Prove direct cancellation during a pending sync

[onechat] / schedule.go

diff --git a/schedule.go b/schedule.go
index 28a5a767777bd341e880b046dde2fac9e8d7f675..3c3456ddbcc6363be07b9398b01b737c00653366 100644 (file)
--- a/schedule.go
+++ b/schedule.go
@@ -48,6 +48,40 @@ const (
        scheduleLateLine = "This run is late: the daemon was stopped at that time."
 )
 
        scheduleLateLine = "This run is late: the daemon was stopped at that time."
 )
 

+// Schedules holds the schedules of the agent: tasks that start a turn at one
+// time or at the times of a cron expression. Each change writes the file whole
+// before it returns, so a schedule survives a restart. The mutex protects the
+// schedules, because the tools change them from a turn while Run reads them.
+// changed tells Run that a set or a remove changed the times.
+type Schedules struct {
+       path    string
+       owner   string
+       clock   func() time.Time
+       logger  *slog.Logger
+       changed chan struct{}
+
+       mutex sync.Mutex
+       file  ScheduleFile
+}
+
+// ScheduleFile is the content of the file of the schedules: the ID of the last
+// schedule, so that an ID is never used again, and the schedules.
+type ScheduleFile struct {
+       Next      int        `json:"next"`
+       Schedules []Schedule `json:"schedules"`
+}
+
+// Schedule is one schedule: its owner, its ID, the task for the agent, the cron
+// expression of a repeating schedule, empty for a one-time schedule, and its
+// next time.
+type Schedule struct {
+       Owner string    `json:"owner"`
+       ID    int       `json:"id"`
+       Text  string    `json:"text"`
+       Cron  string    `json:"cron"`
+       Due   time.Time `json:"due"`
+}
+

 // openSchedules reads the schedules of the file at path. A missing file holds
 // none. The owner names its agent. Schedules without an owner take this name. A
 // different stored owner is an error. The clock gives the time and the time
 // openSchedules reads the schedules of the file at path. A missing file holds
 // none. The owner names its agent. Schedules without an owner take this name. A
 // different stored owner is an error. The clock gives the time and the time


@@ -107,20 +141,18 @@ func openSchedules(path, owner string, clock func() time.Time, logger *slog.Logg
        return s, nil
 }
 
        return s, nil
 }
 

-// Schedules holds the schedules of the agent: tasks that start a turn at one
-// time or at the times of a cron expression. Each change writes the file whole
-// before it returns, so a schedule survives a restart. The mutex protects the
-// schedules, because the tools change them from a turn while Run reads them.
-// changed tells Run that a set or a remove changed the times.
-type Schedules struct {
-       path    string
-       owner   string
-       clock   func() time.Time
-       logger  *slog.Logger
-       changed chan struct{}
+// save writes the file whole, with mode 0600. The caller holds the mutex.
+func (s *Schedules) save() error {
+       data, err := json.Marshal(s.file)
+       if err == nil {
+               err = writeFileAtomic(s.path, append(data, '\n'))
+       }

 
 

-       mutex sync.Mutex
-       file  ScheduleFile
+       if err != nil {
+               return fmt.Errorf("save schedules: %w", err)
+       }
+
+       return nil

 }
 
 // Run starts the runs of the due schedules in l until ctx ends. It waits until
 }
 
 // Run starts the runs of the due schedules in l until ctx ends. It waits until


@@ -159,116 +191,6 @@ func (s *Schedules) Run(ctx context.Context, l *TurnLoop) error {
        }
 }
 
