Merge pull request #56 from guolinke/master to dev

merge to dev

include/LightGBM/c_api.h

+#ifndef LIGHTGBM_C_API_H_
+#define LIGHTGBM_C_API_H_
+#include<cstdint>
+
+#ifdef __cplusplus
+#define DLL_EXTERN_C extern "C"
+#else
+#define DLL_EXTERN_C
+#endif
+
+#ifdef _MSC_VER
+#define DllExport DLL_EXTERN_C __declspec(dllexport)
+#else
+#define DllExport DLL_EXTERN_C
+#endif
+
+typedef void* DatesetHandle;
+typedef void* BoosterHandle;
+
+/*!
+* \brief get string message of the last error
+*  all function in this file will return 0 when success
+*  and -1 when an error occured,
+* \return const char* error inforomation
+*/
+DllExport const char* LGBM_GetLastError();
+
+
+// --- start Dataset inferfaces
+
+/*!
+* \brief load data set from file like the command_line LightGBM do
+* \param parameters additional parameters
+* \param filename the name of the file
+* \param reference used to align bin mapper with other dataset, nullptr means don't used
+* \param out a loaded dataset
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_CreateDatasetFromFile(const char* filename,
+  const char* parameters,
+  const DatesetHandle* reference,
+  DatesetHandle* out);
+
+/*!
+* \brief load data set from binary file like the command_line LightGBM do
+* \param filename the name of the file
+* \param out a loaded dataset
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_CreateDatasetFromBinaryFile(const char* filename,
+  DatesetHandle* out);
+
+/*!
+* \brief create a dataset from CSR format
+* \param indptr pointer to row headers
+* \param indices findex
+* \param data fvalue
+* \param nindptr number of rows in the matix + 1
+* \param nelem number of nonzero elements in the matrix
+* \param num_col number of columns; when it's set to 0, then guess from data
+* \param parameters additional parameters
+* \param reference used to align bin mapper with other dataset, nullptr means don't used
+* \param out created dataset
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_CreateDatasetFromCSR(const uint64_t* indptr,
+  const unsigned* indices,
+  const float* data,
+  uint64_t nindptr,
+  uint64_t nelem,
+  uint64_t num_col,
+  const char* parameters,
+  const DatesetHandle* reference,
+  DatesetHandle* out);
+
+/*!
+* \brief create a dataset from CSC format
+* \param col_ptr pointer to col headers
+* \param indices findex
+* \param data fvalue
+* \param nindptr number of rows in the matix + 1
+* \param nelem number of nonzero elements in the matrix
+* \param num_row number of rows; when it's set to 0, then guess from data
+* \param parameters additional parameters
+* \param reference used to align bin mapper with other dataset, nullptr means don't used
+* \param out created dataset
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_CreateDatasetFromCSC(const uint64_t* col_ptr,
+  const unsigned* indices,
+  const float* data,
+  uint64_t nindptr,
+  uint64_t nelem,
+  uint64_t num_row,
+  const char* parameters,
+  const DatesetHandle* reference,
+  DatesetHandle* out);
+
+/*!
+* \brief create dataset from dense matrix
+* \param data pointer to the data space
+* \param nrow number of rows
+* \param ncol number columns
+* \param missing which value to represent missing value
+* \param parameters additional parameters
+* \param reference used to align bin mapper with other dataset, nullptr means don't used
+* \param out created dataset
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_CreateDatasetFromMat(const float* data,
+  uint64_t nrow,
+  uint64_t ncol,
+  float missing,
+  const char* parameters,
+  const DatesetHandle* reference,
+  DatesetHandle* out);
+
+/*!
+* \brief free space for dataset
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_DatasetFree(DatesetHandle* handle);
+
+/*!
+* \brief save dateset to binary file
+* \param handle a instance of dataset
+* \param filename file name
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_DatasetSaveBinary(DatesetHandle handle,
+  const char* filename);
+
+/*!
+* \brief set vector to a content in info
+* \param handle a instance of dataset
+* \param field_name field name, can be label, weight, group
+* \param field_data pointer to float vector
+* \param field_len number of element in field_data
+* \param type float:0, int:1
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_DatasetSetField(DatesetHandle handle,
+  const char* field_name,
+  const void* field_data,
+  uint64_t num_element,
+  int type);
+
+/*!
+* \brief get float info vector from dataset
+* \param handle a instance of data matrix
+* \param field_name field name
+* \param out_len used to set result length
+* \param out_ptr pointer to the result
+* \param out_type float:0, int:1
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_DatasetGetField(DatesetHandle handle,
+  const char* field_name,
+  uint64_t* out_len,
+  const void** out_ptr,
+  int* out_type);
+
+/*!
+* \brief get number of data.
+* \param handle the handle to the dataset
+* \param out The address to hold number of data
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_DatasetGetNumData(DatesetHandle handle,
+  uint64_t* out);
+
+/*!
+* \brief get number of features
+* \param handle the handle to the dataset
+* \param out The output of number of features
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_DatasetGetNumFeature(DatesetHandle handle,
