ramfs::RamFs::RamFsFileOps Class Reference

File 操作实现类 More...

#include <ramfs.hpp>

Inheritance diagram for ramfs::RamFs::RamFsFileOps:

Collaboration diagram for ramfs::RamFs::RamFsFileOps:

Public Member Functions
	RamFsFileOps (RamFs *fs)
auto	Read (vfs::File *file, void *buf, size_t count) -> Expected< size_t > override
	从文件读取数据
auto	Write (vfs::File *file, const void *buf, size_t count) -> Expected< size_t > override
	向文件写入数据
auto	Seek (vfs::File *file, int64_t offset, vfs::SeekWhence whence) -> Expected< uint64_t > override
	调整文件偏移量
auto	Close (vfs::File *file) -> Expected< void > override
	关闭文件
auto	ReadDir (vfs::File *file, vfs::DirEntry *dirent, size_t count) -> Expected< size_t > override
	读取目录项
Public Member Functions inherited from vfs::FileOps
	FileOps ()=default
	FileOps (const FileOps &)=delete
	FileOps (FileOps &&)=delete
auto	operator= (const FileOps &) -> FileOps &=delete
auto	operator= (FileOps &&) -> FileOps &=delete
virtual	~FileOps ()=default

Private Attributes
RamFs *	fs_

Detailed Description

File 操作实现类

Definition at line 108 of file ramfs.hpp.

Constructor & Destructor Documentation

RamFsFileOps()

ramfs::RamFs::RamFsFileOps::RamFsFileOps ( RamFs *  fs )

inlineexplicit

Definition at line 110 of file ramfs.hpp.

: fs_(fs) {}

Member Function Documentation

Close()

auto ramfs::RamFs::RamFsFileOps::Close ( vfs::File *  file ) -> Expected< void >

overridevirtual

关闭文件

Parameters

file

文件对象

Returns

Expected<void> 成功或错误

Precondition

file != nullptr

Postcondition

file 对象将被释放

Implements vfs::FileOps.

Definition at line 415 of file ramfs.cpp.

                                                          {
  if (file == nullptr) {
    return std::unexpected(Error(ErrorCode::kInvalidArgument));
  }
 
  // ramfs 没有特殊的关闭操作
  // File 对象由调用者释放
  return {};
}

Read()

auto ramfs::RamFs::RamFsFileOps::Read ( vfs::File *  file, void *  buf, size_t  count  ) -> Expected< size_t >

overridevirtual

从文件读取数据

Parameters

file	文件对象
buf	输出缓冲区
count	最大读取字节数

Returns

Expected<size_t> 实际读取的字节数或错误

Precondition

file != nullptr && buf != nullptr

Postcondition

返回值 <= count

Implements vfs::FileOps.

Definition at line 299 of file ramfs.cpp.

                        {
  if (file == nullptr || buf == nullptr) {
    return std::unexpected(Error(ErrorCode::kInvalidArgument));
  }
 
  if (file->inode == nullptr) {
    return std::unexpected(Error(ErrorCode::kFsCorrupted));
  }
 
  if (file->inode->type != FileType::kRegular) {
    return std::unexpected(Error(ErrorCode::kFsIsADirectory));
  }
 
  RamInode* ram_inode = static_cast<RamInode*>(file->inode->fs_private);
 
  // 计算可读字节数
  if (file->offset >= file->inode->size) {
    return 0;  // EOF
  }
 
  size_t available = file->inode->size - file->offset;
  size_t to_read = (count < available) ? count : available;
 
  if (to_read == 0) {
    return 0;
  }
 
  // 复制数据
  memcpy(buf, static_cast<uint8_t*>(ram_inode->data) + file->offset, to_read);
 
  file->offset += to_read;
  return to_read;
}

ReadDir()

auto ramfs::RamFs::RamFsFileOps::ReadDir ( vfs::File *  file, vfs::DirEntry *  dirent, size_t  count  ) -> Expected< size_t >

overridevirtual

读取目录项

Parameters

file	目录文件对象
dirent	输出目录项数组
count	最多读取的条目数

Returns

Expected<size_t> 实际读取的条目数或错误

Precondition

file != nullptr && file->inode->type == FileType::kDirectory

dirent != nullptr

Implements vfs::FileOps.

Definition at line 425 of file ramfs.cpp.

                        {
  if (file == nullptr || dirent == nullptr) {
    return std::unexpected(Error(ErrorCode::kInvalidArgument));
  }
 
  if (file->inode == nullptr || file->inode->type != FileType::kDirectory) {
    return std::unexpected(Error(ErrorCode::kFsNotADirectory));
  }
 
  RamInode* ram_dir = static_cast<RamInode*>(file->inode->fs_private);
 
  RamDirEntry* entries = static_cast<RamDirEntry*>(ram_dir->data);
 
  size_t read_count = 0;
  size_t offset = file->offset;
 
