Basic FDs

kernel/include/fs/FileDescriptor.h

@@ -0,0 +1,35 @@
+#pragma once
+#include "fs/VFS.h"
+#include <stdint.h>
+
+struct Descriptor
+{
+    bool is_open()
+    {
+        return m_is_open;
+    }
+
+    bool can_read()
+    {
+        return m_can_read && m_is_open;
+    }
+
+    void close()
+    {
+        m_is_open = false;
+    }
+
+    ssize_t read(size_t size, char* buffer);
+
+    void open(VFS::Node* node, bool can_read);
+
+    Descriptor(const Descriptor& other);
+    Descriptor();
+
+  private:
+    uint64_t m_offset;
+    VFS::Node* m_node;
+    bool m_can_read;
+
+    bool m_is_open;
+}

kernel/src/fs/FileDescriptor.cpp

@@ -0,0 +1,24 @@
+#include "fs/FileDescriptor.h"
+
+Descriptor::Descriptor() : m_is_open(false)
+{
+}
+
+Descriptor::Descriptor(const Descriptor& other)
+    : m_is_open(other.is_open()), m_can_read(other.can_read()), m_node(other.m_node), m_offset(other.m_offset)
+{
+}
+
+void Descriptor::open(VFS::Node* node, bool can_read)
+{
+    m_can_read = can_read;
+    m_node = node;
+    m_offset = 0;
+}
+
+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;
+}