DE-2319: Add GRIB reader as data source feature for NWP emulator

Author: cducher

.github/ci-config.yml

@@ -3,6 +3,7 @@ dependencies: |
   ecmwf/eckit
   ecmwf/fckit
   ecmwf/atlas
+  ecmwf/eccodes
 dependency_cmake_options: |
   ecmwf/atlas: "-DENABLE_FORTRAN=ON"
 dependency_branch: develop

.github/ci-hpc-config.yml

@@ -6,6 +6,7 @@ build:
     - ecmwf/eckit@develop
     - ecmwf/fckit@develop
     - ecmwf/atlas@develop
+    - ecmwf/eccodes@develop
   dependency_cmake_options:
     - ecmwf/atlas:-DENABLE_FORTRAN=ON
   parallel: 64

CMakeLists.txt

@@ -20,6 +20,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 ### dependencies and options
 ecbuild_find_package( NAME eckit  VERSION  1.18 REQUIRED )
 ecbuild_find_package( NAME atlas )
+ecbuild_find_package( NAME eccodes )
 
 ecbuild_add_option( FEATURE BUILD_TOOLS
                     DEFAULT ON
@@ -47,6 +48,15 @@ ecbuild_info("FCKIT_FOUND ${fckit_FOUND}")
 ecbuild_info("FCKIT_LIBRARIES ${FCKIT_LIBRARIES}")
 ecbuild_info("FCKIT_INCLUDE_DIRS ${FCKIT_INCLUDE_DIRS}")
 
+############## PRECISION
+ecbuild_add_option( FEATURE NWP_EMULATOR_SINGLE_PRECISION
+                    DESCRIPTION "Single precision Atlas fields"
+                    DEFAULT OFF )
+
+if( HAVE_NWP_EMULATOR_SINGLE_PRECISION ) 
+  list(APPEND NWP_EMULATOR_DEFINITIONS WITH_NWP_EMULATOR_SINGLE_PRECISION )
+endif()
+
 add_subdirectory( src )
 add_subdirectory( tests )
 add_subdirectory( examples )

src/CMakeLists.txt

@@ -8,3 +8,5 @@
 # does it submit to any jurisdiction.
 
 add_subdirectory(plume)
+
+add_subdirectory(nwp_emulator)

src/nwp_emulator/CMakeLists.txt

@@ -0,0 +1,33 @@
+# (C) Copyright 2025- ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation nor
+# does it submit to any jurisdiction.
+ecbuild_add_library(
+    TARGET plume_nwp_emulator
+    INSTALL_HEADERS LISTED
+    HEADER_DESTINATION
+        ${INSTALL_INCLUDE_DIR}/nwp_emulator
+    SOURCES
+        data_reader.h
+        grib_file_reader.h
+        nwp_definitions.h
+        nwp_data_provider.h
+        nwp_data_provider.cc
+        grib_file_reader.cc
+    PUBLIC_INCLUDES
+       $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/src>
+       $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src>
+    PRIVATE_INCLUDES
+        "${MPI_INCLUDE_DIRS}"
+    DEFINITIONS
+        ${NWP_EMULATOR_DEFINITIONS}
+    PUBLIC_LIBS
+        plume_plugin
+        plume_plugin_manager
+        eccodes
+        eckit
+)

src/nwp_emulator/data_reader.h

@@ -0,0 +1,62 @@
+/*
+ * (C) Copyright 2025- ECMWF.
+ *
+ * This software is licensed under the terms of the Apache Licence Version 2.0
+ * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * In applying this licence, ECMWF does not waive the privileges and immunities
+ * granted to it by virtue of its status as an intergovernmental organisation nor
+ * does it submit to any jurisdiction.
+ */
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "nwp_definitions.h"
+
+namespace nwp_emulator {
+
+/**
+ * @class DataReader
+ * @brief Base class for handling different types of data sources for the emulator.
+ */
+class DataReader {
+protected:
+    std::string gridName_;
+    std::vector<std::string> params_;
+
+    int stepCountLimit_;  ///< Limitation on the number of steps the emulator can run
+    int step_{0};         ///< Number of model steps
+    int count_{0};        ///< Number of messages for the current step
+    int index_{0};        ///< Index of the considered message at the current step
+
+public:
+    DataReader(int stepCountLimit) : stepCountLimit_(stepCountLimit) {}
+    virtual ~DataReader() = default;
+
+    /**
+     * @brief Provides the raw values for a single levelin the next message from the data source.
+     *
+     * Each of the inheriting readers will have a different way to generate raw model data for the provider,
+     * which can use the parameters to map the raw values to a specific field, levtype and level.
+     *
+     * @param[out] shortName The name of the parameter represented by the raw values for the caller use.
+     * @param[out] levtype The levtype of the parameter for the caller use.
+     * @param[out] level The level of the levtype for the caller use.
+     * @param[out] data The vector that contains the raw values for the field.
+     *
+     * @return true if the data generation is successful, false otherwise.
+     */
+    virtual bool nextMessage(std::string& shortName, std::string& levtype, std::string& level,
+                             std::vector<FIELD_TYPE_REAL>& data) = 0;
+
+    /// Returns true when the reader has read model data for all the steps.
+    virtual bool done() = 0;
+
+    /// Getters
+    const std::string& getGridName() const { return gridName_; }
+    int getStep() const { return step_; }
+    const std::vector<std::string>& getParams() const { return params_; }
+};
+}  // namespace nwp_emulator