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xgboost/include/xgboost/c_api.h
Jiaming Yuan 3fbb221fec
[coll] Implement shutdown for tracker and comm. (#10208) 
- Force shutdown the tracker.
- Implement shutdown notice for error handling thread in comm.
2024-04-20 04:08:17 +08:00

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/**
* Copyright 2015-2024, XGBoost Contributors
* \file c_api.h
* \author Tianqi Chen
* \brief C API of XGBoost, used for interfacing to other languages.
*/
#ifndef XGBOOST_C_API_H_
#define XGBOOST_C_API_H_
#ifdef __cplusplus
#define XGB_EXTERN_C extern "C"
#include <cstddef>
#include <cstdio>
#include <cstdint>
#else
#define XGB_EXTERN_C
#include <stddef.h>
#include <stdio.h>
#include <stdint.h>
#endif // __cplusplus
#if defined(_MSC_VER) || defined(_WIN32)
#define XGB_DLL XGB_EXTERN_C __declspec(dllexport)
#else
#define XGB_DLL XGB_EXTERN_C __attribute__ ((visibility ("default")))
#endif // defined(_MSC_VER) || defined(_WIN32)
// manually define unsigned long
typedef uint64_t bst_ulong; // NOLINT(*)
/**
* @mainpage
*
* \brief XGBoost C API reference.
*
* For the official document page see:
* <a href="https://xgboost.readthedocs.io/en/stable/c.html">XGBoost C Package</a>.
*/
/**
* @defgroup Library Library
*
* These functions are used to obtain general information about XGBoost including version,
* build info and current global configuration.
*
* @{
*/
/*! \brief handle to DMatrix */
typedef void *DMatrixHandle; // NOLINT(*)
/*! \brief handle to Booster */
typedef void *BoosterHandle; // NOLINT(*)
/*!
* \brief Return the version of the XGBoost library being currently used.
*
* The output variable is only written if it's not NULL.
*
* \param major Store the major version number
* \param minor Store the minor version number
* \param patch Store the patch (revision) number
*/
XGB_DLL void XGBoostVersion(int* major, int* minor, int* patch);
/*!
* \brief Get compile information of shared library.
*
* \param out string encoded JSON object containing build flags and dependency version.
*
* \return 0 for success, -1 for failure
*/
XGB_DLL int XGBuildInfo(char const **out);
/*!
* \brief get string message of the last error
*
* all function in this file will return 0 when success
* and -1 when an error occurred,
* XGBGetLastError can be called to retrieve the error
*
* this function is thread safe and can be called by different thread
* \return const char* error information
*/
XGB_DLL const char *XGBGetLastError();
/*!
* \brief register callback function for LOG(INFO) messages -- helpful messages
* that are not errors.
* Note: this function can be called by multiple threads. The callback function
* will run on the thread that registered it
* \return 0 for success, -1 for failure
*/
XGB_DLL int XGBRegisterLogCallback(void (*callback)(const char*));
/*!
* \brief Set global configuration (collection of parameters that apply globally). This function
* accepts the list of key-value pairs representing the global-scope parameters to be
* configured. The list of key-value pairs are passed in as a JSON string.
* \param config a JSON string representing the list of key-value pairs. The JSON object shall
* be flat: no value can be a JSON object or an array.
* \return 0 for success, -1 for failure
*/
XGB_DLL int XGBSetGlobalConfig(char const *config);
/*!
* \brief Get current global configuration (collection of parameters that apply globally).
* \param out_config pointer to received returned global configuration, represented as a JSON string.
* \return 0 for success, -1 for failure
*/
XGB_DLL int XGBGetGlobalConfig(char const **out_config);
/**@}*/
/**
* @defgroup DMatrix DMatrix
*
* @brief DMatrix is the baisc data storage for XGBoost used by all XGBoost algorithms
* including both training, prediction and explanation. There are a few variants of
* `DMatrix` including normal `DMatrix`, which is a CSR matrix, `QuantileDMatrix`,
* which is used by histogram-based tree methods for saving memory, and lastly the
* experimental external-memory-based DMatrix, which reads data in batches during
* training. For the last two variants, see the @ref Streaming group.
*
* @{
*/
/*!
* \brief load a data matrix
* \deprecated since 2.0.0
* \see XGDMatrixCreateFromURI()
* \param fname the name of the file
* \param silent whether print messages during loading
* \param out a loaded data matrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromFile(const char *fname, int silent, DMatrixHandle *out);
/*!
* \brief load a data matrix
* \param config JSON encoded parameters for DMatrix construction. Accepted fields are:
* - uri: The URI of the input file. The URI parameter `format` is required when loading text data.
* \verbatim embed:rst:leading-asterisk
* See :doc:`/tutorials/input_format` for more info.
* \endverbatim
* - silent (optional): Whether to print message during loading. Default to true.
* - data_split_mode (optional): Whether the file was split by row or column beforehand for distributed computing. Default to row.
* \param out a loaded data matrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromURI(char const *config, DMatrixHandle *out);
/*!
* \brief create a matrix content from CSR format
* \deprecated since 2.0.0
* \see XGDMatrixCreateFromCSR()
*/
XGB_DLL int XGDMatrixCreateFromCSREx(const size_t *indptr, const unsigned *indices,
const float *data, size_t nindptr, size_t nelem,
size_t num_col, DMatrixHandle *out);
/**
* @brief Create a DMatrix from columnar data. (table)
*
* @param data See @ref XGBoosterPredictFromColumnar for details.
* @param config See @ref XGDMatrixCreateFromDense for details.
* @param out The created dmatrix.
*
* @return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromColumnar(char const *data, char const *config, DMatrixHandle *out);
/**
* @example c-api-demo.c
*/
/*!
* \brief Create a matrix from CSR matrix.
* \param indptr JSON encoded __array_interface__ to row pointers in CSR.
* \param indices JSON encoded __array_interface__ to column indices in CSR.
* \param data JSON encoded __array_interface__ to values in CSR.
* \param ncol Number of columns.
* \param config JSON encoded configuration. Required values are:
* - missing: Which value to represent missing value.
* - nthread (optional): Number of threads used for initializing DMatrix.
* - data_split_mode (optional): Whether the data was split by row or column beforehand. Default to row.
* \param out created dmatrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromCSR(char const *indptr, char const *indices, char const *data,
bst_ulong ncol, char const *config, DMatrixHandle *out);
/*!
* \brief Create a matrix from dense array.
* \param data JSON encoded __array_interface__ to array values.
* \param config JSON encoded configuration. Required values are:
* - missing: Which value to represent missing value.
* - nthread (optional): Number of threads used for initializing DMatrix.
* - data_split_mode (optional): Whether the data was split by row or column beforehand. Default to row.
* \param out created dmatrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromDense(char const *data, char const *config, DMatrixHandle *out);
/*!
* \brief Create a matrix from a CSC matrix.