        }
 }
 

-// Set adds a schedule with text and returns the answer of the tool. Exactly one
-// of at and cron is not nil. at is a local time in scheduleAtLayout after now,
-// and it goes through scheduleWallTime, so a time in the hour that the clock
-// repeats is its first occurrence. cron is an expression of scheduleParseCron.
-func (s *Schedules) Set(text string, at, cron *string) (string, error) {
-       text = strings.TrimSpace(text)
-       if text == "" || len(text) > scheduleTextBytes {
-               return "", fmt.Errorf("the text must have 1 to %d bytes", scheduleTextBytes)
-       }
-
-       now := s.clock()
-       schedule := Schedule{
-               Text:  text,
-               Owner: s.owner,
-       }
-
-       switch {
-       case (at == nil) == (cron == nil):
-               return "", errors.New("give either at or cron, and null for the other")
-       case at != nil:
-               parsed, err := time.Parse(scheduleAtLayout, *at)
-               if err != nil {
-                       return "", fmt.Errorf("at must be a local time such as %s", now.Format(scheduleAtLayout))
-               }
-
-               schedule.Due = scheduleWallTime(parsed.Year(), parsed.Month(), parsed.Day(), parsed.Hour(), parsed.Minute(), now.Location())
-               if !schedule.Due.After(now) {
-                       return "", fmt.Errorf("the time %s is not after now, %s", schedule.Due.Format(scheduleTimeLayout), now.Format(scheduleTimeLayout))
-               }
-       default:
-               parsed, err := scheduleParseCron(*cron)
-               if err != nil {
-                       return "", err
-               }
-
-               next, found := parsed.Next(now)
-               if !found {
-                       return "", fmt.Errorf("the cron expression %q matches no time in %d years", *cron, scheduleCronYears)
-               }
-
-               schedule.Cron = parsed.String()
-               schedule.Due = next
-       }
-
-       s.mutex.Lock()
-       defer s.mutex.Unlock()
-
-       s.file.Next++
-       schedule.ID = s.file.Next
-       s.file.Schedules = append(s.file.Schedules, schedule)
-       err := s.save()
-       if err != nil {
-               return "", err
-       }
-
-       s.change()
-
-       return fmt.Sprintf("Schedule %d set. Next: %s.", schedule.ID, schedule.Due.In(now.Location()).Format(scheduleTimeLayout)), nil
-}
-
-// List returns the answer of the tool: one line for each schedule, by due time,
-// with its ID, its next time, its cron expression or once, and its text on one
-// line.
-func (s *Schedules) List() string {
-       location := s.clock().Location()
-       schedules := s.sorted()
-       if len(schedules) == 0 {
-               return "No schedules."
-       }
-
-       lines := make([]string, 0, len(schedules))
-       for _, schedule := range schedules {
-               lines = append(lines, strconv.Itoa(schedule.ID)+" | "+schedule.Due.In(location).Format(scheduleTimeLayout)+" | "+cmp.Or(schedule.Cron, "once")+" | "+strings.Join(strings.Fields(schedule.Text), " "))
-       }
-
-       return strings.Join(lines, "\n")
-}
-
-// Len returns the number of schedules.
-func (s *Schedules) Len() int {
-       s.mutex.Lock()
-       defer s.mutex.Unlock()
-
-       return len(s.file.Schedules)
-}
-
-// Remove removes the schedule id and returns the answer of the tool.
-func (s *Schedules) Remove(id int) (string, error) {
-       s.mutex.Lock()
-       defer s.mutex.Unlock()
-
-       index := slices.IndexFunc(s.file.Schedules, func(schedule Schedule) bool {
-               return schedule.ID == id
-       })
-
-       if index < 0 {
-               return "", fmt.Errorf("no schedule %d", id)
-       }
-
-       s.file.Schedules = slices.Delete(s.file.Schedules, index, index+1)
-       err := s.save()
-       if err != nil {
-               return "", err
-       }
-
-       s.change()
-
-       return fmt.Sprintf("Schedule %d removed.", id), nil
-}
-

 // deliver logs the message of each due schedule in l, in due order, as a work
 // message of scheduleSource, and wakes the loop once with all of them. A
 // schedule ends its run with Done after its message is durable in the log. A
 // deliver logs the message of each due schedule in l, in due order, as a work
 // message of scheduleSource, and wakes the loop once with all of them. A
 // schedule ends its run with Done after its message is durable in the log. A


@@ -303,7 +225,7 @@ func (s *Schedules) deliver(ctx context.Context, l *TurnLoop) error {
 
                err = s.Done(schedule, now)
                if err != nil {
 
                err = s.Done(schedule, now)
                if err != nil {

-                       return err
+                       return fmt.Errorf("acknowledge schedule run: %w", err)

