DeviceFile.cxx

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#include "DeviceFile.hxx"
 
#include <fcntl.h>
 
int DeviceFile::open(File* file, const char *path, int flags, int mode)
{
    if (flags & O_APPEND || flags & O_TRUNC)
    {
        return -EINVAL;
    }
 
    if ((flags & O_CREAT) && (flags & O_EXCL))
    {
        return -EEXIST;
    }
 
    file->offset = 0;
 
    return Node::open(file, path, flags, mode);
}
 
ssize_t DeviceFile::read(File *file, void *buf, size_t count)
{
    ssize_t result = 0;
 
    if ((file->flags & O_ACCMODE) == O_WRONLY)
    {
        return -EBADF;
    }
 
    lock_.lock();
    if (count > 0)
    {
        /* if there is anything left to read */
        result = read(file->offset, buf, count);
        if (result > 0)
        {
            file->offset += result;
        }
    }
    lock_.unlock();
 
    return result;
}
 
ssize_t DeviceFile::write(File *file, const void *buf, size_t count)
{
    ssize_t result = 0;
 
    if ((file->flags & O_ACCMODE) == O_RDONLY)
    {
        return -EBADF;
    }
 
    lock_.lock();
    if (count > 0)
    {
        /* if there is anything left to write */
        result = write(file->offset, buf, count);
        if (result > 0)
        {
            file->offset += result;
        }
    }
    lock_.unlock();
 
    return result;
}