finish refactor, need debug

src/learner/dmatrix.h

@@ -7,6 +7,7 @@
  * \author Tianqi Chen
  */
 #include <vector>
+#include <cstring>
 #include "../data.h"
 #include "../utils/io.h"
 namespace xgboost {
@@ -150,8 +151,6 @@ struct DMatrix {
   const int magic;
   /*! \brief meta information about the dataset */
   MetaInfo info;
-  /*! \brief feature matrix about data content */
-  IFMatrix *fmat;
   /*! 
    * \brief cache pointer to verify if the data structure is cached in some learner
    *  used to verify if DMatrix is cached
@@ -159,10 +158,10 @@ struct DMatrix {
   void *cache_learner_ptr_;
   /*! \brief default constructor */
   explicit DMatrix(int magic) : magic(magic), cache_learner_ptr_(NULL) {}
+  /*! \brief get feature matrix about data content */
+  virtual IFMatrix *fmat(void) const = 0;
   // virtual destructor
-  virtual ~DMatrix(void){
-    delete fmat;
-  }
+  virtual ~DMatrix(void){}
 };
 
 }  // namespace learner

src/learner/learner-inl.hpp

@@ -158,7 +158,7 @@ class BoostLearner {
    * \param p_train pointer to the matrix used by training
    */
   inline void CheckInit(DMatrix *p_train) {
-    p_train->fmat->InitColAccess(prob_buffer_row);
+    p_train->fmat()->InitColAccess(prob_buffer_row);
   }
   /*!
    * \brief update the model for one iteration
@@ -168,7 +168,7 @@ class BoostLearner {
   inline void UpdateOneIter(int iter, const DMatrix &train) {
     this->PredictRaw(train, &preds_);
     obj_->GetGradient(preds_, train.info, iter, &gpair_);
-    gbm_->DoBoost(train.fmat, train.info.info, &gpair_);
+    gbm_->DoBoost(train.fmat(), train.info.info, &gpair_);
   }
   /*!
    * \brief evaluate the model for specific iteration
@@ -248,7 +248,7 @@ class BoostLearner {
    */
   inline void PredictRaw(const DMatrix &data,
                          std::vector<float> *out_preds) const {
-    gbm_->Predict(data.fmat, this->FindBufferOffset(data),
+    gbm_->Predict(data.fmat(), this->FindBufferOffset(data),
                   data.info.info, out_preds);
     // add base margin
     std::vector<float> &preds = *out_preds;