HTTP Client¶

class HttpClient¶

Asynchronous HTTP client.

This class can be used to fetch data from different HTTP sources asynchronously.

Internally, it uses libcurl for HTTP handling and libuv for socket and polling management. By default, the default loop is used.

Public Functions

HttpClient()¶: Create a new HTTP client.

~HttpClient()¶

Destructor of HTTP client.

This function will abort all requests created within this client.

inline std::shared_ptr<Request> download(std::string url, Request::HeadersCallback headers_cb, Request::BodyCallback body_cb, Request::ResponseCallback response_cb)¶

Download content from an URL.

This function will create a GET request to download the data from the provided URL.

Parameters:

url – [in] The URL to use
headers_cb – [in] The function to call when headers have been received
body_cb – [in] The function to call when a body chunk has been received
response_cb – [in] The function to call when full response has been received

Returns:

a reference to a new request holding the request / response, nullptr otherwise.

inline std::shared_ptr<Request> download(std::string url, Request::HeadersCallback headers_cb, Request::BodyCallback body_cb)¶

Download content from an URL.

This function will create a GET request to download the data from the provided URL.

Parameters:

url – [in] The URL to use
headers_cb – [in] The function to call when headers have been received
body_cb – [in] The function to call when a body chunk has been received

Returns:

a reference to a new request holding the request / response, nullptr otherwise.

inline std::shared_ptr<Request> download(std::string url, Request::ResponseCallback cb)¶

Download content from an URL.

This function will create a GET request to download the data from the provided URL.

Parameters:

url – [in] The URL to use
cb – [in] The function to call when full response has been received

Returns:

a reference to a new request holding the request / response, nullptr otherwise.

std::shared_ptr<Request> send_request(std::string type, std::string url, std::string body, Request::HeadersCallback headers_cb, Request::BodyCallback body_cb, Request::ResponseCallback response_cb)¶

Send an HTTP request.

This function will create a request to send the specified body and received theresponse data from the provided URL.

Parameters:

type – [in] The request type
url – [in] The URL to use
body – [in] The request body to send
headers_cb – [in] The function to call when headers have been received
body_cb – [in] The function to call when a body chunk has been received
response_cb – [in] The function to call when full response has been received

Returns:

a reference to a new request holding the request / response, nullptr otherwise.

std::shared_ptr<Request> create_request(std::string type, std::string url)¶

Create a new HTTP request.

This function will create a request. All settings have to be set manually and the Request::send() function has to be called manually as well.

Parameters:

type – [in] The request type
url – [in] The URL to use

Returns:

a reference to a new request holding the request / response, nullptr otherwise.

class Request : public std::enable_shared_from_this<Request>¶

HTTP client request.

This class will hold a unique HTTP request.

Public Types

using HeadersCallback = std::function<bool(Request &req, int code, ssize_t size)>¶

Headers received callback.

This function is called when all response headers have been received. The header value can be retrieved with get_header().

Param req:: [in] The current request
Param code:: [in] The HTTP response code
Param size:: [in] The HTTP response body size
Return:: true if the response body should be received, false to abort request.

using BodyCallback = std::function<size_t(Request &req, const char *buffer, size_t size)>¶

Body chunk received callback.

This function is called when a chunk of the response body has been received.

A call to pause() can be done if all the data have not been consumed during the call. A subsequent call to resume() will call this function again if more data are available.

Param req:: [in] The current request
Param buffer:: [in] The buffer containing the body chunk
Param size:: [in] The body chunk size in bytes
Return:: the number of bytes used from buffer.

using ResponseCallback = std::function<void(Request &req, int code, const std::string &buffer)>¶

Full response callback.

This function is called when the full response has been received.

Param req:: [in] The current request
Param code:: [in] The HTTP response code
Param buffer:: [in] The buffer containing the response body

Public Functions

void set_header(const std::string &key, const std::string &value)¶

Set HTTP request headers.

This function can be used to add headers to the HTTP request.

Parameters:

key – [in] The HTTP header key
value – [in] The HTTP header value

inline void set_body(std::string data)¶

Set HTTP request body.

This function can be used to set the HTTP body.

Parameters:: data – [in] The HTTP body content

bool send()¶

Send the request.

This function will send the request. It can be called from any threads.

Returns:: true if the request has been sent, false otherwise.

void abort()¶

Abort the request.

This function will abort the request. It can be called from any threads and the body and/or response callback will be called with invalid code.

const char *get_header(const char *key)¶

Get an HTTP response header by key.

Parameters:: key – [in] The HTTP header key
Returns:: the value of the HTTP header if found, nullptr otherwise.

void pause()¶

Pause current request.

This function can be used to pause the request. It must be called from one of the callbacks provided to the request.

void resume()¶

Resume current request.

This function can be called to unpause a request and can be called from any threads.

inline bool is_paused() const¶

Check if the request is paused.

Returns:: true if the request is paused, false otherwise.

inline void set_headers_handler(HeadersCallback cb)¶

Set headers received callback.

Parameters:: cb – [in] The function to call when all headers have been received

inline void set_body_handler(BodyCallback cb)¶

Set body chunk received callback.

Parameters:: cb – [in] The function to call when a new body chunk has heen received

inline void set_response_handler(ResponseCallback cb)¶

Set full response callback.

Parameters:: cb – [in] The function to call when full response has been received