refactor: migrate stagewise_poly to builder

vowpalwabbit/stagewise_poly.cc

@@ -8,6 +8,7 @@
 
 #include "gd.h"
 #include "accumulate.h"
+#include "label_parser.h"
 #include "reductions.h"
 #include "vw.h"
 #include "vw_allreduce.h"
@@ -34,34 +35,34 @@ struct sort_data
 
 struct stagewise_poly
 {
-  vw *all;  // many uses, unmodular reduction
+  vw* all = nullptr;  // many uses, unmodular reduction
 
-  float sched_exponent;
-  uint32_t batch_sz;
-  bool batch_sz_double;
+  float sched_exponent = 0.f;
+  uint32_t batch_sz = 0;
+  bool batch_sz_double = false;
 
-  sort_data *sd;
-  size_t sd_len;
-  uint8_t *depthsbits;  // interleaved array storing depth information and parent/cycle bits
+  sort_data* sd = nullptr;
+  size_t sd_len = 0;
+  uint8_t* depthsbits = nullptr;  // interleaved array storing depth information and parent/cycle bits
 
-  uint64_t sum_sparsity;        // of synthetic example
-  uint64_t sum_input_sparsity;  // of input example
-  uint64_t num_examples;
+  uint64_t sum_sparsity = 0;        // of synthetic example
+  uint64_t sum_input_sparsity = 0;  // of input example
+  uint64_t num_examples = 0;
   // following three are for parallel (see end_pass())
-  uint64_t sum_sparsity_sync;
-  uint64_t sum_input_sparsity_sync;
-  uint64_t num_examples_sync;
+  uint64_t sum_sparsity_sync = 0;
+  uint64_t sum_input_sparsity_sync = 0;
+  uint64_t num_examples_sync = 0;
 
   example synth_ec;
   // following is bookkeeping in synth_ec creation (dfs)
-  feature synth_rec_f;
-  example *original_ec;
-  uint32_t cur_depth;
-  bool training;
-  uint64_t last_example_counter;
-  size_t numpasses;
-  uint32_t next_batch_sz;
-  bool update_support;
+  feature synth_rec_f{0.f, 0};
+  example* original_ec = nullptr;
+  uint32_t cur_depth = 0;
+  bool training = false;
+  uint64_t last_example_counter = 0;
+  size_t numpasses = 0;
+  uint32_t next_batch_sz = 0;
+  bool update_support = false;
 
 #ifdef DEBUG
   uint32_t max_depth;
@@ -655,7 +656,7 @@ base_learner* stagewise_poly_setup(VW::setup_base_i& stack_builder)
 {
   options_i& options = *stack_builder.get_options();
   vw& all = *stack_builder.get_all_pointer();
-  auto poly = scoped_calloc_or_throw<stagewise_poly>();
+  auto poly = VW::make_unique<stagewise_poly>();
   bool stage_poly = false;
   option_group_definition new_options("Stagewise polynomial options");
   new_options
@@ -675,8 +676,8 @@ base_learner* stagewise_poly_setup(VW::setup_base_i& stack_builder)
   if (!options.add_parse_and_check_necessary(new_options)) return nullptr;
 
   poly->all = &all;
-  depthsbits_create(*poly.get());
-  sort_data_create(*poly.get());
+  depthsbits_create(*poly);
+  sort_data_create(*poly);
 
   poly->batch_sz_double = !poly->batch_sz_double;
 
@@ -692,12 +693,14 @@ base_learner* stagewise_poly_setup(VW::setup_base_i& stack_builder)
   poly->original_ec = nullptr;
   poly->next_batch_sz = poly->batch_sz;
 
-  learner<stagewise_poly, example>& l = init_learner(poly, as_singleline(stack_builder.setup_base_learner()), learn,
-      predict, stack_builder.get_setupfn_name(stagewise_poly_setup));
+  auto* l = VW::LEARNER::make_reduction_learner(std::move(poly), as_singleline(stack_builder.setup_base_learner()),
+      learn, predict, stack_builder.get_setupfn_name(stagewise_poly_setup))
+                .set_label_type(label_type_t::simple)
+                .set_prediction_type(prediction_type_t::scalar)
+                .set_save_load(save_load)
+                .set_finish_example(finish_example)
+                .set_end_pass(end_pass)
+                .build();
 
-  l.set_save_load(save_load);
-  l.set_finish_example(finish_example);
-  l.set_end_pass(end_pass);
-
-  return make_base(l);
+  return make_base(*l);
 }