fix: conditions reset does not work if the service is down at the tri…

…ggering time (#1585)

* incorporating new struct TimeBasedReset to encapsulate reset state/spec

Signed-off-by: Julie Vogelman <julievogelman0@gmail.com>

common/cronutil.go

@@ -0,0 +1,134 @@
+package common
+
+import (
+	"fmt"
+	"time"
+
+	cronlib "github.com/robfig/cron/v3"
+)
+
+const (
+	// Set the top bit if a star was included in the expression.
+	starBit = 1 << 63
+)
+
+// For a given cron specification, return the previous activation time
+// If no time can be found to satisfy the schedule, return the zero time.
+func PrevCronTime(cronSpec string, parser cronlib.Parser, t time.Time) (time.Time, error) {
+	var tm time.Time
+	sched, err := parser.Parse(cronSpec)
+	if err != nil {
+		return tm, fmt.Errorf("can't derive previous Cron time for cron spec %s; couldn't parse; err=%v", cronSpec, err)
+	}
+	s, castOk := sched.(*cronlib.SpecSchedule)
+	if !castOk {
+		return tm, fmt.Errorf("can't derive previous Cron time for cron spec %s: unexpected type for %v", cronSpec, sched)
+	}
+
+	// General approach is based on approach to SpecSchedule.Next() implementation
+
+	origLocation := t.Location()
+	loc := s.Location
+	if loc == time.Local {
+		loc = t.Location()
+	}
+	if s.Location != time.Local {
+		t = t.In(s.Location)
+	}
+
+	// Start at the previous second
+	t = t.Add(-1*time.Second - time.Duration(t.Nanosecond())*time.Nanosecond)
+
+	// If no time is found within five years, return zero.
+	yearLimit := t.Year() - 5
+
+WRAP:
+	if t.Year() < yearLimit {
+		return tm, fmt.Errorf("can't derive previous Cron time for cron spec %s: no time found within %d years", cronSpec, yearLimit)
+	}
+
+	// Find the first applicable month.
+	// If it's this month, then do nothing.
+	for 1<<uint(t.Month())&s.Month == 0 {
+		// set t to the last second of the previous month
+		t = time.Date(t.Year(), t.Month(), 1, 0, 0, 0, 0, loc)
+		t = t.Add(-1 * time.Second)
+
+		// Wrapped around.
+		if t.Month() == time.December {
+			goto WRAP
+		}
+	}
+
+	// Now get a day in that month.
+	for !dayMatches(s, t) {
+		// set t to the last second of the previous day
+
+		saveMonth := t.Month()
+		t = time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, loc)
+
+		// NOTE: This causes issues for daylight savings regimes where midnight does
+		// not exist.  For example: Sao Paulo has DST that transforms midnight on
+		// 11/3 into 1am. Handle that by noticing when the Hour ends up != 0.
+
+		// Notice if the hour is no longer midnight due to DST.
+		// Add an hour if it's 23, subtract an hour if it's 1.
+		if t.Hour() != 0 {
+			if t.Hour() > 12 {
+				t = t.Add(time.Duration(24-t.Hour()) * time.Hour)
+			} else {
+				t = t.Add(time.Duration(-t.Hour()) * time.Hour)
+			}
+		}
+
+		t = t.Add(-1 * time.Second)
+
+		if saveMonth != t.Month() {
+			goto WRAP
+		}
+	}
+
+	for 1<<uint(t.Hour())&s.Hour == 0 {
+		// set t to the last second of the previous hour
+		t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), 0, 0, 0, loc)
+		t = t.Add(-1 * time.Second)
+
+		if t.Hour() == 23 {
+			goto WRAP
+		}
+	}
+
+	for 1<<uint(t.Minute())&s.Minute == 0 {
+		// set t to the last second of the previous minute
+		t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute(), 0, 0, loc)
+		t = t.Add(-1 * time.Second)
+
+		if t.Minute() == 59 {
+			goto WRAP
+		}
+	}
+
+	for 1<<uint(t.Second())&s.Second == 0 {
+		// set t to the previous second
+		t = t.Add(-1 * time.Second)
+
+		if t.Second() == 59 {
+			goto WRAP
+		}
+	}
+
+	return t.In(origLocation), nil
+}
+
+// dayMatches returns true if the schedule's day-of-week and day-of-month
+// restrictions are satisfied by the given time.
+func dayMatches(s *cronlib.SpecSchedule, t time.Time) bool {
+	var (
+		domMatch bool = 1<<uint(t.Day())&s.Dom > 0
+		dowMatch bool = 1<<uint(t.Weekday())&s.Dow > 0
+	)
+	if s.Dom&starBit > 0 || s.Dow&starBit > 0 {
+		return domMatch && dowMatch
+	}
+	return domMatch || dowMatch
+}

