pkg/logs/processor: use custom marshaler for json payload message

[AlexanderYastrebov]

What does this PR do?

Change jsonPayload Message field type to use encoding.TextMarshaler/TextUnmarshaler
to avoid allocation due to conversion of valid UTF-8 bytes to string in the common case.

goos: darwin
goarch: arm64
pkg: github.com/DataDog/datadog-agent/pkg/logs/processor
cpu: Apple M4 Max
                              │    HEAD~1    │                HEAD                 │
                              │    sec/op    │    sec/op     vs base               │
JSONEncoder_Encode/valid-16     563.1n ± 17%   543.7n ± 12%  -3.45% (p=0.009 n=10)
JSONEncoder_Encode/invalid-16   567.0n ±  1%   550.0n ±  1%  -3.00% (p=0.000 n=10)
geomean                         565.0n         546.8n        -3.22%

                              │    HEAD~1    │                HEAD                 │
                              │     B/op     │     B/op      vs base               │
JSONEncoder_Encode/valid-16     1.127Ki ± 0%   1.017Ki ± 0%  -9.79% (p=0.000 n=10)
JSONEncoder_Encode/invalid-16   1.127Ki ± 0%   1.017Ki ± 0%  -9.79% (p=0.000 n=10)
geomean                         1.127Ki        1.017Ki       -9.79%

                              │   HEAD~1    │                HEAD                │
                              │  allocs/op  │ allocs/op   vs base                │
JSONEncoder_Encode/valid-16     10.000 ± 0%   9.000 ± 0%  -10.00% (p=0.000 n=10)
JSONEncoder_Encode/invalid-16   10.000 ± 0%   9.000 ± 0%  -10.00% (p=0.000 n=10)
geomean                          10.00        9.000       -10.00%

Motivation

Reduce memory allocations.

Describe how you validated your changes

By introducing benchmark and comparing results before and after the change.

Additional Notes

Better review per commit. This is related to #33906

[AlexanderYastrebov]

Note: use test payload type to parse message as string.

[AlexanderYastrebov]

Note: its unfortunate that #30924 exported jsonPayload type. Maybe this type could be unexported given it is only used as fmt.Stringer:

datadog-agent/cmd/agent/subcommands/analyzelogs/command.go

Line 124 in b665fd4

fmt.Println(parsedMessage.Message)

[agent-platform-auto-pr]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor dae02eb
📊 Static Quality Gates Dashboard

