feat(profiler): update proftest to support parsing floating-point bac…

…koff durations (#2588)

The first duration string in the Python profiling agent's backoff log messages has the form "2400.000s". This change allows the backoff durations to be parsed correctly for the Python agent.

TESTED: I originally tested this change by trying to parse exact log message printed by the python agent in the unit test, then simplified the unit test.

profiler/proftest/proftest.go

@@ -45,7 +45,7 @@ const (
 
 var (
 	logtimeRE     = regexp.MustCompile(`[A-Z][a-z]{2} [A-Z][a-z]{2}  ?\d+ \d\d:\d\d:\d\d [A-Z]{3} \d{4}`)
-	backoffTimeRE = regexp.MustCompile(`(\d+(h|m|s|ms|us))+`)
+	backoffTimeRE = regexp.MustCompile(`(\d+(\.\d+)?(h|m|s|ms|us))+`)
 )
 
 // BaseStartupTmpl is the common part of the startup script that

profiler/proftest/proftest_test.go

@@ -124,6 +124,11 @@ func TestParseBackoffDuration(t *testing.T) {
 			line:           "Fri May 15 22:05:01 UTC 2020: benchmark 0: failed to create profile, will retry: rpc error: code = Aborted desc = generic::aborted: action throttled, backoff for 32m0s",
 			wantBackoffDur: 32 * time.Minute,
 		},
+		{
+			desc:           "a floating-point backoff duration is parsed correctly",
+			line:           "Fri May 15 22:05:01 UTC 2020: benchmark 0: failed to create profile, will retry: rpc error: code = Aborted desc = generic::aborted: action throttled, backoff for 2000.000s",
+			wantBackoffDur: 2000 * time.Second,
+		},
 		{
 			desc:    "an error is returned when the backoff duration is invalid",
 			line:    "Fri May 15 22:05:01 UTC 2020: benchmark 0: failed to create profile, will retry: rpc error: code = Aborted desc = generic::aborted: action throttled, backoff for 32..0.s",
@@ -139,7 +144,7 @@ func TestParseBackoffDuration(t *testing.T) {
 				return
 			}
 			if backoffDur != tc.wantBackoffDur {
-				t.Errorf("got log time = %v, want %v", backoffDur, tc.wantBackoffDur)
+				t.Errorf("backoff duration: got %v, want %v", backoffDur, tc.wantBackoffDur)
 			}
 		})
 	}