Use binary search in getLineIndex method

src/app/backend/resource/container/logs_test.go

@@ -15,6 +15,7 @@
 package container
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
 
@@ -47,6 +48,40 @@ var log5 = logs.LogLine{
 	Content:   "log5",
 }
 
+var details *logs.LogDetails
+
+func benchmarkGetLogDetails(lines int, timestamp string, b *testing.B) {
+	// Generate raw logs.
+	rawLogs := ""
+	for i := 0; i < lines; i++ {
+		rawLogs += fmt.Sprintf("%[1]d log%[1]d\n", i)
+	}
+
+	selector := &logs.Selection{
+		ReferencePoint: logs.LogLineId{
+			LogTimestamp: logs.LogTimestamp(timestamp),
+			LineNum:      1,
+		},
+		OffsetFrom: -2,
+		OffsetTo:   0,
+	}
+
+	var d *logs.LogDetails
+
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		d = ConstructLogDetails("pod-1", rawLogs, "list", selector)
+	}
+	b.StopTimer()
+
+	details = d
+}
+
+func BenchmarkGetLogDetails1(b *testing.B) { benchmarkGetLogDetails(2000, "1999", b) }
+func BenchmarkGetLogDetails2(b *testing.B) { benchmarkGetLogDetails(2000, "999", b) }
+func BenchmarkGetLogDetails3(b *testing.B) { benchmarkGetLogDetails(2000, "99", b) }
+func BenchmarkGetLogDetails4(b *testing.B) { benchmarkGetLogDetails(2000, "9", b) }
+
 func TestGetLogs(t *testing.T) {
 	// for the test cases, the line read limit is reduced to 10
 	lineReadLimit = int64(10)

src/app/backend/resource/logs/logs.go

@@ -15,6 +15,7 @@
 package logs
 
 import (
+	"sort"
 	"strings"
 )
 
@@ -193,18 +194,19 @@ func (self LogLines) getLineIndex(logLineId *LogLineId) int {
 		return 0
 	}
 	logTimestamp := logLineId.LogTimestamp
-	linesMatched := 0
+
 	matchingStartedAt := 0
-	for idx := range self {
-		if self[idx].Timestamp == logTimestamp {
-			if linesMatched == 0 {
-				matchingStartedAt = idx
-			}
+	matchingStartedAt = sort.Search(len(self), func(i int) bool {
+		return self[i].Timestamp >= logTimestamp
+	})
+
+	linesMatched := 0
+	if matchingStartedAt < len(self) && self[matchingStartedAt].Timestamp == logTimestamp { // match found
+		for (matchingStartedAt+linesMatched) < len(self) && self[matchingStartedAt+linesMatched].Timestamp == logTimestamp {
 			linesMatched += 1
-		} else if linesMatched > 0 {
-			break
 		}
 	}
+
 	var offset int
 	if logLineId.LineNum < 0 {
 		offset = linesMatched + logLineId.LineNum