@sun-asterisk/sunlint/docs/PERFORMANCE_OPTIMIZATION_PLAN.md

☀️ SunLint - Multi-language static analysis tool for code quality and security | Sun* Engineering Standards

# 🚀 SunLint Performance Optimization Plan

## 📊 Current Performance Challenges

### **Critical Issues Identified**
1. **Timeout Issues**: `Engine heuristic failed: Engine undefined timed out after 30000ms`
2. **Memory Exhaustion**: `Maximum call stack size exceeded` with large projects
3. **Symbol Table Bottleneck**: Loading 73 rules × large file count = performance disaster
4. **Batch Processing Gap**: No intelligent rule batching for large projects

### **Performance Metrics (Current)**
- **Total Rules**: 100 (Common: 34, Security: 49, Others: 17)
- **SunLint Rules**: 73 rules with analyzers (3x growth from ~22)
- **AST-Powered**: 65+ rules requiring semantic analysis
- **Memory Impact**: Symbol table × file count × rule count = O(n³) complexity

---

## 🎯 Optimization Strategy

### **Phase 1: Immediate Performance Fixes**

#### **1.1 Timeout Management**
```bash
# Current: Fixed 30s timeout
# Solution: Dynamic timeout based on project size
--timeout=60000          # 60s for large projects
--timeout=120000         # 120s for enterprise projects
--adaptive-timeout       # Auto-scale based on file count
```

#### **1.2 File Filtering Enhancement**
```bash
# Current: Basic exclude patterns
# Solution: Smart exclusion patterns
--exclude-patterns="node_modules/**,.next/**,dist/**,build/**"
--max-files=1000         # Hard limit for safety
--smart-sampling         # Intelligent file sampling for large projects
```

#### **1.3 Rule Batching**
```bash
# Current: All rules processed together
# Solution: Intelligent rule batching
--batch-size=10          # Process 10 rules at a time
--priority-rules=C019,S027,C041  # High-priority rules first
--parallel-batches=2     # Parallel batch processing
```

### **Phase 2: Memory Optimization**

#### **2.1 Symbol Table Streaming**
```javascript
// Current: Load all files into memory
const symbolTable = await loadAllFiles(); // ❌ Memory explosion

// Solution: Streaming symbol table
const symbolTable = new StreamingSymbolTable({
  maxMemoryFiles: 100,    // Keep max 100 files in memory
  swapToTemp: true,       // Swap to temp files when needed
  lazyLoading: true       // Load files on-demand
});
```

#### **2.2 Rule-Specific Analysis**
```javascript
// Current: All rules analyze all files
rules.forEach(rule => files.forEach(file => rule.analyze(file))); // ❌ O(n²)

// Solution: Smart rule targeting
const fileToRulesMap = buildFileRuleMapping(files, rules);
fileToRulesMap.forEach((rules, file) => {
  rules.forEach(rule => rule.analyze(file)); // ✅ Optimized
});
```

### **Phase 3: Architecture Optimization**

#### **3.1 Worker Process Architecture**
```javascript
// Solution: Multi-process rule execution
const workers = {
  syntaxRules: createWorker('./workers/syntax-rules.js'),
  securityRules: createWorker('./workers/security-rules.js'),
  semanticRules: createWorker('./workers/semantic-rules.js')
};

// Distribute rules across workers
const results = await Promise.all([
  workers.syntaxRules.analyze(files, syntaxRules),
  workers.securityRules.analyze(files, securityRules),
  workers.semanticRules.analyze(files, semanticRules)
]);
```

#### **3.2 Progressive Analysis**
```javascript
// Solution: Progressive disclosure of violations
const analyzer = new ProgressiveAnalyzer({
  fastRules: ['C002', 'C003', 'C006'],      // Quick regex rules first
  mediumRules: ['C019', 'C041', 'S027'],    // Moderate AST rules
  slowRules: ['C033', 'C047', 'C076']       // Heavy semantic rules last
});

// Show results progressively
analyzer.on('fastComplete', (violations) => {
  console.log(`Quick scan: ${violations.length} issues found`);
});
```

---

## 🛠️ Implementation Roadmap

### **Week 1: Critical Fixes**
- [ ] **Dynamic timeout configuration**
- [ ] **Enhanced file exclusion patterns** 
- [ ] **Memory limit safeguards**
- [ ] **Rule batching implementation**

### **Week 2: Memory Optimization**
- [ ] **Streaming symbol table**
- [ ] **File-to-rule mapping optimization**
- [ ] **Lazy loading for AST analysis**
- [ ] **Memory monitoring & alerts**

