From 0d06afc38d7a8443a079d25d72ec4b4b15353974 Mon Sep 17 00:00:00 2001
From: Willem Jan Palenstijn <Willem.Jan.Palenstijn@cwi.nl>
Date: Tue, 3 Jul 2018 14:32:23 +0200
Subject: Allow access to python plugin object via algorithm interface

---
 python/astra/algorithm.py                  | 11 +++++++++++
 python/astra/algorithm_c.pyx               | 17 +++++++++++++++++
 python/astra/src/PythonPluginAlgorithm.cpp |  8 ++++++++
 python/astra/src/PythonPluginAlgorithm.h   |  3 +++
 python/builder.py                          |  2 +-
 5 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/python/astra/algorithm.py b/python/astra/algorithm.py
index 33cca85..8862af3 100644
--- a/python/astra/algorithm.py
+++ b/python/astra/algorithm.py
@@ -66,6 +66,17 @@ def delete(ids):
     """
     return a.delete(ids)
 
+def get_plugin_object(i):
+    """Return the Python object instance of a plugin algorithm.
+
+    :param i: ID of object corresponding to a plugin algorithm.
+    :type i: :class:`int`
+    :returns: The Python object instance of the plugin algorithm.
+
+    """
+    return a.get_plugin_object(i)
+
+
 def clear():
     """Clear all matrix objects."""
     return a.clear()
diff --git a/python/astra/algorithm_c.pyx b/python/astra/algorithm_c.pyx
index a190ee1..50f6052 100644
--- a/python/astra/algorithm_c.pyx
+++ b/python/astra/algorithm_c.pyx
@@ -47,6 +47,13 @@ cdef extern from *:
     CReconstructionAlgorithm2D * dynamic_cast_recAlg2D "dynamic_cast<astra::CReconstructionAlgorithm2D*>" (CAlgorithm * )
     CReconstructionAlgorithm3D * dynamic_cast_recAlg3D "dynamic_cast<astra::CReconstructionAlgorithm3D*>" (CAlgorithm * )
 
+cdef extern from "src/PythonPluginAlgorithm.h" namespace "astra":
+    cdef cppclass CPluginAlgorithm:
+        object getInstance()
+
+cdef extern from *:
+    CPluginAlgorithm * dynamic_cast_PluginAlg "dynamic_cast<astra::CPluginAlgorithm*>" (CAlgorithm * )
+
 
 def create(config):
     cdef Config * cfg = utils.dictToConfig(six.b('Algorithm'), config)
@@ -104,6 +111,16 @@ def delete(ids):
         manAlg.remove(ids)
 
 
+def get_plugin_object(algorithm_id):
+    cdef CAlgorithm *alg
+    cdef CPluginAlgorithm *pluginAlg
+    alg = getAlg(algorithm_id)
+    pluginAlg = dynamic_cast_PluginAlg(alg)
+    if not pluginAlg:
+        raise Exception("Not a plugin algorithm")
+    return pluginAlg.getInstance()
+
+
 def clear():
     manAlg.clear()
 
diff --git a/python/astra/src/PythonPluginAlgorithm.cpp b/python/astra/src/PythonPluginAlgorithm.cpp
index d461f06..3c892ff 100644
--- a/python/astra/src/PythonPluginAlgorithm.cpp
+++ b/python/astra/src/PythonPluginAlgorithm.cpp
@@ -124,6 +124,14 @@ void CPluginAlgorithm::run(int _iNrIterations){
     PyGILState_Release(state);
 }
 
+PyObject *CPluginAlgorithm::getInstance() const {
+	if (instance)
+		Py_INCREF(instance);
+	return instance;
+}
+
+
+
 CPythonPluginAlgorithmFactory::CPythonPluginAlgorithmFactory(){
     if(!Py_IsInitialized()){
         Py_Initialize();
diff --git a/python/astra/src/PythonPluginAlgorithm.h b/python/astra/src/PythonPluginAlgorithm.h
index 947e30d..b7072d6 100644
--- a/python/astra/src/PythonPluginAlgorithm.h
+++ b/python/astra/src/PythonPluginAlgorithm.h
@@ -49,6 +49,9 @@ public:
     bool initialize(const Config& _cfg);
     void run(int _iNrIterations);
 
+    // Return instance (including INCREF)
+    PyObject *getInstance() const;
+
 private:
     PyObject * instance;
 
diff --git a/python/builder.py b/python/builder.py
index dd99633..b373366 100644
--- a/python/builder.py
+++ b/python/builder.py
@@ -66,7 +66,7 @@ ext_modules = cythonize(os.path.join(self_path, 'astra', '*.pyx'),
 cmdclass = {'build_ext': build_ext}
 
 for m in ext_modules:
-    if m.name == 'astra.plugin_c':
+    if m.name in ('astra.plugin_c', 'astra.algorithm_c'):
         m.sources.append(os.path.join(self_path, 'astra', 'src',
                                       'PythonPluginAlgorithm.cpp'))
 
-- 
cgit v1.2.3