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
• Serialization to/from buffers and files

Building

In both Linux and Windows compile_commands.json can be generated to improve intelisense and LSP servers.

cmake -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
ln -s build/compile_commands.json compile_commands.json # link/move to the root directory

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

Usage Example (with Serialization)

#include "queue.h"
#include <stdio.h>
#include <stdlib.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"};
    Person p3 = {3, "Charlie"};

    enqueue(q, &p1);
    enqueue(q, &p2);
    enqueue(q, &p3);

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

    // Demonstrate serialization - save queue to file
    SerializeResult result = serializeQueueToFile(q, "people_queue.dat");
    if (result != SERIALIZE_SUCCESS) {
        fprintf(stderr, "Serialization failed: %d\n", result);
        destroyQueue(&q);
        return 1;
    }
    printf("Queue serialized to file successfully\n");

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

    // Remove some elements
    Person dequeued;
    dequeue(q, &dequeued);
    printf("Dequeued: %s (ID: %d)\n", dequeued.name, dequeued.id);

    dequeue(q, &dequeued);
    printf("Dequeued: %s (ID: %d)\n", dequeued.name, dequeued.id);

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

    // Now demonstrate deserialization - restore queue from file
    destroyQueue(&q);  // Clean up original queue
    
    queue *restored_queue;
    result = deserializeQueueFromFile("people_queue.dat", &restored_queue);
    if (result != SERIALIZE_SUCCESS) {
        fprintf(stderr, "Deserialization failed: %d\n", result);
        return 1;
    }
    printf("Queue deserialized from file successfully\n");
    printf("Restored queue size: %zu\n", getSize(restored_queue));

    // Process all elements from restored queue
    while (!isEmpty(restored_queue)) {
        dequeue(restored_queue, &dequeued);
        printf("Dequeued: %s (ID: %d)\n", dequeued.name, dequeued.id);
    }

    // Clean up
    destroyQueue(&restored_queue);
    remove("people_queue.dat");  // Clean up file
    return 0;
}