* \param indptr JSON encoded __array_interface__ to column pointers in CSC.
* \param indices JSON encoded __array_interface__ to row indices in CSC.
* \param data JSON encoded __array_interface__ to values in CSC.
* \param nrow number of rows in the matrix.
* \param config JSON encoded configuration. Supported values are:
* - missing: Which value to represent missing value.
* - nthread (optional): Number of threads used for initializing DMatrix.
* - data_split_mode (optional): Whether the data was split by row or column beforehand. Default to row.
* \param out created dmatrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromCSC(char const *indptr, char const *indices, char const *data,
bst_ulong nrow, char const *config, DMatrixHandle *out);
/*!
* \brief create a matrix content from CSC format
* \deprecated since 2.0.0
* \see XGDMatrixCreateFromCSC()
*/
XGB_DLL int XGDMatrixCreateFromCSCEx(const size_t *col_ptr, const unsigned *indices,
const float *data, size_t nindptr, size_t nelem,
size_t num_row, DMatrixHandle *out);
/*!
* \brief create matrix content 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 out created dmatrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromMat(const float *data,
bst_ulong nrow,
bst_ulong ncol,
float missing,
DMatrixHandle *out);
/*!
* \brief create matrix content 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 out created dmatrix
* \param nthread number of threads (up to maximum cores available, if <=0 use all cores)
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromMat_omp(const float *data, // NOLINT
bst_ulong nrow, bst_ulong ncol,
float missing, DMatrixHandle *out,
int nthread);
/*!
* \brief create matrix content from python data table
* \param data pointer to pointer to column data
* \param feature_stypes pointer to strings
* \param nrow number of rows
* \param ncol number columns
* \param out created dmatrix
* \param nthread number of threads (up to maximum cores available, if <=0 use all cores)
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromDT(void** data,
const char ** feature_stypes,
bst_ulong nrow,
bst_ulong ncol,
DMatrixHandle* out,
int nthread);
/*!
* \brief Create DMatrix from CUDA columnar format. (cuDF)
* \param data Array of JSON encoded __cuda_array_interface__ for each column.
* \param config JSON encoded configuration. Required values are:
* - missing: Which value to represent missing value.
* - nthread (optional): Number of threads used for initializing DMatrix.
* - data_split_mode (optional): Whether the data was split by row or column beforehand. Default to row.
* \param out created dmatrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromCudaColumnar(char const *data, char const *config,
DMatrixHandle *out);
/*!
* \brief Create DMatrix from CUDA array.
* \param data JSON encoded __cuda_array_interface__ for array data.
* \param config JSON encoded configuration. Required values are:
* - missing: Which value to represent missing value.
* - nthread (optional): Number of threads used for initializing DMatrix.
* - data_split_mode (optional): Whether the data was split by row or column beforehand. Default to row.
* \param out created dmatrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromCudaArrayInterface(char const *data, char const *config,
DMatrixHandle *out);
/**
* @defgroup Streaming Streaming
* @ingroup DMatrix
*
* @brief Quantile DMatrix and external memory DMatrix can be created from batches of
* data.
*
* There are 2 sets of data callbacks for DMatrix. The first one is currently exclusively
* used by JVM packages. It uses `XGBoostBatchCSR` to accept batches for CSR formated
* input, and concatenate them into 1 final big CSR. The related functions are:
*
* - \ref XGBCallbackSetData
* - \ref XGBCallbackDataIterNext
* - \ref XGDMatrixCreateFromDataIter
*
* Another set is used by external data iterator. It accept foreign data iterators as
* callbacks. There are 2 different senarios where users might want to pass in callbacks
* instead of raw data. First it's the Quantile DMatrix used by hist and GPU Hist. For
* this case, the data is first compressed by quantile sketching then merged. This is
* particular useful for distributed setting as it eliminates 2 copies of data. 1 by a
* `concat` from external library to make the data into a blob for normal DMatrix
* initialization, another by the internal CSR copy of DMatrix. The second use case is
* external memory support where users can pass a custom data iterator into XGBoost for
* loading data in batches. There are short notes on each of the use cases in respected
* DMatrix factory function.
*
* Related functions are:
*
* # Factory functions
* - \ref XGDMatrixCreateFromCallback for external memory
* - \ref XGQuantileDMatrixCreateFromCallback for quantile DMatrix
*
* # Proxy that callers can use to pass data to XGBoost
* - \ref XGProxyDMatrixCreate
* - \ref XGDMatrixCallbackNext
* - \ref DataIterResetCallback
* - \ref XGProxyDMatrixSetDataCudaArrayInterface
* - \ref XGProxyDMatrixSetDataCudaColumnar
* - \ref XGProxyDMatrixSetDataDense
* - \ref XGProxyDMatrixSetDataCSR
* - ... (data setters)
*
* @{
*/
/* ==== First set of callback functions, used exclusively by JVM packages. ==== */
/*! \brief handle to a external data iterator */
typedef void *DataIterHandle; // NOLINT(*)
/*! \brief handle to a internal data holder. */
typedef void *DataHolderHandle; // NOLINT(*)
/*! \brief Mini batch used in XGBoost Data Iteration */
typedef struct { // NOLINT(*)
/*! \brief number of rows in the minibatch */
size_t size;
/* \brief number of columns in the minibatch. */
size_t columns;
/*! \brief row pointer to the rows in the data */
#ifdef __APPLE__
/* Necessary as Java on MacOS defines jlong as long int
* and gcc defines int64_t as long long int. */
long* offset; // NOLINT(*)
#else
int64_t* offset; // NOLINT(*)
#endif // __APPLE__
/*! \brief labels of each instance */
float* label;
/*! \brief weight of each instance, can be NULL */
float* weight;
/*! \brief feature index */
int* index;
/*! \brief feature values */
float* value;
} XGBoostBatchCSR;
/*!
* \brief Callback to set the data to handle,
* \param handle The handle to the callback.
* \param batch The data content to be set.
*/
XGB_EXTERN_C typedef int XGBCallbackSetData( // NOLINT(*)
DataHolderHandle handle, XGBoostBatchCSR batch);
/*!
* \brief The data reading callback function.
* The iterator will be able to give subset of batch in the data.
*
* If there is data, the function will call set_function to set the data.
*
* \param data_handle The handle to the callback.
* \param set_function The batch returned by the iterator
* \param set_function_handle The handle to be passed to set function.
* \return 0 if we are reaching the end and batch is not returned.
*/
XGB_EXTERN_C typedef int XGBCallbackDataIterNext( // NOLINT(*)
DataIterHandle data_handle, XGBCallbackSetData *set_function,
DataHolderHandle set_function_handle);
/*!
* \brief Create a DMatrix from a data iterator.
* \param data_handle The handle to the data.
* \param callback The callback to get the data.
* \param cache_info Additional information about cache file, can be null.
* \param out The created DMatrix
* \return 0 when success, -1 when failure happens.
