* TODO: updated

* python/Makefile.am python/generator.py python/libvir.c
  python/libvir.py: improved python binding, raise exception
  when an instance creation or lookup fails, and add support
  for the global error handler, per conn handler still needed
* python/tests/error.py python/tests/Makefile.am: adding a
  regression test
Daniel

ChangeLog

+Tue Feb 28 13:12:50 CET 2006 Daniel Veillard <veillard@redhat.com>
+
+	* TODO: updated
+	* python/Makefile.am python/generator.py python/libvir.c 
+	  python/libvir.py: improved python binding, raise exception 
+	  when an instance creation or lookup fails, and add support
+	  for the global error handler, per conn handler still needed
+	* python/tests/error.py python/tests/Makefile.am: adding a
+	  regression test
+
 Mon Feb 27 17:36:29 EST 2006 Daniel Veillard <veillard@redhat.com>
 
 	* doc//*: rebuilt

TODO

@@ -32,6 +32,7 @@ Would-be-nice TODO:
 - man page for virsh and the libraries entry points
 - support for QEmu and other virtualization engines
 - more documentation and examples on using the toolkit
+- examples and docs for the principle in the error handling code
 
 Cleanup:
 - now that libxml2 is linked in, drop hash.[ch] and get back to libxml2 ones ?

python/Makefile.am

@@ -18,6 +18,7 @@ EXTRA_DIST =		\
 	generator.py	\
 	libvirt_wrap.h	\
 	libvirt.py	\
+	libvir.py	\
 	libvirt-python-api.xml \
 	$(DOCS)
 
@@ -33,6 +34,8 @@ python_LTLIBRARIES = libvirtmod.la
 libvirtmod_la_SOURCES = libvir.c types.c libvirt-py.c libvirt-py.h
 libvirtmod_la_LIBADD = $(mylibs) 
 
+libvirt.py: $(srcdir)/libvir.py libvirtclass.py
+	cat $(srcdir)/libvir.py libvirtclass.py > libvirt.py
 
 install-data-local:
 	$(mkinstalldirs) $(DESTDIR)$(pythondir)

python/generator.py

@@ -251,7 +251,7 @@ foreign_encoding_args = (
 
 #######################################################################
 #
-#  This part writes the C <-> Python stubs libxml2-py.[ch] and
+#  This part writes the C <-> Python stubs libvirt2-py.[ch] and
 #  the table libxml2-export.c to add when registrering the Python module
 #
 #######################################################################
@@ -691,17 +691,7 @@ def buildWrappers():
 	info = (0, func, name, ret, args, file)
 	function_classes['None'].append(info)
    
-    classes = open("libvirt.py", "w")
-    classes.write("""#!/usr/bin/python -u
-#
-# Those are the autogenerated Python bindings for libvirt.
-# Check python/generator.py in the source distribution of libvirt
-# to find out more about the generation process
-#
-""")
-
-    classes.write("import libvirtmod\n")
-    classes.write("import types\n\n")
+    classes = open("libvirtclass.py", "w")
 
     txt = open("libvirtclass.txt", "w")
     txt.write("          Generated Classes for libvir-python\n\n")
@@ -754,7 +744,12 @@ def buildWrappers():
 		    # Raise an exception
 		    #
 		    if functions_noexcept.has_key(name):
-		        classes.write("    if ret is None:return None\n");
+			classes.write("    if ret is None:return None\n");
+		    else:
+			classes.write(
+		     "    if ret is None:raise libvirtError('%s() failed')\n" %
+				      (name))
+
 		    classes.write("    return ");
 		    classes.write(classes_type[ret[0]][1] % ("ret"));
 		    classes.write("\n");
@@ -867,6 +862,10 @@ def buildWrappers():
 			if functions_noexcept.has_key(name):
 			    classes.write(
 			        "        if ret is None:return None\n");
+			else:
+			    classes.write(
+		     "        if ret is None:raise libvirtError('%s() failed')\n" %
+					  (name))
 
