netsurf/content/fetchers.h

153 lines
4.1 KiB
C

/*
* Copyright 2014 Vincent Sanders <vince@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* \file content/fetchers.h
*
* Interface for fetchers factory.
*/
#ifndef _NETSURF_DESKTOP_FETCHERS_H_
#define _NETSURF_DESKTOP_FETCHERS_H_
#include "utils/inet.h" /* this is necessary for the fd_set definition */
#include <libwapcaplet/libwapcaplet.h>
struct nsurl;
struct fetch_multipart_data;
struct fetch;
/**
* Fetcher operations API
*
* These are the operations a fetcher must implement.
*
* Each fetcher is called once for initialisaion and finalisation.
* The poll entry point will be called to allow all active fetches to progress.
* The flow of a fetch operation is:
* URL is checked for aceptability.
* setup with all applicable data.
* start is called before the first poll
* after completion or abort it is freed
*
*/
struct fetcher_operation_table {
/**
* The initialiser for the fetcher.
*
* Called once to initialise the fetcher.
*/
bool (*initialise)(lwc_string *scheme);
/**
* Can this fetcher accept a url.
*
* \param url the URL to check
* \return true if the fetcher can handle the url else false.
*/
bool (*acceptable)(const struct nsurl *url);
/**
* Setup a fetch
*/
void *(*setup)(struct fetch *parent_fetch, struct nsurl *url,
bool only_2xx, bool downgrade_tls, const char *post_urlenc,
const struct fetch_multipart_data *post_multipart,
const char **headers);
/**
* start a fetch.
*/
bool (*start)(void *fetch);
/**
* abort a fetch.
*/
void (*abort)(void *fetch);
/**
* free a fetch allocated through the setup method.
*/
void (*free)(void *fetch);
/**
* poll a fetcher to let it make progress.
*/
void (*poll)(lwc_string *scheme);
/**
* Finalise the fetcher.
*/
void (*finalise)(lwc_string *scheme);
};
/**
* Register a fetcher for a scheme
*
* \param scheme The scheme fetcher is for (caller relinquishes ownership)
* \param ops The operations for the fetcher.
* \return NSERROR_OK or appropriate error code.
*/
nserror fetcher_add(lwc_string *scheme, const struct fetcher_operation_table *ops);
/**
* Initialise all registered fetchers.
*
* \return NSERROR_OK or error code
*/
nserror fetcher_init(void);
/**
* Clean up for quit.
*
* Must be called before exiting.
*/
void fetcher_quit(void);
/**
* Get the set of file descriptors the fetchers are currently using.
*
* This obtains the file descriptors the fetch system is using to
* obtain data. It will cause the fetchers to make progress, if
* possible, potentially completing fetches before requiring activity
* on file descriptors.
*
* If a set of descriptors is returned (maxfd is not -1) The caller is
* expected to wait on them (with select etc.) and continue to obtain
* the fdset with this call. This will switch the fetchers from polled
* mode to waiting for network activity which is much more efficient.
*
* \note If the caller does not subsequently obtain the fdset again
* the fetchers will fall back to the less efficient polled
* operation. The fallback to polled operation will only occour after
* a timeout which introduces additional delay.
*
* \param[out] read_fd_set The fd set for read.
* \param[out] write_fd_set The fd set for write.
* \param[out] except_fd_set The fd set for exceptions.
* \param[out] maxfd The highest fd number in the set or -1 if no fd available.
* \return NSERROR_OK on success or appropriate error code.
*/
nserror fetcher_fdset(fd_set *read_fd_set, fd_set *write_fd_set, fd_set *except_fd_set, int *maxfd);
#endif