Implement prediction and label reuse

vowpalwabbit/cache.cc

@@ -67,6 +67,7 @@ int read_cached_features(vw* all, v_array<example*>& examples)
   ae->sorted = all->p->sorted_cache;
   io_buf* input = all->p->input;
 
+  all->p->lp.default_label(ae->l);
   size_t total = all->p->lp.read_cached_label(all->p->_shared_data, ae->l, *input);
   if (total == 0)
     return 0;

vowpalwabbit/cb.cc

@@ -49,7 +49,7 @@ size_t read_cached_label(shared_data*, CB::label& ld, io_buf& cache)
 
 size_t read_cached_label(shared_data* s, polylabel& v, io_buf& cache)
 {
-  return CB::read_cached_label(s, v.init_as_cb(), cache);
+  return CB::read_cached_label(s, v.cb(), cache);
 }
 
 float weight(CB::label& ld) { return ld.weight; }
@@ -87,11 +87,12 @@ void default_label(CB::label& ld)
 
 void default_label(polylabel& v)
 {
-  if (v.get_type() != label_type_t::unset)
+  if (v.get_type() != label_type_t::cb)
   {
     v.reset();
+    v.init_as_cb();
   }
-  CB::default_label(v.init_as_cb());
+  CB::default_label(v.cb());
 }
 
 bool test_label(CB::label& ld)
@@ -256,11 +257,13 @@ void cache_label(polylabel& v, io_buf& cache)
 
 void default_label(polylabel& v)
 {
-  if (v.get_type() != label_type_t::unset)
+  if (v.get_type() != label_type_t::cb_eval)
   {
     v.reset();
+    v.init_as_cb_eval();
+
   }
-  auto& ld = v.init_as_cb_eval();
+  auto& ld = v.cb_eval();
   CB::default_label(ld.event);
   ld.action = 0;
 }

vowpalwabbit/ccb_label.cc

@@ -168,11 +168,13 @@ void cache_label(polylabel& v, io_buf& cache)
 
 void default_label(polylabel& v)
 {
-  if (v.get_type() != label_type_t::unset)
+  if (v.get_type() != label_type_t::conditional_contextual_bandit)
   {
     v.reset();
+    v.init_as_ccb();
+
   }
-  CCB::label& ld = v.init_as_conditional_contextual_bandit();
+  CCB::label& ld = v.ccb();
 
   // This is tested against nullptr, so unfortunately as things are this must be deleted when not used.
   if (ld.outcome)

vowpalwabbit/conditional_contextual_bandit.cc

@@ -459,7 +459,7 @@ void learn_or_predict(ccb& data, multi_learner& base, multi_ex& examples)
   // Restore ccb labels to the example objects.
   for (size_t i = 0; i < examples.size(); i++)
   {
-    examples[i]->l.init_as_conditional_contextual_bandit(std::move(data.stored_labels[i]));
+    examples[i]->l.init_as_ccb(std::move(data.stored_labels[i]));
   }
   data.stored_labels.clear();
 

vowpalwabbit/cost_sensitive.cc

@@ -54,7 +54,7 @@ char* bufread_label(label& ld, char* c, io_buf& cache)
 
 size_t read_cached_label(shared_data*, polylabel& v, io_buf& cache)
 {
-  auto& ld = v.init_as_cs();
+  auto& ld = v.cs();
 
   ld.costs.clear();
   char* c;
@@ -92,11 +92,13 @@ void default_label(label& label) { label.costs.clear(); }
 
 void default_label(polylabel& v)
 {
-  if (v.get_type() != label_type_t::unset)
+  if (v.get_type() != label_type_t::cs)
   {
     v.reset();
+    v.init_as_cs();
   }
-  auto& ld = v.init_as_cs();
+
+  auto& ld = v.cs();
   default_label(ld);
 }
 

vowpalwabbit/label.h

@@ -145,7 +145,7 @@ struct polylabel
         init_as_cb(other._cb);
         break;
       case (label_type_t::conditional_contextual_bandit):
-        init_as_conditional_contextual_bandit(other._conditional_contextual_bandit);
+        init_as_ccb(other._conditional_contextual_bandit);
         break;
       case (label_type_t::cb_eval):
         init_as_cb_eval(other._cb_eval);
@@ -179,7 +179,7 @@ struct polylabel
         init_as_cb(std::move(other._cb));
         break;
       case (label_type_t::conditional_contextual_bandit):
-        init_as_conditional_contextual_bandit(std::move(other._conditional_contextual_bandit));
+        init_as_ccb(std::move(other._conditional_contextual_bandit));
         break;
       case (label_type_t::cb_eval):
         init_as_cb_eval(std::move(other._cb_eval));
@@ -228,7 +228,7 @@ struct polylabel
     {
       case (label_type_t::unset):
         // Nothing to do! Whatever was in here has already been destroyed.
-        break;
+        return;
       case (label_type_t::empty):
         destruct(_empty);
         break;
@@ -364,7 +364,7 @@ struct polylabel
   }
 
