Caching in C++: Cache++ Library

What is Cache++ and why is it needed?

Cache++ is a lightweight and high-performance library for caching data in C++ that provides a convenient interface for temporary storage of frequently used computation results, database queries, or network responses. It implements several eviction strategies (LRU, LFU, TTL) and supports thread safety, making it an ideal choice for server applications, game engines, and real-time systems.

Main Features

• LRU Cache (Least Recently Used) — automatically removes the least recently used items when the limit is exceeded.
• LFU Cache (Least Frequently Used) — removes items with the lowest access frequency.
• TTL Cache (Time To Live) — items expire after a specified time.
• Thread Safety — all operations can be performed from multiple threads without additional synchronization.
• Customizable Eviction Policies — flexible configuration for specific tasks.

Installation

Cache++ is distributed as a header-only library, so to install it you just need to copy the files into your project. If you use CMake, add to CMakeLists.txt:

add_subdirectory(path/to/cachepp)target_link_libraries(your_project cachepp)

Or simply include the header file:

#include "cachepp/cache.hpp"

Code Example

#include <iostream>#include "cachepp/cache.hpp"

int main() {    // Create an LRU cache for 100 items    cachepp::lru_cache<std::string, int> cache(100);

    // Add items    cache.put("key1", 42);    cache.put("key2", 100);

    // Get a value    if (auto val = cache.get("key1")) {        std::cout << "Found: " << *val << std::endl;    }

    // Check for existence    if (cache.contains("key2")) {        std::cout << "key2 exists" << std::endl;    }

    // Remove an item    cache.erase("key1");

    return 0;}

When to use Cache++

The library is suitable for:

• Accelerating repeated requests to external APIs.
• Caching results of heavy computations (e.g., image processing).
• Implementing a cache for a web server (e.g., HTTP request responses).
• Optimizing database operations (query cache).

Not recommended for:

• Caching very large objects (e.g., video files) — disk cache is better suited.
• When persistence is required (saving the cache between application runs).

Conclusion

Cache++ is a powerful tool for optimizing the performance of C++ applications. Thanks to support for various eviction strategies and thread safety, it integrates easily into existing projects. Start using caching today to reduce your application's response time by millions of times.