nuttx/include/sys/sendfile.h
Xiang Xiao 92b2f1bd3d fs: Undefine CONFIG_FS_LARGEFILE if compiler doesn't support long long
to simplify the large file check in many place

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2023-03-02 09:37:58 +01:00

115 lines
4.4 KiB
C

/****************************************************************************
* include/sys/sendfile.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_SYS_SENDFILE_H
#define __INCLUDE_SYS_SENDFILE_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_SENDFILE_BUFSIZE
# define CONFIG_SENDFILE_BUFSIZE 512
#endif
#if defined(CONFIG_FS_LARGEFILE)
# define sendfile64 sendfile
#endif
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: sendfile
*
* Description:
* sendfile() copies data between one file descriptor and another.
* sendfile() basically just wraps a sequence of reads() and writes()
* to perform a copy. It serves a purpose in systems where there is
* a penalty for copies to between user and kernel space, but really
* nothing in NuttX but provide some Linux compatible (and adding
* another 'almost standard' interface).
*
* NOTE: This interface is *not* specified in POSIX.1-2001, or other
* standards. The implementation here is very similar to the Linux
* sendfile interface. Other UNIX systems implement sendfile() with
* different semantics and prototypes. sendfile() should not be used
* in portable programs.
*
* Input Parameters:
* infd - A file (or socket) descriptor opened for reading
* outfd - A descriptor opened for writing.
* offset - If 'offset' is not NULL, then it points to a variable
* holding the file offset from which sendfile() will start
* reading data from 'infd'. When sendfile() returns, this
* variable will be set to the offset of the byte following
* the last byte that was read. If 'offset' is not NULL,
* then sendfile() does not modify the current file offset of
* 'infd'; otherwise the current file offset is adjusted to
* reflect the number of bytes read from 'infd.'
*
* If 'offset' is NULL, then data will be read from 'infd'
* starting at the current file offset, and the file offset
* will be updated by the call.
* count - The number of bytes to copy between the file descriptors.
*
* Returned Value:
* If the transfer was successful, the number of bytes written to outfd is
* returned. On error, -1 is returned, and errno is set appropriately.
* There error values are those returned by read() or write() plus:
*
* EINVAL - Bad input parameters.
* ENOMEM - Could not allocated an I/O buffer
*
****************************************************************************/
ssize_t sendfile(int outfd, int infd, FAR off_t *offset, size_t count);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_SYS_SENDFILE_H */