[IO] Add filename[_run]_params generator, base class of saving_params

include/lima/io/multi.hpp

@@ -19,8 +19,6 @@
 #include <mpi.h>
 #endif //defined(LIMA_ENABLE_MPI)
 
-#include <fmt/format.h>
-
 #include <lima/exceptions.hpp>
 #include <lima/logging.hpp>
 #include <lima/core/frame.hpp>
@@ -143,16 +141,6 @@ namespace io
         std::vector<std::shared_ptr<driver_counter>> m_drivers; // Vector elements must be copy-constructible
         std::function<driver_t(std::string const&)> m_driver_factory;
 
-        /// Format the filename according to base path, prefix, start_number and suffix
-        std::filesystem::path filename(std::size_t driver_idx = 0)
-        {
-            using namespace fmt::literals;
-
-            return fmt::format(m_params.filename_format, "filename_prefix"_a = m_params.filename_prefix,
-                               "rank"_a = m_rank, "file_number"_a = m_params.start_number + driver_idx,
-                               "filename_suffix"_a = m_params.filename_suffix);
-        }
-
         bool is_driver_available(std::size_t driver_idx) { return (bool) m_drivers[driver_idx]; }
 
         /// Open and initialize a file
@@ -161,7 +149,8 @@ namespace io
             if (driver_idx >= m_drivers.size())
                 LIMA_THROW_EXCEPTION(io_error("Unexpected I/O driver index"));
 
-            std::filesystem::path filepath = m_params.base_path / filename(driver_idx);
+            filename_run_params run_pars{int(m_params.start_number + driver_idx), m_rank};
+            std::filesystem::path filepath = m_params.filename(run_pars);
             LIMA_LOG(trace, io) << "Opening file " << filepath;
 
             //Check whether the file exists, etc

include/lima/io/params.describe.hpp

@@ -18,28 +18,41 @@ namespace lima
 {
 namespace io
 {
-    BOOST_DESCRIBE_STRUCT(saving_params, (),
-                          (base_path, filename_format, filename_prefix, filename_suffix, start_number,
-                           file_exists_policy, nb_frames_per_file))
+    BOOST_DESCRIBE_STRUCT(filename_run_params, (), (index, rank))
 
     // clang-format off
-    BOOST_ANNOTATE_MEMBER(saving_params, base_path,
-        (desc, "base path"),
-        (doc, "The base path where the files will be saved"))
+    BOOST_ANNOTATE_MEMBER(filename_run_params, index,
+        (desc, "index"),
+        (doc, "The index of the file in the sequence"))
 
-    BOOST_ANNOTATE_MEMBER(saving_params, filename_format,
-        (desc, "filename format"),
-        (doc, "The format of the generated filename "
-              "[default: {filename_prefix}_{rank}_{file_number:05d}{filename_suffix}]"))
+    BOOST_ANNOTATE_MEMBER(filename_run_params, rank,
+        (desc, "rank"),
+        (doc, "The (MPI) rank of the file writer (in the receivers group)"))
+    // clang-format on
+
+// clang-format off
+#define LIMA_IO_DESCRIBE_FILENAME(x)                                                                               \
+    BOOST_DESCRIBE_STRUCT(x, (), (base_path, filename_format, filename_prefix, filename_suffix, filename))         \
+                                                                                                                   \
+    BOOST_ANNOTATE_MEMBER(x, base_path, (desc, "base path"), (doc, "The base path where the files will be saved")) \
+                                                                                                                   \
+    BOOST_ANNOTATE_MEMBER(x, filename_format, (desc, "filename format"),                                           \
+                          (doc, "The format of the generated filename "                                            \
+                                "[default: {filename_prefix}_{rank}_{file_number:05d}{filename_suffix}]"))         \
+                                                                                                                   \
+    BOOST_ANNOTATE_MEMBER(x, filename_prefix, (desc, "filename prefix"),                                           \
+                          (doc, "The prefix of the filename, see <filename_format> for usage description"))        \
+                                                                                                                   \
+    BOOST_ANNOTATE_MEMBER(x, filename_suffix, (desc, "filename suffix"),                                           \
+                          (doc, "The suffix of the filename, see <filename_format> for usage description"))
+    // clang-format on
 
-    BOOST_ANNOTATE_MEMBER(saving_params, filename_prefix,
-        (desc, "filename prefix"),
-        (doc, "The prefix of the filename, see <filename_format> for usage description"))
+    LIMA_IO_DESCRIBE_FILENAME(filename_saving_params)
 
-    BOOST_ANNOTATE_MEMBER(saving_params, filename_suffix,
-        (desc, "filename suffix"),
-        (doc, "The suffix of the filename, see <filename_format> for usage description"))
+    BOOST_DESCRIBE_STRUCT(saving_params, (filename_saving_params),
+                          (start_number, file_exists_policy, nb_frames_per_file))
 
+    // clang-format off
     BOOST_ANNOTATE_MEMBER(saving_params, start_number,
         (desc, "start number"),
         (doc, "Start number in the file sequence"))

include/lima/io/params.hpp

@@ -12,6 +12,8 @@
 #include <lima/io/const.hpp>
 #include <lima/io/enums.hpp>
 
+#include <fmt/format.h>
+
 namespace lima
 {
 namespace io
@@ -20,12 +22,43 @@ namespace io
     // only by the standard library so safe to bind here
     using std::string_literals::operator"" s;
 
-    struct saving_params
+    struct filename_run_params
+    {
+        int index = 0;
+        int rank = 0;
+    };
+
+    struct DefaultFilenameValues
+    {
+        static constexpr char prefix[] = "";
+    };
+
+    template <typename DefaultValues>
+    struct filename_params_base
     {
         std::filesystem::path base_path = std::filesystem::temp_directory_path();
         std::string filename_format = default_filename_format;
-        std::string filename_prefix = "output"s;
+        std::string filename_prefix = DefaultValues::prefix;
         std::string filename_suffix = ".h5"s;
+
+        std::filesystem::path filename(filename_run_params const& run_pars = {}) const
+        {
+            using namespace fmt::literals;
+
+            auto name = fmt::format(filename_format, "filename_prefix"_a = filename_prefix, "rank"_a = run_pars.rank,
+                                    "file_number"_a = run_pars.index, "filename_suffix"_a = filename_suffix);
+            return base_path / name;
+        }
+    };
+
+    struct DefaultSavingValues : DefaultFilenameValues
+    {
+        static constexpr char prefix[] = "output";
+    };
+    using filename_saving_params = filename_params_base<DefaultSavingValues>;
+
+    struct saving_params : filename_saving_params
+    {
         int start_number = 0;
         file_exists_policy_enum file_exists_policy = file_exists_policy_enum::abort;
         int nb_frames_per_file = 1;