Kernel: Rename FileDescriptor to FileDescription.

After reading a bunch of POSIX specs, I've learned that a file descriptor
is the number that refers to a file description, not the description itself.
So this patch renames FileDescriptor to FileDescription, and Process now has
FileDescription* file_description(int fd).

1 files changed, 125 insertions, 0 deletions

diff --git a/Kernel/FileSystem/FileDescription.h b/Kernel/FileSystem/FileDescription.h
new file mode 100644
index 0000000000..7c1d1ef4bb
--- /dev/null
+++ b/Kernel/FileSystem/FileDescription.h
@@ -0,0 +1,125 @@
+#pragma once
+
+#include <AK/Badge.h>
+#include <AK/ByteBuffer.h>
+#include <AK/CircularQueue.h>
+#include <AK/Retainable.h>
+#include <Kernel/FileSystem/FIFO.h>
+#include <Kernel/FileSystem/Inode.h>
+#include <Kernel/FileSystem/InodeMetadata.h>
+#include <Kernel/FileSystem/VirtualFileSystem.h>
+#include <Kernel/LinearAddress.h>
+#include <Kernel/Net/Socket.h>
+
+class File;
+class TTY;
+class MasterPTY;
+class Process;
+class Region;
+class CharacterDevice;
+class SharedMemory;
+
+class FileDescription : public Retainable<FileDescription> {
+public:
+    static Retained<FileDescription> create(RetainPtr<Custody>&&);
+    static Retained<FileDescription> create(RetainPtr<File>&&, SocketRole = SocketRole::None);
+    ~FileDescription();
+
+    Retained<FileDescription> clone();
+
+    int close();
+
+    off_t seek(off_t, int whence);
+    ssize_t read(byte*, ssize_t);
+    ssize_t write(const byte* data, ssize_t);
+    KResult fstat(stat&);
+
+    KResult fchmod(mode_t);
+
+    bool can_read();
+    bool can_write();
+
+    ssize_t get_dir_entries(byte* buffer, ssize_t);
+
+    ByteBuffer read_entire_file();
+
+    String absolute_path() const;
+
+    bool is_directory() const;
+
+    File& file() { return *m_file; }
+    const File& file() const { return *m_file; }
+
+    bool is_device() const;
+
+    bool is_tty() const;
+    const TTY* tty() const;
+    TTY* tty();
+
+    bool is_master_pty() const;
+    const MasterPTY* master_pty() const;
+    MasterPTY* master_pty();
+
+    InodeMetadata metadata() const;
+    Inode* inode() { return m_inode.ptr(); }
+    const Inode* inode() const { return m_inode.ptr(); }
+
+    Custody* custody() { return m_custody.ptr(); }
+    const Custody* custody() const { return m_custody.ptr(); }
+
+    KResultOr<Region*> mmap(Process&, LinearAddress, size_t offset, size_t, int prot);
+
+    bool is_blocking() const { return m_is_blocking; }
+    void set_blocking(bool b) { m_is_blocking = b; }
+    bool should_append() const { return m_should_append; }
+    void set_should_append(bool s) { m_should_append = s; }
+
+    dword file_flags() const { return m_file_flags; }
+    void set_file_flags(dword);
+
+    bool is_socket() const;
+    Socket* socket();
+    const Socket* socket() const;
+
+    bool is_fifo() const;
+    FIFO* fifo();
+    FIFO::Direction fifo_direction() { return m_fifo_direction; }
+    void set_fifo_direction(Badge<FIFO>, FIFO::Direction direction) { m_fifo_direction = direction; }
+
+    bool is_shared_memory() const;
+    SharedMemory* shared_memory();
+    const SharedMemory* shared_memory() const;
+
+    ByteBuffer& generator_cache() { return m_generator_cache; }
+
+    void set_original_inode(Badge<VFS>, Retained<Inode>&& inode) { m_inode = move(inode); }
+
+    SocketRole socket_role() const { return m_socket_role; }
+    void set_socket_role(SocketRole);
+
+    KResult truncate(off_t);
+
+    off_t offset() const { return m_current_offset; }
+
+    KResult chown(uid_t, gid_t);
+
+private:
+    friend class VFS;
+    FileDescription(RetainPtr<File>&&, SocketRole = SocketRole::None);
+    FileDescription(FIFO&, FIFO::Direction);
+
+    RetainPtr<Custody> m_custody;
+    RetainPtr<Inode> m_inode;
+    RetainPtr<File> m_file;
+
+    off_t m_current_offset { 0 };
+
+    ByteBuffer m_generator_cache;
+
+    dword m_file_flags { 0 };
+
+    bool m_is_blocking { true };
+    bool m_should_append { false };
+    SocketRole m_socket_role { SocketRole::None };
+    FIFO::Direction m_fifo_direction { FIFO::Direction::Neither };
+};