+  uint64_t* out);
+
+// --- start Booster interfaces
+
+/*!
+* \brief create an new boosting learner
+* \param train_data traning data set
+* \param valid_datas validation data sets
+* \param valid_names names of validation data sets
+* \param n_valid_datas number of validation set
+* \param parameters format: 'key1=value1 key2=value2'
+* \prama out handle of created Booster
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterCreate(DatesetHandle train_data,
+  DatesetHandle valid_datas[],
+  const char* valid_names[],
+  int n_valid_datas,
+  const char* parameters,
+  BoosterHandle* out);
+
+/*!
+* \brief load an exsiting boosting from model file
+* \param filename filename of model
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterLoadFromModelfile(
+  const char* filename,
+  BoosterHandle* out);
+
+/*!
+* \brief free obj in handle
+* \param handle handle to be freed
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterFree(BoosterHandle handle);
+
+/*!
+* \brief update the model in one round
+* \param handle handle
+* \param is_finished 1 means finised
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterUpdateOneIter(BoosterHandle handle, int* is_finished);
+
+/*!
+* \brief update the model, by directly specify gradient and second order gradient,
+*       this can be used to support customized loss function
+* \param handle handle
+* \param grad gradient statistics
+* \param hess second order gradient statistics
+* \param is_finished 1 means finised
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterUpdateOneIterCustom(BoosterHandle handle,
+  float* grad,
+  float* hess,
+  int* is_finished);
+
+/*!
+* \brief get evaluation for training data and validation datas
+* \param handle handle
+* \param data 0:training data, 1: 1st valid data, 2:2nd valid data ...
+* \param out_result the string containing evaluation statistics
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterEval(BoosterHandle handle,
+  int data,
+  const char** out_result);
+
+/*!
+* \brief make prediction for training data and validation datas
+this can be used to support customized eval function
+* \param handle handle
+* \param data 0:training data, 1: 1st valid data, 2:2nd valid data ...
+* \param predict_type
+*          0:raw score
+*          1:with sigmoid transform(if needed)
+*          2:leaf index
+* \param out_result used to set a pointer to array
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterPredict(BoosterHandle handle,
+  int data,
+  int predict_type,
+  const float** out_result);
+
+/*!
+* \brief make prediction for an new data set
+* \param handle handle
+* \param indptr pointer to row headers
+* \param indices findex
+* \param data fvalue
+* \param nindptr number of rows in the matix + 1
+* \param nelem number of nonzero elements in the matrix
+* \param num_col number of columns; when it's set to 0, then guess from data
+* \param predict_type
+*          0:raw score
+*          1:with sigmoid transform(if needed)
+*          2:leaf index
+* \param n_used_trees number of used tree
+* \param out_result used to set a pointer to array
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterPredictForCSR(BoosterHandle handle,
+  const uint64_t* indptr,
+  const unsigned* indices,
+  const float* data,
+  uint64_t nindptr,
+  uint64_t nelem,
+  uint64_t num_col,
+  int predict_type,
+  uint64_t n_used_trees,
+  const float** out_result);
+
+/*!
+* \brief make prediction for an new data set
+* \param handle handle
+* \param col_ptr pointer to col headers
+* \param indices findex
+* \param data fvalue
+* \param nindptr number of rows in the matix + 1
+* \param nelem number of nonzero elements in the matrix
+* \param num_row number of rows; when it's set to 0, then guess from data
+* \param predict_type
+*          0:raw score
+*          1:with sigmoid transform(if needed)
+*          2:leaf index
+* \param n_used_trees number of used tree
+* \param out_result used to set a pointer to array
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterPredictForCSC(BoosterHandle handle,
+  const uint64_t* col_ptr,
+  const unsigned* indices,
+  const float* data,
+  uint64_t nindptr,
+  uint64_t nelem,
+  uint64_t num_row,
+  int predict_type,
+  uint64_t n_used_trees,
+  const float** out_result);
+
+/*!
+* \brief make prediction for an new data set
+* \param handle handle
+* \param data pointer to the data space
+* \param nrow number of rows
+* \param ncol number columns
+* \param missing which value to represent missing value
+* \param predict_type
+*          0:raw score
+*          1:with sigmoid transform(if needed)
+*          2:leaf index
+* \param n_used_trees number of used tree
+* \param out_result used to set a pointer to array
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterPredictForMat(BoosterHandle handle,
+  const float* data,
+  uint64_t nrow,
+  uint64_t ncol,
+  float missing,
+  int predict_type,
+  uint64_t n_used_trees,
+  const float** out_result);
+
+/*!
+* \brief save model into file
+* \param handle handle
+* \param is_finished 1 means finised
+* \param filename file name
+* \return 0 when success, -1 when failure happens
+*/
+DllExport int LGBM_BoosterSaveModel(BoosterHandle handle,
+  int is_finished,
+  const char* filename);
+
+#endif // LIGHTGBM_C_API_H_