common/cronutil_test.go

@@ -0,0 +1,106 @@
+package common
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	cronlib "github.com/robfig/cron/v3"
+)
+
+func TestPrevCronTime(t *testing.T) {
+	runs := []struct {
+		time, spec  string
+		expected    string
+		expectedErr bool
+	}{
+		// Simple cases
+		{"Mon Jul 9 15:00 2012", "0 0/15 * * * *", "Mon Jul 9 14:45 2012", false},
+		{"Mon Jul 9 14:59 2012", "0 0/15 * * * *", "Mon Jul 9 14:45 2012", false},
+		{"Mon Jul 9 15:01:59 2012", "0 0/15 * * * *", "Mon Jul 9 15:00 2012", false},
+
+		// Wrap around hours
+		{"Mon Jul 9 15:10 2012", "0 20-35/15 * * * *", "Mon Jul 9 14:35 2012", false},
+
+		// Wrap around days
+		{"Tue Jul 10 00:00 2012", "0 */15 * * * *", "Tue Jul 9 23:45 2012", false},
+		{"Tue Jul 10 00:00 2012", "0 20-35/15 * * * *", "Tue Jul 9 23:35 2012", false},
+
+		// Wrap around months
+		{"Mon Jul 9 09:35 2012", "0 0 12 9 Apr-Oct ?", "Sat Jun 9 12:00 2012", false},
+
+		// Leap year
+		{"Mon Jul 9 23:35 2018", "0 0 0 29 Feb ?", "Mon Feb 29 00:00 2016", false},
+
+		// Daylight savings time 3am EDT (-4) -> 2am EST (-5)
+		{"2013-03-11T02:30:00-0400", "TZ=America/New_York 0 0 12 9 Mar ?", "2013-03-09T12:00:00-0500", false},
+
+		// hourly job
+		{"2012-03-11T01:00:00-0500", "TZ=America/New_York 0 0 * * * ?", "2012-03-11T00:00:00-0500", false},
+
+		// 2am nightly job (skipped)
+		{"2012-03-12T00:00:00-0400", "TZ=America/New_York 0 0 2 * * ?", "2012-03-10T02:00:00-0500", false},
+
+		// 2am nightly job
+		{"2012-11-04T02:00:00-0500", "TZ=America/New_York 0 0 0 * * ?", "2012-11-04T00:00:00-0400", false},
+		{"2012-11-05T02:00:00-0500", "TZ=America/New_York 0 0 2 * * ?", "2012-11-04T02:00:00-0500", false},
+
+		// Unsatisfiable
+		{"Mon Jul 9 23:35 2012", "0 0 0 30 Feb ?", "", true},
+		{"Mon Jul 9 23:35 2012", "0 0 0 31 Apr ?", "", true},
+
+		// Monthly job
+		{"TZ=America/New_York 2012-12-03T00:00:00-0500", "0 0 3 3 * ?", "2012-11-03T03:00:00-0400", false},
+	}
+
+	parser := cronlib.NewParser(cronlib.Second | cronlib.Minute | cronlib.Hour | cronlib.Dom | cronlib.Month | cronlib.DowOptional | cronlib.Descriptor)
+
+	for _, c := range runs {
+		actual, err := PrevCronTime(c.spec, parser, getTime(c.time))
+		if c.expectedErr {
+			if err == nil {
+				t.Errorf("%s, \"%s\": should have received error but didn't", c.time, c.spec)
+			}
+		} else {
+			if err != nil {
+				t.Errorf("%s, \"%s\": error: %v", c.time, c.spec, err)
+			} else {
+				expected := getTime(c.expected)
+				if !actual.Equal(expected) {
+					t.Errorf("%s, \"%s\": (expected) %v != %v (actual)", c.time, c.spec, expected, actual)
+				}
+			}
+		}
+	}
+}
+
+func getTime(value string) time.Time {
+	if value == "" {
+		return time.Time{}
+	}
+
+	var location = time.Local
+	if strings.HasPrefix(value, "TZ=") {
+		parts := strings.Fields(value)
+		loc, err := time.LoadLocation(parts[0][len("TZ="):])
+		if err != nil {
+			panic("could not parse location:" + err.Error())
+		}
+		location = loc
+		value = parts[1]
+	}
+
+	var layouts = []string{
+		"Mon Jan 2 15:04 2006",
+		"Mon Jan 2 15:04:05 2006",
+	}
+	for _, layout := range layouts {
+		if t, err := time.ParseInLocation(layout, value, location); err == nil {
+			return t
+		}
+	}
+	if t, err := time.ParseInLocation("2006-01-02T15:04:05-0700", value, location); err == nil {
+		return t
+	}
+	panic("could not parse time value " + value)
+}

eventbus/driver/driver.go

@@ -2,6 +2,7 @@ package driver
 
 import (
 	"context"
+	"time"
 
 	eventbusv1alpha1 "github.com/argoproj/argo-events/pkg/apis/eventbus/v1alpha1"
 	cloudevents "github.com/cloudevents/sdk-go/v2"
@@ -21,7 +22,7 @@ type Driver interface {
 	// Parameter - dependencies, array of dependencies information
 	// Parameter - filter, a function used to filter the message
 	// Parameter - action, a function to be triggered after all conditions meet
-	SubscribeEventSources(ctx context.Context, conn Connection, group string, closeCh <-chan struct{}, resetConditionsCh <-chan struct{}, dependencyExpr string, dependencies []Dependency, transform func(depName string, event cloudevents.Event) (*cloudevents.Event, error), filter func(string, cloudevents.Event) bool, action func(map[string]cloudevents.Event)) error
+	SubscribeEventSources(ctx context.Context, conn Connection, group string, closeCh <-chan struct{}, resetConditionsCh <-chan struct{}, lastResetTime time.Time, dependencyExpr string, dependencies []Dependency, transform func(depName string, event cloudevents.Event) (*cloudevents.Event, error), filter func(string, cloudevents.Event) bool, action func(map[string]cloudevents.Event)) error
 
 	// Publish a message
 	Publish(conn Connection, message []byte) error