Struct CrushHeader 

#[repr(C)]
pub struct CrushHeader {
    pub magic: [u8; 4],
    pub original_size: u64,
    pub flags: u8,
    pub reserved: [u8; 3],
}

Crush compressed file header (16 bytes, little-endian)

Format:

Offset | Size | Field
-------|------|-------
0      | 4    | magic_number ([u8; 4])
4      | 8    | original_size (u64, little-endian)
12     | 1    | flags (u8)
13     | 3    | reserved (padding to 16 bytes)

Flags byte (bit fields):

• Bit 0: Has CRC32 (if set, CRC32 follows header)
• Bit 1: Has metadata (if set, variable-length metadata follows header)
• Bits 2-7: Reserved for future use

Fields

magic: [u8; 4]

Magic number identifying the compression plugin

original_size: u64

Original uncompressed size in bytes

flags: u8

Feature flags (see struct documentation)

reserved: [u8; 3]

Reserved bytes for future extensions (must be zero)

Implementations

impl CrushHeader

pub const SIZE: usize = 16

Size of the header in bytes (fixed at 16 bytes)

pub const MAGIC_PREFIX: [u8; 2]

Crush file format identifier prefix (“CR” = 0x43 0x52)

pub const VERSION: u8 = 0x01

Crush format version (V1 = 0x01)

pub fn new(magic: [u8; 4], original_size: u64) -> Self

Create a new header with the given plugin magic number and original size

pub fn with_crc32(self) -> Self

Create a header with CRC32 flag set

pub fn with_metadata(self) -> Self

Create a header with metadata flag set

pub fn has_valid_prefix(&self) -> bool

Check if this header has a valid Crush magic number prefix

pub fn has_valid_version(&self) -> bool

Check if this header has a valid Crush format version

pub fn plugin_id(&self) -> u8

Get the plugin ID from the magic number (4th byte)

pub fn has_crc32(&self) -> bool

Check if CRC32 flag is set

pub fn has_metadata(&self) -> bool

Check if metadata flag is set

pub fn to_bytes(&self) -> [u8; 16]

Serialize header to bytes (little-endian)

pub fn from_bytes(bytes: &[u8; 16]) -> Result<Self>

Deserialize header from bytes

Errors

Returns an error if:

• The magic number prefix is not valid (not “CR”)
• The version byte is unsupported

pub fn write_to<W: Write>(&self, writer: &mut W) -> Result<()>

Write header to a writer

Errors

Returns an error if the write operation fails

pub fn read_from<R: Read>(reader: &mut R) -> Result<Self>

Read header from a reader

Errors

Returns an error if:

• The read operation fails
• The header validation fails (invalid magic or version)

Trait Implementations

impl Clone for CrushHeader

fn clone(&self) -> CrushHeader

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CrushHeader

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

Formats the value using the given formatter.

impl PartialEq for CrushHeader

fn eq(&self, other: &CrushHeader) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for CrushHeader

impl Eq for CrushHeader

impl StructuralPartialEq for CrushHeader