include/LightGBM/config.h

@@ -99,6 +99,8 @@ public:
   bool is_enable_sparse = true;
   bool use_two_round_loading = false;
   bool is_save_binary_file = false;
+  bool enable_load_from_binary_file = true;
+  int bin_construct_sample_cnt = 50000;
   bool is_sigmoid = true;
 
   bool has_header = false;

include/LightGBM/dataset.h

@@ -17,6 +17,7 @@ namespace LightGBM {
 
 /*! \brief forward declaration */
 class Feature;
+class BinMapper;
 
 /*!
 * \brief This class is used to store some meta(non-feature) data for training data,
@@ -79,6 +80,13 @@ public:
   void CheckOrPartition(data_size_t num_all_data,
     const std::vector<data_size_t>& used_data_indices);
 
+
+  void SetLabel(const float* label, data_size_t len);
+
+  void SetWeights(const float* weights, data_size_t len);
+
+  void SetQueryBoundaries(const data_size_t* QueryBoundaries, data_size_t len);
+
   /*!
   * \brief Set initial scores
   * \param init_score Initial scores, this class will manage memory for init_score.
@@ -188,8 +196,6 @@ private:
   data_size_t num_weights_;
   /*! \brief Label data */
   float* label_;
-  /*! \brief Label data, int type */
-  int16_t* label_int_;
   /*! \brief Weights data */
   float* weights_;
   /*! \brief Query boundaries */
@@ -262,9 +268,24 @@ public:
     : Dataset(data_filename, "", io_config, predict_fun) {
   }
 
+  /*!
+  * \brief Constructor, without filename, used to load data from memory 
+  * \param io_config configs for IO
+  * \param predict_fun Used for initial model, will give a prediction score based on this function, then set as initial score
+  */
+  Dataset(const IOConfig& io_config, const PredictFunction& predict_fun);
+
   /*! \brief Destructor */
   ~Dataset();
 
+  /*! \brief Init Dataset with specific binmapper */
+  void InitByBinMapper(std::vector<const BinMapper*> bin_mappers, data_size_t num_data);
+
+  /*! \brief push raw data into dataset */
+  void PushData(const std::vector<std::vector<std::pair<int, float>>>& datas, data_size_t start_idx, bool is_finished);
+
+  void SetField(const char* field_name, const void* field_data, data_size_t num_element, int type);
+
   /*!
   * \brief Load training data on parallel training
   * \param rank Rank of local machine
@@ -290,10 +311,21 @@ public:
   */
   void LoadValidationData(const Dataset* train_set, bool use_two_round_loading);
 
+  /*!
+  * \brief Load data set from binary file
+  * \param bin_filename filename of bin data 
+  * \param rank Rank of local machine
+  * \param num_machines Total number of all machines
+  * \param is_pre_partition True if data file is pre-partitioned
+  */
+  void LoadDataFromBinFile(const char* bin_filename, int rank, int num_machines, bool is_pre_partition);
+
   /*!
   * \brief Save current dataset into binary file, will save to "filename.bin"
   */
-  void SaveBinaryFile();
+  void SaveBinaryFile(const char* bin_filename);
+
+  std::vector<const BinMapper*> GetBinMappers() const;
 