Successful checks

Info

	Quality gate	Delta	On disk size (MiB)	Delta	On wire size (MiB)
✅	agent_deb_amd64	$${+0}$$	$${708.09}$$ < $${708.41}$$	$${+0.01}$$	$${173.91}$$ < $${174.49}$$
✅	agent_deb_amd64_fips	$${+0}$$	$${703.39}$$ < $${704.0}$$	$${+0.01}$$	$${172.7}$$ < $${173.75}$$
✅	agent_heroku_amd64	$${+0}$$	$${328.71}$$ < $${329.53}$$	$${-0}$$	$${87.44}$$ < $${88.45}$$
✅	agent_msi	$${+0}$$	$${570.69}$$ < $${982.08}$$	$${+0}$$	$${142.69}$$ < $${143.02}$$
✅	agent_rpm_amd64	$${+0}$$	$${708.08}$$ < $${708.38}$$	$${-0}$$	$${176.45}$$ < $${177.66}$$
✅	agent_rpm_amd64_fips	$${+0}$$	$${703.38}$$ < $${703.99}$$	$${+0.06}$$	$${175.95}$$ < $${176.6}$$
✅	agent_rpm_arm64	$${+0.01}$$	$${689.62}$$ < $${693.52}$$	$${-0.03}$$	$${159.94}$$ < $${161.26}$$
✅	agent_rpm_arm64_fips	$${0}$$	$${685.76}$$ < $${688.48}$$	$${+0}$$	$${159.4}$$ < $${160.55}$$
✅	agent_suse_amd64	$${+0}$$	$${708.08}$$ < $${708.38}$$	$${-0}$$	$${176.45}$$ < $${177.66}$$
✅	agent_suse_amd64_fips	$${+0}$$	$${703.38}$$ < $${703.99}$$	$${+0.06}$$	$${175.95}$$ < $${176.6}$$
✅	agent_suse_arm64	$${+0.01}$$	$${689.62}$$ < $${693.52}$$	$${-0.03}$$	$${159.94}$$ < $${161.26}$$
✅	agent_suse_arm64_fips	$${0}$$	$${685.76}$$ < $${688.48}$$	$${+0}$$	$${159.4}$$ < $${160.55}$$
✅	docker_agent_amd64	$${+0}$$	$${769.93}$$ < $${770.72}$$	$${-0.01}$$	$${261.75}$$ < $${262.45}$$
✅	docker_agent_arm64	$${+0.01}$$	$${776.05}$$ < $${780.2}$$	$${+0.01}$$	$${250.83}$$ < $${252.63}$$
✅	docker_agent_jmx_amd64	$${0}$$	$${960.8}$$ < $${961.6}$$	$${-0}$$	$${330.38}$$ < $${331.08}$$
✅	docker_agent_jmx_arm64	$${+0.01}$$	$${955.64}$$ < $${959.8}$$	$${+0.01}$$	$${315.45}$$ < $${317.27}$$
✅	docker_cluster_agent_amd64	$${-0}$$	$${180.7}$$ < $${181.08}$$	$${+0}$$	$${63.85}$$ < $${64.49}$$
✅	docker_cluster_agent_arm64	$${0}$$	$${196.55}$$ < $${198.49}$$	$${+0}$$	$${60.12}$$ < $${61.17}$$
✅	docker_cws_instrumentation_amd64	$${0}$$	$${7.13}$$ < $${7.18}$$	$${+0}$$	$${2.99}$$ < $${3.33}$$
✅	docker_cws_instrumentation_arm64	$${0}$$	$${6.69}$$ < $${6.92}$$	$${+0}$$	$${2.73}$$ < $${3.09}$$
✅	docker_dogstatsd_amd64	$${0}$$	$${38.78}$$ < $${39.38}$$	$${+0}$$	$${15.01}$$ < $${15.82}$$
✅	docker_dogstatsd_arm64	$${+0}$$	$${37.07}$$ < $${37.94}$$	$${+0}$$	$${14.34}$$ < $${14.83}$$
✅	dogstatsd_deb_amd64	$${0}$$	$${30.0}$$ < $${30.61}$$	$${-0}$$	$${7.94}$$ < $${8.79}$$
✅	dogstatsd_deb_arm64	$${0}$$	$${28.15}$$ < $${29.11}$$	$${-0}$$	$${6.81}$$ < $${7.71}$$
✅	dogstatsd_rpm_amd64	$${0}$$	$${30.0}$$ < $${30.61}$$	$${+0}$$	$${7.95}$$ < $${8.8}$$
✅	dogstatsd_suse_amd64	$${0}$$	$${30.0}$$ < $${30.61}$$	$${+0}$$	$${7.95}$$ < $${8.8}$$
✅	iot_agent_deb_amd64	$${0}$$	$${42.96}$$ < $${43.29}$$	$${+0}$$	$${11.25}$$ < $${12.04}$$
✅	iot_agent_deb_arm64	$${+0}$$	$${40.09}$$ < $${40.92}$$	$${+0}$$	$${9.62}$$ < $${10.45}$$
✅	iot_agent_deb_armhf	$${0}$$	$${40.67}$$ < $${41.03}$$	$${-0}$$	$${9.81}$$ < $${10.62}$$
✅	iot_agent_rpm_amd64	$${0}$$	$${42.96}$$ < $${43.29}$$	$${+0}$$	$${11.27}$$ < $${12.06}$$
✅	iot_agent_suse_amd64	$${0}$$	$${42.96}$$ < $${43.29}$$	$${+0}$$	$${11.27}$$ < $${12.06}$$

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 66ef93b9-9f90-47dd-b5c7-f43a44a21417

