Class: GraphQL::Dataloader::AsyncDataloader

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

Defined Under Namespace

Classes: Run

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ AsyncDataloader

Returns a new instance of AsyncDataloader.



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 21

def initialize(...)
  super
  create_pending_run
end

Instance Attribute Details

#pending_sources ⇒ Object (readonly)

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. 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 27

def pending_sources
  @pending_sources
end

Class Method Details

.install_graphql_methods ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 11

def self.install_graphql_methods
  if !Async::Task.method_defined?(:cancel)
    Async::Task.alias_method(:cancel, :stop)
  end
  if !Async::Task.method_defined?(:graphql_async_dataloader_run)
    Async::Task.attr_accessor(:graphql_async_dataloader_run)
    Async::Task.attr_accessor(:graphql_async_dataloader_condition)
  end
end

.use ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 6

def self.use(...)
  install_graphql_methods
  super
end

Instance Method Details

#active_run ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 177

def active_run
  @pending_run || Async::Task.current?&.graphql_async_dataloader_run || raise(GraphQL::Error, "No available Run to append to, GraphQL-Ruby bug")
end

#append_job(callable = nil, &block) ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 168

def append_job(callable = nil, &block)
  active_run.jobs.push(callable || block)
  nil
end

#create_pending_run ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 29

def create_pending_run
  jobs_fiber_limit, total_fiber_limit = calculate_fiber_limit
  @pending_run = Run.new(self, total_fiber_limit, jobs_fiber_limit)
end

#lazy_at_depth(depth, lazy) ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 173

def lazy_at_depth(depth, lazy)
  active_run.lazies_at_depth[depth] << lazy
end

#run(trace_query_lazy: nil) ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 216

def run(trace_query_lazy: nil)
  trace = Fiber[:__graphql_current_multiplex]&.current_trace
  run = @pending_run || Async::Task.current?&.graphql_async_dataloader_run || raise(GraphQL::Error, "No available Run, GraphQL-Ruby internal bug")
  @pending_run = nil
  run.trace = trace
  first_pass = true
  trace&.begin_dataloader(self)
  fiber_vars = get_fiber_variables
  raised_error = nil
  jobs = run.jobs
  Sync do |_maybe_new_task|
    # Make sure there's a new task instance to hold `.graphql_...` state:
    task = Async::Task.new do |root_task|
      run.root_task = root_task
      root_task.graphql_async_dataloader_run = run
      set_fiber_variables(fiber_vars)

      while first_pass || run.running? || !jobs.empty?
        first_pass = false
        run_queue(run, run.snoozed_jobs_condition, :jobs)
        run_queue(run, run.snoozed_sources_condition, :sources)

        if !run.lazies_at_depth.empty?
          with_trace_query_lazy(trace_query_lazy) do
            if enqueue_next_pending_lazies(run.lazies_at_depth)
              run_queue(run, run.snoozed_jobs_condition, :jobs)
            end
          end
        end
      end
    rescue StandardError => err
      raised_error = err
      root_task.cancel
    end

    task.run
    task.wait
  end
  create_pending_run
  if raised_error
    raise raised_error
  end
  trace&.end_dataloader(self)
rescue UncaughtThrowError => e
  throw e.tag, e.value
end

#run_isolated ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 181

def run_isolated
  previous_run = Async::Task.current?&.graphql_async_dataloader_run
  prev_pending_keys = {}
  # Clear pending loads but keep already-cached records
  # in case they are useful to the given block.
  @source_cache.each do |source_class, batched_sources|
    batched_sources.each do |batch_args, batched_source_instance|
      if batched_source_instance.pending?
        prev_pending_keys[batched_source_instance] = batched_source_instance.pending.dup
        batched_source_instance.pending.clear
      end
    end
  end

  res = nil
  create_pending_run
  @pending_run.jobs << -> { res = yield }
  run
  res
ensure
  if previous_run
    Async::Task.current.graphql_async_dataloader_run = previous_run
    # clear the one created in #run:
    @pending_run = nil
  end
  prev_pending_keys.each do |source_instance, pending|
    pending.each do |key, value|
      next if source_instance.results.key?(key)

      queue_pending_source(source_instance) if source_instance.pending.empty?
      source_instance.pending[key] = value
    end
  end
end

#yield(source = Fiber[:__graphql_current_dataloader_source]) ⇒ Object 



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# File 'lib/graphql/dataloader/async_dataloader.rb', line 34

def yield(source = Fiber[:__graphql_current_dataloader_source])
  task = Async::Task.current
  run = task.graphql_async_dataloader_run
  trace = run.trace
  trace&.dataloader_fiber_yield(source)
  run.tasks_channel.push([:paused_task, task])
  condition = task.graphql_async_dataloader_condition
  condition.wait
  run.tasks_channel.push([:resumed_task, task])
  trace&.dataloader_fiber_resume(source)
  nil
end