*/
XGB_DLL int XGDMatrixCreateFromDataIter(
DataIterHandle data_handle,
XGBCallbackDataIterNext* callback,
const char* cache_info,
DMatrixHandle *out);
/**
* Second set of callback functions, used by constructing Quantile DMatrix or external
* memory DMatrix using custom iterator.
*/
/*!
* \brief Create a DMatrix proxy for setting data, can be free by XGDMatrixFree.
*
* \param out The created Device Quantile DMatrix
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGProxyDMatrixCreate(DMatrixHandle* out);
/*!
* \brief Callback function prototype for getting next batch of data.
*
* \param iter A handler to the user defined iterator.
*
* \return 0 when success, -1 when failure happens
*/
XGB_EXTERN_C typedef int XGDMatrixCallbackNext(DataIterHandle iter); // NOLINT(*)
/*!
* \brief Callback function prototype for resetting external iterator
*/
XGB_EXTERN_C typedef void DataIterResetCallback(DataIterHandle handle); // NOLINT(*)
/*!
* \brief Create an external memory DMatrix with data iterator.
*
* Short note for how to use second set of callback for external memory data support:
*
* - Step 0: Define a data iterator with 2 methods `reset`, and `next`.
* - Step 1: Create a DMatrix proxy by \ref XGProxyDMatrixCreate and hold the handle.
* - Step 2: Pass the iterator handle, proxy handle and 2 methods into
* \ref XGDMatrixCreateFromCallback, along with other parameters encoded as a JSON object.
* - Step 3: Call appropriate data setters in `next` functions.
*
* \param iter A handle to external data iterator.
* \param proxy A DMatrix proxy handle created by \ref XGProxyDMatrixCreate.
* \param reset Callback function resetting the iterator state.
* \param next Callback function yielding the next batch of data.
* \param config JSON encoded parameters for DMatrix construction. Accepted fields are:
* - missing: Which value to represent missing value
* - cache_prefix: The path of cache file, caller must initialize all the directories in this path.
* - nthread (optional): Number of threads used for initializing DMatrix.
* \param[out] out The created external memory DMatrix
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixCreateFromCallback(DataIterHandle iter, DMatrixHandle proxy,
DataIterResetCallback *reset, XGDMatrixCallbackNext *next,
char const *config, DMatrixHandle *out);
/**
* @example external_memory.c
*/
/*!
* \brief Create a Quantile DMatrix with data iterator.
*
* Short note for how to use the second set of callback for (GPU)Hist tree method:
*
* - Step 0: Define a data iterator with 2 methods `reset`, and `next`.
* - Step 1: Create a DMatrix proxy by \ref XGProxyDMatrixCreate and hold the handle.
* - Step 2: Pass the iterator handle, proxy handle and 2 methods into
* `XGQuantileDMatrixCreateFromCallback`.
* - Step 3: Call appropriate data setters in `next` functions.
*
* See test_iterative_dmatrix.cu or Python interface for examples.
*
* \param iter A handle to external data iterator.
* \param proxy A DMatrix proxy handle created by \ref XGProxyDMatrixCreate.
* \param ref Reference DMatrix for providing quantile information.
* \param reset Callback function resetting the iterator state.
* \param next Callback function yielding the next batch of data.
* \param config JSON encoded parameters for DMatrix construction. Accepted fields are:
* - missing: Which value to represent missing value
* - nthread (optional): Number of threads used for initializing DMatrix.
* - max_bin (optional): Maximum number of bins for building histogram.
* \param out The created Device Quantile DMatrix
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGQuantileDMatrixCreateFromCallback(DataIterHandle iter, DMatrixHandle proxy,
DataIterHandle ref, DataIterResetCallback *reset,
XGDMatrixCallbackNext *next, char const *config,
DMatrixHandle *out);
/*!
* \brief Create a Device Quantile DMatrix with data iterator.
* \deprecated since 1.7.0
* \see XGQuantileDMatrixCreateFromCallback()
*/
XGB_DLL int XGDeviceQuantileDMatrixCreateFromCallback(DataIterHandle iter, DMatrixHandle proxy,
DataIterResetCallback *reset,
XGDMatrixCallbackNext *next, float missing,
int nthread, int max_bin, DMatrixHandle *out);
/*!
* \brief Set data on a DMatrix proxy.
*
* \param handle A DMatrix proxy created by \ref XGProxyDMatrixCreate
* \param c_interface_str Null terminated JSON document string representation of CUDA
* array interface.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int
XGProxyDMatrixSetDataCudaArrayInterface(DMatrixHandle handle,
const char *c_interface_str);
/**
* @brief Set columnar (table) data on a DMatrix proxy.
*
* @param handle A DMatrix proxy created by @ref XGProxyDMatrixCreate
* @param c_interface_str See @ref XGBoosterPredictFromColumnar for details.
*
* @return 0 when success, -1 when failure happens
*/
XGB_DLL int XGProxyDMatrixSetDataColumnar(DMatrixHandle handle, char const *c_interface_str);
/*!
* \brief Set data on a DMatrix proxy.
*
* \param handle A DMatrix proxy created by \ref XGProxyDMatrixCreate
* \param c_interface_str Null terminated JSON document string representation of CUDA
* array interface, with an array of columns.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGProxyDMatrixSetDataCudaColumnar(DMatrixHandle handle,
const char *c_interface_str);
/*!
* \brief Set data on a DMatrix proxy.
*
* \param handle A DMatrix proxy created by \ref XGProxyDMatrixCreate
* \param c_interface_str Null terminated JSON document string representation of array
* interface.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGProxyDMatrixSetDataDense(DMatrixHandle handle,
char const *c_interface_str);
/*!
* \brief Set data on a DMatrix proxy.
*
* \param handle A DMatrix proxy created by \ref XGProxyDMatrixCreate
* \param indptr JSON encoded __array_interface__ to row pointer in CSR.
* \param indices JSON encoded __array_interface__ to column indices in CSR.
* \param data JSON encoded __array_interface__ to values in CSR..
* \param ncol The number of columns of input CSR matrix.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGProxyDMatrixSetDataCSR(DMatrixHandle handle, char const *indptr,
char const *indices, char const *data,
bst_ulong ncol);
/** @} */ // End of Streaming
/*!
* \brief create a new dmatrix from sliced content of existing matrix
* \param handle instance of data matrix to be sliced
* \param idxset index set
* \param len length of index set
* \param out a sliced new matrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixSliceDMatrix(DMatrixHandle handle,
const int *idxset,
bst_ulong len,
DMatrixHandle *out);
/*!
* \brief create a new dmatrix from sliced content of existing matrix
* \param handle instance of data matrix to be sliced
* \param idxset index set
* \param len length of index set
* \param out a sliced new matrix
* \param allow_groups allow slicing of an array with groups
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixSliceDMatrixEx(DMatrixHandle handle,
const int *idxset,
bst_ulong len,
DMatrixHandle *out,
int allow_groups);
/*!
