Create log.py

log.py

@@ -0,0 +1,29 @@
+class Log:
+    def __init__(self, path):
+        dirname = os.path.dirname(path)
+        os.makedirs(dirname, exist_ok=True)
+        f = open(path, "a+")
+
+        # Check that the file is newline-terminated
+        size = os.path.getsize(path)
+        if size > 0:
+            f.seek(size - 1)
+            end = f.read(1)
+            if end != "\n":
+                f.write("\n")
+        self.f = f
+        self.path = path
+
+    def log(self, event):
+        event["_event_id"] = str(uuid.uuid4())
+        json.dump(event, self.f)
+        self.f.write("\n")
+
+    def state(self):
+        state = {"complete": set(), "last": None}
+        for line in open(self.path):
+            event = json.loads(line)
+            if event["type"] == "submit" and event["success"]:
+                state["complete"].add(event["id"])
+                state["last"] = event
+        return state