mirror of
https://github.com/DragonOS-Community/DragonOS.git
synced 2025-06-11 04:56:48 +00:00
376 lines
12 KiB
Rust
376 lines
12 KiB
Rust
use core::mem::MaybeUninit;
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use alloc::{boxed::Box, string::String, sync::Arc, vec::Vec};
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use crate::{
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arch::asm::current::current_pcb,
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driver::tty::TtyFilePrivateData,
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filesystem::procfs::ProcfsFilePrivateData,
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include::bindings::bindings::{
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process_control_block,
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},
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io::SeekFrom,
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kerror, syscall::SystemError,
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};
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use super::{Dirent, FileType, IndexNode, Metadata};
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/// 文件私有信息的枚举类型
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#[derive(Debug, Clone)]
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pub enum FilePrivateData {
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/// procfs文件私有信息
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Procfs(ProcfsFilePrivateData),
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/// Tty设备的私有信息
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Tty(TtyFilePrivateData),
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/// 不需要文件私有信息
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Unused,
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}
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impl Default for FilePrivateData {
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fn default() -> Self {
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return Self::Unused;
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}
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}
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bitflags! {
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/// @brief 文件打开模式
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/// 其中，低2bit组合而成的数字的值，用于表示访问权限。其他的bit，才支持通过按位或的方式来表示参数
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///
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/// 与Linux 5.19.10的uapi/asm-generic/fcntl.h相同
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/// https://opengrok.ringotek.cn/xref/linux-5.19.10/tools/include/uapi/asm-generic/fcntl.h#19
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pub struct FileMode: u32{
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/* File access modes for `open' and `fcntl'. */
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/// Open Read-only
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const O_RDONLY = 0o0;
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/// Open Write-only
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const O_WRONLY = 0o1;
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/// Open read/write
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const O_RDWR = 0o2;
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/// Mask for file access modes
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const O_ACCMODE = 0o00000003;
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/* Bits OR'd into the second argument to open. */
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/// Create file if it does not exist
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const O_CREAT = 0o00000100;
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/// Fail if file already exists
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const O_EXCL = 0o00000200;
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/// Do not assign controlling terminal
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const O_NOCTTY = 0o00000400;
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/// 文件存在且是普通文件，并以O_RDWR或O_WRONLY打开，则它会被清空
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const O_TRUNC = 0o00001000;
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/// 文件指针会被移动到文件末尾
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const O_APPEND = 0o00002000;
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/// 非阻塞式IO模式
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const O_NONBLOCK = 0o00004000;
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/// 每次write都等待物理I/O完成，但是如果写操作不影响读取刚写入的数据，则不等待文件属性更新
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const O_DSYNC = 0o00010000;
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/// fcntl, for BSD compatibility
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const FASYNC = 0o00020000;
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/* direct disk access hint */
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const O_DIRECT = 0o00040000;
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const O_LARGEFILE = 0o00100000;
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/// 打开的必须是一个目录
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const O_DIRECTORY = 0o00200000;
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/// Do not follow symbolic links
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const O_NOFOLLOW = 0o00400000;
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const O_NOATIME = 0o01000000;
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/// set close_on_exec
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const O_CLOEXEC = 0o02000000;
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/// 每次write都等到物理I/O完成，包括write引起的文件属性的更新
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const O_SYNC = 0o04000000;
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}
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}
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impl FileMode {
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/// @brief 获取文件的访问模式的值
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#[inline]
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pub fn accmode(&self) -> u32 {
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return self.bits() & FileMode::O_ACCMODE.bits();
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}
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}
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/// @brief 抽象文件结构体
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#[derive(Debug)]
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pub struct File {
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inode: Arc<dyn IndexNode>,
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/// 对于文件，表示字节偏移量；对于文件夹，表示当前操作的子目录项偏移量
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offset: usize,
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/// 文件的打开模式
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mode: FileMode,
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/// 文件类型
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file_type: FileType,
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/// readdir时候用的，暂存的本次循环中，所有子目录项的名字的数组
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readdir_subdirs_name: Vec<String>,
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pub private_data: FilePrivateData,
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}
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impl File {
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/// @brief 创建一个新的文件对象
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///
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/// @param inode 文件对象对应的inode
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/// @param mode 文件的打开模式
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pub fn new(inode: Arc<dyn IndexNode>, mode: FileMode) -> Result<Self, SystemError> {
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let file_type: FileType = inode.metadata()?.file_type;
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let mut f = File {
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inode,
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offset: 0,
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mode,
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file_type,
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readdir_subdirs_name: Vec::new(),
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private_data: FilePrivateData::default(),
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};
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// kdebug!("inode:{:?}",f.inode);
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f.inode.open(&mut f.private_data, &mode)?;
