First steps into importing FMI3 ME models

setup.py

@@ -232,6 +232,9 @@ def check_extensions():
     ext_list += cythonize([os.path.join("src", "pyfmi", "fmi2.pyx")],
                     include_path = incl_path,
                     compiler_directives={'language_level' : "3str"})
+    ext_list += cythonize([os.path.join("src", "pyfmi", "fmi3.pyx")],
+                    include_path = incl_path,
+                    compiler_directives={'language_level' : "3str"})
 
     #FMI UTIL
     ext_list += cythonize([os.path.join("src", "pyfmi", "fmi_util.pyx")],

src/pyfmi/fmi.pyx

@@ -28,12 +28,11 @@ import os
 cimport cython
 
 cimport pyfmi.fmil_import as FMIL
-cimport pyfmi.fmil1_import as FMIL1
-cimport pyfmi.fmil2_import as FMIL2
 
 cimport pyfmi.fmi_base as FMI_BASE
 cimport pyfmi.fmi1 as FMI1
 cimport pyfmi.fmi2 as FMI2
+cimport pyfmi.fmi3 as FMI3
 
 from pyfmi.common.core import create_temp_dir
 
@@ -168,6 +167,12 @@ from pyfmi.fmi2 import (
     FMI_OUTPUTS,
 )
 
+from pyfmi.fmi3 import (
+    # Classes
+    FMUModelBase3,
+    FMUModelME3,
+)
+
 # Callbacks
 cdef void importlogger_load_fmu(FMIL.jm_callbacks* c, FMIL.jm_string module, FMIL.jm_log_level_enu_t log_level, FMIL.jm_string message):
     (<list>c.context).append("FMIL: module = %s, log level = %d: %s"%(module, log_level, message))
@@ -264,34 +269,7 @@ cpdef load_fmu(fmu, log_file_name = "", kind = 'auto',
     fmu_full_path = FMI_BASE.encode(fmu_full_path)
     version = FMI_BASE.import_and_get_version(context, fmu_full_path, fmu_temp_dir, allow_unzipped_fmu)
 
-    # Check the version
-    if version == FMIL.fmi_version_unknown_enu:
-        # Delete context
-        last_error = FMIL.jm_get_last_error(&callbacks)
-        FMIL.fmi_import_free_context(context)
-        if not allow_unzipped_fmu:
-            FMIL.fmi_import_rmdir(&callbacks, fmu_temp_dir)
-        if callbacks.log_level >= FMIL.jm_log_level_error:
-            _handle_load_fmu_exception(fmu, log_data)
-            raise InvalidVersionException("The FMU could not be loaded. The FMU version could not be determined. "+FMI_BASE.decode(last_error))
-        else:
-            _handle_load_fmu_exception(fmu, log_data)
-            raise InvalidVersionException("The FMU could not be loaded. The FMU version could not be determined. Enable logging for possibly more information.")
-
-    if version > 2: # TODO: FMI3 remove this part?; simply use the final else in the if version = ... elif ... else ?
-        # Delete the context
-        last_error = FMIL.jm_get_last_error(&callbacks)
-        FMIL.fmi_import_free_context(context)
-        if not allow_unzipped_fmu:
-            FMIL.fmi_import_rmdir(&callbacks, fmu_temp_dir)
-        if callbacks.log_level >= FMIL.jm_log_level_error:
-            _handle_load_fmu_exception(fmu, log_data)
-            raise InvalidVersionException("The FMU could not be loaded. The FMU version is unsupported. "+FMI_BASE.decode(last_error))
-        else:
-            _handle_load_fmu_exception(fmu, log_data)
-            raise InvalidVersionException("The FMU could not be loaded. The FMU version is unsupported. Enable logging for possibly more information.")
-
-    # Parse the xml
+    # Check the version & parse XML
     if version == FMIL.fmi_version_1_enu:
         model = FMI1._load_fmi1_fmu(
             fmu, log_file_name, kind, log_level, allow_unzipped_fmu,
@@ -302,19 +280,21 @@ cpdef load_fmu(fmu, log_file_name = "", kind = 'auto',
             fmu, log_file_name, kind, log_level, allow_unzipped_fmu,
             context, fmu_temp_dir, callbacks, log_data
         )
+    elif version == FMIL.fmi_version_3_0_enu:
+        model = FMI3._load_fmi3_fmu(
+            fmu, log_file_name, kind, log_level, allow_unzipped_fmu,
+            context, fmu_temp_dir, callbacks, log_data
+        )
     else:
-        # This else-statement ensures that the variables "context" and "version" are defined before proceeding
-
-        # Delete the context
         last_error = FMIL.jm_get_last_error(&callbacks)
         FMIL.fmi_import_free_context(context)
         if not allow_unzipped_fmu:
             FMIL.fmi_import_rmdir(&callbacks, fmu_temp_dir)
         if callbacks.log_level >= FMIL.jm_log_level_error:
             _handle_load_fmu_exception(fmu, log_data)
-            raise InvalidVersionException("The FMU could not be loaded. The FMU version is not found. "+FMI_BASE.decode(last_error))
+            raise InvalidVersionException("The FMU could not be loaded. The FMU version is unsupported. " + FMI_BASE.decode(last_error))
         else:
             _handle_load_fmu_exception(fmu, log_data)
-            raise InvalidVersionException("The FMU could not be loaded. The FMU version is not found. Enable logging for possibly more information.")
+            raise InvalidVersionException("The FMU could not be loaded. The FMU version is unsupported. Enable logging for possibly more information.")
 
