lib: remove incorrect period scaling

A dimensional analysis would have shown this to be incorrect; per is the
period over which the rate value is applied and so should be in s, but
this makes it in s², giving a rate in s¯².

Author: efd6

lib/limit.go

@@ -489,7 +489,6 @@ func limitPolicy(h http.Header, prefix string, canonical, delta bool, window tim
 		m["error"] = fmt.Sprintf("could not parse %q as number or timestamp", reset)
 		return m
 	}
-	per *= window.Seconds()
 
 	m["next"] = rate.Limit(lim / window.Seconds())
 	m["rate"] = rate.Limit(rem / per)

testdata/limit_general.txt

@@ -45,6 +45,11 @@ cmp stdout want.txt
 		"X-RateLimit-Remaining": ["100"],
 		"X-RateLimit-Reset": [string(int(timestamp("9999-12-31T23:59:59.999999999Z")))]
 	}.as(h, rate_limit(h, 'X-RateLimit', false, false, duration('1s'), 100)),
+	{
+		"X-RateLimit-Limit": ["5000"],
+		"X-RateLimit-Remaining": ["100"],
+		"X-RateLimit-Reset": [string(int(timestamp("9999-12-31T23:59:59.999999999Z")))]
+	}.as(h, rate_limit(h, 'X-RateLimit', false, false, duration('1m'), 100)),
 ]
 -- want.txt --
 [
@@ -103,5 +108,12 @@ cmp stdout want.txt
 		"next": 5000,
 		"rate": 1.0842021724855044e-8,
 		"reset": "9999-12-31T23:59:59Z"
+	},
+	{
+		"burst": 100,
+		"headers": "X-RateLimit-Limit=\"5000\" X-RateLimit-Remaining=\"100\" X-RateLimit-Reset=\"253402300799\"",
+		"next": 83.33333333333333,
+		"rate": 1.0842021724855044e-8,
+		"reset": "9999-12-31T23:59:59Z"
 	}
 ]