fix bug in save binary

include/LightGBM/dataset_loader.h

@@ -20,7 +20,7 @@ public:
 
   Dataset* LoadFromFileAlignWithOtherDataset(const char* filename, const Dataset* train_data);
 
-  Dataset* LoadFromBinFile(const char* bin_filename, int rank, int num_machines);
+  Dataset* LoadFromBinFile(const char* data_filename, const char* bin_filename, int rank, int num_machines);
 
   Dataset* CostructFromSampleData(std::vector<std::vector<double>>& sample_values, size_t total_sample_size, data_size_t num_data);
 

src/io/dataset.cpp

@@ -131,13 +131,17 @@ bool Dataset::GetIntField(const char* field_name, int64_t* out_len, const int**
 }
 
 void Dataset::SaveBinaryFile(const char* bin_filename) {
+  if (bin_filename != nullptr 
+      && std::string(bin_filename) == std::string(data_filename_)) {
+    Log::Warning("Bianry file %s already existed", bin_filename);
+    return;
+  }
   // if not pass a filename, just append ".bin" of original file
-  if (bin_filename == nullptr || bin_filename[0] == '\0') {
   std::string bin_filename_str(data_filename_);
+  if (bin_filename == nullptr || bin_filename[0] == '\0') {
     bin_filename_str.append(".bin");
     bin_filename = bin_filename_str.c_str();
   }
-
   bool is_file_existed = false;
   FILE* file;
 #ifdef _MSC_VER

src/io/dataset_loader.cpp

@@ -210,7 +210,7 @@ Dataset* DatasetLoader::LoadFromFile(const char* filename, int rank, int num_mac
     }
   } else {
     // load data from binary file
-    dataset.reset(LoadFromBinFile(bin_filename.c_str(), rank, num_machines));
+    dataset.reset(LoadFromBinFile(filename, bin_filename.c_str(), rank, num_machines));
   }
   // check meta data
   dataset->metadata_.CheckOrPartition(num_global_data, used_data_indices);
@@ -257,7 +257,7 @@ Dataset* DatasetLoader::LoadFromFileAlignWithOtherDataset(const char* filename,
     }
   } else {
     // load data from binary file
-    dataset.reset(LoadFromBinFile(bin_filename.c_str(), 0, 1));
+    dataset.reset(LoadFromBinFile(filename, bin_filename.c_str(), 0, 1));
   }
   // not need to check validation data
   // check meta data
@@ -265,7 +265,7 @@ Dataset* DatasetLoader::LoadFromFileAlignWithOtherDataset(const char* filename,
   return dataset.release();
 }
 
-Dataset* DatasetLoader::LoadFromBinFile(const char* bin_filename, int rank, int num_machines) {
+Dataset* DatasetLoader::LoadFromBinFile(const char* data_filename, const char* bin_filename, int rank, int num_machines) {
   auto dataset = std::unique_ptr<Dataset>(new Dataset());
   FILE* file;
 #ifdef _MSC_VER
@@ -273,7 +273,7 @@ Dataset* DatasetLoader::LoadFromBinFile(const char* bin_filename, int rank, int
 #else
   file = fopen(bin_filename, "rb");
 #endif
-
+  dataset->data_filename_ = data_filename;
   if (file == NULL) {
     Log::Fatal("Could not read binary data from %s", bin_filename);
   }