scope.h

#pragma once

#include <list>           //std::list
#include <mutex>          //std::mutex
#include <unordered_map>  //std::unordered_map
#include "variable.h"

namespace paddle_mobile {
namespace framework {
class Scope {
 public:
  Scope() {}
  ~Scope() {}

  Scope &NewScope() const;

  /// Create a variable with given name if it doesn't exist.
  Variable *Var(const std::string &name);

  /// Create a variable with a scope-unique name.
  Variable *Var(std::string *name = nullptr);

  void EraseVars(const std::vector<std::string> &var_names);

  /// Find a variable in the scope or any of its ancestors.  Returns
  /// nullptr if cannot find.
  Variable *FindVar(const std::string &name) const;

  const Scope *parent() const { return parent_; }

  /// Find the scope or an ancestor scope that contains the given
  /// variable.
  const Scope *FindScope(const Variable *var) const;

  void DeleteScope(Scope *scope) const;

  /// Drop all kids scopes belonged to this scope.
  void DropKids();

  // enumerate all the variables current contains.
  std::vector<std::string> LocalVarNames() const;

  // Rename variable to a new name
  void Rename(const std::string &origin_name,
              const std::string &new_name) const;

  // Rename variable to a new name and return the new name
  std::string Rename(const std::string &origin_name) const;

  Variable *FindVarLocally(const std::string &name) const;

 private:
  // Call Scope::NewScope for a sub-scope.
  explicit Scope(Scope const *parent) : parent_(parent) {}

  mutable std::unordered_map<std::string, Variable *> vars_;
  mutable std::list<Scope *> kids_;
  Scope const *parent_{nullptr};

  mutable std::mutex mutex_;
};
}  // namespace framework
}  // namespace paddle_mobile