Ticket #4242: copy_async.2.py

import tempfile

from gi.repository import GObject
from gi.repository import Gio
from gi.repository import GLib

# Avoid "Fatal Python error: GC object already tracked"
# http://stackoverflow.com/questions/7496629/gstreamer-appsrc-causes-random-crashes
GObject.threads_init()


class FileTransfer(GObject.GObject):
    _CHUNK_SIZE = 10240

    def __init__(self, input_stream, output_stream):
        GObject.GObject.__init__(self)

        self._input_stream = input_stream
        self._output_stream = output_stream
        self._pending_buffers = []

    def start(self):
        self._input_stream.read_bytes_async(
            self._CHUNK_SIZE, GLib.PRIORITY_LOW,
            None, self.__read_async_cb, None)

    def __read_async_cb(self, input_stream, result, user_data=None):
        data = input_stream.read_bytes_finish(result)
        print 'Read Size:', data, 'Type:', type(data)
        print 'Result:', result, 'Propagate ERROR:', result.propagate_error()

        if data is None:
            # TODO: an error occured. Report something
            print 'An error occured'
        elif data.get_size() == 0:
            # We read the file completely
            print 'Closing the File.'
            self._input_stream.close(None)
        else:
            self._pending_buffers.append(data)
            self._input_stream.read_bytes_async(
                self._CHUNK_SIZE, GLib.PRIORITY_LOW,
                None, self.__read_async_cb, None)
        self._write_next_buffer()

    def __write_async_cb(self, output_stream, result, user_data=None):
        size = self._output_stream.write_bytes_finish(result)
        print 'Size written:', size

        if not self._pending_buffers and \
                not self._output_stream.has_pending() and \
                not self._input_stream.has_pending():
            output_stream.close(None)
            print 'DONE'
            loop.quit()
        else:
            self._write_next_buffer()

    def _write_next_buffer(self):

        if self._pending_buffers and not self._output_stream.has_pending():
            data = self._pending_buffers.pop(0)
            self._output_stream.write_bytes_async(
                data, GLib.PRIORITY_LOW, None, self.__write_async_cb,
                None)


test_file_name = '/home/humitos/mozilla.pdf'
test_input_stream = Gio.File.new_for_path(test_file_name).read(None)
PATH = tempfile.mkstemp()[1]
print PATH

test_output_stream = Gio.File.new_for_path(PATH)\
    .append_to(Gio.FileCreateFlags.PRIVATE, None)

splicer = FileTransfer(test_input_stream, test_output_stream)
splicer.start()

loop = GObject.MainLoop()
loop.run()