OK

R-package/src/xgboost_R.cpp

@@ -76,17 +76,6 @@ extern "C" {
     _WrapperEnd();
     return ret;
   }
-  SEXP XGDMatrixCreateCache_R(SEXP fname, SEXP cache_file, SEXP silent) {
-    _WrapperBegin();
-    void *handle = XGDMatrixCreateCache(CHAR(asChar(fname)),
-                                        CHAR(asChar(cache_file)),
-                                        asInteger(silent));
-    SEXP ret = PROTECT(R_MakeExternalPtr(handle, R_NilValue, R_NilValue));
-    R_RegisterCFinalizerEx(ret, _DMatrixFinalizer, TRUE);
-    UNPROTECT(1);
-    _WrapperEnd();
-    return ret;
-  }
   SEXP XGDMatrixCreateFromMat_R(SEXP mat, 
                                 SEXP missing) {
     _WrapperBegin();

R-package/src/xgboost_R.h

@@ -24,15 +24,6 @@ extern "C" {
    * \return a loaded data matrix
    */
   SEXP XGDMatrixCreateFromFile_R(SEXP fname, SEXP silent);
-  /*!
-   * \brief load a cached DMatrix, this is backed by several cache_files
-   *  and usually cost less memory
-   * \param fname the name of the file, can be a cached buffer or text
-   * \param cache_file the name of cached file
-   * \param silent whether print messages during loading
-   * \return a loaded data matrix
-   */
-  SEXP XGDMatrixCreateCache_R(SEXP fname, SEXP cache_file, SEXP silent);
   /*!
    * \brief create matrix content from dense matrix
    * This assumes the matrix is stored in column major format

src/io/io.cpp

@@ -16,6 +16,7 @@ DataMatrix* LoadDataMatrix(const char *fname,
                            bool loadsplit,
                            const char *cache_file) {
   std::string fname_ = fname;
+  
   const char *dlm = strchr(fname, '#');
   if (dlm != NULL) {
     utils::Check(strchr(dlm + 1, '#') == NULL,
@@ -51,6 +52,13 @@ DataMatrix* LoadDataMatrix(const char *fname,
     dmat->CacheLoad(fname, silent, savebuffer);
     return dmat;
   } else {
+    std::string cache_fname = cache_file;
+    if (loadsplit) {
+      std::ostringstream os;
+      os << cache_file << ".r" << rabit::GetRank();
+      cache_fname = os.str();
+      cache_file = cache_fname.c_str();
+    }
     FILE *fi = fopen64(cache_file, "rb");
     if (fi != NULL) {
       DMatrixPage *dmat = new DMatrixPage();

wrapper/xgboost.py

@@ -87,7 +87,7 @@ def c_array(ctype, values):
 
 
 class DMatrix(object):
-    def __init__(self, data, label=None, missing=0.0, weight=None, cache_file=None):
+    def __init__(self, data, label=None, missing=0.0, weight=None):
         """
         Data matrix used in XGBoost.
 
@@ -102,24 +102,13 @@ class DMatrix(object):
             Value in the data which needs to be present as a missing value.
         weight : list or numpy 1-D array (optional)
             Weight for each instance.
-        cache_file: string
-            Path to the binary cache of input data, when this is enabled,
-            several binary cache files with the prefix cache_file will be created,
-            xgboost will try to use external memory as much as possible,
-            thus save memory during computation in general
         """
 
         # force into void_p, mac need to pass things in as void_p
         if data is None:
             self.handle = None
             return
-        if cache_file is not None:
-            if not isinstance(data, string_types):
-                raise Exception('cache_file must be used together with input file name')
-            if not isinstance(cache_file, string_types):
-                raise Exception('cache_file must be string')
-            self.handle = ctypes.c_void_p(xglib.XGDMatrixCreateCache(c_str(data), c_str(cache_file), 0))
-        elif isinstance(data, string_types):
+        if isinstance(data, string_types):
             self.handle = ctypes.c_void_p(xglib.XGDMatrixCreateFromFile(c_str(data), 0))
         elif isinstance(data, scipy.sparse.csr_matrix):
             self._init_from_csr(data)

wrapper/xgboost_wrapper.cpp

@@ -114,11 +114,6 @@ extern "C"{
   void* XGDMatrixCreateFromFile(const char *fname, int silent) {
     return LoadDataMatrix(fname, silent != 0, false, false);
   }
-  void* XGDMatrixCreateCache(const char *fname,
-                             const char *cache_file, 
-                             int silent) {
-    return LoadDataMatrix(fname, silent != 0, false, false, cache_file);
-  }
   void* XGDMatrixCreateFromCSR(const bst_ulong *indptr,
                                const unsigned *indices,
                                const float *data,

wrapper/xgboost_wrapper.h

@@ -24,17 +24,6 @@ extern "C" {
    * \return a loaded data matrix
    */
   XGB_DLL void* XGDMatrixCreateFromFile(const char *fname, int silent);
-  /*!
-   * \brief load a cached DMatrix, this is backed by several cache_files
-   *  and usually cost less memory
-   * \param fname the name of the file, can be a cached buffer or text
-   * \param cache_file the name of cached file
-   * \param silent whether print messages during loading
-   * \return a loaded data matrix
-   */
-  XGB_DLL void* XGDMatrixCreateCache(const char *fname,
-                                     const char *cache_file,
-                                     int silent);
   /*!
    * \brief create a matrix content from csr format
    * \param indptr pointer to row headers