def test_lockedfd(self):
        my_file = tempfile.mktemp()
        orig_data = "hello"
        new_data = "world"
        my_file_fp = open(my_file, "wb")
        my_file_fp.write(orig_data)
        my_file_fp.close()

        try:
            lfd = LockedFD(my_file)
            lockfilepath = lfd._lockfilepath()

            # cannot end before it was started
            self.failUnlessRaises(AssertionError, lfd.rollback)
            self.failUnlessRaises(AssertionError, lfd.commit)

            # open for writing
            assert not os.path.isfile(lockfilepath)
            wfd = lfd.open(write=True)
            assert lfd._fd is wfd
            assert os.path.isfile(lockfilepath)

            # write data and fail
            os.write(wfd, new_data)
            lfd.rollback()
            assert lfd._fd is None
            self._cmp_contents(my_file, orig_data)
            assert not os.path.isfile(lockfilepath)

            # additional call doesnt fail
            lfd.commit()
            lfd.rollback()

            # test reading
            lfd = LockedFD(my_file)
            rfd = lfd.open(write=False)
            assert os.read(rfd, len(orig_data)) == orig_data

            assert os.path.isfile(lockfilepath)
            # deletion rolls back
            del (lfd)
            assert not os.path.isfile(lockfilepath)

            # write data - concurrently
            lfd = LockedFD(my_file)
            olfd = LockedFD(my_file)
            assert not os.path.isfile(lockfilepath)
            wfdstream = lfd.open(write=True,
                                 stream=True)  # this time as stream
            assert os.path.isfile(lockfilepath)
            # another one fails
            self.failUnlessRaises(IOError, olfd.open)

            wfdstream.write(new_data)
            lfd.commit()
            assert not os.path.isfile(lockfilepath)
            self._cmp_contents(my_file, new_data)

            # could test automatic _end_writing on destruction
        finally:
            os.remove(my_file)
        # END final cleanup

        # try non-existing file for reading
        lfd = LockedFD(tempfile.mktemp())
        try:
            lfd.open(write=False)
        except OSError:
            assert not os.path.exists(lfd._lockfilepath())
        else:
            self.fail("expected OSError")
    def set_reference(self, ref, logmsg=None):
        """Set ourselves to the given ref. It will stay a symbol if the ref is a Reference.
        Otherwise an Object, given as Object instance or refspec, is assumed and if valid,
        will be set which effectively detaches the refererence if it was a purely
        symbolic one.

        :param ref: SymbolicReference instance, Object instance or refspec string
            Only if the ref is a SymbolicRef instance, we will point to it. Everthing
            else is dereferenced to obtain the actual object.
        :param logmsg: If set to a string, the message will be used in the reflog.
            Otherwise, a reflog entry is not written for the changed reference.
            The previous commit of the entry will be the commit we point to now.

            See also: log_append()

        :return: self
        :note: This symbolic reference will not be dereferenced. For that, see
            ``set_object(...)``"""
        write_value = None
        obj = None
        if isinstance(ref, SymbolicReference):
            write_value = "ref: %s" % ref.path
        elif isinstance(ref, Object):
            obj = ref
            write_value = ref.hexsha
        elif isinstance(ref, string_types):
            try:
                obj = self.repo.rev_parse(ref + "^{}")    # optionally deref tags
                write_value = obj.hexsha
            except (BadObject, BadName):
                raise ValueError("Could not extract object from %s" % ref)
            # END end try string
        else:
            raise ValueError("Unrecognized Value: %r" % ref)
        # END try commit attribute

        # typecheck
        if obj is not None and self._points_to_commits_only and obj.type != Commit.type:
            raise TypeError("Require commit, got %r" % obj)
        # END verify type

        oldbinsha = None
        if logmsg is not None:
            try:
                oldbinsha = self.commit.binsha
            except ValueError:
                oldbinsha = Commit.NULL_BIN_SHA
            # END handle non-existing
        # END retrieve old hexsha

        fpath = self.abspath
        assure_directory_exists(fpath, is_file=True)

        lfd = LockedFD(fpath)
        fd = lfd.open(write=True, stream=True)
        fd.write(write_value.encode('ascii'))
        lfd.commit()