  // 添加 . 和 .. 条目
  if (offset == 0 && read_count < count) {
    dirent[read_count].ino = file->inode->ino;
    dirent[read_count].type = static_cast<uint8_t>(FileType::kDirectory);
    strncpy(dirent[read_count].name, ".", sizeof(dirent[read_count].name));
    ++read_count;
    ++offset;
  }
 
  if (offset == 1 && read_count < count) {
    Inode* parent_inode =
        (file->dentry != nullptr && file->dentry->parent != nullptr)
            ? file->dentry->parent->inode
            : file->inode;
    dirent[read_count].ino = parent_inode->ino;
    dirent[read_count].type = static_cast<uint8_t>(FileType::kDirectory);
    strncpy(dirent[read_count].name, "..", sizeof(dirent[read_count].name));
    ++read_count;
    ++offset;
  }
 
  // 读取实际目录项（跳过 . 和 .. 的偏移）
  size_t entry_idx = (offset > 2) ? offset - 2 : 0;
  while (read_count < count && entry_idx < ram_dir->child_count) {
    dirent[read_count].ino = entries[entry_idx].inode->ino;
    dirent[read_count].type =
        static_cast<uint8_t>(entries[entry_idx].inode->type);
    strncpy(dirent[read_count].name, entries[entry_idx].name,
            sizeof(dirent[read_count].name));
    ++read_count;
    ++entry_idx;
  }
 
  file->offset = offset + read_count;
  return read_count;
}

Seek()

auto ramfs::RamFs::RamFsFileOps::Seek ( vfs::File *  file, int64_t  offset, vfs::SeekWhence  whence  ) -> Expected< uint64_t >

overridevirtual

调整文件偏移量

Parameters

file	文件对象
offset	偏移量
whence	基准位置

Returns

Expected<uint64_t> 新的偏移量或错误

Precondition

file != nullptr

Implements vfs::FileOps.

Definition at line 372 of file ramfs.cpp.

                          {
  if (file == nullptr) {
    return std::unexpected(Error(ErrorCode::kInvalidArgument));
  }
 
  uint64_t new_offset = 0;
 
  switch (whence) {
    case SeekWhence::kSet:
      if (offset < 0) {
        return std::unexpected(Error(ErrorCode::kInvalidArgument));
      }
      new_offset = static_cast<uint64_t>(offset);
      break;
 
    case SeekWhence::kCur:
      if (offset < 0 && static_cast<uint64_t>(-offset) > file->offset) {
        return std::unexpected(Error(ErrorCode::kInvalidArgument));
      }
      new_offset =
          static_cast<uint64_t>(static_cast<int64_t>(file->offset) + offset);
      break;
 
    case SeekWhence::kEnd:
      if (file->inode == nullptr) {
        return std::unexpected(Error(ErrorCode::kFsCorrupted));
      }
      if (offset < 0 && static_cast<uint64_t>(-offset) > file->inode->size) {
        return std::unexpected(Error(ErrorCode::kInvalidArgument));
      }
      new_offset = static_cast<uint64_t>(
          static_cast<int64_t>(file->inode->size) + offset);
      break;
 
    default:
      return std::unexpected(Error(ErrorCode::kInvalidArgument));
  }
 
  file->offset = new_offset;
  return new_offset;
}

Write()

auto ramfs::RamFs::RamFsFileOps::Write ( vfs::File *  file, const void *  buf, size_t  count  ) -> Expected< size_t >

overridevirtual

向文件写入数据

Parameters

file	文件对象
buf	输入缓冲区
count	要写入的字节数

Returns

Expected<size_t> 实际写入的字节数或错误

Precondition

file != nullptr && buf != nullptr

Postcondition

返回值 <= count

Implements vfs::FileOps.

Definition at line 334 of file ramfs.cpp.

                        {
  if (file == nullptr || buf == nullptr) {
    return std::unexpected(Error(ErrorCode::kInvalidArgument));
  }
 
  if (file->inode == nullptr) {
    return std::unexpected(Error(ErrorCode::kFsCorrupted));
  }
 
  if (file->inode->type != FileType::kRegular) {
    return std::unexpected(Error(ErrorCode::kFsIsADirectory));
  }
 
  RamInode* ram_inode = static_cast<RamInode*>(file->inode->fs_private);
 
  // 检查是否需要扩展文件
  size_t new_size = file->offset + count;
  if (new_size > ram_inode->capacity) {
    auto expand_result = fs_->ExpandFile(ram_inode, new_size);
    if (!expand_result.has_value()) {
      return std::unexpected(expand_result.error());
    }
  }
 
  // 写入数据
  memcpy(static_cast<uint8_t*>(ram_inode->data) + file->offset, buf, count);
 
  file->offset += count;
 
  // 更新文件大小
  if (file->offset > file->inode->size) {
    file->inode->size = file->offset;
  }
 
  return count;
}

Member Data Documentation

fs_

RamFs* ramfs::RamFs::RamFsFileOps::fs_

private

Definition at line 122 of file ramfs.hpp.

---

The documentation for this class was generated from the following files:

• /workspaces/SimpleKernel/src/filesystem/ramfs/include/ramfs.hpp
• /workspaces/SimpleKernel/src/filesystem/ramfs/ramfs.cpp