Fix support for win32 in iter_lines (#500)

plumbum/commands/processes.py

@@ -1,7 +1,6 @@
 import time
 import atexit
 import heapq
-from subprocess import Popen
 from threading import Thread
 from plumbum.lib import IS_WIN32, six
 
@@ -24,7 +23,7 @@ def _check_process(proc, retcode, timeout, stdout, stderr):
     return proc.returncode, stdout, stderr
 
 
-def _iter_lines(proc, decode, linesize, line_timeout=None):
+def _iter_lines_posix(proc, decode, linesize, line_timeout=None):
     try:
         from selectors import DefaultSelector, EVENT_READ
     except ImportError:
@@ -62,6 +61,62 @@ def selector():
         yield 1, decode(line)
 
 
+def _iter_lines_win32(proc, decode, linesize, line_timeout=None):
+
+    class Piper(Thread):
+
+        def __init__(self, fd, pipe):
+            super().__init__(name="PlumbumPiper%sThread" % fd)
+            self.pipe = pipe
+            self.fd = fd
+            self.empty = False
+            self.daemon = True
+            super().start()
+
+        def read_from_pipe(self):
+            return self.pipe.readline(linesize)
+
+        def run(self):
+            for line in iter(self.read_from_pipe, b''):
+                queue.put((self.fd, decode(line)))
+            # self.pipe.close()
+
+    if line_timeout is None:
+        line_timeout = float("inf")
+    queue = Queue()
+    pipers = [Piper(0, proc.stdout), Piper(1, proc.stderr)]
+    last_line_ts = time.time()
+    empty = True
+    while True:
+        try:
+            yield queue.get_nowait()
+            last_line_ts = time.time()
+            empty = False
+        except QueueEmpty:
+            empty = True
+        if time.time() - last_line_ts > line_timeout:
+            raise ProcessLineTimedOut("popen line timeout expired", getattr(proc, "argv", None), getattr(proc, "machine", None))
+        if proc.poll() is not None:
+            break
+        if empty:
+            time.sleep(0.1)
+
+    for piper in pipers:
+        piper.join()
+
+    while True:
+        try:
+            yield queue.get_nowait()
+        except QueueEmpty:
+            break
+
+
+if IS_WIN32:
+    _iter_lines = _iter_lines_win32
+else:
+    _iter_lines = _iter_lines_posix
+
+
 #===================================================================================================
 # Exceptions
 #===================================================================================================