utility_containers_example.cpp

Demonstrates CircularBuffer and ObjectPool utility containers.

Demonstrates CircularBuffer and ObjectPool utility containers.Shows mutex-protected circular buffer, SPSC lock-free buffer for producer-consumer scenarios, and object pool with automatic recycling.

See also

kcenon::common::CircularBuffer

kcenon::common::SPSCCircularBuffer

kcenon::common::ObjectPool

// BSD 3-Clause License
// Copyright (c) 2021-2025, 🍀☀🌕🌥 🌊
// See the LICENSE file in the project root for full license information.
 
 
#include <kcenon/common/utils/circular_buffer.h>
#include <kcenon/common/utils/object_pool.h>
 
#include <iostream>
#include <string>
 
using namespace kcenon::common;
using namespace kcenon::common::utils;
 
// A sample resource for the object pool
struct Connection
{
    int id;
    std::string endpoint;
 
    Connection() : id(0), endpoint("default") {}
    Connection(int i, const std::string& ep) : id(i), endpoint(ep) {}
};
 
int main()
{
    std::cout << "=== Utility Containers Example ===\n\n";
 
    // --- Circular Buffer ---
    std::cout << "1. CircularBuffer (mutex-protected, capacity=5):\n";
    {
        CircularBuffer<int, 5> buffer;
 
        // Push elements
        for (int i = 1; i <= 5; ++i)
        {
            buffer.push(i);
        }
        std::cout << "   Pushed 1-5. Size=" << buffer.size() << ", Full=" << buffer.full() << "\n";
 
        // Overwrite oldest when full
        buffer.push(99, true); // overwrite=true
        std::cout << "   Pushed 99 with overwrite. Size=" << buffer.size() << "\n";
 
        // Pop elements
        std::cout << "   Popping: ";
        while (auto val = buffer.pop())
        {
            std::cout << *val << " ";
        }
        std::cout << "\n   Empty=" << buffer.empty() << "\n";
    }
 
    // --- SPSC Lock-Free Buffer ---
    std::cout << "\n2. SPSCCircularBuffer (lock-free, capacity=4):\n";
    {
        SPSCCircularBuffer<std::string, 4> spsc;
 
        spsc.push("alpha");
        spsc.push("beta");
        spsc.push("gamma");
        std::cout << "   Pushed 3 strings. Size=" << spsc.size() << "\n";
 
        // Pop one
        if (auto val = spsc.pop())
        {
            std::cout << "   Popped: '" << *val << "'\n";
        }
        std::cout << "   Remaining size=" << spsc.size() << "\n";
    }
 
    // --- Object Pool ---
    std::cout << "\n3. ObjectPool (growth=4):\n";
    {
        ObjectPool<Connection> pool(4);
 
        // Pre-allocate
        pool.reserve(8);
        std::cout << "   Reserved 8 slots. Available=" << pool.available() << "\n";
 
        // Acquire objects
        bool reused = false;
        auto conn1 = pool.acquire(&reused, 1, "db-primary");
        std::cout << "   Acquired conn1: id=" << conn1->id << ", endpoint=" << conn1->endpoint
                  << ", reused=" << (reused ? "true" : "false") << "\n";
 
        auto conn2 = pool.acquire(&reused, 2, "db-replica");
        std::cout << "   Acquired conn2: id=" << conn2->id
                  << ", available=" << pool.available() << "\n";
 
        // Release conn1 back to pool (via unique_ptr destructor)
        std::cout << "   Releasing conn1...\n";
        conn1.reset();
        std::cout << "   Available after release=" << pool.available() << "\n";
 
        // Re-acquire — should reuse
        auto conn3 = pool.acquire(&reused, 3, "db-analytics");
        std::cout << "   Acquired conn3: reused=" << (reused ? "true" : "false") << "\n";
 
        // Clear the pool
        conn2.reset();
        conn3.reset();
        pool.clear();
        std::cout << "   Pool cleared. Available=" << pool.available() << "\n";
    }
 
    std::cout << "\nDone.\n";
    return 0;
}