   /*!
   * \brief Get a feature pointer for specific index
@@ -371,14 +403,6 @@ private:
   /*! \brief Check can load from binary file */
   void CheckCanLoadFromBin();
 
-  /*!
-  * \brief Load data set from binary file
-  * \param rank Rank of local machine
-  * \param num_machines Total number of all machines
-  * \param is_pre_partition True if data file is pre-partitioned
-  */
-  void LoadDataFromBinFile(int rank, int num_machines, bool is_pre_partition);
-
   /*! \brief Check this data set is null or not */
   void CheckDataset();
 
@@ -424,6 +448,8 @@ private:
   std::unordered_set<int> ignore_features_;
   /*! \brief store feature names */
   std::vector<std::string> feature_names_;
+  /*! \brief store feature names */
+  int bin_construct_sample_cnt_;
 };
 
 }  // namespace LightGBM

src/application/application.cpp

@@ -150,7 +150,7 @@ void Application::LoadData() {
   }
   // need save binary file
   if (config_.io_config.is_save_binary_file) {
-    train_data_->SaveBinaryFile();
+    train_data_->SaveBinaryFile(nullptr);
   }
   // create training metric
   if (config_.boosting_config->is_provide_training_metric) {
@@ -175,7 +175,7 @@ void Application::LoadData() {
                 config_.io_config.use_two_round_loading);
     // need save binary file
     if (config_.io_config.is_save_binary_file) {
-      valid_datas_.back()->SaveBinaryFile();
+      valid_datas_.back()->SaveBinaryFile(nullptr);
     }
 
     // add metric for validation data

src/boosting/boosting.cpp

@@ -25,7 +25,7 @@ void LoadFileToBoosting(Boosting* boosting, const char* filename) {
 }
 
 Boosting* Boosting::CreateBoosting(BoostingType type, const char* filename) {
-  if (filename[0] == '\0') {
+  if (filename == nullptr || filename[0] == '\0') {
     if (type == BoostingType::kGBDT) {
       return new GBDT();
     } else {

src/c_api.cpp

+
+#include <LightGBM/c_api.h>
+#include <LightGBM/dataset.h>
+#include <LightGBM/boosting.h>
+#include <LightGBM/objective_function.h>
+#include <LightGBM/metric.h>
+#include <LightGBM/config.h>
+
+#include <cstdio>
+#include <vector>
+#include <string>
+#include <cstring>
+
+namespace LightGBM {
+
+class Booster {
+public:
+  explicit Booster(const char* filename):
+    boosting_(Boosting::CreateBoosting(filename)) {
+  }
+
+  Booster(const Dataset* train_data, 
+    std::vector<const Dataset*> valid_data, 
+    std::vector<std::string> valid_names,
+    const char* parameters)
+    :train_data_(train_data), valid_datas_(valid_data) {
+    config_.LoadFromString(parameters);
+    // create boosting
+    if (config_.io_config.input_model.size() > 0) {
+      Log::Error("continued train from model is not support for c_api, \
+        please use continued train with input score");
+    }
+    boosting_ = Boosting::CreateBoosting(config_.boosting_type, "");
+    // create objective function
+    objective_fun_ =
+      ObjectiveFunction::CreateObjectiveFunction(config_.objective_type,
+        config_.objective_config);
+    // create training metric
+    if (config_.boosting_config->is_provide_training_metric) {
+      for (auto metric_type : config_.metric_types) {
+        Metric* metric =
+          Metric::CreateMetric(metric_type, config_.metric_config);
+        if (metric == nullptr) { continue; }
+        metric->Init("training", train_data_->metadata(),
+          train_data_->num_data());
+        train_metric_.push_back(metric);
+      }
+    }
+    // add metric for validation data
+    for (size_t i = 0; i < valid_datas_.size(); ++i) {
+      valid_metrics_.emplace_back();
+      for (auto metric_type : config_.metric_types) {
+        Metric* metric = Metric::CreateMetric(metric_type, config_.metric_config);
+        if (metric == nullptr) { continue; }
+        metric->Init(valid_names[i].c_str(),
+          valid_datas_[i]->metadata(),
+          valid_datas_[i]->num_data());
+        valid_metrics_.back().push_back(metric);
+      }
+    }
+    // initialize the objective function
+    objective_fun_->Init(train_data_->metadata(), train_data_->num_data());
+    // initialize the boosting
+    boosting_->Init(config_.boosting_config, train_data_, objective_fun_,
+      ConstPtrInVectorWarpper<Metric>(train_metric_));
+    // add validation data into boosting
+    for (size_t i = 0; i < valid_datas_.size(); ++i) {
+      boosting_->AddDataset(valid_datas_[i],
+        ConstPtrInVectorWarpper<Metric>(valid_metrics_[i]));
+    }
+  }
+
+  ~Booster() {
+    for (auto& metric : train_metric_) {
+      if (metric != nullptr) { delete metric; }
+    }
+    for (auto& metric : valid_metrics_) {
+      for (auto& sub_metric : metric) {
+        if (sub_metric != nullptr) { delete sub_metric; }
+      }
+    }
+    valid_metrics_.clear();
+    if (boosting_ != nullptr) { delete boosting_; }
+    if (objective_fun_ != nullptr) { delete objective_fun_; }
+  }
+private:
+  Boosting* boosting_;
+  /*! \brief All configs */
+  OverallConfig config_;
+  /*! \brief Training data */
+  const Dataset* train_data_;
+  /*! \brief Validation data */
+  std::vector<const Dataset*> valid_datas_;
+  /*! \brief Metric for training data */
+  std::vector<Metric*> train_metric_;
+  /*! \brief Metrics for validation data */
+  std::vector<std::vector<Metric*>> valid_metrics_;
+  /*! \brief Training objective function */
+  ObjectiveFunction* objective_fun_;
+};
+
+}