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return Ok(f);
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}
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/// @brief 从文件中读取指定的字节数到buffer中
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///
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/// @param len 要读取的字节数
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/// @param buf 目标buffer
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///
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/// @return Ok(usize) 成功读取的字节数
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/// @return Err(SystemError) 错误码
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pub fn read(&mut self, len: usize, buf: &mut [u8]) -> Result<usize, SystemError> {
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// 先检查本文件在权限等规则下，是否可读取。
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self.readable()?;
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if buf.len() < len {
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return Err(SystemError::ENOBUFS);
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}
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let len = self
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.inode
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.read_at(self.offset, len, buf, &mut self.private_data)?;
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self.offset += len;
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return Ok(len);
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}
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/// @brief 从buffer向文件写入指定的字节数的数据
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///
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/// @param len 要写入的字节数
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/// @param buf 源数据buffer
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///
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/// @return Ok(usize) 成功写入的字节数
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/// @return Err(SystemError) 错误码
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pub fn write(&mut self, len: usize, buf: &[u8]) -> Result<usize, SystemError> {
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// 先检查本文件在权限等规则下，是否可写入。
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self.writeable()?;
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if buf.len() < len {
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return Err(SystemError::ENOBUFS);
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}
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let len = self
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.inode
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.write_at(self.offset, len, buf, &mut self.private_data)?;
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self.offset += len;
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return Ok(len);
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}
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/// @brief 获取文件的元数据
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pub fn metadata(&self) -> Result<Metadata, SystemError> {
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return self.inode.metadata();
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}
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/// @brief 根据inode号获取子目录项的名字
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pub fn get_entry_name(&self, ino: usize) -> Result<String, SystemError> {
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return self.inode.get_entry_name(ino);
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}
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/// @brief 调整文件操作指针的位置
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///
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/// @param origin 调整的起始位置
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pub fn lseek(&mut self, origin: SeekFrom) -> Result<usize, SystemError> {
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if self.inode.metadata().unwrap().file_type == FileType::Pipe {
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return Err(SystemError::ESPIPE);
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}
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let pos: i64;
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match origin {
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SeekFrom::SeekSet(offset) => {
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pos = offset;
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}
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SeekFrom::SeekCurrent(offset) => {
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pos = self.offset as i64 + offset;
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}
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SeekFrom::SeekEnd(offset) => {
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let metadata = self.metadata()?;
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pos = metadata.size + offset;
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}
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SeekFrom::Invalid => {
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return Err(SystemError::EINVAL);
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}
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}
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if pos < 0 || pos > self.metadata()?.size {
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return Err(SystemError::EOVERFLOW);
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}
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self.offset = pos as usize;
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return Ok(self.offset);
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}
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/// @brief 判断当前文件是否可读
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#[inline]
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pub fn readable(&self) -> Result<(), SystemError> {
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// 暂时认为只要不是write only, 就可读
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if self.mode == FileMode::O_WRONLY {
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return Err(SystemError::EPERM);
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}
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return Ok(());
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}
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/// @brief 判断当前文件是否可写
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#[inline]
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pub fn writeable(&self) -> Result<(), SystemError> {
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// 暂时认为只要不是read only, 就可写
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if self.mode == FileMode::O_RDONLY {
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return Err(SystemError::EPERM);
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}
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return Ok(());
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}
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/// @biref 充填dirent结构体
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/// @return 返回dirent结构体的大小
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pub fn readdir(&mut self, dirent: &mut Dirent) -> Result<u64, SystemError> {
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let inode: &Arc<dyn IndexNode> = &self.inode;
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// 如果偏移量为0
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if self.offset == 0 {
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self.readdir_subdirs_name = inode.list()?;
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self.readdir_subdirs_name.sort();
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}
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// kdebug!("sub_entries={sub_entries:?}");
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if self.readdir_subdirs_name.is_empty() {
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self.offset = 0;
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return Ok(0);
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}
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let name: String = self.readdir_subdirs_name.remove(0);
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let sub_inode: Arc<dyn IndexNode> = match inode.find(&name) {
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Ok(i) => i,
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Err(e) => {
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kerror!("Readdir error: Failed to find sub inode, file={self:?}");
