python: call gnutls_global_init/gnutls_global_deinit on module load/unload

python/opendht.pyx

@@ -34,6 +34,20 @@ cimport opendht_cpp as cpp
 
 import threading
 
+cdef inline void _initialize_gnutls():
+    cdef int err = cpp.gnutls_global_init()
+    if err != 0:
+        print(f"Failed to initialize GnuTLS: {cpp.gnutls_strerror(err).decode()}")
+    else:
+        import atexit
+        atexit.register(_deinitialize_gnutls)
+
+cdef inline _deinitialize_gnutls():
+    cpp.gnutls_global_deinit()
+
+# Initialize GnuTLS when this module is imported
+_initialize_gnutls()
+
 cdef inline void lookup_callback(cpp.vector[cpp.shared_ptr[cpp.IndexValue]]* values, cpp.Prefix* p, void *user_data) noexcept with gil:
     cbs = <object>user_data
     if 'lookup' in cbs and cbs['lookup']:

python/opendht_cpp.pxd

@@ -326,3 +326,8 @@ cdef extern from "opendht/indexation/pht.h" namespace "dht::indexation":
         void insert(IndexKey k, IndexValue v, DoneCallbackSimple cb)
         @staticmethod
         LookupCallback bindLookupCb(LookupCallbackRaw cb, void *user_data)
+
+cdef extern from "gnutls/gnutls.h" nogil:
+    int gnutls_global_init()
+    void gnutls_global_deinit()
+    const char* gnutls_strerror(int error)

python/setup.py.in

@@ -42,7 +42,7 @@ setup(name="opendht",
           language="c++",
           extra_compile_args=["-std=c++17", "-DMSGPACK_NO_BOOST", "-DMSGPACK_DISABLE_LEGACY_NIL", "-DMSGPACK_DISABLE_LEGACY_CONVERT", "-DOPENDHT_INDEXATION", "-Dopendht_EXPORTS"],
           extra_link_args=["-std=c++17"],
-          libraries=["opendht"],
+          libraries=["opendht", "gnutls"],
           include_dirs = ['@PROJECT_SOURCE_DIR@/include'@OPENDHT_PYTHON_INCLUDE_DIRS@],
           library_dirs = ['@CURRENT_BINARY_DIR@', '@PROJECT_BINARY_DIR@'@OPENDHT_PYTHON_LIBRARY_DIRS@]
       )]