   template <typename... Args>
-  CCB::label& init_as_conditional_contextual_bandit(Args&&... args)
+  CCB::label& init_as_ccb(Args&&... args)
   {
     ensure_is_type(label_type_t::unset);
     new (&_conditional_contextual_bandit) CCB::label(std::forward<Args>(args)...);

vowpalwabbit/multiclass.cc

@@ -22,7 +22,7 @@ char* bufread_label(label_t& ld, char* c)
 
 size_t read_cached_label(shared_data*, polylabel& v, io_buf& cache)
 {
-  auto& ld = v.init_as_multi();
+  auto& ld = v.multi();
   char* c;
   size_t total = sizeof(ld.label) + sizeof(ld.weight);
   if (cache.buf_read(c, total) < total)
@@ -57,11 +57,12 @@ void cache_label(polylabel& v, io_buf& cache)
 
 void default_label(polylabel& v)
 {
-  if (v.get_type() != label_type_t::unset)
+  if (v.get_type() != label_type_t::multi)
   {
     v.reset();
+    v.init_as_multi();
   }
-  auto& ld = v.init_as_multi();
+  auto& ld = v.multi();
   ld.label = (uint32_t)-1;
   ld.weight = 1.;
 }

vowpalwabbit/multilabel.cc

@@ -31,7 +31,7 @@ char* bufread_label(labels& ld, char* c, io_buf& cache)
 
 size_t read_cached_label(shared_data*, polylabel& v, io_buf& cache)
 {
-  auto& ld = v.init_as_multilabels();
+  auto& ld = v.multilabels();
   ld.label_v.clear();
   char* c;
   size_t total = sizeof(size_t);
@@ -66,11 +66,12 @@ void cache_label(polylabel& v, io_buf& cache)
 
 void default_label(polylabel& v)
 {
-  if (v.get_type() != label_type_t::unset)
+  if (v.get_type() != label_type_t::multilabels)
   {
     v.reset();
+    v.init_as_multilabels();
   }
-  auto& ld = v.init_as_multilabels();
+  auto& ld = v.multilabels();
   ld.label_v.clear();
 }
 

vowpalwabbit/no_label.cc

@@ -32,7 +32,7 @@ void cache_no_label(polylabel&, io_buf&) {}
 // This is wasted work, ideally empty and unset should be the same thing.
 void default_no_label(polylabel& label)
 {
-  if (label.get_type() != label_type_t::empty)
+  if (label.get_type() != label_type_t::empty && label.get_type() != label_type_t::empty)
   {
     label.reset();
     label.init_as_empty();

vowpalwabbit/parser.cc

@@ -749,8 +749,9 @@ void setup_example(vw& all, example* ae)
   ae->total_sum_feat_sq += new_features_sum_feat_sq;
 
   // Prediction type should be preinitialized for the given reductions expected type.
-  if(ae->pred.get_type() == prediction_type_t::unset)
+  if(ae->pred.get_type() != all.l->pred_type)
   {
+    ae->pred.reset();
     switch (all.l->pred_type)
     {
       case (prediction_type_t::scalar):
@@ -895,10 +896,6 @@ void empty_example(vw& /*all*/, example& ec)
   for (features& fs : ec)
     fs.clear();
 
-  // TODO - This is inefficient as we are losing allocated buffers. Once tests are passing this should be removed.
-  ec.l.reset();
-  ec.pred.reset();
-
   ec.indices.clear();
   ec.tag.clear();
   ec.sorted = false;

vowpalwabbit/prediction.h

@@ -231,7 +231,7 @@ struct polyprediction
     {
       case (prediction_type_t::unset):
         // Nothing to do! Whatever was in here has already been destroyed.
-        break;
+        return;
       case (prediction_type_t::scalar):
         destruct(_scalar);
         break;

vowpalwabbit/simple_label.cc

@@ -29,7 +29,7 @@ char* bufread_simple_label(shared_data* sd, label_data& ld, char* c)
 
 size_t read_cached_simple_label(shared_data* sd, polylabel& in_ld, io_buf& cache)
 {
-  auto& ld = in_ld.init_as_simple();
+  auto& ld = in_ld.simple();
   char* c;
   size_t total = sizeof(ld.label) + sizeof(ld.weight) + sizeof(ld.initial);
   if (cache.buf_read(c, total) < total)