Function peek_input_until_with_options 

pub fn peek_input_until_with_options<R, O, P>(
    reader: &mut R,
    buffer: &mut [u8],
    offset: usize,
    timeout: Option<Duration>,
    max_attempts: Option<NonZero<usize>>,
    predicate: P,
) -> impl Future<Output = PeekOutput<O>>
where
    R: AsyncRead + Unpin,
    P: Fn(&[u8]) -> Option<O>,

Available on crate feature std only.

Same as peek_input_until but with explicit control over the starting offset and the read-attempt budget. The predicate is evaluated against the prefilled prefix before reading.

max_attempts:

• Some(n) — stop after n read attempts even if the predicate did not match.
• None — no attempt cap; rely on the reader’s EOF and the optional timeout.

The default budget used by peek_input_until and peek_input_until_with_offset is derived from the buffer length (max(buffer.len() / 4, 1) + 1), which is a reasonable fallback for sizable buffers but can be too tight for small protocol- sniffing buffers under TCP fragmentation. Prefer this function with an explicit budget when reading from untrusted/proxied peers.

This is an Option-predicate wrapper over peek_input_until_verdict_with_options: Some maps to PeekVerdict::Match and None to PeekVerdict::NeedMore (it never rejects). Use the verdict variant directly when you want fail-fast rejection.