* \brief free space in data matrix
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixFree(DMatrixHandle handle);
/**
* @example c-api-demo.c inference.c external_memory.c
*/
/*!
* \brief load a data matrix into binary file
* \param handle a instance of data matrix
* \param fname file name
* \param silent print statistics when saving
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixSaveBinary(DMatrixHandle handle,
const char *fname, int silent);
/*!
* \brief Set content in array interface to a content in info.
* \param handle a instance of data matrix
* \param field field name.
* \param c_interface_str JSON string representation of array interface.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixSetInfoFromInterface(DMatrixHandle handle,
char const* field,
char const* c_interface_str);
/*!
* \brief set float vector to a content in info
* \param handle a instance of data matrix
* \param field field name, can be label, weight
* \param array pointer to float vector
* \param len length of array
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixSetFloatInfo(DMatrixHandle handle, const char *field, const float *array,
bst_ulong len);
/**
* @deprecated since 2.1.0
*
* Use @ref XGDMatrixSetInfoFromInterface instead.
*/
XGB_DLL int XGDMatrixSetUIntInfo(DMatrixHandle handle, const char *field, const unsigned *array,
bst_ulong len);
/*!
* \brief Set string encoded information of all features.
*
* Accepted fields are:
* - feature_name
* - feature_type
*
* \param handle An instance of data matrix
* \param field Field name
* \param features Pointer to array of strings.
* \param size Size of `features` pointer (number of strings passed in).
*
* \return 0 when success, -1 when failure happens
*
* \code
*
* char const* feat_names [] {"feat_0", "feat_1"};
* XGDMatrixSetStrFeatureInfo(handle, "feature_name", feat_names, 2);
*
* // i for integer, q for quantitive, c for categorical. Similarly "int" and "float"
* // are also recognized.
* char const* feat_types [] {"i", "q"};
* XGDMatrixSetStrFeatureInfo(handle, "feature_type", feat_types, 2);
*
* \endcode
*/
XGB_DLL int XGDMatrixSetStrFeatureInfo(DMatrixHandle handle, const char *field,
const char **features,
const bst_ulong size);
/*!
* \brief Get string encoded information of all features.
*
* Accepted fields are:
* - feature_name
* - feature_type
*
* Caller is responsible for copying out the data, before next call to any API function of
* XGBoost.
*
* \param handle An instance of data matrix
* \param field Field name
* \param size Size of output pointer `features` (number of strings returned).
* \param out_features Address of a pointer to array of strings. Result is stored in
* thread local memory.
*
* \return 0 when success, -1 when failure happens
*
* \code
*
* char const **c_out_features = NULL;
* bst_ulong out_size = 0;
*
* // Asumming the feature names are already set by `XGDMatrixSetStrFeatureInfo`.
* XGDMatrixGetStrFeatureInfo(handle, "feature_name", &out_size,
* &c_out_features)
*
* for (bst_ulong i = 0; i < out_size; ++i) {
* // Here we are simply printing the string. Copy it out if the feature name is
* // useful after printing.
* printf("feature %lu: %s\n", i, c_out_features[i]);
* }
*
* \endcode
*/
XGB_DLL int XGDMatrixGetStrFeatureInfo(DMatrixHandle handle, const char *field,
bst_ulong *size,
const char ***out_features);
/**
* @deprecated since 2.1.0
*
* Use @ref XGDMatrixSetInfoFromInterface instead.
*/
XGB_DLL int XGDMatrixSetDenseInfo(DMatrixHandle handle, const char *field, void const *data,
bst_ulong size, int type);
/*!
* \brief get float info vector from matrix.
* \param handle a instance of data matrix
* \param field field name
* \param out_len used to set result length
* \param out_dptr pointer to the result
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixGetFloatInfo(const DMatrixHandle handle, const char *field, bst_ulong *out_len,
const float **out_dptr);
/**
* @example c-api-demo.c
*/
/*!
* \brief get uint32 info vector from matrix
* \param handle a instance of data matrix
* \param field field name
* \param out_len The length of the field.
* \param out_dptr pointer to the result
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixGetUIntInfo(const DMatrixHandle handle,
const char *field,
bst_ulong* out_len,
const unsigned **out_dptr);
/*!
* \brief get number of rows.
* \param handle the handle to the DMatrix
* \param out The address to hold number of rows.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixNumRow(DMatrixHandle handle, bst_ulong *out);
/*!
* \brief get number of columns
* \param handle the handle to the DMatrix
* \param out The output of number of columns
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixNumCol(DMatrixHandle handle, bst_ulong *out);
/*!
* \brief Get number of valid values from DMatrix.
*
* \param handle the handle to the DMatrix
* \param out The output of number of non-missing values
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixNumNonMissing(DMatrixHandle handle, bst_ulong *out);
/*!
* \brief Get the data split mode from DMatrix.
*
* \param handle the handle to the DMatrix
* \param out The output of the data split mode
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixDataSplitMode(DMatrixHandle handle, bst_ulong *out);
/**
* \brief Get the predictors from DMatrix as CSR matrix for testing. If this is a
* quantized DMatrix, quantized values are returned instead.
*
* Unlike most of XGBoost C functions, caller of `XGDMatrixGetDataAsCSR` is required to
* allocate the memory for return buffer instead of using thread local memory from
* XGBoost. This is to avoid allocating a huge memory buffer that can not be freed until
* exiting the thread.
*
* @since 1.7.0
*
* \param handle the handle to the DMatrix
* \param config JSON configuration string. At the moment it should be an empty document,
* preserved for future use.
* \param out_indptr indptr of output CSR matrix.
* \param out_indices Column index of output CSR matrix.
* \param out_data Data value of CSR matrix.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGDMatrixGetDataAsCSR(DMatrixHandle const handle, char const *config,
bst_ulong *out_indptr, unsigned *out_indices, float *out_data);
/**
* @brief Export the quantile cuts used for training histogram-based models like `hist` and
* `approx`. Useful for model compression.
*
* @since 2.0.0
*
* @param handle the handle to the DMatrix
* @param config JSON configuration string. At the moment it should be an empty document,
* preserved for future use.
*
* @param out_indptr indptr of output CSC matrix represented by a JSON encoded
* __(cuda_)array_interface__.
* @param out_data Data value of CSC matrix represented by a JSON encoded
* __(cuda_)array_interface__.
*/
XGB_DLL int XGDMatrixGetQuantileCut(DMatrixHandle const handle, char const *config,
char const **out_indptr, char const **out_data);
/** @} */ // End of DMatrix
/**
* @defgroup Booster Booster
*
* @brief The `Booster` class is the gradient-boosted model for XGBoost.
* @{
*/
/*!
* \brief create xgboost learner
* \param dmats matrices that are set to be cached
* \param len length of dmats
* \param out handle to the result booster
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterCreate(const DMatrixHandle dmats[], bst_ulong len, BoosterHandle *out);
/**
* @example c-api-demo.c
*/
/*!