     return model

src/pyfmi/fmi2.pxd

@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-# Module containing the FMI interface Python wrappers.
+# Module containing the FMI2 interface Python wrappers.
 
 import numpy as np
 cimport numpy as np

src/pyfmi/fmi2.pyx

@@ -5273,7 +5273,7 @@ cdef object _load_fmi2_fmu(
     list log_data
 ):
     """
-    The FMI1 part of fmi.pyx load_fmu.
+    The FMI2 part of fmi.pyx load_fmu.
     """
     # TODO: Tons of duplicated code here for error handling
     cdef FMIL.jm_string last_error

src/pyfmi/fmi3.pxd

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright (C) 2025 Modelon AB
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, version 3 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Module containing the FMI3 interface Python wrappers.
+
+cimport pyfmi.fmil_import as FMIL
+cimport pyfmi.fmil3_import as FMIL3
+cimport pyfmi.fmi_base as FMI_BASE
+
+cdef class FMUModelBase3(FMI_BASE.ModelBase):
+    pass
+
+cdef class FMUModelME3(FMUModelBase3):
+    pass
+
+cdef object _load_fmi3_fmu(
+    fmu, 
+    object log_file_name, 
+    str kind, 
+    int log_level, 
+    int allow_unzipped_fmu,
+    FMIL.fmi_import_context_t* context, 
+    bytes fmu_temp_dir,
+    FMIL.jm_callbacks callbacks,
+    list log_data
+)

src/pyfmi/fmi3.pyx

@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright (C) 2025Modelon AB
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, version 3 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# distutils: define_macros=NPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION
+
+cimport cython
+
+cimport pyfmi.fmil_import as FMIL
+cimport pyfmi.fmil3_import as FMIL3
+cimport pyfmi.fmi_base as FMI_BASE
+
+cdef class FMUModelBase3(FMI_BASE.ModelBase):
+    """TODO"""
+    def __init__(self):
+        pass
+
+cdef class FMUModelME3(FMUModelBase3):
+    """TODO"""
+    def __init__(self):
+        pass
+
+cdef object _load_fmi3_fmu(
+    fmu, 
+    object log_file_name, 
+    str kind, 
+    int log_level, 
+    int allow_unzipped_fmu,
+    FMIL.fmi_import_context_t* context, 
+    bytes fmu_temp_dir,
+    FMIL.jm_callbacks callbacks,
+    list log_data
+):
+    """
+    The FMI3 part of fmi.pyx load_fmu.
+    """
+    return FMUModelME3()

