# 💾 PMAT Memory Management & Optimization - Comprehensive Guide

## Table of Contents
1. [Overview](#overview)
2. [Architecture](#architecture)
3. [Memory Commands](#memory-commands)
4. [Pool Management](#pool-management)
5. [Pressure Detection](#pressure-detection)
6. [Optimization Strategies](#optimization-strategies)
7. [CI/CD Integration](#cicd-integration)
8. [Best Practices](#best-practices)

## Overview

PMAT provides sophisticated memory management capabilities to optimize performance, prevent out-of-memory errors, and ensure efficient resource utilization across large-scale code analysis operations.

### Key Features
- **🎯 Real-time Monitoring**: Track memory usage across all PMAT components
- **🔄 Automatic Cleanup**: Smart garbage collection and cache eviction
- **📊 Pool Statistics**: Detailed memory pool analysis and optimization
- **⚠️ Pressure Detection**: Early warning system for memory constraints
- **🚀 Performance Tuning**: Adaptive memory allocation strategies
- **📈 Historical Tracking**: Memory usage patterns and trend analysis

## Architecture

```
┌────────────────────────────────────────────────────────────────┐
│                     Memory Management System                     │
├────────────────────────────────────────────────────────────────┤
│                         Core Components                          │
│                                                                  │
│  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐         │
│  │   Monitor    │  │   Allocator  │  │   Cleanup    │         │
│  │   Service    │  │    Pools     │  │    Engine    │         │
│  └──────────────┘  └──────────────┘  └──────────────┘         │
│                                                                  │
│  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐         │
│  │   Pressure   │  │    Cache     │  │   Metrics    │         │
│  │   Detector   │  │   Manager    │  │   Collector  │         │
│  └──────────────┘  └──────────────┘  └──────────────┘         │
└────────────────────────────────────────────────────────────────┘
```

### Memory Pools

PMAT uses specialized memory pools for different operations:

| Pool | Purpose | Default Size | Growth Strategy |
|------|---------|--------------|-----------------|
| **AST Pool** | Syntax tree parsing | 512 MB | Exponential |
| **Analysis Pool** | Code analysis operations | 256 MB | Linear |
| **Cache Pool** | Result caching | 1 GB | Adaptive |
| **Temp Pool** | Temporary allocations | 128 MB | Fixed |
| **String Pool** | String interning | 64 MB | Incremental |

## Memory Commands

### 1. Memory Statistics

```bash
# Show current memory usage
pmat memory stats

# Detailed statistics with breakdown
pmat memory stats --detailed

# Export statistics as JSON
pmat memory stats --format json > memory-stats.json

# Real-time monitoring (updates every second)
pmat memory stats --watch
```

**Example Output:**
```
Memory Statistics
═════════════════════════════════════════════
Total Allocated:     1,247 MB
Total Used:           892 MB (71.5%)
Total Available:      355 MB (28.5%)

Pool Breakdown:
├─ AST Pool:          312 MB / 512 MB (60.9%)
├─ Analysis Pool:     156 MB / 256 MB (60.9%)
├─ Cache Pool:        380 MB / 1024 MB (37.1%)
├─ Temp Pool:          28 MB / 128 MB (21.9%)
└─ String Pool:        16 MB / 64 MB (25.0%)

Pressure Level: LOW (0.28)
GC Last Run: 2 minutes ago
GC Next Run: In 8 minutes
```

### 2. Memory Cleanup

```bash
# Force immediate cleanup
pmat memory cleanup

# Cleanup with specific targets
pmat memory cleanup --target cache,temp

# Aggressive cleanup (may impact performance)
pmat memory cleanup --aggressive

# Cleanup and compact memory
pmat memory cleanup --compact
```

### 3. Memory Configuration

```bash
# Configure memory limits
pmat memory configure --max-total 4GB

# Set pool-specific limits
pmat memory configure --ast-pool 1GB --cache-pool 2GB

# Configure GC behavior
pmat memory configure --gc-interval 300 --gc-threshold 0.8

# Enable swap usage (when available)
pmat memory configure --allow-swap --swap-threshold 0.9
```

### 4. Pool Management

```bash
# Show pool statistics
pmat memory pools

# Detailed pool analysis
pmat memory pools --detailed

# Reset specific pool
pmat memory pools --reset ast

# Optimize pool sizes based on usage
pmat memory pools --optimize
```

