Struct SniffWindow 

pub struct SniffWindow<'a> { /* private fields */ }

A bounded window of bytes handed to a prober. Holds a prefix of the source (the head) plus the absolute base offset that prefix starts at, so a prober reads magic without an unbounded scan and without touching the source directly. It also carries the source’s total_len and a tail window (the last N bytes), so a prober can match a trailer signature — e.g. the DMG koly footer at total_len - 512 — that the head window never reaches.

Implementations

impl<'a> SniffWindow<'a>

pub fn new(base: u64, bytes: &'a [u8]) -> Self

A head-only window of bytes that begins at absolute base in the source. total_len is inferred as base + bytes.len() and the tail is empty — existing head-magic probers are unaffected.

pub fn with_tail( base: u64, bytes: &'a [u8], total_len: u64, tail: &'a [u8], ) -> Self

A window carrying both a head (bytes at base) and a tail (the last bytes of the source), plus the source’s total_len. tail must end at total_len for the from-end probes to be correct.

pub fn base(&self) -> u64

The absolute offset the window starts at.

pub fn bytes(&self) -> &[u8]

The window (head) bytes.

pub fn total_len(&self) -> u64

The total length of the source this window was sniffed from.

pub fn at(&self, off: usize, n: usize) -> Option<&[u8]>

The n bytes at window-relative off, or None if out of range. Never panics — the panic-free way to test a magic.

pub fn has_magic(&self, off: usize, magic: &[u8]) -> bool

True when the window has magic at window-relative off.

pub fn tail_at(&self, from_end: usize, n: usize) -> Option<&[u8]>

The n bytes of the tail beginning from_end bytes before the source’s end, or None when the tail is too short. Never panics.

pub fn has_magic_from_end(&self, from_end: usize, magic: &[u8]) -> bool

True when the tail carries magic starting from_end bytes before the source’s end (e.g. has_magic_from_end(512, b"koly") for a DMG footer). False if the tail is too short — the panic-free trailer probe.