[libvirt] [PATCH python] Optimize callback lookup in event handlers

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; The event handler code currently invokes PyImport_ImportModule which is very heavyweight. This is not in fact required, since we know the libvirt module has already been imported. We can thus use PyImport_ImportModuleNoBlock and do away with the global variables caching the imported module reference. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- libvirt-override.c | 35 +++++++++++------------------------ 1 file changed, 11 insertions(+), 24 deletions(-) diff --git a/libvirt-override.c b/libvirt-override.c index 03aab89..aaee6b8 100644 --- a/libvirt-override.c +++ b/libvirt-override.c @@ -4929,39 +4929,26 @@ cleanup: * Helper functions to avoid importing modules * for every callback *******************************************/ -static PyObject *libvirt_module = NULL; -static PyObject *libvirt_dict = NULL; static PyObject * -getLibvirtModuleObject(void) { - if (libvirt_module) - return libvirt_module; - - // PyImport_ImportModule returns a new reference - /* Bogus (char *) cast for RHEL-5 python API brokenness */ - libvirt_module = PyImport_ImportModule((char *)"libvirt"); - if (!libvirt_module) { - DEBUG("%s Error importing libvirt module\n", __FUNCTION__); +getLibvirtDictObject(void) { + PyObject *libvirt_mod; + PyObject *libvirt_dict; + + libvirt_mod = PyImport_ImportModuleNoBlock("libvirt"); + if (!libvirt_mod) { + DEBUG("%s Error finding libvirt in imports\n", + __FUNCTION__); PyErr_Print(); return NULL; } - - return libvirt_module; -} - -static PyObject * -getLibvirtDictObject(void) { - if (libvirt_dict) - return libvirt_dict; - - // PyModule_GetDict returns a borrowed reference - libvirt_dict = PyModule_GetDict(getLibvirtModuleObject()); + libvirt_dict = PyModule_GetDict(libvirt_mod); if (!libvirt_dict) { - DEBUG("%s Error importing libvirt dictionary\n", __FUNCTION__); + DEBUG("%s Error finding libvirt dict\n", + __FUNCTION__); PyErr_Print(); return NULL; } - Py_INCREF(libvirt_dict); return libvirt_dict; } -- 1.8.3.1