mpd/src/lib/curl/Handler.hxx
2022-07-01 12:45:07 +02:00

82 lines
2.5 KiB
C++

/*
* Copyright 2008-2021 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "Headers.hxx"
#include <cstddef>
#include <exception>
#include <span>
/**
* Asynchronous response handler for a #CurlRequest.
*
* Its methods must be thread-safe.
*/
class CurlResponseHandler {
public:
/**
* OnData() shall throw this to pause the stream. Call
* CurlEasy::Unpause() or CurlRequest::Resume() to resume the
* transfer.
*/
struct Pause {};
/**
* Status line and headers have been received.
*
* Exceptions thrown by this method will be passed to
* OnError(), aborting the request.
*/
virtual void OnHeaders(unsigned status, Curl::Headers &&headers) = 0;
/**
* Response body data has been received.
*
* May throw #Pause.
*
* Other exceptions thrown by this method will be passed to
* OnError(), aborting the request.
*/
virtual void OnData(std::span<const std::byte> data) = 0;
/**
* The response has ended. The method is allowed to delete the
* #CurlRequest.
*/
virtual void OnEnd() = 0;
/**
* An error has occurred. The method is allowed to delete the
* #CurlRequest.
*/
virtual void OnError(std::exception_ptr e) noexcept = 0;
};