Improve daemon subcommand using fsnotify

go.mod

@@ -4,6 +4,7 @@ go 1.15
 
 require (
 	github.com/cpuguy83/go-md2man/v2 v2.0.3 // indirect
+	github.com/fsnotify/fsnotify v1.7.0
 	github.com/google/go-cmp v0.6.0
 	github.com/jmoiron/sqlx v1.3.5
 	github.com/kr/pretty v0.1.0 // indirect

go.sum

@@ -2,6 +2,8 @@ github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbi
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/cpuguy83/go-md2man/v2 v2.0.3 h1:qMCsGGgs+MAzDFyp9LpAe1Lqy/fY/qCovCm0qnXZOBM=
 github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
+github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/go-sql-driver/mysql v1.6.0 h1:BCTh4TKNUYmOmMUcQ3IipzF5prigylS7XXjEkfCHuOE=
 github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
@@ -24,6 +26,8 @@ github.com/urfave/cli/v2 v2.27.1 h1:8xSQ6szndafKVRmfyeUMxkNUJQMjL1F2zmsZ+qHpfho=
 github.com/urfave/cli/v2 v2.27.1/go.mod h1:8qnjx1vcq5s2/wpsqoZFndg2CE5tNFyrTvS6SinrnYQ=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
+golang.org/x/sys v0.4.0 h1:Zr2JFtRQNX3BCZ8YtxRE9hNJYC8J6I1MVbMg6owUp18=
+golang.org/x/sys v0.4.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

timefor.go

@@ -16,6 +16,7 @@ import (
 	"text/template"
 	"time"
 
+	"github.com/fsnotify/fsnotify"
 	"github.com/jmoiron/sqlx"
 	_ "github.com/mattn/go-sqlite3"
 	"github.com/urfave/cli/v2"
@@ -249,6 +250,7 @@ func newCmd(db *sqlx.DB) error {
 					intervalToShowBreakReminder := cCtx.Duration("break-interval")
 					intervalToRepeatBreakReminder := cCtx.Duration("repeat-interval")
 					hook := cCtx.String("hook")
+
 					err := Daemon(db, intervalToUpdateDb, intervalToShowBreakReminder, intervalToRepeatBreakReminder, hook)
 					if err != nil {
 						return err
@@ -493,6 +495,10 @@ func Daemon(
 ) error {
 	var notified time.Time
 	var lastHook string
+	change := make(chan ChangeEvent)
+
+	go watchDbFile(change)
+
 	for {
 		activity, err := Latest(db)
 		if err != nil {
@@ -512,17 +518,12 @@ func Daemon(
 				}
 			}
 		}
-		if activity.Active() && time.Since(activity.Updated()) > intervalToUpdateDb {
-			fmt.Printf("updating time for %s\n", activity.Name)
-			_, err := UpdateIfExists(db, "", false)
-			if err != nil {
-				return err
-			}
+		if activity.Active() {
 			duration, err := activeDuration(db)
 			if err != nil {
 				return err
 			}
-			if activity.Active() && duration > intervalToShowBreakReminder && time.Since(notified) > intervalToRepeatBreakReminder {
+			if duration > intervalToShowBreakReminder && time.Since(notified) > intervalToRepeatBreakReminder {
 				args := []string{
 					"Take a break!",
 					fmt.Sprintf("Active for %v already", formatDuration(duration)),
@@ -540,10 +541,64 @@ func Daemon(
 				notified = time.Now()
 			}
 		}
-		time.Sleep(1 * time.Second)
+
+		nextUpdate := activity.TimeSince().Truncate(time.Minute) + time.Minute - activity.TimeSince()
+		log.Printf("next update in %s\n", nextUpdate)
+
+		select {
+		case c := <-change:
+			log.Println("change", c)
+
+		case <-time.After(nextUpdate):
+			if activity.Active() && time.Since(activity.Updated()) > intervalToUpdateDb {
+				fmt.Printf("updating time for %s\n", activity.Name)
+				_, err := UpdateIfExists(db, "", false)
+				if err != nil {
+					return err
+				}
+			}
+		}
 	}
 }
 
+type ChangeEvent struct {
+	Event fsnotify.Event
+	Error error
+}
+
+func watchDbFile(change chan ChangeEvent) error {
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		return err
+	}
+	defer watcher.Close()
+
+	go func() {
+		for {
+			select {
+			case event, ok := <-watcher.Events:
+				if !ok {
+					return
+				}
+				change <- ChangeEvent{Event: event}
+
+			case err, ok := <-watcher.Errors:
+				if !ok {
+					return
+				}
+				change <- ChangeEvent{Error: err}
+			}
+		}
+	}()
+
+	if err := watcher.Add(dbFile); err != nil {
+		return err
+	}
+
+	<-make(chan struct{})
+	return nil
+}
+
 func activeDuration(db *sqlx.DB) (time.Duration, error) {
 	rows, err := db.Queryx(`SELECT * FROM log ORDER BY started DESC LIMIT 100`)
 	if err != nil {