fix: switch to less aggressive backoff algorithm

This results in retry delays of:

* 2 seconds
* 4 seconds
* 6 seconds
* 8 seconds
* 10 seconds

Author: kylef

palaver.cpp

@@ -10,7 +10,6 @@
 #define ZNC_PALAVER_VERSION "1.2.1"
 
 #include <algorithm>
-#include <cmath>
 
 #include <znc/Modules.h>
 #include <znc/User.h>
@@ -128,9 +127,9 @@ class RetryStrategy {
 	}
 
 	unsigned int GetDelay(unsigned int uAttempts) {
-		double minimumBackoff = 1;
-		double maximumBackoff = 10;
-		return std::max(std::min(pow((double)uAttempts, 2), maximumBackoff), minimumBackoff);
+		unsigned int minimumBackoff = 1;
+		unsigned int maximumBackoff = 10;
+		return std::max(std::min(uAttempts * 2, maximumBackoff), minimumBackoff);
 	}
 };
 

test/test_palaver.py

@@ -320,7 +320,7 @@ async def connected(reader, writer):
     line = await reader.readline()
     assert line == b':*[email protected] PRIVMSG admin :Notification sent to 1 clients.\r\n'
 
-    await asyncio.sleep(1.2)
+    await asyncio.sleep(2.2)
     server.close()
     await server.wait_closed()
 
@@ -376,7 +376,7 @@ async def connected(reader, writer):
     line = await reader.readline()
     assert line == b':*[email protected] PRIVMSG admin :Notification sent to 1 clients.\r\n'
 
-    await asyncio.sleep(1.2)
+    await asyncio.sleep(2.2)
     server.close()
     await server.wait_closed()
 
@@ -433,7 +433,7 @@ async def connected(reader, writer):
     line = await reader.readline()
     assert line == b':*[email protected] PRIVMSG admin :Notification sent to 1 clients.\r\n'
 
-    await asyncio.sleep(1.2)
+    await asyncio.sleep(2.2)
     server.close()
     await server.wait_closed()