Class: Lyra::Projections::EventStoreReader

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

Overview

Reads model state from event store when projections are disabled.

Uses CachedProjection (backed by Solid Cache or Rails.cache) for fast reads while keeping events as the source of truth.

Usage:

EventStoreReader.find(User, 123)
EventStoreReader.find_by(User, email: "[email protected]")
EventStoreReader.where(User, status: "active")

Class Method Summary collapse

Class Method Details

.all(model_class) ⇒ CachedRelation

Load all records of a given type (cached) Warning: Can be expensive for large datasets

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

Returns:

  • (CachedRelation) —

    A relation containing all reconstructed records



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# File 'lib/lyra/projections/event_store_reader.rb', line 65

def all(model_class)
  relation(model_class)
end

.count(model_class, conditions = {}) ⇒ Integer

Count records (cached)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

  • conditions (Hash) (defaults to: {}) —

    Optional conditions

Returns:

  • (Integer) —

    Count of matching records



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# File 'lib/lyra/projections/event_store_reader.rb', line 83

def count(model_class, conditions = {})
  CachedProjection.count(model_class, conditions)
end

.exists?(model_class, id) ⇒ Boolean

Check if a record exists (cached)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

  • id (Integer, String) —

    The record ID

Returns:

  • (Boolean) —

    True if record exists and is not destroyed



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# File 'lib/lyra/projections/event_store_reader.rb', line 46

def exists?(model_class, id)
  CachedProjection.exists?(model_class, id)
end

.find(model_class, id) ⇒ ActiveRecord::Base?

Find a record by ID (cached)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

  • id (Integer, String) —

    The record ID

Returns:

  • (ActiveRecord::Base, nil) —

    The reconstructed record or nil



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# File 'lib/lyra/projections/event_store_reader.rb', line 22

def find(model_class, id)
  attributes = CachedProjection.find(model_class, id)
  return nil unless attributes

  build_instance(model_class, attributes)
end

.find_by(model_class, attributes) ⇒ ActiveRecord::Base?

Find a record by attributes (cached)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

  • attributes (Hash) —

    The attributes to match

Returns:

  • (ActiveRecord::Base, nil) —

    The first matching record or nil



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# File 'lib/lyra/projections/event_store_reader.rb', line 34

def find_by(model_class, attributes)
  result = CachedProjection.find_by(model_class, attributes)
  return nil unless result

  build_instance(model_class, result)
end

.invalidate(model_class, id) ⇒ Object

Invalidate cache for a record (call after event stored)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

  • id (Integer, String) —

    The record ID



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# File 'lib/lyra/projections/event_store_reader.rb', line 91

def invalidate(model_class, id)
  CachedProjection.invalidate(model_class, id)
end

.relation(model_class) ⇒ CachedRelation

Get a CachedRelation for the model (supports method chaining)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

Returns:



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# File 'lib/lyra/projections/event_store_reader.rb', line 54

def relation(model_class)
  results = CachedProjection.all(model_class)
  records = results.map { |attrs| build_instance(model_class, attrs) }.compact
  CachedRelation.new(model_class, records)
end

.warm(model_class, id) ⇒ Object

Warm cache for a record (call after event stored)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

  • id (Integer, String) —

    The record ID



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# File 'lib/lyra/projections/event_store_reader.rb', line 99

def warm(model_class, id)
  CachedProjection.warm(model_class, id)
end

.where(model_class, conditions) ⇒ CachedRelation

Query records with conditions (cached)

Parameters:

  • model_class (Class) —

    The ActiveRecord model class

  • conditions (Hash) —

    Query conditions

Returns:



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# File 'lib/lyra/projections/event_store_reader.rb', line 74

def where(model_class, conditions)
  relation(model_class).where(conditions)
end