cache_demo.py

#!/usr/bin/env python3
"""
Example demonstrating the advanced cache features of PROVESID.

This script shows:
1. Unlimited caching with persistent storage
2. Cache size monitoring and warnings
3. Cache export/import functionality
4. Cache management utilities

Run this script to see the cache system in action.
"""

import provesid
import time
import tempfile
import os
from pathlib import Path

def main():
    print("🚀 PROVESID Advanced Cache System Demo")
    print("=" * 50)
    
    # 1. Demonstrate unlimited caching
    print("\n1. Creating PubChem API instance with unlimited cache...")
    api = provesid.PubChemAPI()
    
    # Clear any existing cache for clean demo
    print("   Clearing existing cache...")
    provesid.clear_cache()
    
    # Show initial cache state
    cache_info = provesid.get_cache_info()
    print(f"   Initial cache: {cache_info['memory_entries']} entries, {cache_info['total_size_mb']:.2f} MB")
    
    # 2. Demonstrate caching with mock functions (since we might not have network)
    print("\n2. Demonstrating caching behavior...")
    
    from provesid.cache import cached
    
    # Use a mutable container to track call count (works with nested functions)
    call_stats = {'count': 0}
    
    @cached
    def expensive_calculation(n):
        """Simulate an expensive API call or calculation."""
        call_stats['count'] += 1
        print(f"      🔄 Actually computing for n={n} (call #{call_stats['count']})")
        time.sleep(0.1)  # Simulate work
        return n * n + n
    
    # First calls - will be cached
    print("   Making function calls...")
    result1 = expensive_calculation(5)
    result2 = expensive_calculation(10)
    result3 = expensive_calculation(5)  # This should be cached!
    
    print(f"   Results: {result1}, {result2}, {result3}")
    print(f"   Total actual function calls: {call_stats['count']} (should be 2, not 3)")
    
    # 3. Show cache statistics
    print("\n3. Cache statistics...")
    cache_info = provesid.get_cache_info()
    print(f"   Cache entries: {cache_info['memory_entries']} in memory, {cache_info['disk_entries']} on disk")
    print(f"   Cache size: {cache_info['total_size_bytes']} bytes ({cache_info['total_size_mb']:.6f} MB)")
    print(f"   Cache directory: {cache_info['cache_directory']}")
    
    # 4. Demonstrate cache size monitoring
    print("\n4. Cache size monitoring...")
    print(f"   Warning threshold: {cache_info['warning_threshold_gb']} GB")
    
    # Set a very low threshold to demonstrate warning
    print("   Setting warning threshold to 0.001 GB to trigger warning...")
    provesid.set_cache_warning_threshold(0.001)
    
    # Add more data to trigger warning
    for i in range(10):
        expensive_calculation(i + 20)
    
    # 5. Demonstrate cache export
    print("\n5. Cache export/import...")
    
    with tempfile.TemporaryDirectory() as temp_dir:
        export_file = os.path.join(temp_dir, "cache_backup.pkl")
        
        # Export cache
        print(f"   Exporting cache to: {export_file}")
        success = provesid.export_cache(export_file)
        if success:
            file_size = os.path.getsize(export_file)
            print(f"   ✅ Export successful! File size: {file_size} bytes")
        else:
            print("   ❌ Export failed!")
        
        # Clear cache
        print("   Clearing cache...")
        provesid.clear_cache()
        cache_info = provesid.get_cache_info()
        print(f"   Cache after clear: {cache_info['memory_entries']} entries")
        
        # Import cache
        print("   Importing cache from backup...")
        success = provesid.import_cache(export_file)
        if success:
            cache_info = provesid.get_cache_info()
            print(f"   ✅ Import successful! Restored {cache_info['disk_entries']} entries")
        else:
            print("   ❌ Import failed!")
    
    # 6. Test that imported cache works
    print("\n6. Testing restored cache...")
    call_count_before = call_stats['count']
    result = expensive_calculation(5)  # Should be cached from import
    if call_stats['count'] == call_count_before:
        print(f"   ✅ Cache working! Got {result} without function call")
    else:
        print(f"   ⚠️  Cache miss - function was called again")
    
    # 7. Cache management utilities
    print("\n7. Cache management...")
    
    # Get cache size breakdown
    size_info = provesid.get_cache_size()
    print(f"   Detailed size info:")
    print(f"   - {size_info['files']} files")
    print(f"   - {size_info['bytes']} bytes")
    print(f"   - {size_info['mb']:.6f} MB")
    print(f"   - {size_info['gb']:.9f} GB")
    
    # Final cache info
    print("\n📊 Final Cache Statistics:")
    final_info = provesid.get_cache_info()
    for key, value in final_info.items():
        if isinstance(value, float):
            print(f"   {key}: {value:.6f}")
        else:
            print(f"   {key}: {value}")
    
    print("\n🎉 Demo completed!")
    print("\n💡 Key Benefits:")
    print("   • Unlimited cache size (no more 512-entry limits)")
    print("   • Persistent storage across sessions")
    print("   • Automatic size monitoring with 5GB warning")
    print("   • Export/import for backup and sharing")
    print("   • Zero-configuration - just import and use!")
    
    print("\n📖 Usage in your code:")
    print("   import provesid")
    print("   api = provesid.PubChemAPI()  # Unlimited cache automatically enabled")
    print("   provesid.export_cache('my_cache.pkl')  # Backup your cache")
    print("   provesid.import_cache('shared_cache.pkl')  # Load shared cache")
    print("   provesid.clear_cache()  # Clear when needed")


if __name__ == "__main__":
    main()