src/pyfmi/fmi_coupled.pyx

@@ -24,8 +24,8 @@ cimport numpy as np
 cimport pyfmi.fmil2_import as FMIL2
 cimport pyfmi.fmi2 as FMI2
 from pyfmi.fmi2 import FMI2_INPUT, FMI2_OUTPUT
-from pyfmi.fmi_base import PyEventInfo
-from pyfmi.fmi_util import enable_caching, Graph
+from pyfmi.fmi_base import PyEventInfo, enable_caching
+from pyfmi.fmi_util import Graph
 from pyfmi.exceptions import FMUException, InvalidFMUException
 
 from collections import OrderedDict

src/pyfmi/fmil2_import.pxd

@@ -29,7 +29,7 @@ from fmil_import cimport (
 )
 
 cdef extern from 'fmilib.h':
-    #FMI VARIABLE TYPE DEFINITIONS
+    # FMI VARIABLE TYPE DEFINITIONS
     ctypedef double fmi2_real_t
     ctypedef int    fmi2_boolean_t
     ctypedef void*  fmi2_component_t
@@ -40,7 +40,7 @@ cdef extern from 'fmilib.h':
     ctypedef void*  fmi2_component_environment_t
     ctypedef size_t fmi2_value_reference_t
 
-    #STRUCTS
+    # STRUCTS
     ctypedef enum fmi2_boolean_enu_t:
         fmi2_true = 1
         fmi2_false = 0

