FIX: Implement caching for InputControlPath display name

[josepmariapujol-unity]

Description

Purpose of this PR is to fix the TODO by caching per path value and only recompute when the string actually changes.

Testing status & QA

Check that it works as before, when inputing in the InputControlPath.

Overall Product Risks

Please rate the potential complexity and halo effect from low to high for the reviewers. Note down potential risks to specific Editor branches if any.

• Complexity: 0
• Halo Effect: 0

Comments to reviewers

Please describe any additional information such as what to focus on, or historical info for the reviewers.

Checklist

Before review:

• Changelog entry added.
  • Explains the change in Changed, Fixed, Added sections.
  • For API change contains an example snippet and/or migration example.
  • JIRA ticket linked, example (case %%). If it is a private issue, just add the case ID without a link.
  • Jira port for the next release set as "Resolved".
• Tests added/changed, if applicable.
  • Functional tests Area_CanDoX, Area_CanDoX_EvenIfYIsTheCase, Area_WhenIDoX_AndYHappens_ThisIsTheResult.
  • Performance tests.
  • Integration tests.
• Docs for new/changed API's.
  • Xmldoc cross references are set correctly.
  • Added explanation how the API works.
  • Usage code examples added.
  • The manual is updated, if needed.

During merge:

• Commit message for squash-merge is prefixed with one of the list:
  • NEW: ___.
  • FIX: ___.
  • DOCS: ___.
  • CHANGE: ___.
  • RELEASE: 1.1.0-preview.3.

[Copilot]

Pull request overview

This PR implements caching for InputControlPath display names to reduce unnecessary garbage collection churn. The change addresses a TODO comment by storing the computed display name and only recalculating it when the input path string actually changes.

Changes:

• Added caching mechanism with string comparison to avoid redundant ToHumanReadableString calls
• Introduced two cache fields (m_CachedPath and m_CachedDisplayName) to track the last computed values

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[u-pr]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
General	Remove conditional check to preserve formatting behavior The explicit string.IsNullOrEmpty check forces the display name to be empty, which might suppress specific formatting for empty paths (e.g., "") that ToHumanReadableString might provide. Removing the check ensures consistency with the previous implementation and simplifies the code. Packages/com.unity.inputsystem/InputSystem/Editor/ControlPicker/InputControlPathEditor.cs [126-139] // Cache the display name per path value and only recompute when the string actually changes. if (!string.Equals(path, m_CachedPath, StringComparison.Ordinal)) { m_CachedPath = path; - - if (string.IsNullOrEmpty(path)) - { - m_CachedDisplayName = string.Empty; - } - else - { - m_CachedDisplayName = InputControlPath.ToHumanReadableString(path); - } + m_CachedDisplayName = InputControlPath.ToHumanReadableString(path); } Suggestion importance[1-10]: 6 __ Why: The suggestion correctly identifies that the explicit empty check might alter the original behavior if ToHumanReadableString handles empty strings specifically (e.g., returning ""). Removing the check restores consistency with the pre-PR logic and simplifies the code.	Low
More suggestions

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[u-pr]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 1 🔵⚪⚪⚪⚪ The PR introduces a simple caching mechanism in a single file with straightforward logic, making it easy to review.

🏅 Score: 95 The code correctly resolves the TODO regarding GC churn with a clean implementation.

🧪 No relevant tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Performance Verification Verify that the InputControlPathEditor instance is not reused to draw multiple different properties within the same frame (e.g., inside a List PropertyDrawer). If the instance is shared and drawn with different paths in a loop, the cache will be invalidated on every call (thrashing), negating the performance benefits. // Cache the display name per path value and only recompute when the string actually changes. if (!string.Equals(path, m_CachedPath, StringComparison.Ordinal)) { m_CachedPath = path; if (string.IsNullOrEmpty(path)) { m_CachedDisplayName = string.Empty; } else { m_CachedDisplayName = InputControlPath.ToHumanReadableString(path); } } var displayName = m_CachedDisplayName;

Update review

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[u-pr]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
General	Remove conditional check to preserve formatting behavior The explicit string.IsNullOrEmpty check forces the display name to be empty, which might suppress specific formatting for empty paths (e.g., "") that ToHumanReadableString might provide. Removing the check ensures consistency with the previous implementation and simplifies the code. Packages/com.unity.inputsystem/InputSystem/Editor/ControlPicker/InputControlPathEditor.cs [126-139] // Cache the display name per path value and only recompute when the string actually changes. if (!string.Equals(path, m_CachedPath, StringComparison.Ordinal)) { m_CachedPath = path; - - if (string.IsNullOrEmpty(path)) - { - m_CachedDisplayName = string.Empty; - } - else - { - m_CachedDisplayName = InputControlPath.ToHumanReadableString(path); - } + m_CachedDisplayName = InputControlPath.ToHumanReadableString(path); } Suggestion importance[1-10]: 6 __ Why: The suggestion correctly identifies that the explicit empty check might alter the original behavior if ToHumanReadableString handles empty strings specifically (e.g., returning ""). Removing the check restores consistency with the pre-PR logic and simplifies the code.	Low
More suggestions

---

🤖 Helpful? Please react with 👍/👎 | Questions❓Please reach out in Slack #ask-u-pr

[codecov-github-com]

Codecov Report

All modified and coverable lines are covered by tests ✅

@@           Coverage Diff            @@
##           develop    #2342   +/-   ##
========================================
  Coverage    77.95%   77.96%           
========================================
  Files          476      476           
  Lines        97453    97434   -19     
========================================
- Hits         75971    75964    -7     
+ Misses       21482    21470   -12     

Files with missing lines	Coverage Δ
...tem/Editor/ControlPicker/InputControlPathEditor.cs	0.00% <ø> (ø)

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