💾 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.

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🚀 Features

• ✅ LRU (Least-Recently-Used) eviction strategy
• ✅ Cost-based cleanup (totalCostLimit)
• ✅ Count-based cleanup (countLimit)
• ✅ Memory-pressure cleanup via DispatchSourceMemoryPressure
• ✅ Actor-isolated thread-safe design
• ✅ No Objective-C / Foundation subclassing
• ✅ 100% Swift + SPM support
• ✅ Clean and minimal API

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📦 Installation

Swift Package Manager

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

Then import where needed:

import SwiftyCache

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🧩 Usage

Create a cache

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

Store & retrieve values

func cacheAvatar(_ imageData:Data)async{await cache.setValue(imageData, forKey:"avatar", cost: imageData.count)letcachedData=await cache.value(forKey:"avatar")}

Eviction

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

Update runtime configuration

await cache.setCountLimit(50)await cache.setTotalCostLimit(5_000)await cache.setClearOnMemoryPressure(false)await cache.setName("avatars")

Remove items

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

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🧪 LRU Example

func lruExample()async{letcache=SwiftyCache<String,Int>(countLimit:3)await cache.setValue(1, forKey:"A")await cache.setValue(2, forKey:"B")await cache.setValue(3, forKey:"C")
_ =await cache.value(forKey:"A") // A is now most recently used
await cache.setValue(4, forKey:"D") // B is evicted (least recently used)
print(await cache.allKeys) // ["C", "A", "D"]
}

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🧱 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

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📁 Project Structure

SwiftyCache/├── Sources/│└── SwiftyCache/│├── SwiftyCache.swift
│└── Resources/│└── PrivacyInfo.xcprivacy
├── Tests/│└── SwiftyCacheTests/│└── SwiftyCacheTests.swift
├──Package.swift
├── Package@swift-5.10.swift
└──README.md ← You are here

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📄 License

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

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🤝 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

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📬 Contact

Feel free to reach out:

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

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Made with ❤️ by @codingiran