updated doc; replace all #

doc/src/sections/solver_options.tex

@@ -423,6 +423,16 @@ \subsubsection{Problem preprocessing}
 \medskip
 
 
+\subsubsection{Checkpointing of the solver state and restarting}
+\Hi can save/load its internal state to/from disk. This can be helphul when running a job on a cluster that enforces limits on the job's running time. This functionality is currently available only for the quasi-Newton algorithm. The checkpointing is done using Axom's scalable Sidre data manager and IO (see \url{https://axom.readthedocs.io/en/develop/axom/sidre/docs/sphinx/index.html}) and requires an Axom-enabled build (use ``-DHIOP_USE_AXOM=ON'' with cmake). 
+
+\noindent \textbf{checkpoint\_save}: Save state of NLP solver to file indicated by value of option ``checkpoint\_file''. String values ``yes'' or ``no'', default ``no''.
+
+\noindent \textbf{checkpoint\_load\_on\_start} On (re)start the NLP solver will load checkpoint file specified by ``checkpoint_file`` option. String values ``yes'' or ``no'', default ``no''.
+
+\noindent \textbf{checkpoint\_file} Path to checkpoint file to load from or save to. If present, the character ``\#'' is replaced with the iteration number at which the checkpointing is saved (but \textit{not} when loaded). \Hi adds a ``.root'' extension internally if the value of the option is a directory. If this option is not specified and loading or saving checkpoints is enabled, \Hi will use a file named ``hiop_state_chk''.
+
+\noindent \textbf{checkpoint\_save\_every\_N\_iter} Iteration frequency of saving checkpoints to disk if ``checkpoint_save'' is ``yes''. Takes positive integer values with a default value $10$.
 
 
 \subsubsection{Miscellaneous options}

src/Optimization/hiopAlgFilterIPM.cpp

@@ -1729,10 +1729,11 @@ void hiopAlgFilterIPMQuasiNewton::checkpointing_stuff()
     using ::std::string;
     // replace "#" in checkpointing file with iteration number
     string path = nlp->options->GetString("checkpoint_file");
+    const auto s_it_num = ::std::to_string(iter_num_);
     auto pos = path.find("#");
-    if(string::npos != pos) {
-      auto s_it_num = ::std::to_string(iter_num_);
+    while(string::npos != pos) {
       path.replace(pos, 1, s_it_num);
+      pos = path.find("#", pos);
     }
 
     nlp->log->printf(hovSummary, "Saving checkpoint at iter %d in '%s'.\n", iter_num_, path.c_str());

src/Utils/hiopOptions.cpp

@@ -1294,18 +1294,17 @@ void hiopOptionsNLP::register_options()
   //  - only available with HIOP_USE_AXOM
   {
     vector<string> range = {"yes", "no"};
-    constexpr char msgcs[] = "Save state of NLP solver to file specified by 'checkpoint_file'.";
+    constexpr char msgcs[] = "Save state of NLP solver to file indicated by 'checkpoint_file'.";
     register_str_option("checkpoint_save", range[1], range, msgcs);
 
     constexpr char msgcsN[] = "Iteration frequency of saving checkpoints to disk.";
     register_int_option("checkpoint_save_every_N_iter", 10, 1, 1e+6, msgcsN);
 
-    constexpr char msgcf[] = "Path to checkpoint file. If present character '#' will be replaced "
-      "with the iteration number.";
-    register_str_option("checkpoint_file", "hiop_state_#.chk", msgcf);
+    constexpr char msgcf[] = "Path to checkpoint file to load from or save to.";
+    register_str_option("checkpoint_file", "hiop_state_chk", msgcf);
 
     constexpr char msgclos[] = "On (re)start the NLP solver will load checkpoint file "
-      "specified by checkpoint_file'.";
+      "specified by 'checkpoint_file' option.";
     register_str_option("checkpoint_load_on_start", range[1], range, msgclos);
   }
 }