Moved client execution/processing code into own module; minor cleanup

gooey/gui/processor.py

@@ -0,0 +1,80 @@
+import os
+import re
+import subprocess
+
+from functools import partial
+from multiprocessing.dummy import Pool
+
+from gooey.gui.pubsub import pub
+from gooey.gui.util.casting import safe_float
+from gooey.gui.util.functional import unit, bind
+
+
+class ProcessController(object):
+  def __init__(self, progress_regex, progress_expr):
+    self._process = None
+    self.progress_regex = progress_regex
+    self.progress_expr = progress_expr
+
+  def was_success(self):
+    self._process.communicate()
+    return self._process.returncode == 0
+
+  def poll(self):
+    if not self._process:
+      raise Exception('Not started!')
+    self._process.poll()
+
+  def run(self, command):
+    env = os.environ.copy()
+    env["GOOEY"] = "1"
+    self._process  = subprocess.Popen(command, bufsize=1, stdout=subprocess.PIPE,
+                     stderr=subprocess.STDOUT, shell=True, env=env)
+    Pool(1).apply_async(self._forward_stdout, (self._process,))
+
+  def _forward_stdout(self, process):
+    '''
+    Reads the stdout of `process` and forwards lines and progress
+    to any interested subscribers
+    '''
+    while True:
+      line = process.stdout.readline()
+      if not line:
+        break
+      pub.send_message('console_update', msg=line)
+      pub.send_message('progress_update', progress=self._extract_progress(line))
+    pub.send_message('execution_complete')
+
+  def _extract_progress(self, text):
+    '''
+    Finds progress information in the text using the
+    user-supplied regex and calculation instructions
+    '''
+    # monad-ish dispatch to avoid the if/else soup
+    find = partial(re.search, string=text.strip())
+    regex = unit(self.progress_regex)
+    match = bind(regex, find)
+    result = bind(match, self._calculate_progress)
+    return result
+
+  def _calculate_progress(self, match):
+    '''
+    Calculates the final progress value found by the regex
+    '''
+    if not self.progress_expr:
+      return safe_float(match.group(1))
+    else:
+      return self._eval_progress(match)
+
+  def _eval_progress(self, match):
+    '''
+    Runs the user-supplied progress calculation rule
+    '''
+    _locals = {k: safe_float(v) for k, v in match.groupdict().items()}
+    if "x" not in _locals:
+      _locals["x"] = [safe_float(x) for x in match.groups()]
+    try:
+      return int(eval(self.progress_expr, {}, _locals))
+    except:
+      return None
+