Generic Queue

A lightweight generic queue implementation in C. This library provides a complete FIFO (First-In-First-Out) queue data structure that works with any data type through void* pointer.

Library: Pure C Tests: C++ with Google Test

Features

• Generic implementation supporting any data type
• Deep copy semantics for safe memory management
• Search functionality with custom predicates or memory comparison
• Queue reversal and copy operations
• Comprehensive error handling
• Zero dependencies for library users

Building

Linux

mkdir build && cd build
cmake ..
make

Windows

mkdir build && cd build
cmake ..
cmake --build .

On Windows, executables and libraries will be in the Debug/ or Release/ folder. You can also open the generated .sln file in Visual Studio.

Running Examples

Linux

./example

Windows

Debug\example.exe

Running Tests

The library includes comprehensive unit tests written in C++ using Google Test.

Linux

cd build
ctest
# Or run the test executable
./tests/QueueTest
# Or run the test target (after make all)
make test

Windows

cd build
ctest
# or 
Debug\QueueTest.exe

Installation

For linux

mkdir build && cd build
cmake ..
make
sudo make install

This installs:

• libgenericQueue.a to /usr/local/lib
• queue.h to /usr/local/include

To install to a custom location:

cmake .. -DCMAKE_INSTALL_PREFIX=/custom/path
make
make install

You can also install on windows using the cmake commands

mkdir build && cd build
cmake .. -DCMAKE_INSTALL_PREFIX=C:<YOUR_PATH>
cmake --build . --config Release
cmake --install . --config Release

You need to configure then your project or cmake file to link using that location

API

• queue *createQueue(size_t allocSize) - Create a new queue
• void destroyQueue(queue **q) - Destroy queue and free memory
• queue *enqueue(queue *q, void *data) - Add element to back
• queue *dequeue(queue *q, void *data) - Remove and retrieve front element
• queue *front(queue *q, void *data) - Peek at front element
• queue *reverse(queue *q) - Reverse the queue order
• queue *clearQueue(queue *q) - Remove all elements
• queue *copyQueue(queue *src) - Create a deep copy
• void *find(queue *q, bool (*predicate)(void *data)) - Find element with predicate
• void *findMem(queue *q, void *data) - Find element by memory comparison
• size_t getSize(queue *q) - Get number of elements
• bool isEmpty(queue *q) - Check if queue is empty
• size_t getAllocationSize(queue *q) - Get element size

See queue.h for detailed documentation.

Usage Example

#include "queue.h"
#include <stdio.h>

typedef struct {
    int id;
    char name[32];
} Person;

int main() {
    // Create queue for Person structs
    queue *q = createQueue(sizeof(Person));
    if (q == NULL) {
        fprintf(stderr, "Failed to create queue\n");
        return 1;
    }

    // Add elements
    Person p1 = {1, "Alice"};
    Person p2 = {2, "Bob"};

    enqueue(q, &p1);
    enqueue(q, &p2);

    printf("Queue size: %zu\n", getSize(q));

    // Peek at front
    Person front_person;
    front(q, &front_person);
    printf("Front: %s\n", front_person.name);

    // Remove elements
    Person dequeued;
    while (!isEmpty(q)) {
        dequeue(q, &dequeued);
        printf("Dequeued: %s\n", dequeued.name);
    }

    // Clean up
    destroyQueue(&q);
    return 0;
}