Avoid including c_api.h in header files. (#5782)

src/data/adapter.h

@@ -18,8 +18,8 @@
 #include "xgboost/base.h"
 #include "xgboost/data.h"
 #include "xgboost/span.h"
-#include "xgboost/c_api.h"
 
+#include "array_interface.h"
 #include "../c_api/c_api_error.h"
 
 namespace xgboost {
@@ -496,6 +496,7 @@ class FileAdapter : dmlc::DataIter<FileAdapterBatch> {
 
 /*! \brief Data iterator that takes callback to return data, used in JVM package for
  *  accepting data iterator. */
+template <typename DataIterHandle, typename XGBCallbackDataIterNext, typename XGBoostBatchCSR>
 class IteratorAdapter : public dmlc::DataIter<FileAdapterBatch> {
  public:
   IteratorAdapter(DataIterHandle data_handle,

src/data/data.cc

@@ -7,6 +7,7 @@
 
 #include "dmlc/io.h"
 #include "xgboost/data.h"
+#include "xgboost/c_api.h"
 #include "xgboost/host_device_vector.h"
 #include "xgboost/logging.h"
 #include "xgboost/version_config.h"
@@ -533,7 +534,7 @@ DMatrix* DMatrix::Load(const std::string& uri,
 
 template <typename AdapterT>
 DMatrix* DMatrix::Create(AdapterT* adapter, float missing, int nthread,
-                         const std::string& cache_prefix,  size_t page_size ) {
+                         const std::string& cache_prefix,  size_t page_size) {
   if (cache_prefix.length() == 0) {
     // Data split mode is fixed to be row right now.
     return new data::SimpleDMatrix(adapter, missing, nthread);
@@ -563,9 +564,11 @@ template DMatrix* DMatrix::Create<data::DataTableAdapter>(
 template DMatrix* DMatrix::Create<data::FileAdapter>(
     data::FileAdapter* adapter, float missing, int nthread,
     const std::string& cache_prefix, size_t page_size);
-template DMatrix* DMatrix::Create<data::IteratorAdapter>(
-    data::IteratorAdapter* adapter, float missing, int nthread,
-    const std::string& cache_prefix, size_t page_size);
+template DMatrix *
+DMatrix::Create(data::IteratorAdapter<DataIterHandle, XGBCallbackDataIterNext,
+                                      XGBoostBatchCSR> *adapter,
+                float missing, int nthread, const std::string &cache_prefix,
+                size_t page_size);
 
 SparsePage SparsePage::GetTranspose(int num_columns) const {
   SparsePage transpose;

src/data/data.cu

@@ -10,7 +10,7 @@
 #include "array_interface.h"
 #include "../common/device_helpers.cuh"
 #include "device_adapter.cuh"
-#include "device_dmatrix.h"
+#include "simple_dmatrix.h"
 
 namespace xgboost {
 

src/data/simple_dmatrix.cc

@@ -4,8 +4,14 @@
  * \brief the input data structure for gradient boosting
  * \author Tianqi Chen
  */
-#include "./simple_dmatrix.h"
-#include <xgboost/data.h>
+#include <vector>
+#include <limits>
+#include <algorithm>
+
+#include "xgboost/data.h"
+#include "xgboost/c_api.h"
+
+#include "simple_dmatrix.h"
 #include "./simple_batch_iterator.h"
 #include "../common/random.h"
 #include "adapter.h"
@@ -195,7 +201,9 @@ template SimpleDMatrix::SimpleDMatrix(DataTableAdapter* adapter, float missing,
                                      int nthread);
 template SimpleDMatrix::SimpleDMatrix(FileAdapter* adapter, float missing,
                                      int nthread);
-template SimpleDMatrix::SimpleDMatrix(IteratorAdapter* adapter, float missing,
-                                     int nthread);
+template SimpleDMatrix::SimpleDMatrix(
+    IteratorAdapter<DataIterHandle, XGBCallbackDataIterNext, XGBoostBatchCSR>
+        *adapter,
+    float missing, int nthread);
 }  // namespace data
 }  // namespace xgboost