Refactor the util directory to use subpackages.

util/registry/queuefile.py

@@ -0,0 +1,58 @@
+from multiprocessing import Queue
+import os
+
+class QueueFile(object):
+  """ Class which implements a file-like interface and reads from a blocking
+      multiprocessing queue.
+  """
+  def __init__(self, queue, name=None):
+    self._queue = queue
+    self._closed = False
+    self._done = False
+    self._buffer = ''
+    self._total_size = 0
+    self._name = name
+    self.raised_exception = False
+    self._exception_handlers = []
+
+  def add_exception_handler(self, handler):
+    self._exception_handlers.append(handler)
+
+  def read(self, size=8192):
+    if self._closed or self._done:
+      buf = self._buffer[0:size]
+      self._buffer = self._buffer[size:]
+      return buf
+
+    while len(self._buffer) < size:
+      result = self._queue.get(block=True)
+      if result is None:
+        self._done = True
+        break
+
+      if isinstance(result, Exception):
+        self._closed = True
+        self.raised_exception = True
+
+        handled = False
+        for handler in self._exception_handlers:
+          handler(result)
+          handled = True
+
+        if handled:
+          return
+
+        raise result
+
+      self._buffer += result
+      self._total_size += len(result)
+
+    buf = self._buffer[0:size]
+    self._buffer = self._buffer[size:]
+    return buf
+
+  def flush(self):
+    pass
+
+  def close(self):
+    self._closed = True