From 2a6f58a5a4ec834b199b5ee16487afbe57444f48 Mon Sep 17 00:00:00 2001
From: Jack Gerrits <jack@jackgerrits.com>
Date: Wed, 7 Apr 2021 11:39:36 -0400
Subject: [PATCH] MIgrate bfgs to new style

---
 vowpalwabbit/bfgs.cc   | 86 +++++++++++++++++++++++-------------------
 vowpalwabbit/learner.h |  8 ++--
 2 files changed, 51 insertions(+), 43 deletions(-)

diff --git a/vowpalwabbit/bfgs.cc b/vowpalwabbit/bfgs.cc
index 1efb3bbed7b..2fca2a1943a 100644
--- a/vowpalwabbit/bfgs.cc
+++ b/vowpalwabbit/bfgs.cc
@@ -61,47 +61,49 @@ constexpr float max_precond_ratio = 10000.f;
 
 struct bfgs
 {
-  vw* all;  // prediction, regressor
-  int m;
-  float rel_threshold;  // termination threshold
+  vw* all = nullptr;  // prediction, regressor
+  int m = 0;
+  float rel_threshold = 0.f;  // termination threshold
 
-  double wolfe1_bound;
+  double wolfe1_bound = 0.0;
 
-  size_t final_pass;
+  size_t final_pass = 0;
 
   std::chrono::time_point<std::chrono::system_clock> t_start_global;
   std::chrono::time_point<std::chrono::system_clock> t_end_global;
-  double net_time;
+  double net_time = 0.0;
 
   v_array<float> predictions;
-  size_t example_number;
-  size_t current_pass;
-  size_t no_win_counter;
-  size_t early_stop_thres;
+  size_t example_number = 0;
+  size_t current_pass = 0;
+  size_t no_win_counter = 0;
+  size_t early_stop_thres = 0;
 
   // default transition behavior
-  bool first_hessian_on;
-  bool backstep_on;
+  bool first_hessian_on = false;
+  bool backstep_on = false;
 
   // set by initializer
-  int mem_stride;
-  bool output_regularizer;
-  float* mem;
-  double* rho;
-  double* alpha;
+  int mem_stride = 0;
+  bool output_regularizer = false;
+  float* mem = nullptr;
+  double* rho = nullptr;
+  double* alpha = nullptr;
 
-  weight* regularizers;
+  weight* regularizers = nullptr;
   // the below needs to be included when resetting, in addition to preconditioner and derivative
-  int lastj, origin;
-  double loss_sum, previous_loss_sum;
-  float step_size;
-  double importance_weight_sum;
-  double curvature;
+  int lastj = 0;
+  int origin = 0;
+  double loss_sum = 0.0;
+  double previous_loss_sum = 0.0;
+  float step_size = 0.f;
+  double importance_weight_sum = 0.0;
+  double curvature = 0.0;
 
   // first pass specification
-  bool first_pass;
-  bool gradient_pass;
-  bool preconditioner_pass;
+  bool first_pass = false;
+  bool gradient_pass = false;
+  bool preconditioner_pass = false;
 
   ~bfgs()
   {
@@ -1053,7 +1055,7 @@ void init_driver(bfgs& b) { b.backstep_on = true; }
 
 base_learner* bfgs_setup(options_i& options, vw& all)
 {
-  auto b = scoped_calloc_or_throw<bfgs>();
+  auto b = VW::make_unique<bfgs>();
   bool conjugate_gradient = false;
   bool bfgs_option = false;
   option_group_definition bfgs_outer_options("Conjugate Gradient options");
@@ -1109,20 +1111,26 @@ base_learner* bfgs_setup(options_i& options, vw& all)
   all.weights.stride_shift(2);
 
   void (*learn_ptr)(bfgs&, base_learner&, example&) = nullptr;
-  if (all.audit)
+  void (*predict_ptr)(bfgs&, base_learner&, example&) = nullptr;
+  std::string learner_name;
+  if (all.audit || all.hash_inv)
+  {
     learn_ptr = learn<true>;
+    predict_ptr = predict<true>;
+    learner_name = all.get_setupfn_name(bfgs_setup) + "-audit";
+  }
   else
+  {
     learn_ptr = learn<false>;
+    predict_ptr = predict<false>;
+    learner_name = all.get_setupfn_name(bfgs_setup);
+  }
 
-  learner<bfgs, example>* l;
-  if (all.audit || all.hash_inv)
-    l = &init_learner(b, learn_ptr, predict<true>, all.weights.stride(), all.get_setupfn_name(bfgs_setup) + "-audit");
-  else
-    l = &init_learner(b, learn_ptr, predict<false>, all.weights.stride(), all.get_setupfn_name(bfgs_setup));
-
-  l->set_save_load(save_load);
-  l->set_init_driver(init_driver);
-  l->set_end_pass(end_pass);
-
-  return make_base(*l);
+  return make_base(*make_base_learner(
+      std::move(b), learn_ptr, predict_ptr, learner_name, prediction_type_t::scalar, label_type_t::simple)
+                        .set_params_per_weight(all.weights.stride())
+                        .set_save_load(save_load)
+                        .set_init_driver(init_driver)
+                        .set_end_pass(end_pass)
+                        .build());
 }
diff --git a/vowpalwabbit/learner.h b/vowpalwabbit/learner.h
index b2612fb38eb..4b7d0f4e00e 100644
--- a/vowpalwabbit/learner.h
+++ b/vowpalwabbit/learner.h
@@ -764,25 +764,25 @@ struct common_learner_builder
 
   FluentBuilderT& set_finish(void (*fn_ptr)(DataT&))
   {
-    _learner->finisher_fd = func_data(_learner->learn_fd.data, _learner->learn_fd.base, (finish_fptr_type)(fn_ptr));
+    _learner->finisher_fd = tuple_dbf(_learner->learn_fd.data, _learner->learn_fd.base, (finish_fptr_type)(fn_ptr));
     return *static_cast<FluentBuilderT*>(this);
   }
 
   FluentBuilderT& set_end_pass(void (*fn_ptr)(DataT&))
   {
-    _learner->end_pass_fd = func_data(_learner->learn_fd.data, _learner->learn_fd.base, (func_data::fn)fn_ptr);
+    _learner->end_pass_fd = tuple_dbf(_learner->learn_fd.data, _learner->learn_fd.base, (func_data::fn)fn_ptr);
     return *static_cast<FluentBuilderT*>(this);
   }
 
   FluentBuilderT& set_end_examples(void (*fn_ptr)(DataT&))
   {
-    _learner->end_examples_fd = func_data(_learner->learn_fd.data, _learner->learn_fd.base, (func_data::fn)fn_ptr);
+    _learner->end_examples_fd = tuple_dbf(_learner->learn_fd.data, _learner->learn_fd.base, (func_data::fn)fn_ptr);
     return *static_cast<FluentBuilderT*>(this);
   }
 
   FluentBuilderT& set_init_driver(void (*fn_ptr)(DataT&))
   {
-    _learner->init_fd = func_data(_learner->learn_fd.data, _learner->learn_fd.base, (func_data::fn)fn_ptr);
+    _learner->init_fd = tuple_dbf(_learner->learn_fd.data, _learner->learn_fd.base, (func_data::fn)fn_ptr);
     return *static_cast<FluentBuilderT*>(this);
   }