implement first draft of a file_descriptor_table and open_file_description

3 files changed, 71 insertions, 0 deletions

diff --git a/kernel/filesystem/include/filesystem/file.hpp b/kernel/filesystem/include/filesystem/file.hpp
new file mode 100644
index 0000000..e7e1b12
--- /dev/null
+++ b/kernel/filesystem/include/filesystem/file.hpp
@@ -0,0 +1,19 @@
+#ifndef TEACH_OS_KERNEL_FILESYSTEM_FILE_HPP
+#define TEACH_OS_KERNEL_FILESYSTEM_FILE_HPP
+
+#include <cstddef>
+
+namespace filesystem
+{
+  struct file
+  {
+    virtual ~file() = default;
+
+    virtual auto open() -> void = 0;
+
+    virtual auto read(void * buffer, size_t offset, size_t size) const -> size_t = 0;
+    virtual auto write(void const * buffer, size_t offset, size_t size) -> size_t = 0;
+  };
+}  // namespace filesystem
+
+#endif
\ No newline at end of file
diff --git a/kernel/filesystem/include/filesystem/file_descriptor_table.hpp b/kernel/filesystem/include/filesystem/file_descriptor_table.hpp
new file mode 100644
index 0000000..a865d32
--- /dev/null
+++ b/kernel/filesystem/include/filesystem/file_descriptor_table.hpp
@@ -0,0 +1,28 @@
+#ifndef TEACH_OS_KERNEL_FILESYSTEM_FILE_DESCRIPTOR_TABLE_HPP
+#define TEACH_OS_KERNEL_FILESYSTEM_FILE_DESCRIPTOR_TABLE_HPP
+
+#include "open_file_description.hpp"
+
+#include <array>
+
+namespace filesystem
+{
+  struct file_descriptor_table
+  {
+    auto static init() -> void;
+    auto static get() -> file_descriptor_table &;
+
+    ~file_descriptor_table() = default;
+
+    auto add_file(open_file_description & f) -> int;
+    auto get_file(int fd) -> open_file_description &;
+    auto remove_file(int fd) -> void;
+
+  private:
+    file_descriptor_table() = default;
+
+    std::array<open_file_description *, 32> m_open_files{};  // TODO BA-FS26 use kstd::vector when available
+  };
+}  // namespace filesystem
+
+#endif
\ No newline at end of file
diff --git a/kernel/filesystem/include/filesystem/open_file_description.hpp b/kernel/filesystem/include/filesystem/open_file_description.hpp
new file mode 100644
index 0000000..e4febbd
--- /dev/null
+++ b/kernel/filesystem/include/filesystem/open_file_description.hpp
@@ -0,0 +1,24 @@
+#ifndef TEACH_OS_KERNEL_FILESYSTEM_OPEN_FILE_DESCRIPTION_HPP
+#define TEACH_OS_KERNEL_FILESYSTEM_OPEN_FILE_DESCRIPTION_HPP
+
+#include "file.hpp"
+
+#include <cstddef>
+
+namespace filesystem
+{
+  struct open_file_description
+  {
+    ~open_file_description() = default;
+
+    auto read(void * buffer, size_t size) -> size_t;
+    auto write(void const * buffer, size_t size) -> size_t;
+
+  private:
+    file * m_file{};
+    size_t m_offset{0};
+  };
+
+}  // namespace filesystem
+
+#endif
\ No newline at end of file