* \brief free obj in handle
* \param handle handle to be freed
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterFree(BoosterHandle handle);
/**
* @example c-api-demo.c inference.c external_memory.c
*/
/*!
* \brief Slice a model using boosting index. The slice m:n indicates taking all trees
* that were fit during the boosting rounds m, (m+1), (m+2), ..., (n-1).
*
* \param handle Booster to be sliced.
* \param begin_layer start of the slice
* \param end_layer end of the slice; end_layer=0 is equivalent to
* end_layer=num_boost_round
* \param step step size of the slice
* \param out Sliced booster.
*
* \return 0 when success, -1 when failure happens, -2 when index is out of bound.
*/
XGB_DLL int XGBoosterSlice(BoosterHandle handle, int begin_layer,
int end_layer, int step,
BoosterHandle *out);
/*!
* \brief Get number of boosted rounds from gradient booster. When process_type is
* update, this number might drop due to removed tree.
* \param handle Handle to booster.
* \param out Pointer to output integer.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterBoostedRounds(BoosterHandle handle, int* out);
/*!
* \brief set parameters
* \param handle handle
* \param name parameter name
* \param value value of parameter
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterSetParam(BoosterHandle handle,
const char *name,
const char *value);
/**
* @example c-api-demo.c
*/
/*!
* \brief get number of features
* \param handle Handle to booster.
* \param out number of features
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterGetNumFeature(BoosterHandle handle, bst_ulong *out);
/**
* @example c-api-demo.c
*/
/*!
* \brief update the model in one round using dtrain
* \param handle handle
* \param iter current iteration rounds
* \param dtrain training data
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterUpdateOneIter(BoosterHandle handle, int iter, DMatrixHandle dtrain);
/**
* @example c-api-demo.c
*/
/**
* @deprecated since 2.1.0
*/
XGB_DLL int XGBoosterBoostOneIter(BoosterHandle handle, DMatrixHandle dtrain, float *grad,
float *hess, bst_ulong len);
/**
* @brief Update a model with gradient and Hessian. This is used for training with a
* custom objective function.
*
* @since 2.0.0
*
* @param handle handle
* @param dtrain The training data.
* @param iter The current iteration round. When training continuation is used, the count
* should restart.
* @param grad Json encoded __(cuda)_array_interface__ for gradient.
* @param hess Json encoded __(cuda)_array_interface__ for Hessian.
*
* @return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterTrainOneIter(BoosterHandle handle, DMatrixHandle dtrain, int iter,
char const *grad, char const *hess);
/*!
* \brief get evaluation statistics for xgboost
* \param handle handle
* \param iter current iteration rounds
* \param dmats pointers to data to be evaluated
* \param evnames pointers to names of each data
* \param len length of dmats
* \param out_result the string containing evaluation statistics
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterEvalOneIter(BoosterHandle handle, int iter, DMatrixHandle dmats[],
const char *evnames[], bst_ulong len, const char **out_result);
/**
* @example c-api-demo.c
*/
/**
* @defgroup Prediction Prediction
* @ingroup Booster
*
* @brief These functions are used for running prediction and explanation algorithms.
*
* @{
*/
/*!
* \brief make prediction based on dmat (deprecated, use \ref XGBoosterPredictFromDMatrix instead)
* \deprecated
* \see XGBoosterPredictFromDMatrix()
*
* \param handle handle
* \param dmat data matrix
* \param option_mask bit-mask of options taken in prediction, possible values
* 0:normal prediction
* 1:output margin instead of transformed value
* 2:output leaf index of trees instead of leaf value, note leaf index is unique per tree
* 4:output feature contributions to individual predictions
* \param ntree_limit limit number of trees used for prediction, this is only valid for boosted trees
* when the parameter is set to 0, we will use all the trees
* \param training Whether the prediction function is used as part of a training loop.
* Prediction can be run in 2 scenarios:
* 1. Given data matrix X, obtain prediction y_pred from the model.
* 2. Obtain the prediction for computing gradients. For example, DART booster performs dropout
* during training, and the prediction result will be different from the one obtained by normal
* inference step due to dropped trees.
* Set training=false for the first scenario. Set training=true for the second scenario.
* The second scenario applies when you are defining a custom objective function.
* \param out_len used to store length of returning result
* \param out_result used to set a pointer to array
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterPredict(BoosterHandle handle,
DMatrixHandle dmat,
int option_mask,
unsigned ntree_limit,
int training,
bst_ulong *out_len,
const float **out_result);
/*!
* \brief Make prediction from DMatrix, replacing \ref XGBoosterPredict.
*
* \param handle Booster handle
* \param dmat DMatrix handle
* \param config String encoded predict configuration in JSON format, with following
* available fields in the JSON object:
*
* "type": [0, 6]
* - 0: normal prediction
* - 1: output margin
* - 2: predict contribution
* - 3: predict approximated contribution
* - 4: predict feature interaction
* - 5: predict approximated feature interaction
* - 6: predict leaf
* "training": bool
* Whether the prediction function is used as part of a training loop. **Not used
* for inplace prediction**.
*
* Prediction can be run in 2 scenarios:
* 1. Given data matrix X, obtain prediction y_pred from the model.
* 2. Obtain the prediction for computing gradients. For example, DART booster performs dropout
* during training, and the prediction result will be different from the one obtained by normal
* inference step due to dropped trees.
* Set training=false for the first scenario. Set training=true for the second
* scenario. The second scenario applies when you are defining a custom objective
* function.
* "iteration_begin": int
* Beginning iteration of prediction.
* "iteration_end": int
* End iteration of prediction. Set to 0 this will become the size of tree model (all the trees).
* "strict_shape": bool
* Whether should we reshape the output with stricter rules. If set to true,
* normal/margin/contrib/interaction predict will output consistent shape
* disregarding the use of multi-class model, and leaf prediction will output 4-dim
* array representing: (n_samples, n_iterations, n_classes, n_trees_in_forest)
*
* Example JSON input for running a normal prediction with strict output shape, 2 dim
* for softprob , 1 dim for others.
* \code
* {
* "type": 0,
* "training": false,
* "iteration_begin": 0,
* "iteration_end": 0,
* "strict_shape": true
* }
* \endcode
*
* \param out_shape Shape of output prediction (copy before use).
* \param out_dim Dimension of output prediction.
* \param out_result Buffer storing prediction value (copy before use).
*
* \return 0 when success, -1 when failure happens
*
* \see XGBoosterPredictFromDense XGBoosterPredictFromCSR XGBoosterPredictFromCudaArray XGBoosterPredictFromCudaColumnar
*/
XGB_DLL int XGBoosterPredictFromDMatrix(BoosterHandle handle, DMatrixHandle dmat,
char const *config, bst_ulong const **out_shape,
bst_ulong *out_dim, float const **out_result);
/**
* @example inference.c
*/
/**
* \brief Inplace prediction from CPU dense matrix.
