syntax = "proto3";

package tensorflow;
option cc_enable_arenas = true;
option java_outer_classname = "SaverProtos";
option java_multiple_files = true;
option java_package = "org.tensorflow.util";

// Protocol buffer representing the configuration of a Saver.
message SaverDef {
  // The name of the tensor in which to specify the filename when saving or
  // restoring a model checkpoint.
  string filename_tensor_name = 1;

  // The operation to run when saving a model checkpoint.
  string save_tensor_name = 2;

  // The operation to run when restoring a model checkpoint.
  string restore_op_name = 3;

  // Maximum number of checkpoints to keep.  If 0, no checkpoints are deleted.
  int32 max_to_keep = 4;

  // Shard the save files, one per device that has Variable nodes.
  bool sharded = 5;

  // How often to keep an additional checkpoint. If not specified, only the last
  // "max_to_keep" checkpoints are kept; if specified, in addition to keeping
  // the last "max_to_keep" checkpoints, an additional checkpoint will be kept
  // for every n hours of training.
  float keep_checkpoint_every_n_hours = 6;

  // A version number that identifies a different on-disk checkpoint format.
  // Usually, each subclass of BaseSaverBuilder works with a particular
  // version/format.  However, it is possible that the same builder may be
  // upgraded to support a newer checkpoint format in the future.
  enum CheckpointFormatVersion {
    // Internal legacy format.
    LEGACY = 0;
    // Current format: tf.Saver() which works with tensorflow::table::Table.
    V1 = 1;
    // Experimental format under development.
    V2 = 2;
  }
  CheckpointFormatVersion version = 7;
}