                }
 
                attrs := []any{"id", schedule.ID}
                }
 
                attrs := []any{"id", schedule.ID}


@@ -321,6 +243,17 @@ func (s *Schedules) deliver(ctx context.Context, l *TurnLoop) error {
        return nil
 }
 
        return nil
 }
 

+// Wait returns how long after now the first schedule is due, or false when
+// there is no schedule.
+func (s *Schedules) Wait(now time.Time) (time.Duration, bool) {
+       schedules := s.sorted()
+       if len(schedules) == 0 {
+               return 0, false
+       }
+
+       return max(schedules[0].Due.Sub(now), 0), true
+}
+

 // Due returns the schedules whose time is not after now, by due time.
 func (s *Schedules) Due(now time.Time) []Schedule {
        var due []Schedule
 // Due returns the schedules whose time is not after now, by due time.
 func (s *Schedules) Due(now time.Time) []Schedule {
        var due []Schedule


@@ -353,7 +286,12 @@ func (s *Schedules) Done(schedule Schedule, now time.Time) error {
        if schedule.Cron == "" {
                s.file.Schedules = slices.Delete(s.file.Schedules, index, index+1)
 
        if schedule.Cron == "" {
                s.file.Schedules = slices.Delete(s.file.Schedules, index, index+1)
 

-               return s.save()
+               err := s.save()
+               if err != nil {
+                       return fmt.Errorf("save completed one-time schedule: %w", err)
+               }
+
+               return nil

        }
 
        cron, err := scheduleParseCron(schedule.Cron)
        }
 
        cron, err := scheduleParseCron(schedule.Cron)


@@ -365,31 +303,22 @@ func (s *Schedules) Done(schedule Schedule, now time.Time) error {
        if !found {
                s.file.Schedules = slices.Delete(s.file.Schedules, index, index+1)
 
        if !found {
                s.file.Schedules = slices.Delete(s.file.Schedules, index, index+1)
 

-               return s.save()
+               err = s.save()
+               if err != nil {
+                       return fmt.Errorf("save exhausted schedule: %w", err)
+               }
+
+               return nil

        }
 
        s.file.Schedules[index].Due = next
 
        }
 
        s.file.Schedules[index].Due = next
 

-       return s.save()
-}
-
-// Wait returns how long after now the first schedule is due, or false when
-// there is no schedule.
-func (s *Schedules) Wait(now time.Time) (time.Duration, bool) {
-       schedules := s.sorted()
-       if len(schedules) == 0 {
-               return 0, false
+       err = s.save()
+       if err != nil {
+               return fmt.Errorf("save next schedule run: %w", err)

        }
 
        }
 

-       return max(schedules[0].Due.Sub(now), 0), true
-}
-
-// change wakes Run after a set or a remove.
-func (s *Schedules) change() {
-       select {
-       case s.changed <- struct{}{}:
-       default:
-       }
+       return nil

 }
 
 // sorted returns a copy of the schedules by due time, then by ID.
 }
 
 // sorted returns a copy of the schedules by due time, then by ID.


@@ -406,36 +335,122 @@ func (s *Schedules) sorted() []Schedule {
        return schedules
 }
 
        return schedules
 }
 

-// save writes the file whole, with mode 0600. The caller holds the mutex.
-func (s *Schedules) save() error {
-       data, err := json.Marshal(s.file)
-       if err == nil {
-               err = writeFileAtomic(s.path, append(data, '\n'))
+// Set adds a schedule with text and returns the answer of the tool. Exactly one
+// of at and cron is not nil. at is a local time in scheduleAtLayout after now,
+// and it goes through scheduleWallTime, so a time in the hour that the clock
+// repeats is its first occurrence. cron is an expression of scheduleParseCron.
+func (s *Schedules) Set(text string, at, cron *string) (string, error) {
+       text = strings.TrimSpace(text)
+       if text == "" || len(text) > scheduleTextBytes {
+               return "", fmt.Errorf("the text must have 1 to %d bytes", scheduleTextBytes)

