new change for mpi

src/tree/updater.cpp

@@ -13,8 +13,8 @@ IUpdater* CreateUpdater(const char *name) {
   using namespace std;
   if (!strcmp(name, "prune")) return new TreePruner();
   if (!strcmp(name, "refresh")) return new TreeRefresher<GradStats>();
-  if (!strcmp(name, "distcol")) return new DistColMaker<GradStats>();
   if (!strcmp(name, "grow_colmaker")) return new ColMaker<GradStats>();
+  if (!strcmp(name, "distcol")) return new DistColMaker<GradStats>();
   if (!strcmp(name, "grow_colmaker5")) return new ColMaker< CVGradStats<5> >();
   if (!strcmp(name, "grow_colmaker3")) return new ColMaker< CVGradStats<3> >();
   utils::Error("unknown updater:%s", name);

src/tree/updater.h

@@ -37,6 +37,16 @@ class IUpdater {
                       IFMatrix *p_fmat,
                       const BoosterInfo &info,
                       const std::vector<RegTree*> &trees) = 0;
+
+  /*! 
+   * \brief this is simply a function for optimizing performance
+   * this function asks the updater to return the leaf position of each instance in the p_fmat,
+   * if it is cached in the updater, if it is not available, return NULL
+   * \return array of leaf position of each instance in the last updated tree
+   */
+  virtual const int* GetLeafPosition(void) const {
+    return NULL;
+  }
   // destructor
   virtual ~IUpdater(void) {}
 };

src/tree/updater_distcol-inl.hpp

@@ -38,7 +38,9 @@ class DistColMaker : public ColMaker<TStats> {
     // update position after the tree is pruned
     builder.UpdatePosition(p_fmat, *trees[0]);
   }
-  
+  virtual const int* GetLeafPosition(void) const {
+    return builder.GetLeafPosition();
+  }  
  private:
   inline void SyncTrees(RegTree *tree) {
     std::string s_model;
@@ -71,6 +73,9 @@ class DistColMaker : public ColMaker<TStats> {
         this->position[ridx] = nid;
       }
     }
+    virtual const int* GetLeafPosition(void) const {
+      return BeginPtr(this->position);
+    }
    protected:    
     virtual void SetNonDefaultPosition(const std::vector<int> &qexpand,
                                        IFMatrix *p_fmat, const RegTree &tree) {