### 5. Pressure Detection

```bash
# Check current memory pressure
pmat memory pressure

# Set pressure thresholds
pmat memory pressure --low 0.3 --medium 0.6 --high 0.8

# Enable automatic response to pressure
pmat memory pressure --auto-respond

# Test pressure response
pmat memory pressure --simulate high
```

## Pool Management

### AST Pool Optimization

```bash
# Analyze AST pool usage patterns
pmat memory pools --analyze ast

# Output:
# AST Pool Analysis
# ═════════════════════════════════
# Current Size: 512 MB
# Peak Usage: 487 MB (95.1%)
# Average Usage: 312 MB (60.9%)
# Fragmentation: 12.3%
# 
# Recommendations:
# - Increase pool size to 768 MB
# - Enable defragmentation at 15% threshold
# - Consider pre-allocation for large files

# Apply recommendations
pmat memory configure --ast-pool 768MB --ast-defrag 0.15
```

### Cache Pool Management

```bash
# View cache statistics
pmat memory pools --cache-stats

# Clear specific cache types
pmat memory cleanup --target cache:tdg,cache:ast

# Configure cache eviction
pmat memory configure --cache-policy lru --cache-ttl 3600
```

## Pressure Detection

### Pressure Levels

| Level | Threshold | System Response | User Action |
|-------|-----------|-----------------|-------------|
| **LOW** | <30% | Normal operation | None required |
| **MEDIUM** | 30-60% | Passive cleanup | Monitor situation |
| **HIGH** | 60-80% | Active cleanup | Consider manual cleanup |
| **CRITICAL** | >80% | Emergency cleanup | Immediate intervention |

### Automatic Responses

```toml
# pmat.toml configuration
[memory.pressure]
auto_respond = true

[memory.pressure.responses.medium]
actions = ["cleanup_temp", "compact_strings"]
notify = false

[memory.pressure.responses.high]
actions = ["cleanup_all", "reduce_cache", "compact_all"]
notify = true
notification_cmd = "notify-send 'PMAT Memory Warning'"

[memory.pressure.responses.critical]
actions = ["emergency_cleanup", "dump_cache", "exit_gracefully"]
notify = true
save_state = true
```

## Optimization Strategies

### 1. Large Project Analysis

```bash
# Pre-configure for large projects (>1M LOC)
pmat memory configure --profile large-project

# This sets:
# - AST Pool: 2 GB
# - Analysis Pool: 1 GB
# - Cache Pool: 4 GB
# - Aggressive GC: Every 2 minutes
# - Incremental processing: Enabled
```

### 2. CI/CD Optimization

```bash
# Optimize for CI environments (limited memory)
pmat memory configure --profile ci-pipeline

# This sets:
# - Total limit: 2 GB
# - Minimal caching
# - Aggressive cleanup
# - Swap disabled
# - Streaming results
```

### 3. Interactive Development

```bash
# Optimize for IDE/editor integration
pmat memory configure --profile interactive

# This sets:
# - Fast response priority
# - Moderate caching
# - Background cleanup
# - Incremental updates
```

## CI/CD Integration

### GitHub Actions Example

```yaml
name: Code Analysis with Memory Management
on: [push, pull_request]

jobs:
  analyze:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      
      - name: Install PMAT
        run: cargo install pmat --locked
      
      - name: Configure Memory for CI
        run: |
          pmat memory configure --profile ci-pipeline
          pmat memory configure --max-total 3GB
      
      - name: Run Analysis with Monitoring
        run: |
          # Start memory monitoring in background
          pmat memory stats --watch --format json > memory-log.json &
          MONITOR_PID=$!
          
          # Run analysis
          pmat analyze complexity . --top-files 100
          pmat tdg . --enforce-thresholds
          
          # Stop monitoring
          kill $MONITOR_PID
      
      - name: Check Memory Health
        run: |
          # Analyze memory usage patterns
          pmat memory stats --analyze-log memory-log.json
          
          # Fail if memory pressure was critical
          if grep -q '"pressure_level":"CRITICAL"' memory-log.json; then
            echo "Critical memory pressure detected during analysis"
            exit 1
          fi
      
      - name: Upload Memory Report
        uses: actions/upload-artifact@v3
        with:
          name: memory-analysis
          path: memory-log.json
```

