Luna/kernel/src/fs/FileDescriptor.cpp

#include "fs/FileDescriptor.h"
#include "errno.h"

Descriptor::Descriptor() : m_is_open(false)
{
}

Descriptor::Descriptor(const Descriptor& other)
    : m_is_open(other.m_is_open), m_can_read(other.m_can_read), m_can_write(other.m_can_write), m_node(other.m_node),
      m_offset(other.m_offset)
{
}

void Descriptor::open(VFS::Node* node, bool can_read, bool can_write)
{
    m_can_read = can_read;
    m_can_write = can_write;
    m_node = node;
    m_offset = 0;
    m_is_open = true;
}

ssize_t Descriptor::read(size_t size, char* buffer)
{
    ssize_t result = VFS::read(m_node, m_offset, size, buffer);
    m_offset += result;
    return result;
}

ssize_t Descriptor::write(size_t size, const char* buffer)
{
    ssize_t result = VFS::write(m_node, m_offset, size, buffer);
    m_offset += result;
    return result;
}

int Descriptor::seek(long offset)
{
    if (m_node->type != VFS_DEVICE && (uint64_t)offset > m_node->length)
        return -EINVAL; // FIXME: Support seeking beyond the current file's length.
    m_offset = (uint64_t)offset;
    return 0;
}