src/io/config.cpp

@@ -191,10 +191,12 @@ void IOConfig::Set(const std::unordered_map<std::string, std::string>& params) {
   }
   GetInt(params, "verbose", &verbosity);
   GetInt(params, "num_model_predict", &num_model_predict);
+  GetInt(params, "bin_construct_sample_cnt", &bin_construct_sample_cnt);
   GetBool(params, "is_pre_partition", &is_pre_partition);
   GetBool(params, "is_enable_sparse", &is_enable_sparse);
   GetBool(params, "use_two_round_loading", &use_two_round_loading);
   GetBool(params, "is_save_binary_file", &is_save_binary_file);
+  GetBool(params, "enable_load_from_binary_file", &enable_load_from_binary_file);
   GetBool(params, "is_sigmoid", &is_sigmoid);
   GetString(params, "output_model", &output_model);
   GetString(params, "input_model", &input_model);

src/io/dataset.cpp

@@ -18,9 +18,11 @@ namespace LightGBM {
 Dataset::Dataset(const char* data_filename, const char* init_score_filename,
   const IOConfig& io_config, const PredictFunction& predict_fun)
   :data_filename_(data_filename), random_(io_config.data_random_seed),
-  max_bin_(io_config.max_bin), is_enable_sparse_(io_config.is_enable_sparse), predict_fun_(predict_fun) {
-
+  max_bin_(io_config.max_bin), is_enable_sparse_(io_config.is_enable_sparse), 
+  predict_fun_(predict_fun), bin_construct_sample_cnt_(io_config.bin_construct_sample_cnt) {
+  if (io_config.enable_load_from_binary_file) {
     CheckCanLoadFromBin();
+  }
   if (is_loading_from_binfile_ && predict_fun != nullptr) {
     Log::Info("Cannot performing initialization of prediction by using binary file, using text file instead");
     is_loading_from_binfile_ = false;
@@ -160,6 +162,17 @@ Dataset::Dataset(const char* data_filename, const char* init_score_filename,
 
