💾 SwiftyCache

SwiftyCache is a lightweight, elegant, and performant in-memory cache written purely in Swift.
It supports Least-Recently-Used (LRU) eviction logic using Swift Collections’ OrderedDictionary, with optional cost-based cleanup and memory warning handling for Apple platforms.

Simple. Fast. Swifty.

🚀 Features

✅ LRU (Least-Recently-Used) eviction strategy
✅ Cost-based cleanup (totalCostLimit)
✅ Count-based cleanup (countLimit)
✅ MemoryWarning cleanup
✅ Thread-safe design ready
✅ No Objective-C / Foundation subclassing
✅ 100% Swift + SPM support
✅ Clean and minimal API

📦 Installation

Swift Package Manager

dependencies: [
    .package(url: "https://github.com/codingiran/SwiftyCache.git", from: "1.0.0")
]

Then import where needed:

import SwiftyCache

🧩 Usage

Create a cache

let cache = SwiftyCache<String, Data>(
    totalCostLimit: 10_000,  // Optional
    countLimit: 100          // Optional
)

Store & retrieve values

cache.setValue(imageData, forKey: "avatar", cost: imageData.count)

let cachedData = cache.value(forKey: "avatar")

Eviction

Least Recently Used items are automatically evicted when:
- countLimit is exceeded
- totalCostLimit is exceeded
- Memory warning(DispatchSourceMemoryPressure) is received

Remove items

cache.removeValue(forKey: "avatar")
cache.removeAllValues()

🧪 LRU Example

let cache = SwiftyCache<String, Int>(countLimit: 3)

cache.setValue(1, forKey: "A")
cache.setValue(2, forKey: "B")
cache.setValue(3, forKey: "C")

_ = cache.value(forKey: "A") // A is now most recently used

cache.setValue(4, forKey: "D") // B is evicted (least recently used)

print(cache.allKeys) // ["C", "A", "D"]

🧱 Implementation Highlights

Using Swift actor for thread safety
Implements NSCache-like API for easy integration
Built atop OrderedDictionary to avoid managing doubly-linked list manually
Reorders keys internally on access to preserve LRU order
Minimal dependencies, cleanly integrated with DispatchSourceMemoryPressure for memory warnings

📁 Project Structure

SwiftyCache/
├── Sources/
│   └── SwiftyCache.swift
├── Package.swift
└── README.md ← You are here

📄 License

This project is licensed under the MIT License.
See LICENSE for more information.

🤝 Contributing

Pull requests are welcome!
If you'd like to add a feature, fix a bug, or improve documentation:

Fork the repo
Create your feature branch: git checkout -b feature/your-feature
Commit your changes: git commit -m "Add some feature"
Push to the branch: git push origin feature/your-feature
Open a Pull Request

📬 Contact

Feel free to reach out:

📧 Email: codingiran@gmail.com
📦 GitHub: github.com/codingiran/SwiftyCache

Made with ❤️ by @codingiran