AgentSkillsCN

iOS Performance

在 Instruments 性能分析、内存管理与优化方面的规范。

SKILL.md
--- frontmatter
name: iOS Performance
description: Standards for Instruments, Memory Management, and Optimization.
metadata:
  labels: [ios, performance, instruments, leaks]
  triggers:
    files: ['**/*.swift']
    keywords: [Instruments, Allocations, Leaks, dequeueReusableCell]

iOS Performance Standards

Priority: P0

Implementation Guidelines

Diagnostic Tools

  • •Instruments: Regularly use Allocations and Leaks to detect memory issues.
  • •Time Profiler: Identify heavy CPU tasks and Main Thread stalls.
  • •Network instrument: Analyze request payload sizes and frequency.

Optimization

  • •Table/Collection Views: Always use dequeueReusableCell and keep cellForRowAt logic lightweight.
  • •Image Caching: Use SDWebImage or Kingfisher for remote assets to prevent redundant fetching and main-thread decoding. (Note: AsyncImage lacks built-in caching; prioritize third-party for lists).
  • •Background threads: Offload expensive work (parsing, encryption) from the Main thread using GCD or Tasks.

Diagnostics

  • •Compiler Warnings: Enable SWIFT_TREAT_WARNINGS_AS_ERRORS in Release builds.
  • •Static Analyzer: Use Xcode's "Analyze" (Product > Analyze) to find logic errors.

Anti-Patterns

  • •CPU work on Main Thread: **No parsing/processing on Main**: Use background thread.
  • •Force Cache Flushes: **No redundant cache clears**: Let the system handle low-memory warnings via AppDelegate.
  • •Retain Cycles: **Check for cycles in Instruments**: Use the Leaks instrument frequently.

References