*
* \note If the booster is configured to run on a CUDA device, XGBoost falls back to run
* prediction with DMatrix with a performance warning.
*
* \param handle Booster handle.
* \param values JSON encoded __array_interface__ to values.
* \param config See \ref XGBoosterPredictFromDMatrix for more info.
* Additional fields for inplace prediction are:
* - "missing": float
* \param m An optional (NULL if not available) proxy DMatrix instance
* storing meta info.
*
* \param out_shape See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_dim See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_result See \ref XGBoosterPredictFromDMatrix for more info.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterPredictFromDense(BoosterHandle handle, char const *values, char const *config,
DMatrixHandle m, bst_ulong const **out_shape,
bst_ulong *out_dim, const float **out_result);
/**
* @example inference.c
*/
/**
* @brief Inplace prediction from CPU columnar data. (Table)
*
* @note If the booster is configured to run on a CUDA device, XGBoost falls back to run
* prediction with DMatrix with a performance warning.
*
* @param handle Booster handle.
* @param values An JSON array of __array_interface__ for each column.
* @param config See @ref XGBoosterPredictFromDMatrix for more info.
* Additional fields for inplace prediction are:
* - "missing": float
* @param m An optional (NULL if not available) proxy DMatrix instance
* storing meta info.
*
* @param out_shape See @ref XGBoosterPredictFromDMatrix for more info.
* @param out_dim See @ref XGBoosterPredictFromDMatrix for more info.
* @param out_result See @ref XGBoosterPredictFromDMatrix for more info.
*
* @return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterPredictFromColumnar(BoosterHandle handle, char const *array_interface,
char const *c_json_config, DMatrixHandle m,
bst_ulong const **out_shape, bst_ulong *out_dim,
const float **out_result);
/**
* \brief Inplace prediction from CPU CSR matrix.
*
* \note If the booster is configured to run on a CUDA device, XGBoost falls back to run
* prediction with DMatrix with a performance warning.
*
* \param handle Booster handle.
* \param indptr JSON encoded __array_interface__ to row pointer in CSR.
* \param indices JSON encoded __array_interface__ to column indices in CSR.
* \param values JSON encoded __array_interface__ to values in CSR..
* \param ncol Number of features in data.
* \param config See \ref XGBoosterPredictFromDMatrix for more info.
* Additional fields for inplace prediction are:
* - "missing": float
* \param m An optional (NULL if not available) proxy DMatrix instance
* storing meta info.
*
* \param out_shape See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_dim See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_result See \ref XGBoosterPredictFromDMatrix for more info.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterPredictFromCSR(BoosterHandle handle, char const *indptr, char const *indices,
char const *values, bst_ulong ncol, char const *config,
DMatrixHandle m, bst_ulong const **out_shape,
bst_ulong *out_dim, const float **out_result);
/**
* \brief Inplace prediction from CUDA Dense matrix (cupy in Python).
*
* \note If the booster is configured to run on a CPU, XGBoost falls back to run
* prediction with DMatrix with a performance warning.
*
* \param handle Booster handle
* \param values JSON encoded __cuda_array_interface__ to values.
* \param config See \ref XGBoosterPredictFromDMatrix for more info.
* Additional fields for inplace prediction are:
* - "missing": float
* \param m An optional (NULL if not available) proxy DMatrix instance
* storing meta info.
* \param out_shape See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_dim See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_result See \ref XGBoosterPredictFromDMatrix for more info.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterPredictFromCudaArray(BoosterHandle handle, char const *values,
char const *config, DMatrixHandle m,
bst_ulong const **out_shape, bst_ulong *out_dim,
const float **out_result);
/**
* \brief Inplace prediction from CUDA dense dataframe (cuDF in Python).
*
* \note If the booster is configured to run on a CPU, XGBoost falls back to run
* prediction with DMatrix with a performance warning.
*
* \param handle Booster handle
* \param values List of __cuda_array_interface__ for all columns encoded in JSON list.
* \param config See \ref XGBoosterPredictFromDMatrix for more info.
* Additional fields for inplace prediction are:
* - "missing": float
* \param m An optional (NULL if not available) proxy DMatrix instance
* storing meta info.
* \param out_shape See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_dim See \ref XGBoosterPredictFromDMatrix for more info.
* \param out_result See \ref XGBoosterPredictFromDMatrix for more info.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterPredictFromCudaColumnar(BoosterHandle handle, char const *values,
char const *config, DMatrixHandle m,
bst_ulong const **out_shape, bst_ulong *out_dim,
const float **out_result);
/**@}*/ // End of Prediction
/**
* @defgroup Serialization Serialization
* @ingroup Booster
*
* @brief There are multiple ways to serialize a Booster object depending on the use case.
*
* Short note for serialization APIs. There are 3 different sets of serialization API.
*
* - Functions with the term "Model" handles saving/loading XGBoost model like trees or
* linear weights. Striping out parameters configuration like training algorithms or
* CUDA device ID. These functions are designed to let users reuse the trained model
* for different tasks, examples are prediction, training continuation or model
* interpretation.
*
* - Functions with the term "Config" handles save/loading configuration. It helps user
* to study the internal of XGBoost. Also user can use the load method for specifying
* parameters in a structured way. These functions are introduced in 1.0.0, and are not
* yet stable.
*
* - Functions with the term "Serialization" are combined of above two. They are used in
* situations like check-pointing, or continuing training task in distributed
* environment. In these cases the task must be carried out without any user
* intervention.
*
* @{
*/
/*!
* \brief Load model from existing file
*
* \param handle handle
* \param fname File URI or file name. The string must be UTF-8 encoded.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterLoadModel(BoosterHandle handle,
const char *fname);
/*!
* \brief Save model into existing file
*
* \param handle handle
* \param fname File URI or file name. The string must be UTF-8 encoded.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterSaveModel(BoosterHandle handle,
const char *fname);
/*!
* \brief load model from in memory buffer
*
* \param handle handle
* \param buf pointer to the buffer
* \param len the length of the buffer
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterLoadModelFromBuffer(BoosterHandle handle,
const void *buf,
bst_ulong len);
/*!
* \brief Save model into raw bytes, return header of the array. User must copy the
* result out, before next xgboost call
*
* \param handle handle
* \param config JSON encoded string storing parameters for the function. Following
* keys are expected in the JSON document:
*
* "format": str
* - json: Output booster will be encoded as JSON.
* - ubj: Output booster will be encoded as Univeral binary JSON.
* - deprecated: Output booster will be encoded as old custom binary format. Do not use
* this format except for compatibility reasons.
*
* \param out_len The argument to hold the output length
* \param out_dptr The argument to hold the output data pointer
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterSaveModelToBuffer(BoosterHandle handle, char const *config, bst_ulong *out_len,
char const **out_dptr);
/*!
* \brief Memory snapshot based serialization method. Saves everything states
* into buffer.
