual_view.rb', line 4

def model_class
  @model_class
end

#model_id ⇒ Object (readonly)

Returns the value of attribute model_id.



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# File 'lib/lyra/dual_view.rb', line 4

def model_id
  @model_id
end

Class Method Details

.compare_all(model_class) ⇒ Object 



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# File 'lib/lyra/dual_view.rb', line 185

def compare_all(model_class)
  model_class.find_each.map do |record|
    new(model_class, record.id).compare
  end
end

.find_discrepancies(model_class) ⇒ Object 



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# File 'lib/lyra/dual_view.rb', line 191

def find_discrepancies(model_class)
  compare_all(model_class).select do |comparison|
    comparison[:differences] != { no_differences: true }
  end
end

Instance Method Details

#audit_trail ⇒ Object

Get audit trail from events



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# File 'lib/lyra/dual_view.rb', line 119

def audit_trail
  AuditProjection.audit_trail(model_class, model_id)
end

#calculate_differences ⇒ Object

Calculate differences between CRUD and Event-sourced states



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# File 'lib/lyra/dual_view.rb', line 83

def calculate_differences
  crud = crud_state
  es = event_sourced_state

  return { exists_mismatch: true } if crud[:exists] != es[:exists]
  return { no_differences: true } if !crud[:exists] && !es[:exists]

  crud_attrs = crud[:attributes] || {}
  es_attrs = es[:state] || {}

  differences = {}

  # Build lookup tables with both string and symbol keys
  crud_lookup = build_key_lookup(crud_attrs)
  es_lookup = build_key_lookup(es_attrs)

  # Compare union of all keys from both sources, excluding DB-managed timestamps
  ignored_keys = %i[created_at updated_at]
  all_keys = (crud_lookup.keys + es_lookup.keys).uniq - ignored_keys

  all_keys.each do |key|
    crud_val = crud_lookup[key]
    es_val = es_lookup[key]

    unless values_equal?(crud_val, es_val)
      differences[key] = {
        crud: crud_val,
        event_sourced: es_val
      }
    end
  end

  differences.empty? ? { no_differences: true } : differences
end

#compare ⇒ Object

Get both CRUD and Event-sourced views



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# File 'lib/lyra/dual_view.rb', line 12

def compare
  {
    crud_view: crud_state,
    event_sourced_view: event_sourced_state,
    differences: calculate_differences,
    metadata: {
      model_class: model_class.name,
      model_id: model_id,
      timestamp: Time.current,
      mode: Lyra.config.mode
    }
  }
end

#crud_state ⇒ Object

CRUD view - current database state



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# File 'lib/lyra/dual_view.rb', line 27

def crud_state
  record = model_class.find_by(id: model_id)

  return { exists: false } unless record

  {
    exists: true,
    attributes: record.attributes,
    timestamps: {
      created_at: record.created_at,
      updated_at: record.updated_at
    }
  }
end

#event_operation(event) ⇒ Object 



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# File 'lib/lyra/dual_view.rb', line 76

def event_operation(event)
  return event.operation if event.respond_to?(:operation)
  op = event.data[:operation] || event.data["operation"]
  op.is_a?(String) ? op.to_sym : op
end

#event_sourced_state ⇒ Object

Event-sourced view - state rebuilt from events



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# File 'lib/lyra/dual_view.rb', line 43

def event_sourced_state
  stream_name = "#{model_class.name}$#{model_id}"

  begin
    events = Lyra.config.event_store.read.stream(stream_name).to_a
  rescue => e
    return {
      exists: false,
      error: e.message,
      events_count: 0
    }
  end

  return { exists: false, events_count: 0 } if events.empty?

  state = StateProjection.new.rebuild_from_events(events)

  {
    exists: true,
    state: state,
    events_count: events.count,
    first_event_at: event_timestamp(events.first),
    last_event_at: event_timestamp(events.last),
    events_summary: events.map { |e| { type: e.class.name, operation: event_operation(e), timestamp: event_timestamp(e) } }
  }
end

#event_timestamp(event) ⇒ Object

Helper methods to extract data from events (works with both Lyra::Event and RubyEventStore::Event)



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# File 'lib/lyra/dual_view.rb', line 71

def event_timestamp(event)
  return event.timestamp if event.respond_to?(:timestamp) && event.timestamp
  event.data[:timestamp] || event.data["timestamp"] || event.metadata[:timestamp]
end