param.h

 
#pragma once
 
#include <cstddef>  // for size_t
 
#include "xgboost/parameter.h"   // for XGBoostParameter
#include "xgboost/tree_model.h"  // for RegTree
 
namespace xgboost::tree {
struct HistMakerTrainParam : public XGBoostParameter<HistMakerTrainParam> {
  constexpr static std::size_t DefaultNodes() { return static_cast<std::size_t>(1) << 16; }
 
  bool debug_synchronize{false};
  std::size_t max_cached_hist_node{DefaultNodes()};
 
  void CheckTreesSynchronized(RegTree const* local_tree) const;
 
  // declare parameters
  DMLC_DECLARE_PARAMETER(HistMakerTrainParam) {
    DMLC_DECLARE_FIELD(debug_synchronize)
        .set_default(false)
        .describe("Check if all distributed tree are identical after tree construction.");
    DMLC_DECLARE_FIELD(max_cached_hist_node)
        .set_default(DefaultNodes())
        .set_lower_bound(1)
        .describe("Maximum number of nodes in CPU histogram cache. Only for internal usage.");
  }
};
}  // namespace xgboost::tree