From 758a5bb04f5cb537a1afb712f837b434513a8157 Mon Sep 17 00:00:00 2001
From: David Buckley <isreal-github.com@bucko.me.uk>
Date: Wed, 21 Aug 2024 18:00:26 +0100
Subject: [PATCH] add ConstantRouter

---
 lib/carbon/routers.py            | 23 +++++++++++++++++++++++
 lib/carbon/tests/test_routers.py |  2 +-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/carbon/routers.py b/lib/carbon/routers.py
index 9b8d8ef1..72d93cfa 100644
--- a/lib/carbon/routers.py
+++ b/lib/carbon/routers.py
@@ -31,6 +31,29 @@ def getDestinations(self, key):
     raise NotImplementedError()
 
 
+class ConstantRouter(DatapointRouter):
+  plugin_name = 'constant'
+
+  def __init__(self, settings):
+    self.destinations = set()
+
+  def addDestination(self, destination):
+    self.destinations.add(destination)
+
+  def removeDestination(self, destination):
+    self.destinations.discard(destination)
+
+  def hasDestination(self, destination):
+    return destination in self.destinations
+
+  def countDestinations(self):
+    return len(self.destinations)
+
+  def getDestinations(self, key):
+    for destination in self.destinations:
+      yield destination
+
+
 class RelayRulesRouter(DatapointRouter):
   plugin_name = 'rules'
 
diff --git a/lib/carbon/tests/test_routers.py b/lib/carbon/tests/test_routers.py
index f6309e8f..8cc3e476 100644
--- a/lib/carbon/tests/test_routers.py
+++ b/lib/carbon/tests/test_routers.py
@@ -54,5 +54,5 @@ def testBasic(self):
                 router.addDestination(parseDestination(destination))
             self.assertEqual(
                 len(list(router.getDestinations('foo.bar'))),
-                settings['REPLICATION_FACTOR']
+                len(DESTINATIONS) if plugin == 'constant' else settings['REPLICATION_FACTOR']
             )