        }
 
        }
 

+       now := s.clock()
+       schedule := Schedule{
+               Text:  text,
+               Owner: s.owner,
+       }
+
+       switch {
+       case (at == nil) == (cron == nil):
+               return "", errors.New("give either at or cron, and null for the other")
+       case at != nil:
+               parsed, err := time.Parse(scheduleAtLayout, *at)
+               if err != nil {
+                       return "", fmt.Errorf("at must be a local time such as %s", now.Format(scheduleAtLayout))
+               }
+
+               schedule.Due = scheduleWallTime(parsed.Year(), parsed.Month(), parsed.Day(), parsed.Hour(), parsed.Minute(), now.Location())
+               if !schedule.Due.After(now) {
+                       return "", fmt.Errorf("the time %s is not after now, %s", schedule.Due.Format(scheduleTimeLayout), now.Format(scheduleTimeLayout))
+               }
+       default:
+               parsed, err := scheduleParseCron(*cron)
+               if err != nil {
+                       return "", fmt.Errorf("parse schedule expression: %w", err)
+               }
+
+               next, found := parsed.Next(now)
+               if !found {
+                       return "", fmt.Errorf("the cron expression %q matches no time in %d years", *cron, scheduleCronYears)
+               }
+
+               schedule.Cron = parsed.String()
+               schedule.Due = next
+       }
+
+       s.mutex.Lock()
+       defer s.mutex.Unlock()
+
+       s.file.Next++
+       schedule.ID = s.file.Next
+       s.file.Schedules = append(s.file.Schedules, schedule)
+       err := s.save()

        if err != nil {
        if err != nil {

-               return fmt.Errorf("save schedules: %w", err)
+               return "", fmt.Errorf("save new schedule: %w", err)

        }
 
        }
 

-       return nil
+       s.change()
+
+       return fmt.Sprintf("Schedule %d set. Next: %s.", schedule.ID, schedule.Due.In(now.Location()).Format(scheduleTimeLayout)), nil

 }
 
 }
 

-// ScheduleFile is the content of the file of the schedules: the ID of the last
-// schedule, so that an ID is never used again, and the schedules.
-type ScheduleFile struct {
-       Next      int        `json:"next"`
-       Schedules []Schedule `json:"schedules"`
+// change wakes Run after a set or a remove.
+func (s *Schedules) change() {
+       select {
+       case s.changed <- struct{}{}:
+       default:
+       }

 }
 
 }
 

-// Schedule is one schedule: its owner, its ID, the task for the agent, the cron
-// expression of a repeating schedule, empty for a one-time schedule, and its
-// next time.
-type Schedule struct {
-       Owner string    `json:"owner"`
-       ID    int       `json:"id"`
-       Text  string    `json:"text"`
-       Cron  string    `json:"cron"`
-       Due   time.Time `json:"due"`
+// List returns the answer of the tool: one line for each schedule, by due time,
+// with its ID, its next time, its cron expression or once, and its text on one
+// line.
+func (s *Schedules) List() string {
+       location := s.clock().Location()
+       schedules := s.sorted()
+       if len(schedules) == 0 {
+               return "No schedules."
+       }
+
+       lines := make([]string, 0, len(schedules))
+       for _, schedule := range schedules {
+               lines = append(lines, strconv.Itoa(schedule.ID)+" | "+schedule.Due.In(location).Format(scheduleTimeLayout)+" | "+cmp.Or(schedule.Cron, "once")+" | "+strings.Join(strings.Fields(schedule.Text), " "))
+       }
+
+       return strings.Join(lines, "\n")
+}
+
+// Len returns the number of schedules.
+func (s *Schedules) Len() int {
+       s.mutex.Lock()
+       defer s.mutex.Unlock()
+
+       return len(s.file.Schedules)
+}
+
+// Remove removes the schedule id and returns the answer of the tool.
+func (s *Schedules) Remove(id int) (string, error) {
+       s.mutex.Lock()
+       defer s.mutex.Unlock()
+
+       index := slices.IndexFunc(s.file.Schedules, func(schedule Schedule) bool {
+               return schedule.ID == id
+       })
+
+       if index < 0 {
+               return "", fmt.Errorf("no schedule %d", id)
+       }
+
+       s.file.Schedules = slices.Delete(s.file.Schedules, index, index+1)
+       err := s.save()
+       if err != nil {
+               return "", fmt.Errorf("save removed schedule: %w", err)
+       }
+
+       s.change()
+
+       return fmt.Sprintf("Schedule %d removed.", id), nil

 }
 
 // Message returns the text of a run at now for the log, with the times in the
 }
 
 // Message returns the text of a run at now for the log, with the times in the