Cluster transactions

[adam-fowler]

Add transaction functionality to ValkeyClientCluster.

• In ValkeyConnection extracted the transaction result processing into separate function _processTransactionPromises, so it can be used by both the original transaction function and the new transactionWithAsk function.
• Removed duplicate code from ValkeyClientCluster.execute(_:)
• Added transaction(_:) to ValkeyClientProtocol

This is currently set to merge into the transaction-rewrite branch to make it easier to see the changes.

[github-actions]

❌ Pull request has performance regressions ❌

Summary

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Threshold deviations for ValkeyBenchmarks:Connection: GET benchmark – NoOpTracer
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Malloc (total) (#, %)	main	pull_request	Difference %	Threshold %
p50	8383	9975	19	5

New baseline 'pull_request' is WORSE than the 'main' baseline thresholds.

Full Benchmark Comparison

Comparing results between 'main' and 'pull_request'

Host '318e8e8f9815' with 4 'x86_64' processors with 15 GB memory, running:
#12~24.04.1-Ubuntu SMP Tue Sep  9 19:01:23 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	82	83	83	85	87	87	87	6
pull_request	81	86	87	87	88	88	88	6
Δ	-1	3	4	2	1	1	1	0
Improvement %	1	-4	-5	-2	-1	-1	-1	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	98	100	104	107	108	113	113	23
pull_request	96	100	103	104	109	110	110	23
Δ	-2	0	-1	-3	1	-3	-3	0
Improvement %	2	0	1	3	-1	3	3	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	10	10	10	8
pull_request	7	8	10	10	10	10	10	7
Δ	0	0	2	0	0	0	0	-1
Improvement %	0	0	-25	0	0	0	0	-1

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	34	34	34	34	34	5
pull_request	33	33	34	34	34	34	34	6
Δ	0	0	0	0	0	0	0	1
Improvement %	0	0	0	0	0	0	0	1

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	5
pull_request	33	33	33	34	34	34	34	5
Δ	0	0	0	0	0	0	0	0
Improvement %	0	0	0	0	0	0	0	0

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	19
pull_request	0	0	0	0	0	0	0	16
Δ	0	0	0	0	0	0	0	-3
Improvement %	0	0	0	0	0	0	0	-3

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	740
pull_request	0	0	0	0	0	0	0	738
Δ	0	0	0	0	0	0	0	-2
Improvement %	0	0	0	0	0	0	0	-2

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	1902
pull_request	0	0	0	0	0	0	0	1882
Δ	0	0	0	0	0	0	0	-20
Improvement %	0	0	0	0	0	0	0	-20

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	348
pull_request	0	0	0	0	0	0	0	358
Δ	0	0	0	0	0	0	0	10
Improvement %	0	0	0	0	0	0	0	10