src/pyfmi/fmil3_import.pxd

@@ -0,0 +1,132 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (C) 2025 Modelon AB
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, version 3 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+#==============================================
+# C headers
+#==============================================
+
+# This file contains FMIL header content specific to FMI3
+cimport pyfmi.fmil_import as FMIL
+from libcpp cimport bool # TODO: Possible issue due to https://github.com/cython/cython/issues/5730 ??
+
+
+# XXX: Copy more header content from FMI3 as it becomes necessary
+
+cdef extern from 'fmilib.h':
+    # FMI VARIABLE TYPE DEFINITIONS
+    ctypedef bool        fmi3_boolean_t
+    ctypedef void*       fmi3_instance_environment_t
+    ctypedef const char* fmi3_string_t
+    ctypedef double      fmi3_float64_t
+
+    # STATUS
+    ctypedef enum fmi3_status_t:
+        fmi3_status_ok      = 0
+        fmi3_status_warning = 1
+        fmi3_status_discard = 2
+        fmi3_status_error   = 3
+        fmi3_status_fatal   = 4
+    cdef enum fmi3_fmu_kind_enu_t:
+        fmi3_fmu_kind_unknown = 1
+        fmi3_fmu_kind_me = 2
+        fmi3_fmu_kind_cs = 4
+        fmi3_fmu_kind_se = 8
+
+    # LOGGING
+    ctypedef void (*fmi3_log_message_callback_ft) (
+        fmi3_instance_environment_t instanceEnvironment,
+        fmi3_status_t status,
+        fmi3_string_t category,
+        fmi3_string_t messages
+    )
+    ctypedef int(*fmi3_xml_element_start_handle_ft)(void*, char*, void*, char*, char**)
+    ctypedef int(*fmi3_xml_element_data_handle_ft)(void*, char*, int)
+    ctypedef int(*fmi3_xml_element_end_handle_ft)(void*, char*)
+    cdef struct fmi3_xml_callbacks_t:
+        fmi3_xml_element_start_handle_ft startHandle
+        fmi3_xml_element_data_handle_ft  dataHandle
+        fmi3_xml_element_end_handle_ft   endHandle
+        void* context
+
+    cdef struct fmi3_import_t:
+        pass
+    # FMI SPECIFICATION METHODS (3.0)
+    # BASIC
+    FMIL.jm_status_enu_t fmi3_import_create_dllfmu(fmi3_import_t*, fmi3_fmu_kind_enu_t, const fmi3_instance_environment_t, const fmi3_log_message_callback_ft)
+    # TODO: CS, SE
+    # FMIL.jm_status_enu_t fmi3_import_instantiate_model_exchange(
+    #     fmi3_import_t* fmu, 
+    #     fmi3_string_t instanceName, 
+    #     fmi3_string_t resourcePath, 
+    #     fmi3_boolean_t visible,
+    #     fmi3_boolean_t loggingOn
+    # )
+    # TODO: This will change with next FMIL release
+    FMIL.jm_status_enu_t fmi3_import_instantiate_model_exchange(
+        fmi3_import_t* fmu, 
+        fmi3_string_t instanceName, 
+        fmi3_string_t resourcePath, 
+        fmi3_boolean_t visible,
+        fmi3_boolean_t loggingOn,
+        fmi3_instance_environment_t instanceEnvironment,
+        fmi3_log_message_callback_ft logMessage
+    )
+    void fmi3_import_free_instance(fmi3_import_t* fmu)
+    FMIL.jm_status_enu_t fmi3_import_terminate(fmi3_import_t*)
+    # modes
+    FMIL.jm_status_enu_t fmi3_import_enter_initialization_mode(
+        fmi3_import_t* fmu,
+        fmi3_boolean_t toleranceDefined,
+        fmi3_float64_t tolerance,
+        fmi3_float64_t startTime,
+        fmi3_boolean_t stopTimeDefined,
+        fmi3_float64_t stopTime
+    );
+    FMIL.jm_status_enu_t fmi3_import_exit_initialization_mode(fmi3_import_t* fmu)
+    FMIL.jm_status_enu_t fmi3_import_enter_continuous_time_mode(fmi3_import_t* fmu)
+
+    # misc
+
+    # setting
+
+    # getting
+
+    # save states
+
+    # FMI HELPER METHODS (3.0)
+    const char* fmi3_import_get_model_name(fmi3_import_t*)
+    fmi3_fmu_kind_enu_t fmi3_import_get_fmu_kind(fmi3_import_t*)
+
+    # FMI XML METHODS
+
+    ### Model information
+
+    # CONVERTER METHODS
+
+    # INTEGER
+
+    # OTHER HELPER METHODS
+
+    # Does NOT invoke CAPI calls
+    # TODO: Categorize these a bit better
+    void fmi3_import_free(fmi3_import_t*)
+    char* fmi3_fmu_kind_to_string(fmi3_fmu_kind_enu_t)
+    const char* fmi3_import_get_model_identifier_CS(fmi3_import_t*)
+    const char* fmi3_import_get_last_error(fmi3_import_t*)
+    void fmi3_log_forwarding(fmi3_instance_environment_t, fmi3_status_t, fmi3_string_t, fmi3_string_t)
+    fmi3_import_t* fmi3_import_parse_xml(FMIL.fmi_import_context_t*, char*, fmi3_xml_callbacks_t*)
+    const char* fmi3_import_get_model_identifier_ME(fmi3_import_t*)
+    void fmi3_import_destroy_dllfmu(fmi3_import_t*)

src/pyfmi/fmil_import.pxd

@@ -74,7 +74,8 @@ cdef extern from 'fmilib.h':
         fmi_version_unknown_enu = 0
         fmi_version_1_enu = 1
         fmi_version_2_0_enu = 2
-        fmi_version_unsupported_enu = 3
+        fmi_version_3_0_enu = 3
+        fmi_version_unsupported_enu = 4
 
     ctypedef int(*jm_compare_ft)(void *, void *)
     ctypedef jm_voidp(*jm_malloc_f)(size_t)

tests/conftest.py

@@ -16,7 +16,7 @@ def setup_reference_fmus():
         Note that this requires an internet connection to work.
     """
 
-    def download_url(url, save_file_to, chunk_size=1024):
+    def download_url(url, save_file_to):
         """ Download file from URL to 'save_file_to' in chunks. """
         try:
             with urllib.request.urlopen(url) as file_to_download:
@@ -52,4 +52,4 @@ def download_url(url, save_file_to, chunk_size=1024):
                     if fobj.filename.startswith('3.0') and fobj.filename.endswith('.fmu'):
                         zf.extract(fobj, zip_unzip_to)
                         with open(md5_file, 'w') as f:
-                            f.write(md5)
+                            f.write(md5)