Custom responses list commands

[nilanshu-sharma]

Adding custom responses for lpop an rpop commands which return:

• nil if key doesn't exist
• ByteBuffer? if invoked without count param
• [ByteBuffer]? if invoked with count

[github-actions]

✅ Pull request no significant performance differences ✅

Summary

New baseline 'pull_request' is WITHIN the 'main' baseline thresholds.

Full Benchmark Comparison

Comparing results between 'main' and 'pull_request'

Host '939bbd0fa115' with 4 'x86_64' processors with 15 GB memory, running:
#18~24.04.1-Ubuntu SMP Sat Jun 28 04:46:03 UTC 2025

ValkeyBenchmarks

Client: GET benchmark metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	76	78	78	79	79	79	79	6
pull_request	71	79	80	81	81	81	81	6
Δ	-5	1	2	2	2	2	2	0
Improvement %	7	-1	-3	-3	-3	-3	-3	0

Client: GET benchmark | parallel 20 | 20 concurrent connections metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	73	77	81	83	87	89	89	28
pull_request	73	77	79	83	86	87	87	28
Δ	0	0	-2	0	-1	-2	-2	0
Improvement %	0	0	2	0	1	2	2	0

Connection: GET benchmark metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	4	4	4	4	4	4	4	8
pull_request	4	4	4	4	4	4	4	8
Δ	0	0	0	0	0	0	0	0
Improvement %	0	0	0	0	0	0	0	0

Connection: GET benchmark – NoOpTracer metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	7	8	8	10	11	11	11	8
pull_request	7	8	8	10	11	11	11	8
Δ	0	0	0	0	0	0	0	0
Improvement %	0	0	0	0	0	0	0	0

Connection: Pipeline array benchmark metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	33	33	33	34	34	34	34	6
pull_request	33	33	34	34	34	34	34	6
Δ	0	0	1	0	0	0	0	0
Improvement %	0	0	-3	0	0	0	0	0

Connection: Pipeline benchmark metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	33	33	33	34	34	34	34	6
pull_request	33	33	33	34	34	34	34	5
Δ	0	0	0	0	0	0	0	-1
Improvement %	0	0	0	0	0	0	0	-1

HashSlot – {user}.whatever metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	0	0	0	0	0	0	0	18
pull_request	0	0	0	0	0	0	0	18
Δ	0	0	0	0	0	0	0	0
Improvement %	0	0	0	0	0	0	0	0

ValkeyCommandEncoder – Command with 7 words metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	0	0	0	0	0	0	0	731
pull_request	0	0	0	0	0	0	0	713
Δ	0	0	0	0	0	0	0	-18
Improvement %	0	0	0	0	0	0	0	-18

ValkeyCommandEncoder – Simple GET metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	0	0	0	0	0	0	0	1879
pull_request	0	0	0	0	0	0	0	1807
Δ	0	0	0	0	0	0	0	-72
Improvement %	0	0	0	0	0	0	0	-72

ValkeyCommandEncoder – Simple MGET 15 keys metrics

Malloc (total): results within specified thresholds, fold down for details.

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	0	0	0	0	0	0	0	357
pull_request	0	0	0	0	0	0	0	339
Δ	0	0	0	0	0	0	0	-18
Improvement %	0	0	0	0	0	0	0	-18

[adam-fowler]

Some additional comments.

This PR does make me wonder about the sense of creating responses for every command instead of allowing some just to return a RESPToken. Note the amount of extra code you needed to add in the CommandTests test

[adam-fowler]

Checking for null here shouldn't be needed, that has already been done because the LPOP/RPOP response is optional. Which means the function can return a non-optional value. It should be RESPBulkString instead of ByteBuffer

[adam-fowler]

This doesn't need to be optional