### Docker Configuration

```dockerfile
# Dockerfile with memory optimization
FROM rust:latest

# Install PMAT
RUN cargo install pmat --locked

# Configure memory limits
ENV PMAT_MEMORY_MAX=2GB
ENV PMAT_MEMORY_PROFILE=container

# Set up memory monitoring
HEALTHCHECK --interval=30s --timeout=3s \
  CMD pmat memory pressure || exit 1

# Configure entrypoint with memory management
ENTRYPOINT ["sh", "-c", "pmat memory configure --profile container && exec $@"]
```

## Best Practices

### 1. Regular Monitoring

```bash
# Add to your development workflow
alias pmat-status='pmat memory stats --format compact'
alias pmat-clean='pmat memory cleanup --target temp,cache'
alias pmat-optimize='pmat memory pools --optimize'
```

### 2. Pre-Analysis Configuration

```bash
#!/bin/bash
# prepare-analysis.sh

# Check available memory
AVAILABLE_MEM=$(free -m | awk '/^Mem:/{print $7}')

if [ $AVAILABLE_MEM -lt 2048 ]; then
    echo "Low memory detected. Configuring conservative settings..."
    pmat memory configure --profile low-memory
elif [ $AVAILABLE_MEM -lt 4096 ]; then
    echo "Moderate memory available. Using balanced settings..."
    pmat memory configure --profile balanced
else
    echo "Ample memory available. Using performance settings..."
    pmat memory configure --profile performance
fi

# Run analysis
pmat analyze complexity . --top-files 50
```

### 3. Memory Leak Detection

```bash
# Enable memory tracking
export PMAT_MEMORY_TRACK=1

# Run analysis
pmat analyze complexity src/

# Check for leaks
pmat memory stats --check-leaks

# Generate leak report
pmat memory stats --leak-report > leaks.json
```

### 4. Cache Management

```bash
# View cache usage
pmat memory pools --cache-stats

# Clear old cache entries (>7 days)
pmat memory cleanup --cache-age 7d

# Optimize cache based on hit rates
pmat memory pools --optimize-cache
```

### 5. Emergency Recovery

```bash
#!/bin/bash
# emergency-cleanup.sh

echo "Performing emergency memory cleanup..."

# Stop all PMAT processes
pkill -TERM pmat

# Clear all caches
rm -rf ~/.pmat/cache/*
rm -rf /tmp/pmat-*

# Reset memory configuration
pmat memory configure --reset

# Restart with minimal memory
pmat memory configure --profile minimal

echo "Memory cleanup complete. System reset to minimal configuration."
```

## Integration with PMAT Ecosystem

### Quality Gate Integration

```toml
# pmat.toml
[quality.gates.memory]
enabled = true
max_memory_usage = "4GB"
max_pressure_level = "HIGH"
require_cleanup_after = true
```

### MCP Tool Integration

```javascript
// Monitor memory during analysis
const memoryBefore = await mcp.callTool('pmat', 'memory_stats');

// Run heavy analysis
await mcp.callTool('pmat', 'analyze_complexity', {
  path: '.',
  deep_analysis: true
});

// Check memory after
const memoryAfter = await mcp.callTool('pmat', 'memory_stats');

// Cleanup if needed
if (memoryAfter.pressure_level === 'HIGH') {
  await mcp.callTool('pmat', 'memory_cleanup', {
    aggressive: true
  });
}
```

### Performance Testing Integration

```bash
# Run performance test with memory monitoring
pmat test performance \
  --scenario large-codebase \
  --monitor memory \
  --memory-limit 2GB \
  --report memory-performance.json
```

## Troubleshooting

### Common Issues

1. **Out of Memory Errors**
   ```bash
   # Immediate relief
   pmat memory cleanup --aggressive
   pmat memory configure --allow-swap
   ```

2. **Slow Performance**
   ```bash
   # Check for memory pressure
   pmat memory pressure
   # Optimize pools
   pmat memory pools --optimize
   ```

3. **Cache Misses**
   ```bash
   # Analyze cache performance
   pmat memory pools --cache-stats --detailed
   # Increase cache size
   pmat memory configure --cache-pool 2GB
   ```

---

**Version**: 2.71.0 | **Last Updated**: 2025-09-09 | **Status**: Production Ready