*
* \param handle handle
* \param out_len the argument to hold the output length
* \param out_dptr the argument to hold the output data pointer
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterSerializeToBuffer(BoosterHandle handle, bst_ulong *out_len,
const char **out_dptr);
/*!
* \brief Memory snapshot based serialization method. Loads the buffer returned
* from \ref XGBoosterSerializeToBuffer.
*
* \param handle handle
* \param buf pointer to the buffer
* \param len the length of the buffer
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterUnserializeFromBuffer(BoosterHandle handle,
const void *buf, bst_ulong len);
/*!
* \brief Save XGBoost's internal configuration into a JSON document. Currently the
* support is experimental, function signature may change in the future without
* notice.
*
* \param handle handle to Booster object.
* \param out_len length of output string
* \param out_str A valid pointer to array of characters. The characters array is
* allocated and managed by XGBoost, while pointer to that array needs to
* be managed by caller.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterSaveJsonConfig(BoosterHandle handle, bst_ulong *out_len,
char const **out_str);
/*!
* \brief Load XGBoost's internal configuration from a JSON document. Currently the
* support is experimental, function signature may change in the future without
* notice.
*
* \param handle handle to Booster object.
* \param config string representation of a JSON document.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterLoadJsonConfig(BoosterHandle handle, char const *config);
/**@}*/ // End of Serialization
/*!
* \brief dump model, return array of strings representing model dump
* \param handle handle
* \param fmap name to fmap can be empty string
* \param with_stats whether to dump with statistics
* \param out_len length of output array
* \param out_dump_array pointer to hold representing dump of each model
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterDumpModel(BoosterHandle handle,
const char *fmap,
int with_stats,
bst_ulong *out_len,
const char ***out_dump_array);
/*!
* \brief dump model, return array of strings representing model dump
* \param handle handle
* \param fmap name to fmap can be empty string
* \param with_stats whether to dump with statistics
* \param format the format to dump the model in
* \param out_len length of output array
* \param out_dump_array pointer to hold representing dump of each model
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterDumpModelEx(BoosterHandle handle,
const char *fmap,
int with_stats,
const char *format,
bst_ulong *out_len,
const char ***out_dump_array);
/*!
* \brief dump model, return array of strings representing model dump
* \param handle handle
* \param fnum number of features
* \param fname names of features
* \param ftype types of features
* \param with_stats whether to dump with statistics
* \param out_len length of output array
* \param out_models pointer to hold representing dump of each model
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterDumpModelWithFeatures(BoosterHandle handle,
int fnum,
const char **fname,
const char **ftype,
int with_stats,
bst_ulong *out_len,
const char ***out_models);
/*!
* \brief dump model, return array of strings representing model dump
* \param handle handle
* \param fnum number of features
* \param fname names of features
* \param ftype types of features
* \param with_stats whether to dump with statistics
* \param format the format to dump the model in
* \param out_len length of output array
* \param out_models pointer to hold representing dump of each model
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterDumpModelExWithFeatures(BoosterHandle handle,
int fnum,
const char **fname,
const char **ftype,
int with_stats,
const char *format,
bst_ulong *out_len,
const char ***out_models);
/*!
* \brief Get string attribute from Booster.
* \param handle handle
* \param key The key of the attribute.
* \param out The result attribute, can be NULL if the attribute do not exist.
* \param success Whether the result is contained in out.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterGetAttr(BoosterHandle handle,
const char* key,
const char** out,
int *success);
/*!
* \brief Set or delete string attribute.
*
* \param handle handle
* \param key The key of the attribute.
* \param value The value to be saved.
* If nullptr, the attribute would be deleted.
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterSetAttr(BoosterHandle handle,
const char* key,
const char* value);
/*!
* \brief Get the names of all attribute from Booster.
* \param handle handle
* \param out_len the argument to hold the output length
* \param out pointer to hold the output attribute stings
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterGetAttrNames(BoosterHandle handle,
bst_ulong* out_len,
const char*** out);
/*!
* \brief Set string encoded feature info in Booster, similar to the feature
* info in DMatrix.
*
* Accepted fields are:
* - feature_name
* - feature_type
*
* \param handle An instance of Booster
* \param field Field name
* \param features Pointer to array of strings.
* \param size Size of `features` pointer (number of strings passed in).
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterSetStrFeatureInfo(BoosterHandle handle, const char *field,
const char **features,
const bst_ulong size);
/*!
* \brief Get string encoded feature info from Booster, similar to feature info
* in DMatrix.
*
* Accepted fields are:
* - feature_name
* - feature_type
*
* Caller is responsible for copying out the data, before next call to any API
* function of XGBoost.
*
* \param handle An instance of Booster
* \param field Field name
* \param len Size of output pointer `features` (number of strings returned).
* \param out_features Address of a pointer to array of strings. Result is stored in
* thread local memory.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterGetStrFeatureInfo(BoosterHandle handle, const char *field,
bst_ulong *len,
const char ***out_features);
/*!
* \brief Calculate feature scores for tree models. When used on linear model, only the
* `weight` importance type is defined, and output scores is a row major matrix with shape
* [n_features, n_classes] for multi-class model. For tree model, out_n_feature is always
* equal to out_n_scores and has multiple definitions of importance type.
*
* \param handle An instance of Booster
* \param config Parameters for computing scores encoded as JSON. Accepted JSON keys are:
* - importance_type: A JSON string with following possible values:
* * 'weight': the number of times a feature is used to split the data across all trees.
* * 'gain': the average gain across all splits the feature is used in.
* * 'cover': the average coverage across all splits the feature is used in.
* * 'total_gain': the total gain across all splits the feature is used in.
* * 'total_cover': the total coverage across all splits the feature is used in.
* - feature_map: An optional JSON string with URI or path to the feature map file.
* - feature_names: An optional JSON array with string names for each feature.
*
* \param out_n_features Length of output feature names.
* \param out_features An array of string as feature names, ordered the same as output scores.
* \param out_dim Dimension of output feature scores.
* \param out_shape Shape of output feature scores with length of `out_dim`.
* \param out_scores An array of floating point as feature scores with shape of `out_shape`.
*
* \return 0 when success, -1 when failure happens
*/
XGB_DLL int XGBoosterFeatureScore(BoosterHandle handle, const char *config,
bst_ulong *out_n_features, char const ***out_features,
bst_ulong *out_dim, bst_ulong const **out_shape,
float const **out_scores);
/**@}*/ // End of Booster
/**
* @defgroup Collective Collective
*
* @brief Experimental support for exposing internal communicator in XGBoost.
*
* @{
*/
/**
* @brief Handle to tracker.
*
* There are currently two types of tracker in XGBoost, first one is `rabit`, while the
* other one is `federated`.
*
* This is still under development.
*/
typedef void *TrackerHandle; /* NOLINT */
/**
* @brief Create a new tracker.
*
* @param config JSON encoded parameters.