        # Adjust the reflog
        if logmsg is not None:
            self.log_append(oldbinsha, logmsg)
        # END handle reflog

        return self
    def test_lockedfd(self):
        my_file = tempfile.mktemp()
        orig_data = "hello"
        new_data = "world"
        with open(my_file, "wb") as my_file_fp:
            my_file_fp.write(orig_data.encode("ascii"))

        try:
            lfd = LockedFD(my_file)
            lockfilepath = lfd._lockfilepath()

            # cannot end before it was started
            self.failUnlessRaises(AssertionError, lfd.rollback)
            self.failUnlessRaises(AssertionError, lfd.commit)

            # open for writing
            assert not os.path.isfile(lockfilepath)
            wfd = lfd.open(write=True)
            assert lfd._fd is wfd
            assert os.path.isfile(lockfilepath)

            # write data and fail
            os.write(wfd, new_data.encode("ascii"))
            lfd.rollback()
            assert lfd._fd is None
            self._cmp_contents(my_file, orig_data)
            assert not os.path.isfile(lockfilepath)

            # additional call doesn't fail
            lfd.commit()
            lfd.rollback()

            # test reading
            lfd = LockedFD(my_file)
            rfd = lfd.open(write=False)
            assert os.read(rfd, len(orig_data)) == orig_data.encode("ascii")

            assert os.path.isfile(lockfilepath)
            # deletion rolls back
            del(lfd)
            assert not os.path.isfile(lockfilepath)

            # write data - concurrently
            lfd = LockedFD(my_file)
            olfd = LockedFD(my_file)
            assert not os.path.isfile(lockfilepath)
            wfdstream = lfd.open(write=True, stream=True)       # this time as stream
            assert os.path.isfile(lockfilepath)
            # another one fails
            self.failUnlessRaises(IOError, olfd.open)

            wfdstream.write(new_data.encode("ascii"))
            lfd.commit()
            assert not os.path.isfile(lockfilepath)
            self._cmp_contents(my_file, new_data)

            # could test automatic _end_writing on destruction
        finally:
            os.remove(my_file)
        # END final cleanup

        # try non-existing file for reading
        lfd = LockedFD(tempfile.mktemp())
        try:
            lfd.open(write=False)
        except OSError:
            assert not os.path.exists(lfd._lockfilepath())
        else:
            self.fail("expected OSError")
    def set_reference(self, ref, logmsg=None):
        """Set ourselves to the given ref. It will stay a symbol if the ref is a Reference.
        Otherwise an Object, given as Object instance or refspec, is assumed and if valid,
        will be set which effectively detaches the refererence if it was a purely
        symbolic one.

        :param ref: SymbolicReference instance, Object instance or refspec string
            Only if the ref is a SymbolicRef instance, we will point to it. Everthing
            else is dereferenced to obtain the actual object.
        :param logmsg: If set to a string, the message will be used in the reflog.
            Otherwise, a reflog entry is not written for the changed reference.
            The previous commit of the entry will be the commit we point to now.

            See also: log_append()

        :return: self
        :note: This symbolic reference will not be dereferenced. For that, see
            ``set_object(...)``"""
        write_value = None
        obj = None
        if isinstance(ref, SymbolicReference):
            write_value = "ref: %s" % ref.path
        elif isinstance(ref, Object):
            obj = ref
            write_value = ref.hexsha
        elif isinstance(ref, string_types):
            try:
                obj = self.repo.rev_parse(ref + "^{}")  # optionally deref tags
                write_value = obj.hexsha
            except (BadObject, BadName):
                raise ValueError("Could not extract object from %s" % ref)
            # END end try string
        else:
            raise ValueError("Unrecognized Value: %r" % ref)
        # END try commit attribute

        # typecheck
        if obj is not None and self._points_to_commits_only and obj.type != Commit.type:
            raise TypeError("Require commit, got %r" % obj)
        # END verify type

        oldbinsha = None
        if logmsg is not None:
            try:
                oldbinsha = self.commit.binsha
            except ValueError:
                oldbinsha = Commit.NULL_BIN_SHA
            # END handle non-existing
        # END retrieve old hexsha

        fpath = self.abspath
        assure_directory_exists(fpath, is_file=True)

        lfd = LockedFD(fpath)
        fd = lfd.open(write=True, stream=True)
        fd.write(write_value.encode('ascii'))
        lfd.commit()

        # Adjust the reflog
        if logmsg is not None:
            self.log_append(oldbinsha, logmsg)
        # END handle reflog

        return self