/*
 * Copyright 2009-2010, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Distributed under the terms of the MIT License.
 */


#include <FileDescriptorIO.h>

#include <errno.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>


BFileDescriptorIO::BFileDescriptorIO(int fd, bool takeOverOwnership)
        :
        fFD(fd),
        fOwnsFD(takeOverOwnership)
{
}


BFileDescriptorIO::~BFileDescriptorIO()
{
        if (fOwnsFD)
                close(fFD);
}


ssize_t
BFileDescriptorIO::Read(void* buffer, size_t size)
{
        ssize_t bytesRead = read(fFD, buffer, size);
        return bytesRead >= 0 ? bytesRead : errno;
}


ssize_t
BFileDescriptorIO::Write(const void* buffer, size_t size)
{
        ssize_t bytesWritten = write(fFD, buffer, size);
        return bytesWritten >= 0 ? bytesWritten : errno;
}


ssize_t
BFileDescriptorIO::ReadAt(off_t position, void* buffer, size_t size)
{
        ssize_t bytesRead = pread(fFD, buffer, size, position);
        return bytesRead >= 0 ? bytesRead : errno;
}


ssize_t
BFileDescriptorIO::WriteAt(off_t position, const void* buffer, size_t size)
{
        ssize_t bytesWritten = pwrite(fFD, buffer, size, position);
        return bytesWritten >= 0 ? bytesWritten : errno;
}


off_t
BFileDescriptorIO::Seek(off_t position, uint32 seekMode)
{
        off_t result = lseek(fFD, position, seekMode);
        return result >= 0 ? result : errno;
}


off_t
BFileDescriptorIO::Position() const
{
        off_t result = lseek(fFD, 0, SEEK_CUR);
        return result >= 0 ? result : errno;
}


status_t
BFileDescriptorIO::SetSize(off_t size)
{
        return ftruncate(fFD, size) == 0 ? B_OK : errno;
}


status_t
BFileDescriptorIO::GetSize(off_t* size) const
{
        struct stat st;
        if (fstat(fFD, &st) < 0)
                return errno;

        *size = st.st_size;
        return B_OK;
}