*
* - dmlc_communicator: String, the type of tracker to create. Available options are `rabit`
* and `federated`.
* - n_workers: Integer, the number of workers.
* - port: (Optional) Integer, the port this tracker should listen to.
* - timeout: (Optional) Integer, timeout in seconds for various networking operations.
*
* Some configurations are `rabit` specific:
* - host: (Optional) String, Used by the the `rabit` tracker to specify the address of the host.
*
* Some `federated` specific configurations:
* - federated_secure: Boolean, whether this is a secure server.
* - server_key_path: Path to the server key. Used only if this is a secure server.
* - server_cert_path: Path to the server certificate. Used only if this is a secure server.
* - client_cert_path: Path to the client certificate. Used only if this is a secure server.
*
* @param handle The handle to the created tracker.
*
* @return 0 for success, -1 for failure.
*/
XGB_DLL int XGTrackerCreate(char const *config, TrackerHandle *handle);
/**
* @brief Get the arguments needed for running workers. This should be called after
* XGTrackerRun().
*
* @param handle The handle to the tracker.
* @param args The arguments returned as a JSON document.
*
* @return 0 for success, -1 for failure.
*/
XGB_DLL int XGTrackerWorkerArgs(TrackerHandle handle, char const **args);
/**
* @brief Start the tracker. The tracker runs in the background and this function returns
* once the tracker is started.
*
* @param handle The handle to the tracker.
* @param config Unused at the moment, preserved for the future.
*
* @return 0 for success, -1 for failure.
*/
XGB_DLL int XGTrackerRun(TrackerHandle handle, char const *config);
/**
* @brief Wait for the tracker to finish, should be called after XGTrackerRun(). This
* function will block until the tracker task is finished or timeout is reached.
*
* @param handle The handle to the tracker.
* @param config JSON encoded configuration. No argument is required yet, preserved for
* the future.
*
* @return 0 for success, -1 for failure.
*/
XGB_DLL int XGTrackerWaitFor(TrackerHandle handle, char const *config);
/**
* @brief Free a tracker instance. This should be called after XGTrackerWaitFor(). If the
* tracker is not properly waited, this function will shutdown all connections with
* the tracker, potentially leading to undefined behavior.
*
* @param handle The handle to the tracker.
*
* @return 0 for success, -1 for failure.
*/
XGB_DLL int XGTrackerFree(TrackerHandle handle);
/*!
* \brief Initialize the collective communicator.
*
* Currently the communicator API is experimental, function signatures may change in the future
* without notice.
*
* Call this once before using anything.
*
* The additional configuration is not required. Usually the communicator will detect settings
* from environment variables.
*
* \param config JSON encoded configuration. Accepted JSON keys are:
* - xgboost_communicator: The type of the communicator. Can be set as an environment variable.
* * rabit: Use Rabit. This is the default if the type is unspecified.
* * federated: Use the gRPC interface for Federated Learning.
* Only applicable to the Rabit communicator (these are case-sensitive):
* - rabit_tracker_uri: Hostname of the tracker.
* - rabit_tracker_port: Port number of the tracker.
* - rabit_task_id: ID of the current task, can be used to obtain deterministic rank assignment.
* - rabit_world_size: Total number of workers.
* - rabit_timeout: Enable timeout.
* - rabit_timeout_sec: Timeout in seconds.
* Only applicable to the Rabit communicator (these are case-sensitive, and can be set as
* environment variables):
* - DMLC_TRACKER_URI: Hostname of the tracker.
* - DMLC_TRACKER_PORT: Port number of the tracker.
* - DMLC_TASK_ID: ID of the current task, can be used to obtain deterministic rank assignment.
* - DMLC_WORKER_CONNECT_RETRY: Number of retries to connect to the tracker.
* - dmlc_nccl_path: The path to NCCL shared object. Only used if XGBoost is compiled with
* `USE_DLOPEN_NCCL`.
* Only applicable to the Federated communicator (use upper case for environment variables, use
* lower case for runtime configuration):
* - federated_server_address: Address of the federated server.
* - federated_world_size: Number of federated workers.
* - federated_rank: Rank of the current worker.
* - federated_server_cert: Server certificate file path. Only needed for the SSL mode.
* - federated_client_key: Client key file path. Only needed for the SSL mode.
* - federated_client_cert: Client certificate file path. Only needed for the SSL mode.
* \return 0 for success, -1 for failure.
*/
XGB_DLL int XGCommunicatorInit(char const* config);
/*!
* \brief Finalize the collective communicator.
*
* Call this function after you finished all jobs.
*
* \return 0 for success, -1 for failure.
*/
XGB_DLL int XGCommunicatorFinalize(void);
/*!
* \brief Get rank of current process.
*
* \return Rank of the worker.
*/
XGB_DLL int XGCommunicatorGetRank(void);
/*!
* \brief Get total number of processes.
*
* \return Total world size.
*/
XGB_DLL int XGCommunicatorGetWorldSize(void);
/*!
* \brief Get if the communicator is distributed.
*
* \return True if the communicator is distributed.
*/
XGB_DLL int XGCommunicatorIsDistributed(void);
/*!
* \brief Print the message to the communicator.
*
* This function can be used to communicate the information of the progress to the user who monitors
* the communicator.
*
* \param message The message to be printed.
* \return 0 for success, -1 for failure.
*/
XGB_DLL int XGCommunicatorPrint(char const *message);
/*!
* \brief Get the name of the processor.
*
* \param name_str Pointer to received returned processor name.
* \return 0 for success, -1 for failure.
*/
XGB_DLL int XGCommunicatorGetProcessorName(const char** name_str);
/*!
* \brief Broadcast a memory region to all others from root. This function is NOT thread-safe.
*
* Example:
* \code
* int a = 1;
* Broadcast(&a, sizeof(a), root);
* \endcode
*
* \param send_receive_buffer Pointer to the send or receive buffer.
* \param size Size of the data.
* \param root The process rank to broadcast from.
* \return 0 for success, -1 for failure.
*/
XGB_DLL int XGCommunicatorBroadcast(void *send_receive_buffer, size_t size, int root);
/*!
* \brief Perform in-place allreduce. This function is NOT thread-safe.
*
* Example Usage: the following code gives sum of the result
* \code
* vector<int> data(10);
* ...
* Allreduce(&data[0], data.size(), DataType:kInt32, Op::kSum);
* ...
* \endcode
* \param send_receive_buffer Buffer for both sending and receiving data.
* \param count Number of elements to be reduced.
* \param data_type Enumeration of data type, see xgboost::collective::DataType in communicator.h.
* \param op Enumeration of operation type, see xgboost::collective::Operation in communicator.h.
* \return 0 for success, -1 for failure.
*/
XGB_DLL int XGCommunicatorAllreduce(void *send_receive_buffer, size_t count, int data_type, int op);
/**@}*/ // End of Collective
#endif // XGBOOST_C_API_H_
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