Struct Header 

pub struct Header { /* private fields */ }

Bundle header containing format metadata.

The header is the first 17 bytes of a .wvb file:

Magic (8)	Version (1)	Index Size (4)	Checksum (4)

• Magic Number: 0xf09f8c90f09f8e81 (🌐🎁 in UTF-8)
• Version: Bundle format version (currently 0x01)
• Index Size: Size of the index section in bytes (u32, big-endian)
• Checksum: xxHash-32 checksum of the header data

Example

use wvb::{Header, Version};

let header = Header::new(Version::V1, 1024);
assert_eq!(header.version(), Version::V1);
assert_eq!(header.index_size(), 1024);

Implementations

impl Header

pub const MAGIC_LEN: usize = 8

Length of the magic number in bytes (8 bytes for “🌐🎁”)

pub const MAGIC: [u8; 8]

Magic number bytes: 0xf09f8c90f09f8e81 (“🌐🎁”)

pub const MAGIC_OFFSET: u64 = 0

Offset of the magic number in the file

pub const VERSION_OFFSET: u64

Offset of the version byte

pub const INDEX_SIZE_OFFSET: u64

Offset of the index size field

pub const INDEX_SIZE_BYTES_LEN: usize = 4

Length of the index size field in bytes

pub const CHECKSUM_OFFSET: u64

Offset of the header checksum

pub const END_OFFSET: u64

Total size of the header in bytes (17 bytes)

pub fn index_end_offset(&self) -> u64

Calculates the byte offset where the index section ends.

This is the starting point of the data section.

pub fn new(version: Version, index_size: u32) -> Self

Creates a new header.

Arguments

• version - Bundle format version
• index_size - Size of the index section in bytes

pub fn version(&self) -> Version

Returns the bundle format version.

pub fn index_size(&self) -> u32

Returns the size of the index section in bytes.

Trait Implementations

impl Clone for Header

fn clone(&self) -> Header

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Header

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

Formats the value using the given formatter.

impl PartialEq for Header

fn eq(&self, other: &Header) -> 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<R: Read + Seek> Reader<Header> for HeaderReader<R>

fn read(&mut self) -> Result<Header, Error>

impl<W: Write> Writer<Header> for HeaderWriter<W>

fn write(&mut self, header: &Header) -> Result<usize, Error>

impl Copy for Header

impl StructuralPartialEq for Header