Baseline: b85aa53
Comparison: dfa206a
Diff

Optimization Goals: ✅ No significant changes detected

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	docker_containers_cpu	% cpu utilization	+1.41	[-1.51, +4.33]	1	Logs

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	docker_containers_memory	memory utilization	+1.68	[+1.52, +1.83]	1	Logs
➖	docker_containers_cpu	% cpu utilization	+1.41	[-1.51, +4.33]	1	Logs
➖	quality_gate_logs	% cpu utilization	+1.05	[-0.43, +2.54]	1	Logs bounds checks dashboard
➖	uds_dogstatsd_20mb_12k_contexts_20_senders	memory utilization	+0.89	[+0.83, +0.95]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	+0.61	[+0.57, +0.64]	1	Logs bounds checks dashboard
➖	otlp_ingest_metrics	memory utilization	+0.43	[+0.27, +0.58]	1	Logs
➖	quality_gate_idle	memory utilization	+0.14	[+0.10, +0.18]	1	Logs bounds checks dashboard
➖	ddot_metrics_sum_cumulativetodelta_exporter	memory utilization	+0.10	[-0.12, +0.33]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	+0.09	[-0.30, +0.48]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	+0.09	[-0.28, +0.46]	1	Logs
➖	ddot_metrics_sum_cumulative	memory utilization	+0.07	[-0.09, +0.24]	1	Logs
➖	uds_dogstatsd_to_api_v3	ingress throughput	+0.02	[-0.11, +0.15]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.00	[-0.13, +0.13]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.08, +0.08]	1	Logs
➖	ddot_metrics	memory utilization	-0.01	[-0.24, +0.21]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	-0.02	[-0.06, +0.03]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-0.02	[-0.45, +0.40]	1	Logs
➖	file_tree	memory utilization	-0.07	[-0.13, -0.02]	1	Logs
➖	ddot_logs	memory utilization	-0.32	[-0.37, -0.26]	1	Logs
➖	ddot_metrics_sum_delta	memory utilization	-0.44	[-0.63, -0.24]	1	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	-0.62	[-0.70, -0.54]	1	Logs
➖	otlp_ingest_logs	memory utilization	-0.62	[-0.72, -0.52]	1	Logs
➖	quality_gate_metrics_logs	memory utilization	-1.18	[-1.38, -0.97]	1	Logs bounds checks dashboard

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	links
✅	docker_containers_cpu	simple_check_run	10/10
✅	docker_containers_memory	memory_usage	10/10
✅	docker_containers_memory	simple_check_run	10/10
✅	file_to_blackhole_0ms_latency	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	lost_bytes	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	lost_bytes	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	lost_bytes	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	quality_gate_idle	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_logs	lost_bytes	10/10	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	lost_bytes	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	bounds checks dashboard

Explanation

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check lost_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check lost_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.

[AlexanderYastrebov]

/merge

[dd-devflow-routing-codex]

View all feedbacks in Devflow UI.

2026-01-06 10:30:51 UTC ℹ️ Start processing command /merge

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2026-01-06 10:30:56 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in main is approximately 51m (p90).

---

2026-01-06 11:00:40 UTC ❌ MergeQueue: The build pipeline contains failing jobs for this merge request

Build pipeline has failing jobs for 2d05196:

• tests_macos_gitlab_amd64

⚠️ Do NOT retry failed jobs directly (why?).

What to do next?

• Investigate the failures and when ready, re-add your pull request to the queue!
• If your PR checks are green, try to rebase/merge. It might be because the CI run is a bit old.
• Any question, go check the FAQ.

Details

Since those jobs are not marked as being allowed to fail, the pipeline will most likely fail.
Therefore, and to allow other builds to be processed, this merge request has been rejected and the pipeline got canceled.

[AlexanderYastrebov]

/merge

[dd-devflow-routing-codex]

View all feedbacks in Devflow UI.

2026-01-07 09:58:29 UTC ℹ️ Start processing command /merge

---

2026-01-07 09:58:34 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in main is approximately 1h (p90).

---

2026-01-07 10:35:31 UTC ℹ️ MergeQueue: This merge request was merged