From c2f55f073e1fe7fa380c8df94238440540b3afd8 Mon Sep 17 00:00:00 2001
From: lash <dev@holbrook.no>
Date: Mon, 2 May 2022 20:12:15 +0000
Subject: [PATCH] Add missing lock file

---
 chaind/lock.py | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 chaind/lock.py

diff --git a/chaind/lock.py b/chaind/lock.py
new file mode 100644
index 0000000..008004f
--- /dev/null
+++ b/chaind/lock.py
@@ -0,0 +1,34 @@
+# standard imports
+import time
+
+# local imports
+from .error import BackendError
+
+BASE_DELAY = 0.01
+BASE_DELAY_LIMIT = 3.0
+
+
+class StoreLock:
+
+    def __init__(self, delay=BASE_DELAY, delay_limit=BASE_DELAY_LIMIT, error=BackendError, description=None):
+        self.base_delay = delay
+        self.delay = delay
+        self.delay_limit = delay_limit
+        self.error = error
+        self.description = description
+
+    
+    def again(self, e=None):
+        if self.delay > self.delay_limit:
+            err = None
+            if e != None:
+                err = str(e)
+            else:
+                err = self.description
+            raise self.error(err)
+        time.sleep(self.delay)
+        self.delay *= 2
+
+
+    def reset(self):
+        self.delay = self.base_delay