In the ctypes-python bindings, when I try to use the Stream class
(either via the RemoteRepository.cat() method, or just on its own), I
find that the program crashes at the moment the C code in
svn_stream_write() calls the callback function which is provided by
subversion/bindings/ctypes-python/csvn/types.py:240:
> class Stream(object):
>
> def __init__(self, buffer, disown=False):
> [...]
> svn_stream_set_read(self.stream, svn_read_fn_t(self._read))
>
> def _write(self, baton, data, l):
> [...]
So, using the attached patch (with or without the experimental edits it
contains in _read() and _write()), I find the tests suite bombs out
without reporting any results. My usage of GDB and the Python debugger
pdb indicates that _write() is never reached.
If I write a test using a ctypes callback type with the C standard
library's qsort(), as shown in the Python ctypes module documentation
<http://docs.python.org/library/ctypes.html#callback-functions>, that
works fine for me.
I wonder if something is wrong with my building and linking of ctypesgen
or the ctypes-python bindings, but on the other hand the obvious bug in
Stream._read() where 'string' is referenced instead of 's' (see my
patch) makes me wonder if this class has ever worked.
Another data point: the log message receiver callback seems to work fine
for me, as tested in
subversion/bindings/ctypes-python/test/remoterepos.py:test_log().
- Julian
In the ctypes-python bindings, fix the Stream class and add tests and doc
strings.
### This is just an attempt, and not yet correct.
* subversion/bindings/ctypes-python/csvn/types.py
(Stream._read): This was totally broken: at the very least it should say
's' instead of 'string'. Try using plain Python code instead of
'memmove'; this might be totally wrong. Another guess: maybe it should
be 'memmove(buffer.raw, create_string_buffer(s, len(s)), len(s))'.
(Stream._write): Try using plain Python code instead of special ctypes
code, for symmetry and simplicity; this might be totally wrong.
(Stream): Add doc strings to the methods, as their argument types are a
little unclear, especially 'buffer' which has two different meanings.
* subversion/bindings/ctypes-python/test/svntypes.py
(StreamTestCase): New test case class containing one simple test.
(suite): Include it.
* subversion/bindings/ctypes-python/test/remoterepos.py
(RemoteRepositoryTestCase): Add a test for 'cat'.
(suite): ### Run it instead of the normal tests, just for debugging.
--This line, and those below, will be ignored--
Index: subversion/bindings/ctypes-python/csvn/types.py
===================================================================
--- subversion/bindings/ctypes-python/csvn/types.py (revision 1157788)
+++ subversion/bindings/ctypes-python/csvn/types.py (working copy)
@@ -246,13 +262,13 @@ class Stream(object):
def _read(self, baton, buffer, l):
s = self.buffer.read(l[0])
- memmove(buffer, string, len(s))
+ buffer.data = s
l[0] = len(s)
return SVN_NO_ERROR
def _write(self, baton, data, l):
- s = string_at(data.raw, l[0])
- self.buffer.write(s)
+ s = str(data)
+ self.buffer.write(s[:l[0]])
return SVN_NO_ERROR
def _close(self, baton):
Index: subversion/bindings/ctypes-python/csvn/types.py
===================================================================
--- subversion/bindings/ctypes-python/csvn/types.py (revision 1157734)
+++ subversion/bindings/ctypes-python/csvn/types.py (working copy)
@@ -232,7 +232,9 @@ class APRFile(object):
class Stream(object):
def __init__(self, buffer, disown=False):
- """Create a stream which wraps a Python file or file-like object"""
+ """Create a stream which wraps the Python file or file-like object
+ BUFFER. If DISOWN is true, closing this stream won't close
+ BUFFER."""
self.pool = Pool()
self.buffer = buffer
@@ -245,17 +247,23 @@ class Stream(object):
_as_parameter_ = property(fget=lambda self: self.stream)
def _read(self, baton, buffer, l):
+ """Read (*L) bytes from self.buffer into BUFFER. Implements svn_read_fn_t.
