Curlion

Introduction

Curlion is a C++ wrapper for libcurl. It provides an easy-to-use interface.

Requirement

A C++11 compatible compiler is required. IDEs listed below are supported:

• XCode 6.0 or greater.
• Visual Studio 2013 or greater.

If you use curlion in non-blocking manner, an event-driven mechanism is also required, such as boost.asio, libevent and so on.

Usage

There are two manners to use curlion: blocking and non-blocking. Blocking manner corresponds to the easy interface of libcurl, and non-blocking manner corresponds to the multi-socket interface.

Blocking manner

This manner is very simple, just like the code shows below:

//Create a connection and set a target URL.	
auto connection = std::make_shared<curlion::Connection>();
connection->SetUrl("http://www.qq.com");

//Start the connection, this call would not return until it is finished.
connection->Start();

//Get result code. 
auto result = connection->GetResult();

//Get response body.
auto response_body = connection->GetResponseBody();

No more explaination is needed.

Non-blocking manner

This manner is more complicated and it needs you to implement an event-driven mechanism. Curlion provides some interfaces to help simplifying the implementation.

Implement Timer

The first interface is curlion::Timer, which is used to start and stop a timer. Implement this interface like below:

class MyTimer : public curlion::Timer {
public:    
    void Start(long timeout_ms, const std::function<void()>& callback) override {
        //Start a timer which expires in timeout_ms, then call callback to notify curlion.
    }	

    void Stop() override {
        //Stop the timer which starts in Start method.
    }
};

Implement SocketWatcher

The second interface is curlion::SocketWatcher, which is used to monitor events on sockets. Implement this interface like below:

class MySocketWatcher : public curlion::SocketWatcher {
public:
    void Watch(curl_socket_t socket, Event event, const EventCallback& callback) override {
        //Start a monitor to watch the socket on event. 
        //When the event is triggered, call callback to notify curlion.
    }

    void StopWatching(curl_socket_t socket) override {
        //Stop the monitor which starts in Watch method.
    }
};

Implement SocketFactory

An optional interface is curlion::SocketFactory, which is used to open and close sockets. If you need to manage sockets by yourself, implement this interface like below:

class MySocketFactory : public curlion::SocketFactory {
public:
    curl_socket_t Open(curlsocktype socket_type, const curl_sockaddr* address) override {
        //Open a socket with specified type and address.
    }

    bool Close(curl_socket_t socket) override {
        //Close the specified socket.
    }
};

Use ConnectionManager

These three interfaces should be installed into a curlion::ConnectionManager, this can be done with the constructor. For instance:

auto timer = std::make_shared<MyTimer>();
auto socket_watcher = std::make_shared<MySocketWatcher>();
auto socket_factory = std::make_shared<MySocketFactory>();

curlion::ConnectionManager connection_manager(socket_factory, socket_watcher, timer);

Next, set a finish callback to a connection, to receive its finish notification. Here we use a lambda express as the callback:

auto connection = std::make_shared<curlion::Connection>();
connection->SetUrl("http://www.qq.com");

connection->SetFinishedCallback([](const std::shared_ptr<Connection>& connection) {

    //Get result code. 
    auto result = connection->GetResult();

    //Get response body.
    auto response_body = connection->GetResponseBody();
});

Finally, you can start a non-bloking connection by calling the Start method of connection manager:

connection_manager.StartConnection(connection);

When the connection is finished, the finish callback will be called.

For more information about usage, see also examples and documentation in source files.

Example

There are some examples in example directory, show how to use curlion.

Documentation

Curlion contains documentation in source files. A HTML version documentation can be generated by doxygen using doc/doxygen script file.