Config for linear updaters. (#5222)

tests/cpp/linear/test_json_io.h

@@ -0,0 +1,41 @@
+/*!
+ * Copyright 2020 XGBoost contributors
+ */
+#ifndef XGBOOST_TEST_JSON_IO_H_
+#define XGBOOST_TEST_JSON_IO_H_
+
+#include <xgboost/linear_updater.h>
+#include <xgboost/json.h>
+#include <string>
+#include "../helpers.h"
+#include "../../../src/gbm/gblinear_model.h"
+
+namespace xgboost {
+inline void TestUpdaterJsonIO(std::string updater_str) {
+  auto runtime = xgboost::CreateEmptyGenericParam(GPUIDX);
+  Json config_0 {Object() };
+
+  {
+    auto updater = std::unique_ptr<xgboost::LinearUpdater>(
+        xgboost::LinearUpdater::Create(updater_str, &runtime));
+    updater->Configure({{"eta", std::to_string(3.14)}});
+    updater->SaveConfig(&config_0);
+  }
+
+  {
+    auto updater = std::unique_ptr<xgboost::LinearUpdater>(
+        xgboost::LinearUpdater::Create(updater_str, &runtime));
+    updater->LoadConfig(config_0);
+    Json config_1 { Object() };
+    updater->SaveConfig(&config_1);
+
+    ASSERT_EQ(config_0, config_1);
+    auto eta = atof(get<String const>(config_1["linear_train_param"]["eta"]).c_str());
+    ASSERT_NEAR(eta, 3.14, kRtEps);
+  }
+
+}
+
+}  // namespace xgboost
+
+#endif  // XGBOOST_TEST_JSON_IO_H_

tests/cpp/linear/test_linear.cc

@@ -5,12 +5,13 @@
 #include <xgboost/gbm.h>
 
 #include "../helpers.h"
-
+#include "test_json_io.h"
 #include "../../../src/gbm/gblinear_model.h"
+#include "xgboost/base.h"
 
 namespace xgboost {
 
-TEST(Linear, shotgun) {
+TEST(Linear, Shotgun) {
   size_t constexpr kRows = 10;
   size_t constexpr kCols = 10;
 
@@ -45,6 +46,10 @@ TEST(Linear, shotgun) {
   delete pp_dmat;
 }
 
+TEST(Shotgun, JsonIO) {
+  TestUpdaterJsonIO("shotgun");
+}
+
 TEST(Linear, coordinate) {
   size_t constexpr kRows = 10;
   size_t constexpr kCols = 10;
@@ -72,4 +77,8 @@ TEST(Linear, coordinate) {
   delete pp_dmat;
 }
 
+TEST(Coordinate, JsonIO){
+  TestUpdaterJsonIO("coord_descent");
+}
+
 }  // namespace xgboost

tests/cpp/linear/test_linear.cu

@@ -3,6 +3,7 @@
 #include <xgboost/gbm.h>
 
 #include "../helpers.h"
+#include "test_json_io.h"
 #include "../../../src/gbm/gblinear_model.h"
 
 namespace xgboost {
@@ -33,4 +34,8 @@ TEST(Linear, GPUCoordinate) {
 
   delete mat;
 }
+
+TEST(GPUCoordinate, JsonIO) {
+  TestUpdaterJsonIO("gpu_coord_descent");
+}
 }  // namespace xgboost