Struct RegularFile 

pub struct RegularFile {
    ffs: Weak<FastFileSystemInner>,
    inode: TrackedInode,
}

A handle to a regular file in the filesystem.

This struct represents a low-level kernel handle to a regular file, associated with a specific TrackedInode and the backing FastFileSystemInner instance.

Fields

ffs: Weak<FastFileSystemInner>

Weak reference to the FastFileSystemInner.

inode: TrackedInode

The inode associated with this file.

Implementations

impl RegularFile

pub fn new(inode: TrackedInode, ffs: Weak<FastFileSystemInner>) -> Option<Self>

Creates a new RegularFile from a given inode and filesystem reference.

Returns None if the provided inode does not represent a regular file.

Parameters

• inode: A tracked reference to the file’s inode.
• ffs: A weak reference to the filesystem context.

Returns

• Some(RegularFile) if the inode is valid and represents a regular file.
• None if the inode is invalid or not a regular file.

Trait Implementations

impl RegularFile for RegularFile

fn ino(&self) -> InodeNumber

Inode number of the file.

fn size(&self) -> usize

Returns the size of the file in bytes.

fn read( &self, fba: FileBlockNumber, buf: &mut [u8; 4096], ) -> Result<bool, KernelError>

Reads data from the file into the provided buffer.

Parameters

• ofs: The FileBlockNumber which to read.
• buf: A mutable array where the file content will be stored.

Returns

• Ok(true): If the read success.
• Ok(false): If the read failed.
• Err(Error): An error occured while the read operation.

fn write( &self, fba: FileBlockNumber, buf: &[u8; 4096], min_size: usize, ) -> Result<(), KernelError>

Writes a 4096-byte data into the specified file block.

This method writes the contents of buf to the file block indicated by fba. If the target block lies beyond the current end of the file, the file may be extended up to new_size bytes to accommodate the write.

However, if the target block lies beyond the current file size and new_size is insufficient to reach it, the write will fail.

Parameters

• fba: The FileBlockNumber indicating the block to write to.
• buf: A buffer containing exactly 4096 bytes of data to write.
• new_size: The desired minimum file size (in bytes) after the write. If this value is less than or equal to the current file size, no growth occurs.

Returns

• Ok(()) if the write is successful.
• Err(KernelError) if the operation fails (e.g., out-of-bounds write, I/O error).

fn writeback(&self) -> Result<(), KernelError>

Write back the file to disk.

fn mmap(&self, fba: FileBlockNumber) -> Result<Page, KernelError>

Maps a file block into memory.