Add cyclic mode to the sfen reader. Make sfen reader take all files at construction

src/learn/learn.cpp

@@ -381,9 +381,13 @@ namespace Learner
         // move match rate, simple comparison is not possible...
         static constexpr uint64_t sfen_for_mse_size = 2000;
 
-        LearnerThink(uint64_t thread_num, const std::string& seed) :
+        LearnerThink(
+            const std::vector<std::string>& filenames,
+            uint64_t thread_num,
+            const std::string& seed
+        ) :
             prng(seed),
-            sr(thread_num, std::to_string(prng.next_random_seed())),
+            sr(filenames, SfenReaderMode::Sequential, thread_num, std::to_string(prng.next_random_seed())),
             learn_loss_sum{}
         {
             save_only_once = false;
@@ -404,11 +408,6 @@ namespace Learner
             sr.set_do_shuffle(v);
         }
 
-        void add_file(const std::string& filename)
-        {
-            sr.add_file(filename);
-        }
-
         void learn();
 
 
@@ -1095,11 +1094,26 @@ namespace Learner
 
         // Right now we only have the individual files.
         // We need to apply base_dir here
-        rebase_files(filenames, base_dir);
         if (!target_dir.empty())
         {
             append_files_from_dir(filenames, base_dir, target_dir);
         }
+        rebase_files(filenames, base_dir);
+
+        // Insert the file name for the number of loops.
+        {
+            std::vector<std::string> filenamesTimesLoop;
+
+            for (int i = 0; i < loop; ++i)
+            {
+                for(auto& file : filenames)
+                {
+                    filenamesTimesLoop.emplace_back(file);
+                }
+            }
+
+            filenames = std::move(filenamesTimesLoop);
+        }
 
         cout << "learn from ";
         for (auto s : filenames)
@@ -1154,8 +1168,6 @@ namespace Learner
 
         cout << "init.." << endl;
 
-        LearnerThink learn_think(thread_num, seed);
-
         Threads.main()->ponder = false;
 
         set_learning_search_limits();
@@ -1164,6 +1176,9 @@ namespace Learner
         Eval::NNUE::initialize_training(seed);
         Eval::NNUE::set_batch_size(nn_batch_size);
         Eval::NNUE::set_options(nn_options);
+
+        LearnerThink learn_think(filenames, thread_num, seed);
+
         if (newbob_decay != 1.0 && !Options["SkipLoadingEval"]) {
             // Save the current net to [EvalSaveDir]\original.
             Eval::NNUE::save_eval("original");
@@ -1190,15 +1205,6 @@ namespace Learner
         learn_think.mini_batch_size = mini_batch_size;
         learn_think.validation_set_file_name = validation_set_file_name;
 
-        // Insert the file name for the number of loops.
-        for (int i = 0; i < loop; ++i)
-        {
-            for(auto& file : filenames)
-            {
-                learn_think.add_file(Path::combine(base_dir, file));
-            }
-        }
-
         cout << "init done." << endl;
 
         // Start learning.

src/learn/sfen_reader.h

@@ -18,6 +18,12 @@
 
 namespace Learner{
 
+    enum struct SfenReaderMode
+    {
+        Sequential,
+        Cyclic
+    };
+
     // Sfen reader
     struct SfenReader
     {
@@ -32,7 +38,14 @@ namespace Learner{
 
         // Do not use std::random_device().
         // Because it always the same integers on MinGW.
-        SfenReader(int thread_num, const std::string& seed) :
+        SfenReader(
+            const std::vector<std::string>& filenames_,
+            SfenReaderMode mode_,
+            int thread_num,
+            const std::string& seed
+        ) :
+            filenames(filenames_.begin(), filenames_.end()),
+            mode(mode_),
             prng(seed)
         {
             packed_sfens.resize(thread_num);
@@ -173,6 +186,9 @@ namespace Learner{
 
         void file_read_worker()
         {
+            std::string currentFilename;
+            uint64_t numEntriesReadFromCurrentFile = 0;
+
             auto open_next_file = [&]() {
                 // no more
                 for(;;)
@@ -183,18 +199,20 @@ namespace Learner{
                         return false;
 
                     // Get the next file name.
-                    std::string filename = filenames.front();
+                    currentFilename = filenames.front();
                     filenames.pop_front();
 
-                    sfen_input_stream = open_sfen_input_file(filename);
+                    numEntriesReadFromCurrentFile = 0;
+
+                    sfen_input_stream = open_sfen_input_file(currentFilename);
 
                     if (sfen_input_stream == nullptr)
                     {
-                        std::cout << "File does not exist: " << filename << '\n';
+                        std::cout << "File does not exist: " << currentFilename << '\n';
                     }
                     else
                     {
-                        std::cout << "Opened file for reading: " << filename << '\n';
+                        std::cout << "Opened file for reading: " << currentFilename << '\n';
 
                         // in case the file is empty or was deleted.
                         if (sfen_input_stream->eof())
@@ -236,13 +254,24 @@ namespace Learner{
                     if (p.has_value())
                     {
                         sfens.push_back(*p);
+                        ++numEntriesReadFromCurrentFile;
                     }
-                    else if(!open_next_file())
+                    else
                     {
-                        // There was no next file. Abort.
-                        std::cout << "..end of files." << std::endl;
-                        end_of_files = true;
-                        return;
+                        if (mode == SfenReaderMode::Cyclic
+                            && numEntriesReadFromCurrentFile > 0)
+                        {
+                            // The file contained data so we add it again to the end of the queue.
+                            filenames.emplace_back(currentFilename);
+                        }
+
+                        if(!open_next_file())
+                        {
+                            // There was no next file. Abort.
+                            std::cout << "..end of files." << std::endl;
+                            end_of_files = true;
+                            return;
+                        }
                     }
                 }
 
@@ -295,11 +324,6 @@ namespace Learner{
             shuffle = v;
         }
 
-        void add_file(const std::string& filename)
-        {
-            filenames.push_back(filename);
-        }
-
     protected:
 
         // worker thread reading file in background
@@ -316,6 +340,8 @@ namespace Learner{
         // Do not shuffle when reading the phase.
         bool shuffle;
 
+        SfenReaderMode mode;
+
         // Random number to shuffle when reading the phase
         PRNG prng;