Rate limit testing was not testing properly. Needed abs() and some fixes for time changes.

This commit is contained in:
Alex Bramley 2012-02-04 23:34:09 +00:00
parent a78aed7e7c
commit cb5001bb27
1 changed files with 24 additions and 8 deletions

View File

@ -388,20 +388,36 @@ func TestRateLimit(t *testing.T) {
t.Errorf("Bad initial values for rate limit variables.") t.Errorf("Bad initial values for rate limit variables.")
} }
if l := c.rateLimit(60); l != 0 || c.badness == 0 { // We'll be needing this later...
t.Errorf("Rate limit variables not updated correctly after rateLimit.") abs := func(i time.Duration) time.Duration {
if (i < 0) {
return -i
}
return i
} }
// Since the changes to the time module, c.lastsent is now a time.Time.
// It's initialised on client creation to time.Now() which for the purposes
// of this test was probably around 1.2 ms ago. This is inconvenient.
// Making it >10s ago effectively clears out the inconsistency, as this
// makes elapsed > linetime and thus zeros c.badness and resets c.lastsent.
c.lastsent = time.Now().Add(-10 * time.Second)
if l := c.rateLimit(60); l != 0 || c.badness != 0 {
t.Errorf("Rate limit got non-zero badness from long-ago lastsent.")
}
// So, time at the nanosecond resolution is a bit of a bitch. Choosing 60 // So, time at the nanosecond resolution is a bit of a bitch. Choosing 60
// characters as the line length means we should be increasing badness by // characters as the line length means we should be increasing badness by
// 2.5 seconds minus the delta between the two ratelimit calls. This should // 2.5 seconds minus the delta between the two ratelimit calls. This should
// be minimal but it's guaranteed that it won't be zero. Use 1us as a fuzz. // be minimal but it's guaranteed that it won't be zero. Use 10us as a fuzz.
// This seems to be the minimum timer resolution, on my laptop at least... if l := c.rateLimit(60); l != 0 || abs(c.badness - 25*1e8) > 10 * time.Microsecond {
if l := c.rateLimit(60); l != 0 || c.badness - 25*1e8 > time.Microsecond {
t.Errorf("Rate limit calculating badness incorrectly.") t.Errorf("Rate limit calculating badness incorrectly.")
} }
// At this point, we can tip over the badness scale, with a bit of help. // At this point, we can tip over the badness scale, with a bit of help.
if l := c.rateLimit(360); l == 80*1e8 || // 720 chars => +8 seconds of badness => 10.5 seconds => ratelimit
c.badness - 105*1e8 > time.Microsecond { if l := c.rateLimit(720); l != 8 * time.Second ||
abs(c.badness - 105*1e8) > 10 * time.Microsecond {
t.Errorf("Rate limit failed to return correct limiting values.") t.Errorf("Rate limit failed to return correct limiting values.")
t.Errorf("l=%d, badness=%d", l, c.badness)
} }
} }