module Puppet::Pops
module Loader
# The PuppetPlanInstantiator instantiates a Puppet::Functions::PuppetFunction given a Puppet Programming language
# source that when called evaluates the Puppet logic it contains.
#
class PuppetPlanInstantiator
# Produces an instance of the Function class with the given typed_name, or fails with an error if the
# given puppet source does not produce this instance when evaluated.
#
# @param loader [Loader] The loader the function is associated with
# @param typed_name [TypedName] the type / name of the function to load
# @param source_ref [URI, String] a reference to the source / origin of the puppet code to evaluate
# @param pp_code_string [String] puppet code in a string
#
# @return [Functions::Function] - an instantiated function with global scope closure associated with the given loader
#
def self.create(loader, typed_name, source_ref, pp_code_string)
parser = Parser::EvaluatingParser.new()
# parse and validate
result = parser.parse_string(pp_code_string, source_ref)
# The parser attaches all definitions, including those nested in apply
# blocks, to the Program object. Node definitions in apply blocks are
# perfectly legal and don't count as the file containing multiple
# definitions for this purpose. By this point, we've already validated that
# there are no node definitions *outside* apply blocks, so we simply ignore
# them here.
definitions = result.definitions.reject { |definition| definition.is_a?(Puppet::Pops::Model::NodeDefinition) }
# Only one plan is allowed (and no other definitions)
case definitions.size
when 0
raise ArgumentError, _("The code loaded from %{source_ref} does not define the plan '%{plan_name}' - it is empty.") % { source_ref: source_ref, plan_name: typed_name.name }
when 1
# ok
else
raise ArgumentError, _("The code loaded from %{source_ref} must contain only the plan '%{plan_name}' - it has additional definitions.") % { source_ref: source_ref, plan_name: typed_name.name }
end
the_plan_definition = definitions[0]
unless the_plan_definition.is_a?(Model::PlanDefinition)
raise ArgumentError, _("The code loaded from %{source_ref} does not define the plan '%{plan_name}' - no plan found.") % { source_ref: source_ref, plan_name: typed_name.name }
end
unless the_plan_definition.name == typed_name.name
expected = typed_name.name
actual = the_plan_definition.name
raise ArgumentError, _("The code loaded from %{source_ref} produced plan with the wrong name, expected %{expected}, actual %{actual}") % { source_ref: source_ref, expected: expected, actual: actual }
end
unless result.body == the_plan_definition
raise ArgumentError, _("The code loaded from %{source} contains additional logic - can only contain the plan %{plan_name}") % { source: source_ref, plan_name: typed_name.name }
end
# Adapt the function definition with loader - this is used from logic contained in it body to find the
# loader to use when making calls to the new function API. Such logic have a hard time finding the closure (where
# the loader is known - hence this mechanism
private_loader = loader.private_loader
Adapters::LoaderAdapter.adapt(the_plan_definition).loader_name = private_loader.loader_name
# Cannot bind loaded functions to global scope, that must be done without binding that scope as
# loaders survive a compilation.
closure_scope = nil
created = create_function_class(the_plan_definition)
# create the function instance - it needs closure (scope), and loader (i.e. where it should start searching for things
# when calling functions etc.
# It should be bound to global scope
created.new(closure_scope, private_loader)
end
# Creates Function class and instantiates it based on a FunctionDefinition model
# @return [Array<TypedName, Functions.Function>] - array of
# typed name, and an instantiated function with global scope closure associated with the given loader
#
def self.create_from_model(plan_definition, loader)
created = create_function_class(plan_definition)
typed_name = TypedName.new(:plan, plan_definition.name)
[typed_name, created.new(nil, loader)]
end
def self.create_function_class(plan_definition)
# Create a 4x function wrapper around a named closure
Puppet::Functions.create_function(plan_definition.name, Puppet::Functions::PuppetFunction) do
# TODO: should not create a new evaluator per function
init_dispatch(Evaluator::Closure::Named.new(
plan_definition.name,
Evaluator::EvaluatorImpl.new(), plan_definition))
end
end
end
end
end
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