python: Implement data callbacks.

* lang/python/gpgme.i (object_to_gpgme_t): Set exception on error.
* lang/python/helpers.c (pyDataReadCb): New function.
(pyDataWriteCb): Likewise.
(pyDataSeekCb): Likewise.
(pyDataReleaseCb): Likewise.
(pygpgme_data_new_from_cbs): Likewise.
* lang/python/helpers.h (pygpgme_data_new_from_cbs): New prototype.
* lang/python/pyme/core.py (Data.__init__): Fix docstring, fix read
callbacks.
(Data.__del__): Fix read callbacks.
(Data._free_readcb): Drop function.
(Data._free_datacbs): New function.
(Data.new_from_cbs): Fix setting the callbacks.
(Data.write): Raise stashed exceptions.
(Data.read): Likewise.
* lang/python/tests/t-callbacks.py: Test new functionality.
* lang/python/tests/t-data.py: Likewise.

Signed-off-by: Justus Winter <[email protected]>

2 files changed, 112 insertions, 0 deletions

diff --git a/lang/python/tests/t-callbacks.py b/lang/python/tests/t-callbacks.py
index 57975264..3219463c 100755
--- a/lang/python/tests/t-callbacks.py
+++ b/lang/python/tests/t-callbacks.py
@@ -17,6 +17,7 @@
 # You should have received a copy of the GNU Lesser General Public
 # License along with this program; if not, see <http://www.gnu.org/licenses/>.
 
+import os
 from pyme import core, constants
 import support
 
@@ -181,3 +182,73 @@ except Exception as e:
     assert e == myException
 else:
     assert False, "Expected an error, got none"
+
+
+
+# Test the data callbacks.
+def read_cb(amount, hook=None):
+    assert hook == cookie
+    return 0
+def release_cb(hook=None):
+    assert hook == cookie
+data = core.Data(cbs=(read_cb, None, None, release_cb, cookie))
+try:
+    data.read()
+except Exception as e:
+    assert type(e) == TypeError
+else:
+    assert False, "Expected an error, got none"
+
+def read_cb(amount):
+    raise myException
+data = core.Data(cbs=(read_cb, None, None, lambda: None))
+try:
+    data.read()
+except Exception as e:
+    assert e == myException
+else:
+    assert False, "Expected an error, got none"
+
+
+def write_cb(what, hook=None):
+    assert hook == cookie
+    return "wrong type"
+data = core.Data(cbs=(None, write_cb, None, release_cb, cookie))
+try:
+    data.write(b'stuff')
+except Exception as e:
+    assert type(e) == TypeError
+else:
+    assert False, "Expected an error, got none"
+
+def write_cb(what):
+    raise myException
+data = core.Data(cbs=(None, write_cb, None, lambda: None))
+try:
+    data.write(b'stuff')
+except Exception as e:
+    assert e == myException
+else:
+    assert False, "Expected an error, got none"
+
+
+def seek_cb(offset, whence, hook=None):
+    assert hook == cookie
+    return "wrong type"
+data = core.Data(cbs=(None, None, seek_cb, release_cb, cookie))
+try:
+    data.seek(0, os.SEEK_SET)
+except Exception as e:
+    assert type(e) == TypeError
+else:
+    assert False, "Expected an error, got none"
+
+def seek_cb(offset, whence):
+    raise myException
+data = core.Data(cbs=(None, None, seek_cb, lambda: None))
+try:
+    data.seek(0, os.SEEK_SET)
+except Exception as e:
+    assert e == myException
+else:
+    assert False, "Expected an error, got none"
diff --git a/lang/python/tests/t-data.py b/lang/python/tests/t-data.py
index 6cf10fab..de60c473 100755
--- a/lang/python/tests/t-data.py
+++ b/lang/python/tests/t-data.py
@@ -17,6 +17,7 @@
 # You should have received a copy of the GNU Lesser General Public
 # License along with this program; if not, see <http://www.gnu.org/licenses/>.
 
+import io
 import os
 import tempfile
 from pyme import core
@@ -79,3 +80,43 @@ with tempfile.NamedTemporaryFile() as tmp:
     # Open using name, offset, and length.
     data = core.Data(file=tmp.name, offset=23, length=42)
     assert data.read() == binjunk[23:23+42]
+
+# Test callbacks.
+class DataObject(object):
+    def __init__(self):
+        self.buffer = io.BytesIO()
+        self.released = False
+
+    def read(self, amount, hook=None):
+        assert not self.released
+        return self.buffer.read(amount)
+
+    def write(self, data, hook=None):
+        assert not self.released
+        return self.buffer.write(data)
+
+    def seek(self, offset, whence, hook=None):
+        assert not self.released
+        return self.buffer.seek(offset, whence)
+
+    def release(self, hook=None):
+        assert not self.released
+        self.released = True
+
+do = DataObject()
+cookie = object()
+data = core.Data(cbs=(do.read, do.write, do.seek, do.release, cookie))
+data.write('Hello world!')
+data.seek(0, os.SEEK_SET)
+assert data.read() == b'Hello world!'
+del data
+assert do.released
+
+# Again, without the cookie.
+do = DataObject()
+data = core.Data(cbs=(do.read, do.write, do.seek, do.release))
+data.write('Hello world!')
+data.seek(0, os.SEEK_SET)
+assert data.read() == b'Hello world!'
+del data
+assert do.released