Class FlatExpressionEvaluatorState

eval/eval/evaluator_core.h:106–155

Class that wraps the state that needs to be allocated for expression evaluation. This can be reused to save on allocations.

// Class that wraps the state that needs to be allocated for expression
// evaluation. This can be reused to save on allocations.
class FlatExpressionEvaluatorState {
 public:
  FlatExpressionEvaluatorState(
      size_t value_stack_size, size_t comprehension_slot_count,
      const cel::TypeProvider& type_provider,
      const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,
      google::protobuf::MessageFactory* absl_nonnull message_factory,
      google::protobuf::Arena* absl_nonnull arena)
      : value_stack_(value_stack_size),
        // We currently use comprehension_slot_count because it is less of an
        // over estimate than value_stack_size. In future we should just
        // calculate the correct capacity.
        iterator_stack_(comprehension_slot_count),
        comprehension_slots_(comprehension_slot_count),
        type_provider_(type_provider),
        descriptor_pool_(descriptor_pool),
        message_factory_(message_factory),
        arena_(arena) {}

  void Reset();

  EvaluatorStack& value_stack() { return value_stack_; }

  cel::runtime_internal::IteratorStack& iterator_stack() {
    return iterator_stack_;
  }

  ComprehensionSlots& comprehension_slots() { return comprehension_slots_; }

  const cel::TypeProvider& type_provider() { return type_provider_; }

  const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool() {
    return descriptor_pool_;
  }

  google::protobuf::MessageFactory* absl_nonnull message_factory() {
    return message_factory_;
  }

  google::protobuf::Arena* absl_nonnull arena() { return arena_; }

 private:
  EvaluatorStack value_stack_;
  cel::runtime_internal::IteratorStack iterator_stack_;
  ComprehensionSlots comprehension_slots_;
  const cel::TypeProvider& type_provider_;
  const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool_;
  google::protobuf::MessageFactory* absl_nonnull message_factory_;
  google::protobuf::Arena* absl_nonnull arena_;
};

// Context needed for evaluation. This is sufficient for supporting
// recursive evaluation, but stack machine programs require an