mana: add a python plugin

CMakeLists.txt

@@ -20,7 +20,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 option(MNODE_BUILD_TESTS "Build mnode test binaries" ${MESYTEC_MNODE_MAIN_PROJECT})
 
 if (MNODE_BUILD_TESTS)
-    find_package(GTest CONFIG)
+    find_package(GTest CONFIG QUIET)
     if (NOT GTest_FOUND)
         include(FetchContent)
         FetchContent_Declare(googletest URL https://github.com/google/googletest/archive/refs/tags/v1.15.2.zip)
@@ -34,6 +34,14 @@ if (MNODE_BUILD_TESTS)
     enable_testing()
 endif()
 
+include(FetchContent)
+    FetchContent_Declare(pybind11 GIT_REPOSITORY https://github.com/pybind/pybind11 GIT_TAG v2.13.6)
+    FetchContent_GetProperties(pybind11)
+    if(NOT pybind11_POPULATED)
+        FetchContent_Populate(pybind11)
+        add_subdirectory(${pybind11_SOURCE_DIR} ${pybind11_BINARY_DIR})
+endif()
+
 include(CMakeRC)
 cmrc_add_resource_library(mnode-resources
     ALIAS mnode::resources NAMESPACE mnode::resources

src/CMakeLists.txt

@@ -38,3 +38,9 @@ if (ROOT_FOUND)
     add_library(mana-plugin-root-histogram SHARED mana_plugin_root_histogram.cc)
     target_link_libraries(mana-plugin-root-histogram PRIVATE mana mesytec-mnode rxi-logc ${ROOT_LIBRARIES})
 endif()
+
+if (pybind11_FOUND)
+    add_library(mana-plugin-python SHARED mana_plugin_python.cc)
+    target_link_libraries(mana-plugin-python PRIVATE mana mesytec-mnode rxi-logc pybind11::embed)
+    file(CREATE_LINK ${CMAKE_CURRENT_SOURCE_DIR}/mana_python_test_plugin.py ${CMAKE_BINARY_DIR}/mana_python_test_plugin.py COPY_ON_ERROR SYMBOLIC)
+endif()

src/mana_plugin_python.cc

@@ -0,0 +1,105 @@
+#include "internal/mana_lib.hpp"
+#include <mesytec-mvlc/cpp_compat.h>
+extern "C"
+{
+#include "internal/rxi/log.h"
+}
+#include <pybind11/embed.h>
+#include <pybind11/stl.h>
+
+using namespace mesytec;
+using namespace mesytec::mnode;
+namespace py = pybind11;
+
+PYBIND11_EMBEDDED_MODULE(py_mana, m) {}
+
+struct Context
+{
+    py::scoped_interpreter interp;
+    py::module usercode;
+    py::object userobject;
+    py::object py_begin_run;
+    py::object py_event_data;
+    py::object py_end_run;
+    std::vector<std::vector<py::object>> eventBuffers;
+};
+
+MANA_DEFINE_PLUGIN_INIT(init)
+{
+    log_set_level(LOG_DEBUG);
+    static Context g_ctx;
+    auto ctx = &g_ctx;
+    log_debug("init: ctx=%p", ctx);
+    // TODO: pass args to init()
+    // TODO: catch exceptions
+    ctx->usercode = py::module::import("mana_python_test_plugin");
+    return ctx;
+}
+
+MANA_DEFINE_PLUGIN_SHUTDOWN(shutdown)
+{
+    (void)context;
+    log_debug("shutdown");
+}
+
+MANA_DEFINE_PLUGIN_BEGIN_RUN(begin_run)
+{
+    log_debug("begin_run: context=%p, descriptor_json=%s", context, descriptor_json);
+    auto jRun = nlohmann::json::parse(descriptor_json);
+    auto ctx = reinterpret_cast<Context *>(context);
+    ctx->usercode.reload();
+    // TODO: check if the retrieved attributes are callable
+    ctx->py_begin_run = ctx->usercode.attr("begin_run");
+    ctx->py_event_data = ctx->usercode.attr("event_data");
+    ctx->py_end_run = ctx->usercode.attr("end_run");
+    ctx->py_begin_run(descriptor_json);
+    ctx->eventBuffers.clear();
+    ctx->eventBuffers.resize(jRun["events"].size());
+
+    for (size_t ei = 0; ei < jRun["events"].size(); ++ei)
+    {
+        auto &jEvent = jRun["events"][ei];
+        ctx->eventBuffers[ei].resize(jEvent["outputs"].size());
+    }
+}
+
+MANA_DEFINE_PLUGIN_END_RUN(end_run)
+{
+    log_debug("end: context=%p, descriptor_json=%s", context, descriptor_json);
+    auto ctx = reinterpret_cast<Context *>(context);
+    ctx->py_end_run(descriptor_json);
+}
+
+MANA_DEFINE_PLUGIN_EVENT_DATA(process_event)
+{
+    log_trace("event: ctx=%p, eventIndex=%d, arrayCount=%zu, totalBytes=%zu", context, eventIndex,
+              arrayCount, totalBytes);
+    auto ctx = reinterpret_cast<Context *>(context);
+    auto &buffers = ctx->eventBuffers.at(eventIndex);
+    assert(buffers.size() == arrayCount);
+    for (size_t ai = 0; ai < arrayCount; ++ai)
+    {
+        auto arraySpan = mana::get_span<float>(arrays[ai]);
+        ctx->eventBuffers[eventIndex][ai] =
+            py::memoryview::from_memory(arraySpan.data(), arraySpan.size() * sizeof(float));
+    }
+    ctx->py_event_data(eventIndex, ctx->eventBuffers);
+}
+
+MANA_DEFINE_PLUGIN_SYSTEM_EVENT(process_system_event)
+{
+    log_trace("system_event: ctx=%p, size=%zu", context, size);
+    auto ctx = reinterpret_cast<Context *>(context);
+}
+
+extern "C" MANA_DEFINE_GET_PLUGIN(mana_get_plugin)
+{
+    mana_plugin_t plugin;
+    plugin.init = init;
+    plugin.shutdown = shutdown;
+    plugin.begin_run = begin_run;
+    plugin.end_run = end_run;
+    plugin.process_event = process_event;
+    plugin.process_system_event = process_system_event;
+    return plugin;
+}

src/mana_python_test_plugin.py

@@ -0,0 +1,13 @@
+
+import json
+import py_mana
+
+def begin_run(runDescription: str):
+    print("begin_run")
+
+def end_run(runDescription: str):
+    print("end_run")
+
+def event_data(eventIndex: int, dataArrays):
+    return
+    print(f"event[{eventIndex}]: {dataArrays}")