Class: IdentityCache::Cached::BelongsTo

Inherits:
Association show all
Defined in:
lib/identity_cache/cached/belongs_to.rb

Overview

:nodoc:

Instance Attribute Summary collapse

Attributes inherited from Association

#cached_accessor_name, #name, #reflection

Instance Method Summary collapse

Methods inherited from Association

#embedded?, #initialize, #inverse_name, #read, #validate

Constructor Details

This class inherits a constructor from IdentityCache::Cached::Association

Instance Attribute Details

#records_variable_name ⇒ Object (readonly)

Returns the value of attribute records_variable_name.



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# File 'lib/identity_cache/cached/belongs_to.rb', line 6

def records_variable_name
  @records_variable_name
end

Instance Method Details

#build ⇒ Object 



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# File 'lib/identity_cache/cached/belongs_to.rb', line 8

def build
  reflection.active_record.class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
    def #{cached_accessor_name}
      association_klass = association(:#{name}).klass
      if #{reflection.foreign_key}.present? && !association(:#{name}).loaded? && (loaded_by_idc? || association_klass.should_use_cache?)
        if defined?(#{records_variable_name})
          #{records_variable_name}
        else
          #{records_variable_name} = association_klass.fetch_by_id(#{reflection.foreign_key})
        end
      else
        #{name}
      end
    end
  RUBY
end

#clear(record) ⇒ Object 



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# File 'lib/identity_cache/cached/belongs_to.rb', line 25

def clear(record)
  if record.instance_variable_defined?(records_variable_name)
    record.remove_instance_variable(records_variable_name)
  end
end

#embedded_by_reference? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/identity_cache/cached/belongs_to.rb', line 102

def embedded_by_reference?
  false
end

#embedded_recursively? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/identity_cache/cached/belongs_to.rb', line 98

def embedded_recursively?
  false
end

#fetch(records) ⇒ Object 



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# File 'lib/identity_cache/cached/belongs_to.rb', line 35

def fetch(records)
  fetch_async(LoadStrategy::Eager, records) { |associated_records| associated_records }
end

#fetch_async(load_strategy, records) ⇒ Object 



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# File 'lib/identity_cache/cached/belongs_to.rb', line 39

def fetch_async(load_strategy, records)
  if reflection.polymorphic?
    type_fetcher_to_db_ids_hash = {}

    records.each do |owner_record|
      associated_id = owner_record.send(reflection.foreign_key)
      next unless associated_id && !owner_record.instance_variable_defined?(records_variable_name)

      foreign_type_fetcher = Object.const_get(
        owner_record.send(reflection.foreign_type)
      ).cached_model.cached_primary_index
      db_ids = type_fetcher_to_db_ids_hash[foreign_type_fetcher] ||= []
      db_ids << associated_id
    end

    load_strategy.load_batch(type_fetcher_to_db_ids_hash) do |batch_load_result|
      batch_records = []

      records.each do |owner_record|
        associated_id = owner_record.send(reflection.foreign_key)
        next unless associated_id && !owner_record.instance_variable_defined?(records_variable_name)

        foreign_type_fetcher = Object.const_get(
          owner_record.send(reflection.foreign_type)
        ).cached_model.cached_primary_index

        associated_record = batch_load_result.fetch(foreign_type_fetcher).fetch(associated_id)
        batch_records << owner_record
        write(owner_record, associated_record)
      end

      yield batch_records
    end
  else
    ids_to_owner_record = records.each_with_object({}) do |owner_record, hash|
      associated_id = owner_record.send(reflection.foreign_key)
      if associated_id && !owner_record.instance_variable_defined?(records_variable_name)
        hash[associated_id] = owner_record
      end
    end

    if ids_to_owner_record.any?
      load_strategy.load_multi(
        reflection.klass.cached_primary_index,
        ids_to_owner_record.keys
      ) do |associated_records_by_id|
        associated_records_by_id.each do |id, associated_record|
          owner_record = ids_to_owner_record.fetch(id)
          write(owner_record, associated_record)
        end

        yield associated_records_by_id.values.compact
      end
    else
      yield records.filter_map { |record| record.instance_variable_get(records_variable_name) }
    end
  end
end

#write(owner_record, associated_record) ⇒ Object 



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# File 'lib/identity_cache/cached/belongs_to.rb', line 31

def write(owner_record, associated_record)
  owner_record.instance_variable_set(records_variable_name, associated_record)
end