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sortix--sortix/kernel/fs/zero.cpp
2018-03-31 00:55:33 +02:00

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1.9 KiB
C++

/*
* Copyright (c) 2013, 2014, 2017 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* fs/zero.cpp
* Bit bucket special device.
*/
#include <sys/types.h>
#include <stdint.h>
#include <string.h>
#include <sortix/stat.h>
#include <sortix/kernel/inode.h>
#include <sortix/kernel/ioctx.h>
#include "zero.h"
namespace Sortix {
Zero::Zero(dev_t dev, ino_t ino, uid_t owner, gid_t group, mode_t mode)
{
inode_type = INODE_TYPE_STREAM;
if ( !dev )
dev = (dev_t) this;
if ( !ino )
ino = (ino_t) this;
this->type = S_IFCHR;
this->stat_uid = owner;
this->stat_gid = group;
this->stat_mode = (mode & S_SETABLE) | this->type;
this->stat_size = 0;
this->dev = dev;
this->ino = ino;
}
Zero::~Zero()
{
}
ssize_t Zero::read(ioctx_t* ctx, uint8_t* buf, size_t count)
{
if ( !ctx->zero_dest(buf, count) )
return -1;
return (ssize_t) count;
}
ssize_t Zero::pread(ioctx_t* ctx, uint8_t* buf, size_t count, off_t /*off*/)
{
return read(ctx, buf, count);
}
ssize_t Zero::write(ioctx_t* /*ctx*/, const uint8_t* /*buf*/, size_t count)
{
return count;
}
ssize_t Zero::pwrite(ioctx_t* /*ctx*/, const uint8_t* /*buf*/, size_t count,
off_t /*off*/)
{
return count;
}
} // namespace Sortix