Class: GraphQL::Dataloader::NullDataloader

Inherits:
Dataloader
  • Object
show all
Defined in:
lib/graphql/dataloader/null_dataloader.rb

Overview

GraphQL-Ruby uses this when Dataloader isn't enabled.

It runs execution code inline and gathers lazy objects (eg. Promises) and resolves them during #run.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ NullDataloader

Returns a new instance of NullDataloader.



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 10

def initialize(*)
  @lazies_at_depth = Hash.new { |h,k| h[k] = [] }
end

Instance Method Details

#append_job(callable = nil) ⇒ Object 



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 59

def append_job(callable = nil)
  callable ? callable.call : yield
  nil
end

#clear_cache ⇒ Object 



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 53

def clear_cache; end

#freeze ⇒ Object 



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 14

def freeze
  @lazies_at_depth.default_proc = nil
  @lazies_at_depth.freeze
  super
end

#run(trace_query_lazy: nil) ⇒ Object 



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 20

def run(trace_query_lazy: nil)
  with_trace_query_lazy(trace_query_lazy) do
    while !@lazies_at_depth.empty?
      smallest_depth = nil
      @lazies_at_depth.each_key do |depth_key|
        smallest_depth ||= depth_key
        if depth_key < smallest_depth
          smallest_depth = depth_key
        end
      end

      if smallest_depth
        lazies = @lazies_at_depth.delete(smallest_depth)
        lazies.each(&:value) # resolve these Lazy instances
      end
    end
  end
end

#run_isolated ⇒ Object 



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 39

def run_isolated
  # Reuse this instance because execution code may already have a reference to _this_ `dataloader` inside the given block.
  prev_lazies_at_depth = @lazies_at_depth
  @lazies_at_depth = @lazies_at_depth.dup.clear
  res = nil
  append_job {
    res = yield
  }
  run
  res
ensure
  @lazies_at_depth = prev_lazies_at_depth
end

#with ⇒ Object

Raises:



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 64

def with(*)
  raise GraphQL::Error, "GraphQL::Dataloader is not running -- add `use GraphQL::Dataloader` to your schema to use Dataloader sources."
end

#yield(_source) ⇒ Object

Raises:



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# File 'lib/graphql/dataloader/null_dataloader.rb', line 55

def yield(_source)
  raise GraphQL::Error, "GraphQL::Dataloader is not running -- add `use GraphQL::Dataloader` to your schema to use Dataloader sources."
end