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Merged
kaovilai merged 11 commits into from
Apr 16, 2026
+18 −13
Merged

perf: better string concatenation #9705

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ee61eb7
perf: better string concatenation
emirot Apr 10, 2026
afd7171
fix: backup deletion silently succeeds when tarball download fails (#…
priyansh17 Apr 14, 2026
5efee83
perf: better string concatenation
Apr 15, 2026
4c64725
Add delay to avoid race conditions during VolumeSnapshotContent delet…
priyansh17 Apr 14, 2026
66229dc
block data mover design
Lyndon-Li Jan 7, 2026
2e246c7
block data mover design
Lyndon-Li Feb 6, 2026
dc68b17
irregular volume size
Lyndon-Li Feb 27, 2026
5d90df1
block data mover design
Lyndon-Li Mar 3, 2026
22d3566
Update the "community" page of website (#9722)
reasonerjt Apr 15, 2026
60597b9
perf: better string concatenation
emirot Apr 16, 2026
ea2b55c
Merge branch 'main' into perf/string_concat
emirot Apr 16, 2026
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1 change: 1 addition & 0 deletions changelogs/unreleased/9705-emirot
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Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
perf: better string concatenation
7 changes: 4 additions & 3 deletions pkg/util/csi/volume_snapshot.go
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Original file line number Diff line number Diff line change
Expand Up @@ -708,17 +708,18 @@ func DiagnoseVS(vs *snapshotv1api.VolumeSnapshot, events *corev1api.EventList) s
}
}

diag := fmt.Sprintf("VS %s/%s, bind to %s, readyToUse %v, errMessage %s\n", vs.Namespace, vs.Name, vscName, readyToUse, errMessage)
var diag strings.Builder
_, _ = fmt.Fprintf(&diag, "VS %s/%s, bind to %s, readyToUse %v, errMessage %s\n", vs.Namespace, vs.Name, vscName, readyToUse, errMessage)

if events != nil {
for _, e := range events.Items {
if e.InvolvedObject.UID == vs.UID && e.Type == corev1api.EventTypeWarning {
diag += fmt.Sprintf("VS event reason %s, message %s\n", e.Reason, e.Message)
_, _ = fmt.Fprintf(&diag, "VS event reason %s, message %s\n", e.Reason, e.Message)
}
}
}

return diag
return diag.String()
}

func DiagnoseVSC(vsc *snapshotv1api.VolumeSnapshotContent) string {
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16 changes: 9 additions & 7 deletions pkg/util/kube/pod.go
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Expand Up @@ -20,6 +20,7 @@ import (
"fmt"
"io"
"os"
"strings"
"time"

"github.com/pkg/errors"
Expand Down Expand Up @@ -183,16 +184,16 @@ func GetPodContainerTerminateMessage(pod *corev1api.Pod, container string) strin

// GetPodTerminateMessage returns the terminate message for all containers of a pod
func GetPodTerminateMessage(pod *corev1api.Pod) string {
message := ""
var message strings.Builder
for _, containerStatus := range pod.Status.ContainerStatuses {
if containerStatus.State.Terminated != nil {
if containerStatus.State.Terminated.Message != "" {
message += containerStatus.State.Terminated.Message + "/"
message.WriteString(containerStatus.State.Terminated.Message + "/")
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Copilot AI Apr 16, 2026

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Inside the loop, this still performs string concatenation (Terminated.Message + "/"), which creates a new temporary string on every iteration and may continue to trigger the concat-loop lint/performance warning. Prefer writing the message and delimiter separately (e.g., write the message then write the "/" delimiter) to avoid per-iteration allocations.

Suggested change
message.WriteString(containerStatus.State.Terminated.Message + "/")
message.WriteString(containerStatus.State.Terminated.Message)
message.WriteString("/")

Copilot uses AI. Check for mistakes.
}
}
}

return message
return message.String()
}

func getPodLogReader(ctx context.Context, podGetter corev1client.CoreV1Interface, pod string, namespace string, logOptions *corev1api.PodLogOptions) (io.ReadCloser, error) {
Expand Down Expand Up @@ -272,21 +273,22 @@ func ToSystemAffinity(loadAffinity *LoadAffinity, volumeTopology *corev1api.Node
}

func DiagnosePod(pod *corev1api.Pod, events *corev1api.EventList) string {
diag := fmt.Sprintf("Pod %s/%s, phase %s, node name %s, message %s\n", pod.Namespace, pod.Name, pod.Status.Phase, pod.Spec.NodeName, pod.Status.Message)
var diag strings.Builder
_, _ = fmt.Fprintf(&diag, "Pod %s/%s, phase %s, node name %s, message %s\n", pod.Namespace, pod.Name, pod.Status.Phase, pod.Spec.NodeName, pod.Status.Message)

for _, condition := range pod.Status.Conditions {
diag += fmt.Sprintf("Pod condition %s, status %s, reason %s, message %s\n", condition.Type, condition.Status, condition.Reason, condition.Message)
_, _ = fmt.Fprintf(&diag, "Pod condition %s, status %s, reason %s, message %s\n", condition.Type, condition.Status, condition.Reason, condition.Message)
}

if events != nil {
for _, e := range events.Items {
if e.InvolvedObject.UID == pod.UID && e.Type == corev1api.EventTypeWarning {
diag += fmt.Sprintf("Pod event reason %s, message %s\n", e.Reason, e.Message)
_, _ = fmt.Fprintf(&diag, "Pod event reason %s, message %s\n", e.Reason, e.Message)
}
}
}

return diag
return diag.String()
}

var funcExit = os.Exit
Expand Down
7 changes: 4 additions & 3 deletions pkg/util/kube/pvc_pv.go
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Expand Up @@ -464,17 +464,18 @@ func GetPVCForPodVolume(vol *corev1api.Volume, pod *corev1api.Pod, crClient crcl
}

func DiagnosePVC(pvc *corev1api.PersistentVolumeClaim, events *corev1api.EventList) string {
diag := fmt.Sprintf("PVC %s/%s, phase %s, binding to %s\n", pvc.Namespace, pvc.Name, pvc.Status.Phase, pvc.Spec.VolumeName)
var diag strings.Builder
_, _ = fmt.Fprintf(&diag, "PVC %s/%s, phase %s, binding to %s\n", pvc.Namespace, pvc.Name, pvc.Status.Phase, pvc.Spec.VolumeName)

if events != nil {
for _, e := range events.Items {
if e.InvolvedObject.UID == pvc.UID && e.Type == corev1api.EventTypeWarning {
diag += fmt.Sprintf("PVC event reason %s, message %s\n", e.Reason, e.Message)
_, _ = fmt.Fprintf(&diag, "PVC event reason %s, message %s\n", e.Reason, e.Message)
}
}
}

return diag
return diag.String()
}

func DiagnosePV(pv *corev1api.PersistentVolume) string {
Expand Down
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