/* Copyright (C) 2017-2018 J.F.Dockes
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef _CURLFETCH_H_INCLUDED_
#define _CURLFETCH_H_INCLUDED_
#include <stddef.h>
#include <stdint.h>
#include <string>
#include <functional>
#include <memory>
#include "bufxchange.h"
#include "abuffer.h"
#include "netfetch.h"
//
// Wrapper for a libcurl transfer. This uses the curl_easy interface
// in a separate thread, so any number of transfers may be performed
// in parallel.
//
// The transfer is aborted when the object is deleted, with proper
// cleanup (in practise, if the curl thread is currently working
// inside curl_easy_transfer, the curl fd is closed to abort any
// current waiting).
//
// The end of transfer is signalled by pushing an empty buffer on the queue
//
// All methods are supposedly thread-safe
class CurlFetch : public NetFetch {
public:
CurlFetch(const std::string& url);
~CurlFetch();
/// Start the transfer to the output queue.
bool start(BufXChange<ABuffer*> *queue, uint64_t offset = 0) override;
// Wait for HTTP headers. This allows, e.g. doing stuff depending
// on content-type before proceeding with the actual data transfer
bool waitForHeaders(int maxSecs = 0) override;
// Retrieve header value (after a successful waitForHeaders).
bool headerValue(const std::string& nm, std::string& val) override;
// Check if the curl thread is done and retrieve the results if it
// is. This does not wait, it returns false if the transfer is
// still running.
bool fetchDone(FetchStatus *code, int *http_code) override;
/// Reset after transfer done, for retrying for exemple.
bool reset() override;
class Internal;
private:
std::unique_ptr<Internal> m;
};
#endif /* _CURLFETCH_H_INCLUDED_ */