 }
 
+Dataset::Dataset(const IOConfig& io_config, const PredictFunction& predict_fun)
+  :data_filename_(""), random_(io_config.data_random_seed),
+  max_bin_(io_config.max_bin), is_enable_sparse_(io_config.is_enable_sparse),
+  predict_fun_(predict_fun), bin_construct_sample_cnt_(io_config.bin_construct_sample_cnt) {
+
+  parser_ = nullptr;
+  text_reader_ = nullptr;
+}
+
+
+
 Dataset::~Dataset() {
   if (parser_ != nullptr) { delete parser_; }
   if (text_reader_ != nullptr) { delete text_reader_; }
@@ -216,7 +229,7 @@ void Dataset::LoadDataToMemory(int rank, int num_machines, bool is_pre_partition
 }
 
 void Dataset::SampleDataFromMemory(std::vector<std::string>* out_data) {
-  const size_t sample_cnt = static_cast<size_t>(num_data_ < 50000 ? num_data_ : 50000);
+  const size_t sample_cnt = static_cast<size_t>(num_data_ < bin_construct_sample_cnt_ ? num_data_ : bin_construct_sample_cnt_);
   std::vector<size_t> sample_indices = random_.Sample(num_data_, sample_cnt);
   out_data->clear();
   for (size_t i = 0; i < sample_indices.size(); ++i) {
@@ -228,7 +241,7 @@ void Dataset::SampleDataFromMemory(std::vector<std::string>* out_data) {
 void Dataset::SampleDataFromFile(int rank, int num_machines, bool is_pre_partition,
                                              std::vector<std::string>* out_data) {
   used_data_indices_.clear();
-  const size_t sample_cnt = 50000;
+  const data_size_t sample_cnt = static_cast<data_size_t>(bin_construct_sample_cnt_);
   if (num_machines == 1 || is_pre_partition) {
     num_data_ = static_cast<data_size_t>(text_reader_->SampleFromFile(random_, sample_cnt, out_data));
     global_num_data_ = num_data_;
@@ -272,6 +285,83 @@ void Dataset::SampleDataFromFile(int rank, int num_machines, bool is_pre_partiti
   }
 }
 
+void Dataset::InitByBinMapper(std::vector<const BinMapper*> bin_mappers, data_size_t num_data) {
+  num_data_ = num_data;
+  global_num_data_ = num_data_;
+  // initialize label
+  metadata_.Init(num_data_, -1, -1);
+  // free old memory
+  for (auto& feature : features_) {
+    delete feature;
+  }
+  features_.clear();
+  used_feature_map_ = std::vector<int>(bin_mappers.size(), -1);
+  for (size_t i = 0; i < bin_mappers.size(); ++i) {
+    if (bin_mappers[i] != nullptr) {
+      features_.push_back(new Feature(static_cast<int>(i), new BinMapper(bin_mappers[i]), num_data_, is_enable_sparse_));
+      used_feature_map_[i] = static_cast<int>(features_.size());
+    }
+  }
+  num_features_ = static_cast<int>(features_.size());
+}
+
+std::vector<const BinMapper*> Dataset::GetBinMappers() const {
+  std::vector<const BinMapper*> ret(num_total_features_, nullptr);
+  for (const auto feature : features_) {
+    ret[feature->feature_index()] = feature->bin_mapper();
+  }
+  return ret;
+}
+
+void Dataset::PushData(const std::vector<std::vector<std::pair<int, float>>>& datas, data_size_t start_idx, bool is_finished) {
+  // if doesn't need to prediction with initial model
+#pragma omp parallel for schedule(guided) 
+  for (data_size_t i = 0; i < static_cast<int>(datas.size()); ++i) {
+    const int tid = omp_get_thread_num();
+    for (auto& inner_data : datas[i]) {
+      int feature_idx = used_feature_map_[inner_data.first];
+      if (feature_idx >= 0) {
+        // if is used feature
+        features_[feature_idx]->PushData(tid, start_idx + i, inner_data.second);
+      } 
+    }
+  }
+  if (is_finished) {
+#pragma omp parallel for schedule(guided)
+    for (int i = 0; i < num_features_; ++i) {
+      features_[i]->FinishLoad();
+    }
+  }
+}
+
+void Dataset::SetField(const char* field_name, const void* field_data, data_size_t num_element, int type) {
+  std::string name(field_name);
+  name = Common::Trim(name);
+  if (name == std::string("label") || name == std::string("target")) {
+    if (type != 0) {
+      Log::Fatal("type of label should be float");
+    }
+    metadata_.SetLabel(static_cast<const float*>(field_data), num_element);
+  }else if (name == std::string("weight") || name == std::string("weights")) {
+    if (type != 0) {
+      Log::Fatal("type of weights should be float");
+    }
+    metadata_.SetWeights(static_cast<const float*>(field_data), num_element);
+  } else if (name == std::string("init_score")) {
+    if (type != 0) {
+      Log::Fatal("type of init_score should be float");
+    }
+    metadata_.SetInitScore(static_cast<const float*>(field_data), num_element);
+  } else if (name == std::string("query") || name == std::string("group")) {
+    if (type != 1) {
+      Log::Fatal("type of init_score should be int");
+    }
+    metadata_.SetQueryBoundaries(static_cast<const data_size_t*>(field_data), num_element);
+  } else {
+    Log::Fatal("unknow field name: %s", field_name);
+  }
+}
+
 void Dataset::ConstructBinMappers(int rank, int num_machines, const std::vector<std::string>& sample_data) {
   // sample_values[i][j], means the value of j-th sample on i-th feature
   std::vector<std::vector<float>> sample_values;
@@ -452,8 +542,10 @@ void Dataset::LoadTrainData(int rank, int num_machines, bool is_pre_partition, b
       ExtractFeaturesFromFile();
     }
   } else {
+    std::string bin_filename(data_filename_);
+    bin_filename.append(".bin");
     // load data from binary file
-    LoadDataFromBinFile(rank, num_machines, is_pre_partition);
+    LoadDataFromBinFile(bin_filename.c_str(), rank, num_machines, is_pre_partition);
   }
   // check meta data
   metadata_.CheckOrPartition(static_cast<data_size_t>(global_num_data_), used_data_indices_);
@@ -497,8 +589,10 @@ void Dataset::LoadValidationData(const Dataset* train_set, bool use_two_round_lo
       ExtractFeaturesFromFile();
     }
   } else {
+    std::string bin_filename(data_filename_);
+    bin_filename.append(".bin");
     // load from binary file
-    LoadDataFromBinFile(0, 1, false);
+    LoadDataFromBinFile(bin_filename.c_str(), 0, 1, false);
   }
   // not need to check validation data
   // check meta data
@@ -646,19 +740,23 @@ void Dataset::ExtractFeaturesFromFile() {
   }
 }
 
