Struct FilesystemWriter 

pub struct FilesystemWriter<'a, 'b, 'c> { /* private fields */ }

Representation of SquashFS filesystem to be written back to an image

• Use Self::from_fs_reader to write with the data from a previous SquashFS image
• Use Self::default to create an empty SquashFS image without an original image. For example:

// Add empty default FilesytemWriter
let mut fs = FilesystemWriter::default();
fs.set_current_time();
fs.set_block_size(DEFAULT_BLOCK_SIZE);
fs.set_only_root_id();
fs.set_kind(Kind::from_const(kind::LE_V4_0).unwrap());

// set root image permissions
let header = NodeHeader {
    permissions: 0o755,
    ..NodeHeader::default()
};
fs.set_root_mode(0o777);

// set extra compression options
let mut xz_extra = ExtraXz::default();
xz_extra.level(9).unwrap();
let extra = CompressionExtra::Xz(xz_extra);
let mut compressor = FilesystemCompressor::new(Compressor::Xz, None).unwrap();
compressor.extra(extra).unwrap();
fs.set_compressor(compressor);

// push some dirs and a file
fs.push_dir("usr", header);
fs.push_dir("usr/bin", header);
fs.push_file(std::io::Cursor::new(vec![0x00, 0x01]), "usr/bin/file", header);

Implementations

impl<'a, 'b, 'c> FilesystemWriter<'a, 'b, 'c>

pub fn set_block_size(&mut self, block_size: u32)

Set block size

Panics

If invalid, must be MIN_BLOCK_SIZE > block_size < MAX_BLOCK_SIZE

pub fn set_time(&mut self, mod_time: u32)

Set time of image as mod_time

Example: Set to Wed Oct 19 01:26:15 2022

let mut fs = FilesystemWriter::default();
fs.set_time(0x634f_5237);

pub fn set_current_time(&mut self)

Set time of image as current time

pub fn set_kind(&mut self, kind: Kind)

Set kind as kind

Example: Set kind to default V4.0

let mut fs = FilesystemWriter::default();
fs.set_kind(Kind::from_const(kind::LE_V4_0).unwrap());

pub fn set_root_mode(&mut self, mode: u16)

Set root mode as mode

Example

 let mut fs = FilesystemWriter::default();
 fs.set_root_mode(0o777);

pub fn set_root_uid(&mut self, uid: u32)

Set root uid as uid

pub fn set_root_gid(&mut self, gid: u32)

Set root gid as gid

pub fn set_compressor(&mut self, compressor: FilesystemCompressor)

Set compressor as compressor

 let mut compressor = FilesystemCompressor::new(Compressor::Xz, None).unwrap();

pub fn set_only_root_id(&mut self)

Set id_table to Id::root, removing old entries

pub fn set_kib_padding(&mut self, pad_kib: u32)

Set padding(zero bytes) added to the end of the image after calling write.

For example, if given pad_kib of 8; a 8K padding will be added to the end of the image.

Default: DEFAULT_PAD_LEN

pub fn set_no_padding(&mut self)

Set no padding(zero bytes) added to the end of the image after calling write.

pub fn set_no_duplicate_files(&mut self, value: bool)

Set if we perform duplicate file checking, on by default

pub fn set_emit_compression_options(&mut self, value: bool)

Set if compression options are written

pub fn from_fs_reader( reader: &'a FilesystemReader<'b>, ) -> Result<Self, BackhandError>

Inherit filesystem structure and properties from reader

pub fn push_file<P>( &mut self, reader: impl Read + 'c, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>,

Insert reader into filesystem with path and metadata header.

The uid and gid in header are added to FilesystemWriters id’s

pub fn mut_file<S>( &mut self, find_path: S, ) -> Option<&mut SquashfsFileWriter<'a, 'b, 'c>>

where S: AsRef<Path>,

Take a mutable reference to existing file at find_path

pub fn replace_file<S>( &mut self, find_path: S, reader: impl Read + 'c, ) -> Result<(), BackhandError>

where S: AsRef<Path>,

Replace an existing file

pub fn push_symlink<P, S>( &mut self, link: S, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>, S: Into<PathBuf>,

Insert symlink path -> link

The uid and gid in header are added to FilesystemWriters id’s

pub fn push_dir<P>( &mut self, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>,

Insert empty dir at path

The uid and gid in header are added to FilesystemWriters id’s

pub fn push_dir_all<P>( &mut self, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>,

Recursively create an empty directory and all of its parent components if they are missing.

The uid and gid in header are added to FilesystemWriters id’s

pub fn push_char_device<P>( &mut self, device_number: u32, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>,

Insert character device with device_number at path

The uid and gid in header are added to FilesystemWriters id’s

pub fn push_block_device<P>( &mut self, device_number: u32, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>,

Insert block device with device_number at path

The uid and gid in header are added to FilesystemWriters id’s

pub fn push_fifo<P>( &mut self, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>,

Insert FIFO (named pipe)

The uid and gid in header are added to FilesystemWriters id’s

pub fn push_socket<P>( &mut self, path: P, header: NodeHeader, ) -> Result<(), BackhandError>

where P: AsRef<Path>,

Insert Socket (UNIX domain socket)

The uid and gid in header are added to FilesystemWriters id’s

pub fn write_with_offset<W>( &mut self, w: W, offset: u64, ) -> Result<(SuperBlock, u64), BackhandError>

where W: Write + Seek,

Same as Self::write, but seek’ing to offset in w before reading. This offset is treated as the base image offset.

pub fn write<W: Write + Seek>( &mut self, w: W, ) -> Result<(SuperBlock, u64), BackhandError>

Generate and write the resulting squashfs image to w

Returns

(written populated SuperBlock, total amount of bytes written including padding)

Trait Implementations

impl<'a, 'b, 'c> Debug for FilesystemWriter<'a, 'b, 'c>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for FilesystemWriter<'_, '_, '_>

fn default() -> Self

Create default FilesystemWriter

block_size: DEFAULT_BLOCK_SIZE, compressor: default XZ compression, no nodes, kind: LE_V4_0, and mod_time: 0.