transmission/libtransmission/fdlimit.h

/******************************************************************************
 * $Id$
 *
 * Copyright (c) 2005-2008 Transmission authors and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *****************************************************************************/

#ifndef __TRANSMISSION__
#error only libtransmission should #include this header.
#endif

#include "transmission.h"
#include "net.h"

/**
 * @addtogroup file_io File IO
 * @{
 */

void tr_fdSetFileLimit( tr_session * session, int limit );

int tr_fdGetFileLimit( const tr_session * session );

void tr_fdSetGlobalPeerLimit( tr_session * session, int limit );

/***
****
***/

int tr_open_file_for_scanning( const char * filename );

int tr_open_file_for_writing( const char * filename );

void tr_close_file( int fd );

tr_bool tr_preallocate_file( const char * filename, uint64_t length );

int64_t tr_lseek( int fd, int64_t offset, int whence );
ssize_t tr_pread(int fd, void *buf, size_t count, off_t offset);
ssize_t tr_pwrite(int fd, void *buf, size_t count, off_t offset);
int tr_prefetch(int fd, off_t offset, size_t count);


/**
 * Returns an fd to the specified filename.
 *
 * A small pool of open files is kept to avoid the overhead of
 * continually opening and closing the same files when downloading
 * piece data.
 *
 * - if doWrite is true, subfolders in torrentFile are created if necessary.
 * - if doWrite is true, the target file is created if necessary.
 *
 * on success, a file descriptor >= 0 is returned.
 * on failure, a -1 is returned and errno is set.
 *
 * @see tr_fdFileClose
 */
int  tr_fdFileCheckout( tr_session             * session,
                        int                      torrentId,
                        tr_file_index_t          fileNum,
                        const char             * fileName,
                        tr_bool                  doWrite,
                        tr_preallocation_mode    preallocationMode,
                        uint64_t                 desiredFileSize );

int tr_fdFileGetCached( tr_session             * session,
                        int                      torrentId,
                        tr_file_index_t          fileNum,
                        tr_bool                  doWrite );

/**
 * Closes a file that's being held by our file repository.
 *
 * If the file isn't checked out, it's closed immediately.
 * If the file is currently checked out, it will be closed upon its return.
 *
 * @see tr_fdFileCheckout
 */
void tr_fdFileClose( tr_session        * session,
                     const tr_torrent  * tor,
                     tr_file_index_t     fileNo );


/**
 * Closes all the files associated with a given torrent id
 */
void tr_fdTorrentClose( tr_session * session, int torrentId );


/***********************************************************************
 * Sockets
 **********************************************************************/
int      tr_fdSocketCreate( tr_session * session, int domain, int type );

int      tr_fdSocketAccept( tr_session  * session,
                            int           b,
                            tr_address  * addr,
                            tr_port     * port );

void     tr_fdSocketClose( tr_session * session, int s );

/***********************************************************************
 * tr_fdClose
 ***********************************************************************
 * Frees resources allocated by tr_fdInit.
 **********************************************************************/
void     tr_fdClose( tr_session * session );


void     tr_fdSetPeerLimit( tr_session * session, int n );

int      tr_fdGetPeerLimit( const tr_session * );

/* @} */