stream: use async I/O to avoid real-time problems.

tests/test_async.py

@@ -0,0 +1,70 @@
+import mock
+import time
+import pytest
+from amodem import async
+import logging
+
+logging.basicConfig(format='%(message)s')
+
+
+def test_async_reader():
+    def _read(n):
+        time.sleep(n * 0.1)
+        return b'\x00' * n
+    s = mock.Mock()
+    s.read = _read
+    r = async.AsyncReader(s, 1)
+
+    n = 5
+    assert r.read(n) == b'\x00' * n
+    r.close()
+    assert r.stream is None
+    r.close()
+
+
+def test_async_write():
+    result = []
+
+    def _write(buf):
+        time.sleep(len(buf) * 0.1)
+        result.append(buf)
+    s = mock.Mock()
+    s.write = _write
+    w = async.AsyncWriter(s)
+
+    w.write('foo')
+    w.write(' ')
+    w.write('bar')
+    w.close()
+    assert w.stream is None
+    w.close()
+    assert result == ['foo', ' ', 'bar']
+
+
+def test_async_reader_error():
+    s = mock.Mock()
+    s.read.side_effect = IOError()
+    r = async.AsyncReader(s, 1)
+    with pytest.raises(IOError):
+        r.read(3)
+
+
+def test_async_writer_error():
+    s = mock.Mock()
+    s.write.side_effect = IOError()
+    w = async.AsyncWriter(s)
+    w.write('123')
+    w.thread.join()
+    with pytest.raises(IOError):
+        w.write('456')
+    assert s.write.mock_calls == [mock.call('123')]
+
+
+def test_underflow():
+    s = mock.Mock()
+    w = async.AsyncWriter(s)
+    w.write('blah')
+    w.thread.join()
+    assert s.write.mock_calls == [mock.call('blah')]
+    with pytest.raises(IOError):
+        w.write('xyzw')

tests/test_transfer.py

@@ -9,6 +9,7 @@ from amodem import common
 from amodem import dsp
 from amodem import sampling
 from amodem import config
+from amodem import async
 config = config.fastest()
 
 import logging
@@ -26,7 +27,7 @@ class Args(object):
         return None
 
 
-def run(size, chan=None, df=0, success=True):
+def run(size, chan=None, df=0, success=True, reader=None):
     tx_data = os.urandom(size)
     tx_audio = BytesIO()
     send.main(config=config, src=BytesIO(tx_data), dst=tx_audio)
@@ -42,13 +43,19 @@ def run(size, chan=None, df=0, success=True):
 
     data = common.dumps(data)
     rx_audio = BytesIO(data)
-
     rx_data = BytesIO()
-    d = BytesIO()
-    result = recv.main(config=config, src=rx_audio, dst=rx_data,
-                       dump_audio=d)
+    dump = BytesIO()
+
+    if reader:
+        rx_audio = reader(rx_audio)
+    try:
+        result = recv.main(config=config, src=rx_audio, dst=rx_data,
+                           dump_audio=dump)
+    finally:
+        rx_audio.close()
+
     rx_data = rx_data.getvalue()
-    assert data.startswith(d.getvalue())
+    assert data.startswith(dump.getvalue())
 
     assert result == success
     if success:
@@ -64,6 +71,11 @@ def test_small(small_size):
     run(small_size, chan=lambda x: x)
 
 
+def test_async():
+    run(1024, chan=lambda x: x,
+        reader=lambda s: async.AsyncReader(s, 128))
+
+
 def test_error():
     skip = 32000  # remove trailing silence
     run(1024, chan=lambda x: x[:-skip], success=False)