 			#
 			# generate the returned class wrapper for the object

python/libvir.c

@@ -11,11 +11,108 @@
 
 #include <Python.h>
 #include <libvirt.h>
+#include <virterror.h>
 #include "libvirt_wrap.h"
 #include "libvirt-py.h"
 
 void initlibvirmod(void);
 
+PyObject *libvirt_virDomainGetUUID(PyObject *self ATTRIBUTE_UNUSED, PyObject *args);
+/************************************************************************
+ *									*
+ *		Global error handler at the Python level		*
+ *									*
+ ************************************************************************/
+
+static PyObject *libvirt_virPythonErrorFuncHandler = NULL;
+static PyObject *libvirt_virPythonErrorFuncCtxt = NULL;
+
+static void
+libvirt_virErrorFuncHandler(ATTRIBUTE_UNUSED void *ctx, virErrorPtr err)
+{
+    PyObject *list, *info;
+    PyObject *result;
+
+#ifdef DEBUG_ERROR
+    printf("libvirt_virErrorFuncHandler(%p, %s, ...) called\n", ctx, msg);
+#endif
+
+    if ((err == NULL) || (err->code == VIR_ERR_OK))
+        return;
+
+    if ((libvirt_virPythonErrorFuncHandler == NULL) ||
+        (libvirt_virPythonErrorFuncHandler == Py_None)) {
+        virDefaultErrorFunc(err);
+    } else {
+        list = PyTuple_New(2);
+        info = PyTuple_New(9);
+        PyTuple_SetItem(list, 0, libvirt_virPythonErrorFuncCtxt);
+        PyTuple_SetItem(list, 1, info);
+        Py_XINCREF(libvirt_virPythonErrorFuncCtxt);
+        PyTuple_SetItem(info, 0, PyInt_FromLong((long) err->code));
+        PyTuple_SetItem(info, 1, PyInt_FromLong((long) err->domain));
+	PyTuple_SetItem(info, 2, libvirt_charPtrWrap(err->message));
+        PyTuple_SetItem(info, 3, PyInt_FromLong((long) err->level));
+	PyTuple_SetItem(info, 4, libvirt_charPtrWrap(err->str1));
+	PyTuple_SetItem(info, 5, libvirt_charPtrWrap(err->str2));
+	PyTuple_SetItem(info, 6, libvirt_charPtrWrap(err->str3));
+        PyTuple_SetItem(info, 7, PyInt_FromLong((long) err->int1));
+        PyTuple_SetItem(info, 8, PyInt_FromLong((long) err->int2));
+	/* TODO pass conn and dom if available */
+        result = PyEval_CallObject(libvirt_virPythonErrorFuncHandler, list);
+        Py_XDECREF(list);
+        Py_XDECREF(result);
+    }
+}
+
+static PyObject *
+libvirt_virRegisterErrorHandler(ATTRIBUTE_UNUSED PyObject * self,
+                               PyObject * args)
+{
+    PyObject *py_retval;
+    PyObject *pyobj_f;
+    PyObject *pyobj_ctx;
+
+    if (!PyArg_ParseTuple
+        (args, (char *) "OO:xmlRegisterErrorHandler", &pyobj_f,
+         &pyobj_ctx))
+        return (NULL);
+
+#ifdef DEBUG_ERROR
+    printf("libvirt_virRegisterErrorHandler(%p, %p) called\n", pyobj_ctx,
+           pyobj_f);
+#endif
+
+    virSetErrorFunc(NULL, libvirt_virErrorFuncHandler);
+    if (libvirt_virPythonErrorFuncHandler != NULL) {
+        Py_XDECREF(libvirt_virPythonErrorFuncHandler);
+    }
+    if (libvirt_virPythonErrorFuncCtxt != NULL) {
+        Py_XDECREF(libvirt_virPythonErrorFuncCtxt);
+    }
+
+    if ((pyobj_f == Py_None) && (pyobj_ctx == Py_None)) {
+        libvirt_virPythonErrorFuncHandler = NULL;
+	libvirt_virPythonErrorFuncCtxt = NULL;
+    } else {
+	Py_XINCREF(pyobj_ctx);
+	Py_XINCREF(pyobj_f);
+
+	/* TODO: check f is a function ! */
+	libvirt_virPythonErrorFuncHandler = pyobj_f;
+	libvirt_virPythonErrorFuncCtxt = pyobj_ctx;
+    }
+
+    py_retval = libvirt_intWrap(1);
+    return (py_retval);
+}
+
+/************************************************************************
+ *									*
+ *		Wrappers for functions where generator fails		*
+ *									*
+ ************************************************************************/
+
 static PyObject *
 libvirt_virDomainFree(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) {
     PyObject *py_retval;
@@ -106,7 +203,6 @@ libvirt_virDomainGetUUID(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) {
     unsigned char uuid[16];
     virDomainPtr domain;
     PyObject *pyobj_domain;
-    virDomainInfo info;
 