### **Week 3: Architecture Enhancement**
- [ ] **Worker process architecture**
- [ ] **Progressive analysis pipeline**
- [ ] **Parallel rule execution**
- [ ] **Result caching system**

### **Week 4: Testing & Validation**
- [ ] **Performance benchmarking**
- [ ] **Large project testing**
- [ ] **Memory leak detection**
- [ ] **Timeout scenario testing**

---

## 📈 Expected Performance Improvements

### **Target Metrics**
| **Scenario** | **Current** | **Target** | **Improvement** |
|--------------|-------------|------------|-----------------|
| **Small Project** (< 100 files) | 30s | 10s | **3x faster** |
| **Medium Project** (100-500 files) | Timeout | 45s | **Functional** |
| **Large Project** (500+ files) | Memory crash | 120s | **Functional** |
| **Enterprise Project** (1000+ files) | Impossible | 300s | **Breakthrough** |

### **Memory Usage**
| **Project Size** | **Current** | **Target** | **Reduction** |
|------------------|-------------|------------|---------------|
| **100 files** | 2GB | 500MB | **75% reduction** |
| **500 files** | Crash | 1.5GB | **Functional** |
| **1000+ files** | Crash | 3GB | **Controlled** |

---

## 🚦 Performance Monitoring

### **Key Performance Indicators (KPIs)**
```javascript
const performanceMetrics = {
  // Analysis Speed
  rulesPerSecond: target >= 5,
  filesPerSecond: target >= 20,
  violationsPerSecond: target >= 100,
  
  // Memory Efficiency  
  memoryUsage: target <= '2GB',
  memoryGrowthRate: target <= '10MB/min',
  garbageCollectionFreq: target <= '5/min',
  
  // Reliability
  timeoutRate: target <= '1%',
  crashRate: target <= '0.1%',
  successRate: target >= '99%'
};
```

### **Performance Alerts**
```bash
# Memory warnings
if (memoryUsage > 1.5GB) warn("High memory usage detected");
if (memoryUsage > 2.5GB) error("Memory limit approaching");

# Timeout warnings  
if (analysisTime > 60s) warn("Analysis taking longer than expected");
if (analysisTime > 120s) error("Consider using --max-files or --batch-size");

# Progress indicators
echo "⚡ Processing batch 1/5 (20 rules)..."
echo "📊 Analyzed 245/1000 files (24.5%)"
echo "🎯 Found 23 violations so far..."
```

---

## 🔧 CLI Enhancement

### **New Performance Options**
```bash
# Timeout Management
sunlint --timeout=120000                    # 2 minutes timeout
sunlint --adaptive-timeout                  # Auto-scale timeout
sunlint --no-timeout                        # Disable timeout (careful!)

# Memory Management  
sunlint --max-memory=2GB                    # Memory limit
sunlint --max-files=1000                    # File count limit
sunlint --streaming-analysis                # Use streaming mode

# Batch Processing
sunlint --batch-size=10                     # Rules per batch
sunlint --parallel-batches=2                # Parallel processing
sunlint --progressive-results               # Show results as available

# Performance Profiles
sunlint --performance-profile=fast          # Quick scan (30 rules)
sunlint --performance-profile=balanced      # Standard scan (50 rules)  
sunlint --performance-profile=comprehensive # Full scan (73 rules)
```

### **Smart Defaults Based on Project Size**
```javascript
const performanceProfiles = {
  small: { files: '<100', timeout: 30000, batchSize: 20, rules: 'fast' },
  medium: { files: '100-500', timeout: 60000, batchSize: 15, rules: 'balanced' },
  large: { files: '500-1000', timeout: 120000, batchSize: 10, rules: 'essential' },
  enterprise: { files: '>1000', timeout: 300000, batchSize: 5, rules: 'critical' }
};
```

---

## 🏆 Success Criteria

### **Performance Goals**
- ✅ **Zero timeouts** on projects < 1000 files
- ✅ **Predictable memory usage** (linear growth, not exponential)
- ✅ **Progressive results** (show violations as they're found)
- ✅ **Graceful degradation** (intelligent fallbacks for large projects)

### **User Experience Goals**
- ✅ **Clear progress indicators** during long analyses
- ✅ **Meaningful performance warnings** before problems occur  
- ✅ **Smart defaults** based on project size
- ✅ **Escape hatches** for power users (custom timeouts, batch sizes)

---

**Performance optimization is critical for SunLint adoption at scale. With 73 heuristic rules and growing, we must proactively address performance bottlenecks to maintain developer experience quality.**

*Engineering Excellence • Performance • Scalability*