ConcurrentHashMap C++ Library

A thread-safe hash map implementation in C++ with support for concurrent read and write operations.

Overview

This is an attempt to create an equivalent of Java's ConcurrentHashMap in C++. It is not a direct equivalent because the underlying concurrency models in Java and C++ are different.

This C++ library provides a ConcurrentHashMap class that allows multiple threads to perform read and write operations on a hash map concurrently.

Features

• Thread-safe read/write operations
• Fine-grained locking with std::shared_mutex
• Modern C++17 API with std::optional returns
• Efficient collision handling using chaining
• Comprehensive unit tests (Google Test)
• CMake build system support

Usage

1. Include the Library:

#include "ConcurrentHashMap.h"

2. Create an Instance:

ConcurrentHashMap<std::string, int> concurrentMap;

3. Perform Operations:

// Insert a key-value pair
concurrentMap.insert("one", 1);

// Retrieve the value for a key
if(auto value = concurrentMap.get("one"))
    std::cout << "Value for key 'one': " << value << std::endl;
} else {
    std::cout << "Key 'one' not found." << std::endl;
}

// Remove a key-value pair
concurrentMap.remove("one");

Advanced Features

Print entire map structure using print().

Custom hash function support:

struct CustomHash { /* ... */ };
ConcurrentHashMap<KeyType, ValueType, CustomHash> customMap;

Build

mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build . --parallel

Running tests

After CMake build

cd build && ctest --verbose

Or directly

./ConcurrentHashMapTest --gtest_color=yes

⛄ Author

Eray Öztürk (@diffstorm)

License

This project is licensed under the MIT License - see the LICENSE file for details.

Feel free to contribute, report issues, or suggest improvements!

Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create your feature branch
3. Submit a Pull Request
4. Ensure all tests pass