     if (!PyArg_ParseTuple(args, (char *)"O:virDomainGetUUID", &pyobj_domain))
         return(NULL);
@@ -161,6 +257,7 @@ static PyMethodDef libvirtMethods[] = {
     {(char *) "virDomainGetInfo", libvirt_virDomainGetInfo, METH_VARARGS, NULL},
     {(char *) "virDomainGetUUID", libvirt_virDomainGetUUID, METH_VARARGS, NULL},
     {(char *) "virDomainLookupByUUID", libvirt_virDomainLookupByUUID, METH_VARARGS, NULL},
+    {(char *) "virRegisterErrorHandler", libvirt_virRegisterErrorHandler, METH_VARARGS, NULL},
     {NULL, NULL, 0, NULL}
 };
 

python/libvir.py

+#!/usr/bin/python -u
+#
+# Those are the autogenerated Python bindings for libvirt.
+# Check python/generator.py in the source distribution of libvir
+# to find out more about the generation process
+#
+import libvirtmod
+import types
+
+# The root of all libxml2 errors.
+class libvirtError(Exception):
+    pass
+
+
+#
+# register the libvirt global error handler
+#
+def registerErrorHandler(f, ctx):
+    """Register a Python written function to for error reporting.
+       The function is called back as f(ctx, error), with error
+       being a list of informations about the error being raised.
+       Returns 1 in case of success."""
+    return libvirtmod.virRegisterErrorHandler(f,ctx)
+
+# WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
+#
+# Everything before this line comes from libvir.py
+# Everything after this line is automatically generated
+#
+# WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING

python/tests/Makefile.am

@@ -3,7 +3,8 @@ EXAMPLE_DIR = $(datadir)/doc/libvirt-python-$(LIBVIRT_VERSION)/examples
 PYTESTS=		\
 	basic.py	\
 	create.py	\
-	uuid.py
+	uuid.py		\
+	error.py
 
 EXTRA_DIST = $(PYTESTS)
 

python/tests/error.py

+#!/usr/bin/python -u
+#
+# Tests global error handlers at the python level.
+#
+import libvirt
+import sys
+import os
+
+errno = None
+
+def handler(ctxt, err):
+    global errno
+
+    #print "handler(%s, %s)" % (ctxt, err)
+    errno = err
+
+libvirt.registerErrorHandler(handler, 'context')
+
+conn = libvirt.openReadOnly(None)
+if conn == None:
+    print 'Failed to open connection to the hypervisor'
+    sys.exit(1)
+
+try:
+    dom0 = conn.lookupByName("Does_not_exist")
+    print 'strange found a Does_not_exist domain'
+    sys.exit(1)
+except:
+    pass
+
+del conn
+
+if errno == None:
+    print 'failed to get an error'
+elif errno[0] == libvirt.VIR_ERR_NO_CONNECT or \
+     errno[0] == libvirt.VIR_ERR_INVALID_DOMAIN:
+    print "OK"
+else:
+    print 'got unexpected error %s' % (errno)
+
+sys.exit(0)