--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/training/unicharset/lstmtester.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,93 @@
+///////////////////////////////////////////////////////////////////////
+// File:        lstmtester.h
+// Description: Top-level line evaluation class for LSTM-based networks.
+// Author:      Ray Smith
+//
+// (C) Copyright 2016, Google Inc.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+///////////////////////////////////////////////////////////////////////
+
+#ifndef TESSERACT_TRAINING_LSTMTESTER_H_
+#define TESSERACT_TRAINING_LSTMTESTER_H_
+
+#include "export.h"
+
+#include "lstmtrainer.h"
+
+#include <mutex>
+#include <string>
+#include <vector>
+
+namespace tesseract {
+
+class TESS_UNICHARSET_TRAINING_API LSTMTester {
+public:
+  LSTMTester(int64_t max_memory);
+
+  // Loads a set of lstmf files that were created using the lstm.train config to
+  // tesseract into memory ready for testing. Returns false if nothing was
+  // loaded. The arg is a filename of a file that lists the filenames, with one
+  // name per line. Conveniently, tesstrain.py generates such a file, along
+  // with the files themselves.
+  bool LoadAllEvalData(const char *filenames_file);
+  // Loads a set of lstmf files that were created using the lstm.train config to
+  // tesseract into memory ready for testing. Returns false if nothing was
+  // loaded.
+  bool LoadAllEvalData(const std::vector<std::string> &filenames);
+
+  // Runs an evaluation asynchronously on the stored eval data and returns a
+  // string describing the results of the previous test. Args match TestCallback
+  // declared in lstmtrainer.h:
+  // iteration: Current learning iteration number.
+  // training_errors: If not null, is an array of size ET_COUNT, indexed by
+  //   the ErrorTypes enum and indicates the current errors measured by the
+  //   trainer, and this is a serious request to run an evaluation. If null,
+  //   then the caller is just polling for the results of the previous eval.
+  // model_data: is the model to evaluate, which should be a serialized
+  //   LSTMTrainer.
+  // training_stage: an arbitrary number on the progress of training.
+  std::string RunEvalAsync(int iteration, const double *training_errors,
+                           const TessdataManager &model_mgr, int training_stage);
+  // Runs an evaluation synchronously on the stored eval data and returns a
+  // string describing the results. Args as RunEvalAsync, except verbosity,
+  // which outputs errors, if 1, or all results if 2.
+  std::string RunEvalSync(int iteration, const double *training_errors, const TessdataManager &model_mgr,
+                          int training_stage, int verbosity);
+
+private:
+  // Helper thread function for RunEvalAsync.
+  // LockIfNotRunning must have returned true before calling ThreadFunc, and
+  // it will call UnlockRunning to release the lock after RunEvalSync completes.
+  void ThreadFunc();
+  // Returns true if there is currently nothing running, and takes the lock
+  // if there is nothing running.
+  bool LockIfNotRunning();
+  // Releases the running lock.
+  void UnlockRunning();
+
+  // The data to test with.
+  DocumentCache test_data_;
+  int total_pages_ = 0;
+  // Flag that indicates an asynchronous test is currently running.
+  // Protected by running_mutex_.
+  bool async_running_ = false;
+  std::mutex running_mutex_;
+  // Stored copies of the args for use while running asynchronously.
+  int test_iteration_ = 0;
+  const double *test_training_errors_ = nullptr;
+  TessdataManager test_model_mgr_;
+  int test_training_stage_ = 0;
+  std::string test_result_;
+};
+
+} // namespace tesseract
+
+#endif // TESSERACT_TRAINING_LSTMTESTER_H_