Initial commit

README.md

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+# Go-Do
+Implement a simple way to "toss" a job to be run
+in parallel with your main application logic
+and when you're ready to use the results of
+that job query if it's finished.
+
+Example:
+
+```python
+from go_do import Do
+
+## From a docker hub api bit of code.
+
+def get_all(url):
+    "Retrieve all paged results"
+    rsp = urllib.request.urlopen(url)
+    while 200 <= int(rsp.getcode()) < 300:
+    	data = json.loads(rsp.read())
+	url = data.get("next")
+	next = Do(urllib.request.urlopen, url) if url else None
+	for item in data['results']:
+	    yield item
+	if next is None:
+	    break
+	# If the result is not ready yet, wait for it.
+	rsp = next.wait_for_it()
+    print("Done")
+```
+
+

go_do.py

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+#!python3
+"""
+go_do.py
+========
+Implement a simple parallel work class.
+"""
+# Uses low level threading.
+import sys
+import _thread as _t
+
+class NotReadyError(RuntimeError):
+    "Job is still running"
+
+class Do:
+    """
+    Easy to use multi-threading.
+    """
+    _tid = None
+    _running = None
+    _result = None
+    _exc_info = None
+
+    def __init__(self, func, *args, **kwarg):
+        assert callable(func)
+        self._running = _t.allocate_lock()
+        self._tid = _t.start_new_thread(self.run, args, kwarg)
+
+    def run(self, func, args, kwarg):
+        "Acquire locks, start thread, return thread id"
+        self._running.acquire()
+        try:
+            self._result = func(*args, **kwarg)
+        except:
+            self._exc_info = sys.exc_info()
+        finally:
+            self._running.release()
+
+    def done(self):
+        "Return True if the job finished running"
+        return not self._running.locked()
+
+    def running(self):
+        "Return True if the job is still running"
+        return self._running.locked()
+
+    def wait_for_it(self, _timeout=-1):
+        "Wait for the result to be available"
+        if self._running.acquire(True, _timeout):
+            self._running.release()
+            return self._result
+        raise NotReadyError("Exceeded the timeout")
+
+    def result(self):
+        "Return the result if available, raise NotReadyError if not"
+        if self._running.acquire(False):
+            self._running.release()
+            return self._result
+        raise NotReadyError("Result is not ready yet")
+
+# Fin