Method test_splice_offset_in

Lib/test/test_os.py:556–590

(self)

    @unittest.skipUnless(hasattr(os, 'splice'), 'test needs os.splice()')
    @requires_splice_pipe
    def test_splice_offset_in(self):
        TESTFN4 = os_helper.TESTFN + ".4"
        data = b'0123456789'
        bytes_to_copy = 6
        in_skip = 3

        create_file(os_helper.TESTFN, data)
        self.addCleanup(os_helper.unlink, os_helper.TESTFN)

        in_file = open(os_helper.TESTFN, 'rb')
        self.addCleanup(in_file.close)
        in_fd = in_file.fileno()

        read_fd, write_fd = os.pipe()
        self.addCleanup(lambda: os.close(read_fd))
        self.addCleanup(lambda: os.close(write_fd))

        try:
            i = os.splice(in_fd, write_fd, bytes_to_copy, offset_src=in_skip)
        except OSError as e:
            # Handle the case in which Python was compiled
            # in a system with the syscall but without support
            # in the kernel.
            if e.errno != errno.ENOSYS:
                raise
            self.skipTest(e)
        else:
            # The number of copied bytes can be less than
            # the number of bytes originally requested.
            self.assertIn(i, range(0, bytes_to_copy+1));

            read = os.read(read_fd, 100)
            # 012 are skipped (in_skip)
            # 345678 are copied in the file (in_skip + bytes_to_copy)
            self.assertEqual(read, data[in_skip:in_skip+i])

    @unittest.skipUnless(hasattr(os, 'splice'), 'test needs os.splice()')
    @requires_splice_pipe