-void Dataset::SaveBinaryFile() {
-  // if is loaded from binary file, not need to save 
+void Dataset::SaveBinaryFile(const char* bin_filename) {
+  
   if (!is_loading_from_binfile_) {
-    std::string bin_filename(data_filename_);
-    bin_filename.append(".bin");
+    // 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_);
+      bin_filename_str.append(".bin");
+      bin_filename = bin_filename_str.c_str();
+    }
     FILE* file;
     #ifdef _MSC_VER
-    fopen_s(&file, bin_filename.c_str(), "wb");
+    fopen_s(&file, bin_filename, "wb");
     #else
-    file = fopen(bin_filename.c_str(), "wb");
+    file = fopen(bin_filename, "wb");
     #endif
     if (file == NULL) {
-      Log::Fatal("Cannot write binary data to %s ", bin_filename.c_str());
+      Log::Fatal("Cannot write binary data to %s ", bin_filename);
     }
 
     Log::Info("Saving data to binary file: %s", data_filename_);
@@ -715,20 +813,18 @@ void Dataset::CheckCanLoadFromBin() {
   }
 }
 
-void Dataset::LoadDataFromBinFile(int rank, int num_machines, bool is_pre_partition) {
-  std::string bin_filename(data_filename_);
-  bin_filename.append(".bin");
+void Dataset::LoadDataFromBinFile(const char* bin_filename, int rank, int num_machines, bool is_pre_partition) {
 
   FILE* file;
 
   #ifdef _MSC_VER
-  fopen_s(&file, bin_filename.c_str(), "rb");
+  fopen_s(&file, bin_filename, "rb");
   #else
-  file = fopen(bin_filename.c_str(), "rb");
+  file = fopen(bin_filename, "rb");
   #endif
 
   if (file == NULL) {
-    Log::Fatal("Cannot read binary data from %s", bin_filename.c_str());
+    Log::Fatal("Cannot read binary data from %s", bin_filename);
   }
 
