Move SETINFO calls to ChannelHandler so they can be written along with HELLO

[adam-fowler]

No description provided.

[github-actions]

✅ Pull request no significant performance differences ✅

Summary

One or more benchmarks, including `ValkeyBenchmarks:Connection: Create and drop benchmark` was not found in one of the baselines.

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

Full Benchmark Comparison

Comparing results between 'main' and 'pull_request'

Host '949ed62af095' 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	79	79	80	83	83	83	83	6
pull_request	78	79	80	81	81	81	81	6
Δ	-1	0	0	-2	-2	-2	-2	0
Improvement %	1	0	0	2	2	2	2	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	93	96	98	100	104	106	106	25
pull_request	93	96	98	100	102	104	104	24
Δ	0	0	0	0	-2	-2	-2	-1
Improvement %	0	0	0	0	2	2	2	-1

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: Pipeline benchmark metrics

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

Malloc (total) *	p0	p25	p50	p75	p90	p99	p100	Samples
main	37	37	37	37	37	37	37	5
pull_request	36	37	37	37	37	37	37	5
Δ	-1	0	0	0	0	0	0	0
Improvement %	3	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	19
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	749
pull_request	0	0	0	0	0	0	0	748
Δ	0	0	0	0	0	0	0	-1
Improvement %	0	0	0	0	0	0	0	-1

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	1895
pull_request	0	0	0	0	0	0	0	1904
Δ	0	0	0	0	0	0	0	9
Improvement %	0	0	0	0	0	0	0	9

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	359
pull_request	0	0	0	0	0	0	0	362
Δ	0	0	0	0	0	0	0	3
Improvement %	0	0	0	0	0	0	0	3

[fabianfett]

I'm afraid this pr shows, that special casing the HELLO command in the state machine, is not the absolute worst idea, even if it initially adds a bit of code.

Focusing on this approach, I would love to see a "ValkeyConnection create and drop" benchmark for it.

Generally looks okay, though.

[fabianfett]

I think the cancel code here should be unreachable. HELLO and SETINFO are triggered from within the channel handler.

[adam-fowler]

Yeah it's unreachable, I can add a precondition instead.

[adam-fowler]

I'm afraid this pr shows, that special casing the HELLO command in the state machine, is not the absolute worst idea, even if it initially adds a bit of code.

This PR shows that having all the commands from the initial handshake in one place is the best thing. I could have pipelined the hello, client setinfo inside the connection as well.