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return Err(e);
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}
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};
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let name_bytes: &[u8] = name.as_bytes();
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self.offset += 1;
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dirent.d_ino = sub_inode.metadata().unwrap().inode_id as u64;
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dirent.d_off = 0;
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dirent.d_reclen = 0;
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dirent.d_type = sub_inode.metadata().unwrap().file_type.get_file_type_num() as u8;
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// 根据posix的规定，dirent中的d_name是一个不定长的数组，因此需要unsafe来拷贝数据
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unsafe {
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let ptr = &mut dirent.d_name as *mut u8;
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let buf: &mut [u8] =
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::core::slice::from_raw_parts_mut::<'static, u8>(ptr, name_bytes.len());
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buf.copy_from_slice(name_bytes);
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}
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// 计算dirent结构体的大小
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return Ok((name_bytes.len() + ::core::mem::size_of::<Dirent>()
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- ::core::mem::size_of_val(&dirent.d_name)) as u64);
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}
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pub fn inode(&self) -> Arc<dyn IndexNode> {
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return self.inode.clone();
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}
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/// @brief 尝试克隆一个文件
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///
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/// @return Option<Box<File>> 克隆后的文件结构体。如果克隆失败，返回None
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pub fn try_clone(&self) -> Option<Box<File>> {
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let mut res: Box<File> = Box::new(Self {
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inode: self.inode.clone(),
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offset: self.offset.clone(),
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mode: self.mode.clone(),
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file_type: self.file_type.clone(),
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readdir_subdirs_name: self.readdir_subdirs_name.clone(),
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private_data: self.private_data.clone(),
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});
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// 调用inode的open方法，让inode知道有新的文件打开了这个inode
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if self.inode.open(&mut res.private_data, &res.mode).is_err() {
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return None;
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}
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return Some(res);
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}
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}
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impl Drop for File {
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fn drop(&mut self) {
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let r: Result<(), SystemError> = self.inode.close(&mut self.private_data);
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// 打印错误信息
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if r.is_err() {
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kerror!(
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"pid: {} failed to close file: {:?}, errno={:?}",
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current_pcb().pid,
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self,
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r.unwrap_err()
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);
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}
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}
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}
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/// @brief pcb里面的文件描述符数组
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#[derive(Debug)]
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pub struct FileDescriptorVec {
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/// 当前进程打开的文件描述符
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pub fds: [Option<Box<File>>; FileDescriptorVec::PROCESS_MAX_FD],
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}
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impl FileDescriptorVec {
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pub const PROCESS_MAX_FD: usize = 32;
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pub fn new() -> Box<FileDescriptorVec> {
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// 先声明一个未初始化的数组
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let mut data: [MaybeUninit<Option<Box<File>>>; FileDescriptorVec::PROCESS_MAX_FD] =
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unsafe { MaybeUninit::uninit().assume_init() };
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// 逐个把每个元素初始化为None
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for i in 0..FileDescriptorVec::PROCESS_MAX_FD {
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data[i] = MaybeUninit::new(None);
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}
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// 由于一切都初始化完毕，因此将未初始化的类型强制转换为已经初始化的类型
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let data: [Option<Box<File>>; FileDescriptorVec::PROCESS_MAX_FD] = unsafe {
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core::mem::transmute::<_, [Option<Box<File>>; FileDescriptorVec::PROCESS_MAX_FD]>(data)
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};
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// 初始化文件描述符数组结构体
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return Box::new(FileDescriptorVec { fds: data });
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}
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/// @brief 克隆一个文件描述符数组
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///
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/// @return Box<FileDescriptorVec> 克隆后的文件描述符数组
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pub fn clone(&self) -> Box<FileDescriptorVec> {
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let mut res: Box<FileDescriptorVec> = FileDescriptorVec::new();
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for i in 0..FileDescriptorVec::PROCESS_MAX_FD {
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if let Some(file) = &self.fds[i] {
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res.fds[i] = file.try_clone();
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}
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}
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return res;
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}
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/// @brief 从pcb的fds字段，获取文件描述符数组的可变引用
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#[inline]
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pub fn from_pcb(pcb: &'static process_control_block) -> Option<&'static mut FileDescriptorVec> {
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return unsafe { (pcb.fds as usize as *mut FileDescriptorVec).as_mut() };
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}
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/// @brief 判断文件描述符序号是否合法
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///
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/// @return true 合法
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///
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/// @return false 不合法
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#[inline]
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pub fn validate_fd(fd: i32) -> bool {
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if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD {
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return false;
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} else {
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return true;
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}
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}
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}
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