#[cfg(feature = "alloc")]
#[allow(
unused_imports,
reason = "alloc prelude items; subset used per cfg/feature combination"
)]
use alloc::{format, vec, vec::Vec};
use bytes::Bytes;
use crate::stream::error::ParseError;
use crate::stream::parse::skip_matter;
use super::types::BlindedStateQuadruples;
pub(super) fn parse(
input: &Bytes,
count: u32,
) -> Result<(BlindedStateQuadruples, Bytes), ParseError> {
let mut offset = 0;
for _ in 0..count {
offset += skip_matter(&input[offset..])?;
offset += skip_matter(&input[offset..])?;
offset += skip_matter(&input[offset..])?;
offset += skip_matter(&input[offset..])?;
}
let raw = input.slice(..offset);
let rest = input.slice(offset..);
Ok((BlindedStateQuadruples::new(raw, count), rest))
}
#[cfg(test)]
#[allow(
clippy::unwrap_used,
clippy::expect_used,
clippy::panic,
clippy::as_conversions,
reason = "test code: panics and type conversions acceptable"
)]
mod tests {
use super::*;
use base64::{Engine, engine::general_purpose as b64};
fn build_blake3_256_qb64() -> Vec<u8> {
let raw = [0xCD_u8; 32];
let ps = 1_usize;
let mut padded = vec![0u8; ps];
padded.extend_from_slice(&raw);
let payload_b64 = b64::URL_SAFE_NO_PAD.encode(&padded);
format!("E{}", &payload_b64[ps..]).into_bytes()
}
fn build_tag3_labeler_qb64() -> Vec<u8> {
b"XAAA".to_vec()
}
fn build_one_quadruple() -> Vec<u8> {
let mut input = Vec::new();
input.extend_from_slice(&build_blake3_256_qb64());
input.extend_from_slice(&build_blake3_256_qb64());
input.extend_from_slice(&build_blake3_256_qb64());
input.extend_from_slice(&build_tag3_labeler_qb64());
input
}
#[test]
fn parse_zero_elements() {
let (group, rest) = parse(&Bytes::new(), 0).unwrap();
assert_eq!(group.count(), 0);
assert!(rest.is_empty());
}
#[test]
fn parse_one_quadruple() {
let input = build_one_quadruple();
let (group, rest) = parse(&Bytes::copy_from_slice(&input), 1).unwrap();
assert_eq!(group.count(), 1);
assert!(rest.is_empty());
}
#[test]
fn parse_two_quadruples() {
let mut input = build_one_quadruple();
input.extend_from_slice(&build_one_quadruple());
let (group, rest) = parse(&Bytes::copy_from_slice(&input), 2).unwrap();
assert_eq!(group.count(), 2);
assert!(rest.is_empty());
}
#[test]
fn trailing_bytes_preserved() {
let mut input = build_one_quadruple();
input.extend_from_slice(b"TAIL");
let (group, rest) = parse(&Bytes::copy_from_slice(&input), 1).unwrap();
assert_eq!(group.count(), 1);
assert_eq!(rest, Bytes::from_static(b"TAIL"));
}
#[test]
fn parse_slices_without_copying() {
let input = build_one_quadruple();
let parent = Bytes::copy_from_slice(&input);
let parent_start = parent.as_ptr() as usize;
let parent_end = parent_start + parent.len();
let (group, _rest) = parse(&parent, 1).unwrap();
let raw_ptr = group.raw_bytes().as_ptr() as usize;
assert!(
raw_ptr >= parent_start && raw_ptr < parent_end,
"BlindedStateQuadruples raw must be a slice of the parent buffer, not a copy"
);
}
}