You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@subversion.apache.org by rd...@apache.org on 2010/08/02 00:19:59 UTC

svn commit: r981330 - in /subversion/trunk/subversion/bindings/swig/python: libsvn_swig_py/swigutil_py.c tests/core.py

Author: rdonch
Date: Sun Aug  1 22:19:59 2010
New Revision: 981330

URL: http://svn.apache.org/viewvc?rev=981330&view=rev
Log:
SWIG/Python: enhance the exception translation mechanism so that a
SubversionException thrown from a callback would be fully translated into an
svn_error_t, including any nested exceptions.

* subversion/bindings/swig/python/libsvn_swig_py/swigutil_py.c:
  (callback_exception_error): Split into two, the other half being
    exception_to_error.
  (exception_to_error): New function for handling the conversion itself.

* subversion/bindings/swig/python/tests/core.py:
  (SubversionCoreTestCase.test_exception_interoperability): New test for
    the exception translation mechanism, including this revision's
    improvements.


Modified:
    subversion/trunk/subversion/bindings/swig/python/libsvn_swig_py/swigutil_py.c
    subversion/trunk/subversion/bindings/swig/python/tests/core.py

Modified: subversion/trunk/subversion/bindings/swig/python/libsvn_swig_py/swigutil_py.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/bindings/swig/python/libsvn_swig_py/swigutil_py.c?rev=981330&r1=981329&r2=981330&view=diff
==============================================================================
--- subversion/trunk/subversion/bindings/swig/python/libsvn_swig_py/swigutil_py.c (original)
+++ subversion/trunk/subversion/bindings/swig/python/libsvn_swig_py/swigutil_py.c Sun Aug  1 22:19:59 2010
@@ -1320,6 +1320,61 @@ commit_item_array_to_list(const apr_arra
 
 /*** Errors ***/
 
+/* Convert a given SubversionException to an svn_error_t. On failure returns
+   NULL and sets a Python exception. */
+static svn_error_t *exception_to_error(PyObject * exc)
+{
+	const char *message, *file = NULL;
+	apr_status_t apr_err;
+	long line = 0;
+	PyObject *apr_err_ob = NULL, *child_ob = NULL, *message_ob = NULL;
+	PyObject *file_ob = NULL, *line_ob = NULL;
+    svn_error_t *rv = NULL, *child = NULL;
+
+	if ((apr_err_ob = PyObject_GetAttrString(exc, "apr_err")) == NULL)
+	    goto finished;
+	apr_err = (apr_status_t) PyInt_AsLong(apr_err_ob);
+	if (PyErr_Occurred()) goto finished;
+
+	if ((message_ob = PyObject_GetAttrString(exc, "message")) == NULL)
+	    goto finished;
+	message = PyString_AsString(message_ob);
+	if (PyErr_Occurred()) goto finished;
+
+	if ((file_ob = PyObject_GetAttrString(exc, "file")) == NULL)
+	    goto finished;
+	if (file_ob != Py_None)
+	    file = PyString_AsString(file_ob);
+	if (PyErr_Occurred()) goto finished;
+
+	if ((line_ob = PyObject_GetAttrString(exc, "line")) == NULL)
+	    goto finished;
+	if (line_ob != Py_None)
+	    line = PyInt_AsLong(line_ob);
+	if (PyErr_Occurred()) goto finished;
+
+	if ((child_ob = PyObject_GetAttrString(exc, "child")) == NULL)
+	    goto finished;
+	/* We could check if the child is a Subversion exception too,
+	   but let's just apply duck typing. */
+	if (child_ob != Py_None)
+	    child = exception_to_error(child_ob);
+	if (PyErr_Occurred()) goto finished;
+
+	rv = svn_error_create(apr_err, child, message);
+	/* Somewhat hacky, but we need to preserve original file/line info. */
+	rv->file = file ? apr_pstrdup(rv->pool, file) : NULL;
+	rv->line = line;
+
+finished:
+	Py_XDECREF(child_ob);
+	Py_XDECREF(line_ob);
+	Py_XDECREF(file_ob);
+	Py_XDECREF(message_ob);
+	Py_XDECREF(apr_err_ob);
+	return rv;
+}
+
 /* If the currently set Python exception is a valid SubversionException,
    clear exception state and transform it into a Subversion error.
    Otherwise, return a Subversion error about an exception in a callback. */
@@ -1327,48 +1382,36 @@ static svn_error_t *callback_exception_e
 {
   PyObject *svn_module = NULL, *svn_exc = NULL;
   PyObject *exc, *exc_type, *exc_traceback;
-  PyObject *message_ob = NULL, *apr_err_ob = NULL;
-  const char *message;
-  int apr_err;
   svn_error_t *rv = NULL;
 
   PyErr_Fetch(&exc_type, &exc, &exc_traceback);
 
   if ((svn_module = PyImport_ImportModule("svn.core")) == NULL)
-    goto finished;
-  if ((svn_exc = PyObject_GetAttrString(svn_module, "SubversionException"))
-      == NULL)
-    goto finished;
-
-  if (!PyErr_GivenExceptionMatches(exc_type, svn_exc))
-    {
-      PyErr_Restore(exc_type, exc, exc_traceback);
-      exc = exc_type = exc_traceback = NULL;
       goto finished;
-    }
 