+ BATON is unused; BUFFER is a String; L is a POINTER(apr_size_t)."""
s = self.buffer.read(l[0])
memmove(buffer, string, len(s))
l[0] = len(s)
return SVN_NO_ERROR
def _write(self, baton, data, l):
+ """Write (*L) bytes into self.buffer from DATA. Implements svn_write_fn_t.
+ BATON is unused; DATA is a String; L is a POINTER(apr_size_t)."""
s = string_at(data.raw, l[0])
self.buffer.write(s)
return SVN_NO_ERROR
def _close(self, baton):
+ """Close this stream and the underlying file-like object
+ 'self.buffer'. Implements svn_close_fn_t."""
self.buffer.close()
return SVN_NO_ERROR
Index: subversion/bindings/ctypes-python/test/svntypes.py
===================================================================
--- subversion/bindings/ctypes-python/test/svntypes.py (revision 1157904)
+++ subversion/bindings/ctypes-python/test/svntypes.py (working copy)
@@ -23,6 +23,15 @@ from csvn.core import *
import csvn.types as _types
from csvn.types import SvnDate, Hash, Array, APRFile, Stream, SvnStringPtr
+from sys import version_info # For Python version check
+if version_info[0] >= 3:
+ # Python >=3.0
+ from io import StringIO
+else:
+ # Python <3.0
+ from StringIO import StringIO
+
+
class SvnDateTestCase(unittest.TestCase):
def test_as_apr_time_t(self):
@@ -86,11 +95,23 @@ class ArrayTestCase(unittest.TestCase):
self.assertEqual(self.svnarray[2], "vici")
self.assertEqual(self.svnarray[1], "vidi")
+class StreamTestCase(unittest.TestCase):
+
+ def test_stream(self):
+ buf = StringIO()
+ s = Stream(buf, disown=True)
+ l = apr_size_t(5)
+ svn_stream_write(s, 'Hello', l)
+ self.assertEqual(l, 5)
+ buf.seek(0)
+ self.assertEqual(buf.read(), 'Hello')
+
def suite():
suite = unittest.TestSuite()
suite.addTest(unittest.makeSuite(SvnDateTestCase, 'test'))
suite.addTest(unittest.makeSuite(HashTestCase, 'test'))
suite.addTest(unittest.makeSuite(ArrayTestCase, 'test'))
+ suite.addTest(unittest.makeSuite(StreamTestCase, 'test'))
return suite
if __name__ == '__main__':
Index: subversion/bindings/ctypes-python/test/remoterepos.py
===================================================================
--- subversion/bindings/ctypes-python/test/remoterepos.py (revision 1157904)
+++ subversion/bindings/ctypes-python/test/remoterepos.py (working copy)
@@ -106,6 +106,15 @@ class RemoteRepositoryTestCase(unittest.
for path in found:
self.svn_dirent_t_assert_equal(found[path], expected[path])
+ ### This test does not merely fail, it bombs right out of the test suite
+ ### at the point where the C svn_stream_write() calls the Python
+ ### callback.
+ def zzz_test_cat(self):
+ buf = StringIO()
+ self.repos.cat(buf, "trunk/README.txt")
+ buf.seek(0)
+ self.assertEqual(buf.read(), "")
+
def test_info(self):
e = svn_dirent_t(kind=svn_node_file, size=159, has_props=True,
created_rev=9, last_author=String('bruce'))
@@ -203,7 +212,7 @@ class RemoteRepositoryTestCase(unittest.
self.assertEqual(commit_info.revision, 10)
def suite():
- return unittest.makeSuite(RemoteRepositoryTestCase, 'test')
+ return unittest.makeSuite(RemoteRepositoryTestCase, 'zzz_test')
if __name__ == '__main__':
runner = unittest.TextTestRunner()