   // buffer to read binary file

src/io/metadata.cpp

@@ -8,7 +8,7 @@
 namespace LightGBM {
 
 Metadata::Metadata()
-  :label_(nullptr), label_int_(nullptr), weights_(nullptr), 
+  :label_(nullptr), weights_(nullptr), 
   query_boundaries_(nullptr),
   query_weights_(nullptr), init_score_(nullptr), queries_(nullptr){
 
@@ -225,6 +225,48 @@ void Metadata::SetInitScore(const float* init_score, data_size_t len) {
   }
 }
 
+void Metadata::SetLabel(const float* label, data_size_t len) {
+  if (num_data_ != len) {
+    Log::Fatal("len of label is not same with #data");
+  }
+  if (label_ != nullptr) { delete[] label_; }
+  label_ = new float[num_data_];
+  for (data_size_t i = 0; i < num_data_; ++i) {
+    label_[i] = label[i];
+  }
+}
+
+void Metadata::SetWeights(const float* weights, data_size_t len) {
+  if (num_data_ != len) {
+    Log::Fatal("len of weights is not same with #data");
+  }
+  if (weights_ != nullptr) { delete[] weights_; }
+  num_weights_ = num_data_;
+  weights_ = new float[num_weights_];
+  for (data_size_t i = 0; i < num_weights_; ++i) {
+    weights_[i] = weights[i];
+  }
+  LoadQueryWeights();
+}
+
+void Metadata::SetQueryBoundaries(const data_size_t* query_boundaries, data_size_t len) {
+  data_size_t sum = 0;
+  for (data_size_t i = 0; i < len; ++i) {
+    sum += query_boundaries[i];
+  }
+  if (num_data_ != sum) {
+    Log::Fatal("sum of query counts is not same with #data");
+  }
+  if (query_boundaries_ != nullptr) { delete[] query_boundaries_; }
+  num_queries_ = len;
+  query_boundaries_ = new data_size_t[num_queries_];
+  for (data_size_t i = 0; i < num_queries_; ++i) {
+    query_boundaries_[i] = query_boundaries[i];
+  }
+  LoadQueryWeights();
+}
+
+
 void Metadata::LoadWeights() {
   num_weights_ = 0;
   std::string weight_filename(data_filename_);

src/io/sparse_bin.hpp

@@ -54,7 +54,7 @@ public:
   void ConstructHistogram(data_size_t*, data_size_t , const score_t* ,
                  const score_t* , HistogramBinEntry*) const override {
     // Will use OrderedSparseBin->ConstructHistogram() instead
-    Log::Info("Should use OrderedSparseBin->ConstructHistogram() instead");
+    Log::Fatal("Should use OrderedSparseBin->ConstructHistogram() instead");
   }
 
   data_size_t Split(unsigned int threshold, data_size_t* data_indices, data_size_t num_data,

windows/LightGBM.vcxproj

@@ -159,6 +159,7 @@
     <ClInclude Include="..\include\LightGBM\bin.h" />
     <ClInclude Include="..\include\LightGBM\boosting.h" />
     <ClInclude Include="..\include\LightGBM\config.h" />
+    <ClInclude Include="..\include\LightGBM\c_api.h" />
     <ClInclude Include="..\include\LightGBM\dataset.h" />
     <ClInclude Include="..\include\LightGBM\feature.h" />
     <ClInclude Include="..\include\LightGBM\meta.h" />
@@ -203,6 +204,7 @@
     <ClCompile Include="..\src\application\application.cpp" />
     <ClCompile Include="..\src\boosting\boosting.cpp" />
     <ClCompile Include="..\src\boosting\gbdt.cpp" />
+    <ClCompile Include="..\src\c_api.cpp" />
     <ClCompile Include="..\src\io\bin.cpp" />
     <ClCompile Include="..\src\io\config.cpp" />
     <ClCompile Include="..\src\io\dataset.cpp" />

windows/LightGBM.vcxproj.filters

@@ -165,6 +165,9 @@
     <ClInclude Include="..\include\LightGBM\utils\lru_pool.h">
       <Filter>include\LightGBM\utils</Filter>
     </ClInclude>
+    <ClInclude Include="..\include\LightGBM\c_api.h">
+      <Filter>include\LightGBM</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\src\application\application.cpp">
@@ -230,5 +233,8 @@
     <ClCompile Include="..\src\main.cpp">
       <Filter>src</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\c_api.cpp">
+      <Filter>src</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file