Add reload-sync action

Close #2816

3 files changed, 41 insertions, 14 deletions

diff --git a/src/core.go b/src/core.go
index 2ddddc35..c6ff3dcf 100644
--- a/src/core.go
+++ b/src/core.go
@@ -213,15 +213,6 @@ func Run(opts *Options, version string, revision string) {
 	clearSelection := util.Once(false)
 	ticks := 0
 	var nextCommand *string
-	restart := func(command string) {
-		reading = true
-		clearCache = util.Once(true)
-		clearSelection = util.Once(true)
-		chunkList.Clear()
-		itemIndex = 0
-		header = make([]string, 0, opts.HeaderLines)
-		go reader.restart(command)
-	}
 	eventBox.Watch(EvtReadNew)
 	total := 0
 	query := []rune{}
@@ -236,6 +227,25 @@ func Run(opts *Options, version string, revision string) {
 			terminal.startChan <- fitpad{-1, -1}
 		}
 	}
+
+	useSnapshot := false
+	var snapshot []*Chunk
+	var prevSnapshot []*Chunk
+	var count int
+	restart := func(command string) {
+		reading = true
+		clearCache = util.Once(true)
+		clearSelection = util.Once(true)
+		// We should not update snapshot if reload is triggered again while
+		// the previous reload is in progress
+		if useSnapshot && prevSnapshot != nil {
+			snapshot, count = chunkList.Snapshot()
+		}
+		chunkList.Clear()
+		itemIndex = 0
+		header = make([]string, 0, opts.HeaderLines)
+		go reader.restart(command)
+	}
 	for {
 		delay := true
 		ticks++
@@ -267,7 +277,13 @@ func Run(opts *Options, version string, revision string) {
 					} else {
 						reading = reading && evt == EvtReadNew
 					}
-					snapshot, count := chunkList.Snapshot()
+					if useSnapshot && evt == EvtReadFin {
+						useSnapshot = false
+						prevSnapshot = nil
+					}
+					if !useSnapshot {
+						snapshot, count = chunkList.Snapshot()
+					}
 					total = count
 					terminal.UpdateCount(total, !reading, value.(*string))
 					if opts.Sync {
@@ -286,6 +302,9 @@ func Run(opts *Options, version string, revision string) {
 					case searchRequest:
 						sort = val.sort
 						command = val.command
+						if command != nil {
+							useSnapshot = val.sync
+						}
 					}
 					if command != nil {
 						if reading {
@@ -296,7 +315,9 @@ func Run(opts *Options, version string, revision string) {
 						}
 						break
 					}
-					snapshot, _ := chunkList.Snapshot()
+					if !useSnapshot {
+						snapshot, _ = chunkList.Snapshot()
+					}
 					reset := clearCache()
 					matcher.Reset(snapshot, input(reset), true, !reading, sort, reset)
 					delay = false
diff --git a/src/options.go b/src/options.go
index 08b48258..79a4a0ad 100644
--- a/src/options.go
+++ b/src/options.go
@@ -892,7 +892,7 @@ const (
 
 func init() {
 	executeRegexp = regexp.MustCompile(
-		`(?si)[:+](execute(?:-multi|-silent)?|reload|preview|change-query|change-prompt|change-preview-window|change-preview|(?:re|un)bind|pos|put|transform-query)`)
+		`(?si)[:+](execute(?:-multi|-silent)?|reload(?:-sync)?|preview|change-query|change-prompt|change-preview-window|change-preview|(?:re|un)bind|pos|put|transform-query)`)
 	splitRegexp = regexp.MustCompile("[,:]+")
 	actionNameRegexp = regexp.MustCompile("(?i)^[a-z-]+")
 }
@@ -1185,6 +1185,8 @@ func isExecuteAction(str string) actionType {
 	switch prefix {
 	case "reload":
 		return actReload
+	case "reload-sync":
+		return actReloadSync
 	case "unbind":
 		return actUnbind
 	case "rebind":
diff --git a/src/terminal.go b/src/terminal.go
index 02b1a5df..7e900c96 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -335,6 +335,7 @@ const (
 	actFirst
 	actLast
 	actReload
+	actReloadSync
 	actDisableSearch
 	actEnableSearch
 	actSelect
@@ -353,6 +354,7 @@ type placeholderFlags struct {
 
 type searchRequest struct {
 	sort    bool
+	sync    bool
 	command *string
 }
 
@@ -2540,6 +2542,7 @@ func (t *Terminal) Loop() {
 	}()
 	for looping {
 		var newCommand *string
+		var reloadSync bool
 		changed := false
 		beof := false
 		queryChanged := false
@@ -3030,7 +3033,7 @@ func (t *Terminal) Loop() {
 						}
 					}
 				}
-			case actReload:
+			case actReload, actReloadSync:
 				t.failed = nil
 
 				valid, list := t.buildPlusList(a.a, false)
@@ -3044,6 +3047,7 @@ func (t *Terminal) Loop() {
 				if valid {
 					command := t.replacePlaceholder(a.a, false, string(t.input), list)
 					newCommand = &command
+					reloadSync = a.t == actReloadSync
 					t.reading = true
 				}
 			case actUnbind:
@@ -3173,7 +3177,7 @@ func (t *Terminal) Loop() {
 		t.mutex.Unlock() // Must be unlocked before touching reqBox
 
 		if changed || newCommand != nil {
-			t.eventBox.Set(EvtSearchNew, searchRequest{sort: t.sort, command: newCommand})
+			t.eventBox.Set(EvtSearchNew, searchRequest{sort: t.sort, sync: reloadSync, command: newCommand})
 		}
 		for _, event := range events {
 			t.reqBox.Set(event, nil)