⚡ Bolt: optimize Context map lookups and lock contention

[ashyanSpada]

💡 What: Refactored get_func, get_variable, and value methods in src/context.rs to avoid cloning the whole ContextValue enum, performing a single .get(name) map lookup, and dropping the MutexGuard explicitly before invoking functions. Also formatted code with cargo fmt.
🎯 Why: The previous implementation performed a double map lookup (.is_none() followed by .unwrap()) and cloned the full ContextValue containing large data types unnecessarily. Furthermore, the MutexGuard was held while func(Vec::new()) was executed, keeping the lock active for the duration of the function execution which creates lock contention.
📊 Impact: Reduced memory allocation and mutex contention. The execute_expression benchmark execution time dropped from ~5.60 µs to ~5.38 µs (a ~4% improvement).
🔬 Measurement: Verify the improvement by running cargo bench.

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PR created automatically by Jules for task 3557716546625986088 started by @ashyanSpada

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[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request focuses on optimizing the Context map lookups and reducing lock contention within the Bolt expression engine. By refactoring key methods to perform single map lookups, avoid full enum cloning, and manage mutex guards more efficiently, the changes aim to enhance overall performance and reduce memory allocation. The improvements are validated by a measurable reduction in benchmark execution time.

Highlights

• Performance Optimization: Refactored get_func, get_variable, and value methods in src/context.rs to improve performance by avoiding redundant map lookups and unnecessary cloning of ContextValue enums.
• Reduced Lock Contention: Modified the value method to explicitly drop the MutexGuard before invoking external functions, significantly reducing lock contention and preventing potential deadlocks.
• Code Formatting: Applied cargo fmt to ensure consistent code style across relevant files.
• Documentation: Added a new markdown document (.jules/bolt.md) detailing the learning and action points related to context map lookups and locking contention optimizations.
• Benchmark Improvement: Achieved a ~4% improvement in the execute_expression benchmark execution time, dropping from ~5.60 µs to ~5.38 µs.

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[gemini-code-assist]

Code Review

The pull request primarily focuses on optimizing context map lookups and reducing lock contention within the Context struct. Specifically, the get_func, get_variable, and value methods in src/context.rs were refactored to acquire the mutex lock explicitly and perform single map lookups, eliminating redundant is_none() and unwrap() calls. Crucially, the value method was updated to ensure the MutexGuard is dropped before invoking external function closures, preventing potential deadlocks and improving concurrency. A new markdown file, .jules/bolt.md, was added to document these performance learnings and actions. Minor stylistic changes were also made to import statements in benches/display_expression.rs and formatting in src/parser.rs. A review comment suggests an if let pattern for improved readability and idiomatic Rust in the get_func method.

[gemini-code-assist]

For improved readability and to make the code more idiomatic, you could consider using if let to handle the Some case directly. This avoids the need for ? followed by a match and makes the intent clearer.

Suggested change

	let binding = self.0.lock().unwrap();
	let value = binding.get(name)?;
	match value {
	ContextValue::Function(func) => Some(func.clone()),
	ContextValue::Variable(_) => None,
	}
	let binding = self.0.lock().unwrap();
	if let Some(ContextValue::Function(func)) = binding.get(name) {
	Some(func.clone())
	} else {
	None
	}

[Copilot]

Pull request overview

This PR optimizes Context lookups and reduces mutex lock contention in the expression engine by avoiding redundant HashMap::get calls, avoiding cloning full ContextValue enums when only the inner value is needed, and ensuring the context lock is not held while invoking stored functions.

Changes:

• Refactored Context::get_func, Context::get_variable, and Context::value to do a single map lookup and clone only the needed inner value.
• Updated Context::value to drop the MutexGuard before calling InnerFunction closures to reduce lock contention / reentrancy risk.
• Applied cargo fmt formatting adjustments (parser display formatting and bench imports) and added a Jules learning note.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/context.rs	Single-lookup accessors; releases mutex before invoking stored functions to reduce contention.
src/parser.rs	Formatting-only changes in fmt::Display implementation.
benches/display_expression.rs	Formatting-only import reordering.
.jules/bolt.md	Documents the optimization lesson/action regarding map lookups and mutex guard scope.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.22%. Comparing base (5576973) to head (8aa3d3a).

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #42      +/-   ##
==========================================
+ Coverage   88.74%   89.22%   +0.47%     
==========================================
  Files          11       11              
  Lines        1066     1067       +1     
==========================================
+ Hits          946      952       +6     
+ Misses        120      115       -5     

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