Rename constant conflicting with built-in type: Hash

[marcotc]

Title: Rename constant conflicting with built-in type: Hash

What does this PR do?
Renames Datadog::Tracing::Contrib::Utils::Quantization::Hash to Datadog::Tracing::Contrib::Utils::Quantization::HashFormatter.

Motivation:
Datadog::Tracing::Contrib::Utils::Quantization::Hash collides with Ruby's standard Hash constant, when referenced through nested constant lookup.
This can cause you to reference Hash, normally wanting the std Hash class, but end up with Datadog::Tracing::Contrib::Utils::Quantization::Hash.

Change log entry
None. Internal.

[dd-octo-sts]

Typing analysis

Note: Ignored files are excluded from the next sections.

steep:ignore comments

This PR introduces 1 steep:ignore comment, and clears 1 steep:ignore comment.

steep:ignore comments (+1-1)

❌ Introduced:

lib/datadog/tracing/contrib/utils/quantization/hash_formatter.rb:15

✅ Cleared:

lib/datadog/tracing/contrib/utils/quantization/hash.rb:15

Untyped methods

This PR introduces 3 untyped methods and 5 partially typed methods, and clears 3 untyped methods and 5 partially typed methods.

Untyped methods (+3-3)

❌ Introduced:

sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:25
└── def self?.merge_options: (untyped original, untyped additional) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:27
└── def self?.indifferent_equals: (untyped value) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:29
└── def self?.convert_value: (untyped value) -> untyped

✅ Cleared:

sig/datadog/tracing/contrib/utils/quantization/hash.rbs:25
└── def self?.merge_options: (untyped original, untyped additional) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash.rbs:27
└── def self?.indifferent_equals: (untyped value) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash.rbs:29
└── def self?.convert_value: (untyped value) -> untyped

Partially typed methods (+5-5)

❌ Introduced:

sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:15
└── def self?.format: (untyped hash_obj, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:17
└── def self?.format!: (untyped hash_obj, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:19
└── def self?.format_hash: (untyped hash_obj, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:21
└── def self?.format_value: (untyped value, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:23
└── def self?.format_array: (untyped value, untyped options) -> (untyped | ::Array[untyped])

✅ Cleared:

sig/datadog/tracing/contrib/utils/quantization/hash.rbs:15
└── def self?.format: (untyped hash_obj, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash.rbs:17
└── def self?.format!: (untyped hash_obj, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash.rbs:19
└── def self?.format_hash: (untyped hash_obj, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash.rbs:21
└── def self?.format_value: (untyped value, ?::Hash[untyped, untyped] options) -> untyped
sig/datadog/tracing/contrib/utils/quantization/hash.rbs:23
└── def self?.format_array: (untyped value, untyped options) -> (untyped | ::Array[untyped])

Untyped other declarations

This PR introduces 1 untyped other declaration and 2 partially typed other declarations, and clears 1 untyped other declaration and 2 partially typed other declarations.

Untyped other declarations (+1-1)

❌ Introduced:

sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:13
└── DEFAULT_OPTIONS: { exclude: untyped, show: untyped, placeholder: untyped }

✅ Cleared:

sig/datadog/tracing/contrib/utils/quantization/hash.rbs:13
└── DEFAULT_OPTIONS: { exclude: untyped, show: untyped, placeholder: untyped }

Partially typed other declarations (+2-2)

❌ Introduced:

sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:9
└── EXCLUDE_KEYS: ::Array[untyped]
sig/datadog/tracing/contrib/utils/quantization/hash_formatter.rbs:11
└── SHOW_KEYS: ::Array[untyped]

✅ Cleared:

sig/datadog/tracing/contrib/utils/quantization/hash.rbs:9
└── EXCLUDE_KEYS: ::Array[untyped]
sig/datadog/tracing/contrib/utils/quantization/hash.rbs:11
└── SHOW_KEYS: ::Array[untyped]

If you believe a method or an attribute is rightfully untyped or partially typed, you can add # untyped:accept on the line before the definition to remove it from the stats.

[datadog-prod-us1-6]

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 97.09% (-0.00%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 55eb893 | Docs | Datadog PR Page | Give us feedback!}

[pr-commenter]

Benchmarks

Benchmark execution time: 2026-05-28 08:51:39

Comparing candidate commit 55eb893 in PR branch rename-quantization-hash-constant with baseline commit b1a5c02 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 45 metrics, 1 unstable metrics.

Explanation

This is an A/B test comparing a candidate commit's performance against that of a baseline commit. Performance changes are noted in the tables below as:

• 🟩 = significantly better candidate vs. baseline
• 🟥 = significantly worse candidate vs. baseline

We compute a confidence interval (CI) over the relative difference of means between metrics from the candidate and baseline commits, considering the baseline as the reference.

If the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD), the change is considered significant.

Feel free to reach out to #apm-benchmarking-platform on Slack if you have any questions.

More details about the CI and significant changes

You can imagine this CI as a range of values that is likely to contain the true difference of means between the candidate and baseline commits.

CIs of the difference of means are often centered around 0%, because often changes are not that big:

---------------------------------(------|---^--------)-------------------------------->
                              -0.6%    0%  0.3%     +1.2%
                                 |          |        |
         lower bound of the CI --'          |        |
sample mean (center of the CI) -------------'        |
         upper bound of the CI ----------------------'

As described above, a change is considered significant if the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD).

For instance, for an execution time metric, this confidence interval indicates a significantly worse performance:

----------------------------------------|---------|---(---------^---------)---------->
                                       0%        1%  1.3%      2.2%      3.1%
                                                  |   |         |         |
       significant impact threshold --------------'   |         |         |
                      lower bound of CI --------------'         |         |
       sample mean (center of the CI) --------------------------'         |
                      upper bound of CI ----------------------------------'