ABANDONED. Use gclient_utils instead.

subprocess2.py

Index: subprocess2.py
diff --git a/subprocess2.py b/subprocess2.py
index a00592f4774a83eaa8e697d38c8ab7a921903fa9..37b9b64394a4606a9405dcb2acfaa20b755fa198 100644
--- a/subprocess2.py
+++ b/subprocess2.py
@@ -462,6 +462,49 @@ def communicate(args, timeout=None, nag_timer=None, nag_max=None, **kwargs):
     return proc.communicate(None, timeout, nag_timer), proc.returncode
 
 
+def communicate_and_stream(args, **kwargs):

[M-A Ruel, 2016/03/08 23:54:08]

There's a function to do something similar in gclient_utils.py. In practice,
subprocess42 does it much better with a for loop.

+  """Same as communicate, but will not just capture, but also stream output
+  streams while command is running.
+
+  Returns ((stdout, stderr), returncode).
+
+  By default, streams and captures both stdout and stderr. You can silence any
+  of the streams, but passing std{err,out} special PIPE or VOID, depending on
+  whether you want it captured or completely ignored.
+
+  This useful for commands that take time to run, such that it's useful to both
+  capture output but also steram as parent process std{out,err}.
+  """
+  # communicate method above won't capture anything if std{err,out} is callable.
+  # So, capture it ourselves essentially the same way.
+  # Aslo, because callbacks are called in asynchroneous thread, we can stream

[Paweł Hajdan Jr., 2016/03/08 23:52:24]

nit: Aslo -> Also ; asynchroneous -> asynchronous

+  # output directly with simple labmbda, no need for yet another thread.
+  def combine_funcs(f1, f2):
+    def f(x):
+      f1(x)
+      f2(x)
+    return f
+
+  result = {}
+  for stream in ('stderr', 'stdout'):
+    if stream in kwargs:
+      # Don't stream/capture streams that user specified explicitely.

[Paweł Hajdan Jr., 2016/03/08 23:52:24]

nit: explicitely -> explicitly

+      continue
+    result[stream] = []  # Container to hold results data chunks.
+    kwargs[stream] = combine_funcs(
+        result[stream].append,
+        getattr(sys, stream).write)
+
+  (out, err), returncode = communicate(args, **kwargs)
+  if 'stderr' in result:
+    assert not err
+    err = ''.join(result['stderr'])
+  if 'stdout' in result:
+    assert not out
+    out = ''.join(result['stdout'])
+  return (out, err), returncode
+
+
 def call(args, **kwargs):
   """Emulates subprocess.call().