fix stream implementation

amodem/stream.py

@@ -1,21 +1,25 @@
 import time
+import logging
 
+log = logging.getLogger(__name__)
+
+
+class Timeout(Exception):
+    pass
 
 
 class Reader(object):
 
-    SAMPLES = 4096
-    BUFSIZE = int(SAMPLES * wave.bytes_per_sample)
-    WAIT = 0.1
-    TIMEOUT = 2.0
-
-    def __init__(self, fd, data_type=None, bufsize=None, eof=False):
+    def __init__(self, fd, data_type=None, bufsize=4096,
+                 eof=False, timeout=2.0, wait=0.2):
         self.fd = fd
-        self.check = None
-        self.total = 0
-        self.bufsize = bufsize if (bufsize is not None) else self.BUFSIZE
-        self.eof = eof
         self.data_type = data_type if (data_type is not None) else lambda x: x
+        self.bufsize = bufsize
+        self.eof = eof
+        self.timeout = timeout
+        self.wait = wait
+        self.total = 0
+        self.check = None
 
     def __iter__(self):
         return self
@@ -26,7 +30,7 @@ class Reader(object):
     def next(self):
         block = bytearray()
         if self.eof:
-            data = self.fd.read(self.BUFSIZE)
+            data = self.fd.read(self.bufsize)
             if data:
                 self.total += len(data)
                 block.extend(data)
@@ -34,20 +38,20 @@ class Reader(object):
             else:
                 raise StopIteration()
 
-        finish_time = time.time() + self.TIMEOUT
+        finish_time = time.time() + self.timeout
         while time.time() <= finish_time:
-            left = self.BUFSIZE - len(block)
+            left = self.bufsize - len(block)
             data = self.fd.read(left)
             if data:
                 self.total += len(data)
                 block.extend(data)
 
-            if len(block) == self.BUFSIZE:
+            if len(block) == self.bufsize:
                 values = self.data_type(block)
                 if self.check:
                     self.check(values)
                 return values
 
-            time.sleep(self.WAIT)
+            time.sleep(self.wait)
 
-        raise IOError('timeout')
+        raise Timeout(self.timeout)

tests/test_stream.py

@@ -31,5 +31,5 @@ def test_read():
     try:
         for buf in f:
             pass
-    except IOError as e:
-        assert str(e) == 'timeout'
+    except stream.Timeout as e:
+        assert e.args == (f.timeout,)