Optimize plugin startup performance with lazy loading

[GowayLee]

• Implement lazy loading for formatters to reduce startup time
• Add caching for formatter availability checks (Python/Clang)
• Implement deferred utility loading to minimize initial dependencies
• Reduce startup time from ~9ms to <1ms

Fixes #2 - Performance optimization for lazy.nvim loading

[claude]

Claude finished @GowayLee's task —— View job

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PR Review: Lazy Loading Performance Optimization

Overview

This PR successfully implements lazy loading for the reform.nvim plugin, reducing startup time from ~9ms to <1ms through strategic deferred loading and caching mechanisms.

Code Quality Assessment

✅ Excellent Implementation Details

Lazy Loading for Formatters (lua/reform/formatters.lua:27-40):

• Smart use of class path registry instead of instantiating formatters at startup
• On-demand formatter instantiation with instance caching
• Clean separation between class registration and instance creation

Caching for Availability Checks:

• Python formatter (lua/reform/formatters/python.lua:54-90): Proper caching of autopep8 availability checks using _availability_cache
• Clang formatter (lua/reform/formatters/clang.lua:16-37): Efficient caching of clang-format executable checks

Deferred Utility Loading:

• Core module (lua/reform/core.lua:8-14): Clean lazy-loading pattern for utils module
• Main module (lua/reform/init.lua:105-113): Metatable-based lazy loading for utils

⚠️ Issues Found

1. Missing import in init.lua (lua/reform/init.lua:19):

   utils.debug_log("Reform initialized with version " .. M.version)

   utils is not defined here - should use the lazy-loaded utils or remove this line.

2. Incorrect formatter exports (lua/reform/formatters.lua:70-71):

   M.PythonFormatter = PythonFormatter
   M.ClangFormatter = ClangFormatter

   These variables are undefined in this scope and will cause runtime errors.

3. Incomplete status function (lua/reform/init.lua:93):

   print("  Supported: " .. tostring(status.supported))

   status.supported is never defined in the M.status() function.

🔍 Performance Considerations

The implementation effectively achieves the stated performance goals:

• Reduced module requires: Only config, core, and formatters are loaded at startup
• Deferred heavy operations: Python/Clang availability checks only happen when needed
• Effective caching: Single availability check per formatter instance

📋 Best Practices Followed

• Single Responsibility: Each module has a clear, focused purpose
• Caching Strategy: Appropriate use of memoization for expensive operations
• Error Handling: Proper pcall usage for external command execution
• Lazy Loading Patterns: Consistent implementation across modules

🐛 Minor Bugs

1. Typo in formatters.lua:70-71: Undefined variable references
2. Missing utils reference: Line 19 in init.lua references undefined utils
3. Status reporting: Missing supported field in status output

Recommendations

1. Fix undefined variables in formatters.lua and init.lua
2. Add nil checks for the cached availability results to handle cache invalidation
3. Consider adding cache invalidation mechanism for long-running sessions
4. Add unit tests to verify lazy loading behavior

Overall Assessment

This is a well-structured performance optimization that successfully implements lazy loading patterns. The core architecture is solid, with only minor issues that need addressing before merging.

Status: ✅ Approved with minor fixes needed

[claude]

Claude finished @GowayLee's task —— View job

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PR Review: Lazy Loading Performance Optimization

Overview

This PR successfully implements lazy loading for the reform.nvim plugin, reducing startup time from ~9ms to <1ms through strategic deferred loading and caching mechanisms.

Code Quality Assessment

✅ Successfully Addressed Previous Issues

The following issues from the previous review have been resolved:

1. Fixed missing import in init.lua: Line 19 now correctly uses the utils module that's properly required at the top
2. Fixed undefined formatter exports: The formatters.lua file no longer has undefined PythonFormatter and ClangFormatter exports
3. Fixed incomplete status function: The print_status() function no longer references undefined status.supported

✅ Excellent Implementation Details

Lazy Loading for Formatters (lua/reform/formatters.lua:25-40):

• Smart use of class path registry instead of instantiating formatters at startup
• On-demand formatter instantiation with instance caching
• Clean separation between class registration and instance creation

Caching for Availability Checks:

• Python formatter (lua/reform/formatters/python.lua:54-90): Proper caching of autopep8 availability checks using _availability_cache
• Clang formatter (lua/reform/formatters/clang.lua:16-37): Efficient caching of clang-format executable checks

Deferred Utility Loading:

• Core module (lua/reform/core.lua:8-14): Clean lazy-loading pattern for utils module
• Main module (lua/reform/init.lua:105-113): Metatable-based lazy loading for utils

✅ Performance Optimizations

The implementation effectively achieves the stated performance goals:

• Reduced module requires: Only config, core, and formatters are loaded at startup
• Deferred heavy operations: Python/Clang availability checks only happen when needed
• Effective caching: Single availability check per formatter instance
• Lazy utility loading: Utils module loaded only when needed

✅ Code Quality & Best Practices

• Single Responsibility: Each module has a clear, focused purpose
• Caching Strategy: Appropriate use of memoization for expensive operations
• Error Handling: Proper pcall usage for external command execution
• Lazy Loading Patterns: Consistent implementation across modules
• Clean Architecture: Clear separation between registry, instantiation, and usage

✅ Security Considerations

• Safe command execution: Uses pcall for Python evaluation
• Path validation: Uses vim.fn.executable for command availability checks
• No hardcoded paths: Commands are resolved from system PATH
• Input sanitization: Text is properly escaped in system commands

⚠️ Minor Suggestions for Improvement

1. Consider cache invalidation: Long-running sessions might benefit from cache invalidation for availability checks
2. Add configuration for cache behavior: Could allow users to configure cache TTL
3. Document lazy loading behavior: README could mention the lazy loading benefits

🔍 Test Coverage Recommendations

While not part of this PR, consider adding tests for:

• Lazy loading behavior verification
• Cache functionality testing
• Performance regression tests
• Formatter availability edge cases

Overall Assessment

This is a well-structured performance optimization that successfully implements lazy loading patterns. The previous issues have been completely resolved, and the implementation follows excellent coding practices. The performance improvements are significant and the code is maintainable.

Status: ✅ Approved for merge - All issues have been addressed and the implementation is solid.

Performance Impact

• Startup time: Reduced from ~9ms to <1ms
• Memory usage: Reduced by deferring formatter instantiation
• CPU usage: Reduced by caching availability checks
• User experience: Faster plugin load times without functional impact

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Review completed - The lazy loading implementation is well-executed and ready for production use.

[GowayLee]

@claude Help me to update README.md in this branch, mention this feature in it

[claude]

Claude finished @GowayLee's task —— View job

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I'll analyze this and get back to you.