-  if ((apr_err_ob = PyObject_GetAttrString(exc, "apr_err")) == NULL)
-    goto finished;
-  apr_err = PyInt_AsLong(apr_err_ob);
-  if (PyErr_Occurred()) goto finished;
+  svn_exc = PyObject_GetAttrString(svn_module, "SubversionException");
+  Py_DECREF(svn_module);
 
-  if ((message_ob = PyObject_GetAttrString(exc, "message")) == NULL)
-    goto finished;
-  message = PyString_AsString(message_ob);
-  if (PyErr_Occurred()) goto finished;
+  if (svn_exc == NULL)
+      goto finished;
 
-  /* A possible improvement here would be to convert the whole
-     SubversionException chain. */
-  rv = svn_error_create(apr_err, NULL, message);
+  if (PyErr_GivenExceptionMatches(exc_type, svn_exc))
+    {
+      rv = exception_to_error(exc);
+    }
+  else
+    {
+      PyErr_Restore(exc_type, exc, exc_traceback);
+      exc_type = exc = exc_traceback = NULL;
+    }
 
 finished:
-  Py_XDECREF(exc);
+  Py_XDECREF(svn_exc);
   Py_XDECREF(exc_type);
+  Py_XDECREF(exc);
   Py_XDECREF(exc_traceback);
-  Py_XDECREF(svn_module);
-  Py_XDECREF(svn_exc);
-  Py_XDECREF(apr_err_ob);
-  Py_XDECREF(message_ob);
+  /* By now, either rv is set and the exception is cleared, or rv is NULL
+     and an exception is pending (possibly a new one). */
   return rv ? rv : svn_error_create(SVN_ERR_SWIG_PY_EXCEPTION_SET, NULL,
                                     "Python callback raised an exception");
 }

Modified: subversion/trunk/subversion/bindings/swig/python/tests/core.py
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/bindings/swig/python/tests/core.py?rev=981330&r1=981329&r2=981330&view=diff
==============================================================================
--- subversion/trunk/subversion/bindings/swig/python/tests/core.py (original)
+++ subversion/trunk/subversion/bindings/swig/python/tests/core.py Sun Aug  1 22:19:59 2010
@@ -20,7 +20,8 @@
 #
 import unittest
 
-import svn.core
+import svn.core, svn.client
+import utils
 
 class SubversionCoreTestCase(unittest.TestCase):
   """Test cases for the basic SWIG Subversion core"""
@@ -46,6 +47,64 @@ class SubversionCoreTestCase(unittest.Te
             svn.core.svn_mime_type_validate, "this\nis\ninvalid\n")
     svn.core.svn_mime_type_validate("unknown/but-valid; charset=utf8")
 
+  def test_exception_interoperability(self):
+    """Test if SubversionException is correctly converted into svn_error_t
+    and vice versa."""
+    t = utils.Temper()
+    (_, _, repos_uri) = t.alloc_empty_repo(suffix='-core')
+    rev = svn.core.svn_opt_revision_t()
+    rev.kind = svn.core.svn_opt_revision_head
+    ctx = svn.client.create_context()
+    
+    class Receiver:
+      def __call__(self, path, info, pool):
+        raise self.e
+    
+    rec = Receiver()
+    args = (repos_uri, rev, rev, rec, svn.core.svn_depth_empty, None, ctx)
+
+    try:
+      # ordinary Python exceptions must be passed through
+      rec.e = TypeError()
+      self.assertRaises(TypeError, svn.client.info2, *args)
+      
+      # SubversionException will be translated into an svn_error_t, propagated
+      # through the call chain and translated back to SubversionException.
+      rec.e = svn.core.SubversionException("Bla bla bla.",
+                                           svn.core.SVN_ERR_INCORRECT_PARAMS,
+                                           file=__file__, line=866)
+      rec.e.child = svn.core.SubversionException("Yada yada.",
+                                             svn.core.SVN_ERR_INCOMPLETE_DATA)
+      self.assertRaises(svn.core.SubversionException, svn.client.info2, *args)
+      
+      # It must remain unchanged through the process.
+      try:
+        svn.client.info2(*args)
+      except svn.core.SubversionException as exc:
+        # find the original exception
+        while exc.file != rec.e.file: exc = exc.child
+        
+        self.assertEqual(exc.message, rec.e.message)
+        self.assertEqual(exc.apr_err, rec.e.apr_err)
+        self.assertEqual(exc.line, rec.e.line)
+        self.assertEqual(exc.child.message, rec.e.child.message)
+        self.assertEqual(exc.child.apr_err, rec.e.child.apr_err)
+        self.assertEqual(exc.child.child, None)
+        self.assertEqual(exc.child.file, None)
+        self.assertEqual(exc.child.line, 0)
+        
+      # Incomplete SubversionExceptions must trigger Python exceptions, which
+      # will be passed through.
+      rec.e = svn.core.SubversionException("No fields except message.")
+      # e.apr_err is None but should be an int
+      self.assertRaises(TypeError, svn.client.info2, args)
+    finally:
+      # This would happen without the finally block as well, but we expliticly
+      # order the operations so that the cleanup is not hindered by any open
+      # handles.
+      del ctx
+      t.cleanup()
+
 def suite():
     return unittest.makeSuite(SubversionCoreTestCase, 'test')