From 3a6a1b2aa949ab97c165b116aab190f2eb77fdc3 Mon Sep 17 00:00:00 2001
From: Albert S <mail@quitesimple.org>
Date: Thu, 19 Aug 2021 21:30:04 +0200
Subject: [PATCH] bash-ctrlr: Improve reverse bash search performance

Remove hack that only starts searching when two chars have been entered

Improve performance by adding LIMIT clause instead.
---
 history.go | 22 ++++++++++------------
 main.go    | 19 ++++++++++++++++---
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/history.go b/history.go
index 0bd4c6e..028643d 100644
--- a/history.go
+++ b/history.go
@@ -12,16 +12,15 @@ type history struct {
 }
 
 func (h *history) GetHistoryByPrefix(prefix string) (ph []string) {
-	/* Hack for performance reasons */
-	if len(prefix) < 2 {
-		return
-	}
 	opts := searchopts{}
-	opts.order = "DESC"
+	o := "DESC"
+	opts.order = &o
+	lim := 100
+	opts.limit = &lim
 	cmdqry := prefix + "%"
 	opts.command = &cmdqry
 	results := search(h.conn, opts)
-	for e := results.Front(); e != nil; e = e.Next() {
+	for e := results.Back(); e != nil; e = e.Prev() {
 		entry, ok := e.Value.(*HistoryEntry)
 		if !ok {
 			log.Panic("Failed to retrieve entries")
@@ -31,16 +30,15 @@ func (h *history) GetHistoryByPrefix(prefix string) (ph []string) {
 	return
 }
 func (h *history) GetHistoryByPattern(pattern string) (ph []string, pos []int) {
-	/* Hack for performance reasons */
-	if len(pattern) < 2 {
-		return
-	}
 	opts := searchopts{}
-	opts.order = "DESC"
+	o := "DESC"
+	opts.order = &o
+	lim := 100
+	opts.limit = &lim
 	cmdqry := "%" + pattern + "%"
 	opts.command = &cmdqry
 	results := search(h.conn, opts)
-	for e := results.Front(); e != nil; e = e.Next() {
+	for e := results.Back(); e != nil; e = e.Prev() {
 		entry, ok := e.Value.(*HistoryEntry)
 		if !ok {
 			log.Panic("Failed to retrieve entries")
diff --git a/main.go b/main.go
index 4f465ce..cdb571a 100644
--- a/main.go
+++ b/main.go
@@ -157,7 +157,8 @@ type searchopts struct {
 	after   *time.Time
 	before  *time.Time
 	retval  *int
-	order   string
+	order   *string
+	limit   *int
 }
 
 func search(conn *sql.DB, opts searchopts) list.List {
@@ -188,7 +189,18 @@ func search(conn *sql.DB, opts searchopts) list.List {
 		args = append(args, opts.retval)
 	}
 	sb.WriteString("ORDER BY timestamp ")
-	sb.WriteString("ASC ")
+	if opts.order != nil {
+		sb.WriteString(*opts.order)
+		sb.WriteRune(' ')
+	} else {
+		sb.WriteString("ASC ")
+	}
+
+	if opts.limit != nil {
+		sb.WriteString("LIMIT ")
+		sb.WriteString(strconv.Itoa(*opts.limit))
+		sb.WriteRune(' ')
+	}
 
 	queryStmt := sb.String()
 
@@ -353,7 +365,8 @@ func main() {
 		q := strings.Join(args, " ")
 
 		opts := searchopts{}
-		opts.order = "ASC"
+		o := "ASC"
+		opts.order = &o
 		if q != "" {
 			cmd := "%" + q + "%"
 			opts.command = &cmd