…but really, it's not super nice especially considering the counting of consumed bytes is based on ptr arithmetic.
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| @@ -8,72 +8,51 @@ use crate::{ · 7 unmodified lines | ||
| 8 | 8 | mod decode { |
| 9 | 9 | use crate::bstr::{BStr, ByteSlice}; |
| 10 | 10 | use nom::branch::alt; |
| 11 | − use nom::bytes::complete::{tag, take_till1, take_until1}; | |
| 12 | − use nom::combinator::{all_consuming, map, opt, peek, recognize}; | |
| 11 | + use nom::bytes::complete::{tag, take_till1}; | |
| 12 | + use nom::combinator::all_consuming; | |
| 13 | 13 | use nom::error::ParseError; |
| 14 | − use nom::multi::{fold_many1, length_data}; | |
| 15 | − use nom::sequence::{pair, terminated}; | |
| 14 | + use nom::sequence::pair; | |
| 16 | 15 | use nom::IResult; |
| 16 | + use std::convert::TryInto; | |
| 17 | 17 | |
| 18 | 18 | fn newline<'a, E: ParseError<&'a [u8]>>(i: &'a [u8]) -> IResult<&'a [u8], &'a [u8], E> { |
| 19 | 19 | alt((tag(b"\r\n"), tag(b"\n")))(i) |
| 20 | 20 | } |
| 21 | 21 | |
| 22 | − fn subject<'a, E: ParseError<&'a [u8]>>(i: &'a [u8]) -> IResult<&'a [u8], &'a BStr, E> { | |
| 23 | − map( | |
| 24 | − length_data(peek(fold_many1( | |
| 25 | − recognize(terminated(take_till1(|c| c == b'\n'), tag(b"\n"))), | |
| 26 | − || 0, | |
| 27 | − |acc: usize, item: &'a [u8]| acc + item.len(), | |
| 28 | − ))), | |
| 29 | − |s| s.as_bstr(), | |
| 30 | − )(i) | |
| 31 | − } | |
| 32 | − | |
| 33 | − #[cfg(test)] | |
| 34 | − mod tests { | |
| 35 | − use super::*; | |
| 36 | − | |
| 37 | − #[test] | |
| 38 | − fn subject_ending_in_newline_with_newline() { | |
| 39 | − assert_eq!(subject::<()>(b"a\nb\n").unwrap(), (b"".as_ref(), b"a\nb\nc".as_bstr())); | |
| 40 | − } | |
| 41 | − | |
| 42 | − #[test] | |
| 43 | − fn subject_with_single_newline() { | |
| 44 | − assert_eq!(subject::<()>(b"a\n").unwrap(), (b"".as_ref(), b"a\n".as_bstr())); | |
| 45 | − } | |
| 46 | − } | |
| 47 | − | |
| 48 | − /// Parse a signature from the bytes input `i` using `nom`. | |
| 49 | 22 | pub fn nomfoo<'a, E: ParseError<&'a [u8]>>(i: &'a [u8]) -> IResult<&'a [u8], (&'a BStr, Option<&'a BStr>), E> { |
| 50 | − let (rest, subject) = opt(terminated(subject, pair(newline, newline)))(i)?; | |
| 51 | − Ok(( | |
| 52 | − &[], | |
| 53 | − match subject { | |
| 54 | − Some(subject) => (subject.as_bstr(), (!rest.is_empty()).then(|| rest.as_bstr())), | |
| 55 | − None => (i.as_bstr(), None), | |
| 56 | − }, | |
| 57 | − )) | |
| 23 | + let mut c = i; | |
| 24 | + while !c.is_empty() { | |
| 25 | + c = match take_till1::<_, _, E>(|c| c == b'\n' || c == b'\r')(c) { | |
| 26 | + Ok((i1, segment)) => match pair::<_, _, _, E, _, _>(newline, newline)(i1) { | |
| 27 | + Ok((body, _)) => { | |
| 28 | + // SAFETY: the pointers are pointing to the same slice. | |
| 29 | + #[allow(unsafe_code)] | |
| 30 | + let consumed_bytes = unsafe { segment.as_ptr_range().end.offset_from(i.as_ptr()) }; | |
| 31 | + return Ok(( | |
| 32 | + &[], | |
| 33 | + ( | |
| 34 | + &i[0usize..consumed_bytes.try_into().expect("positive offset")].as_bstr(), | |
| 35 | + (!body.is_empty()).then(|| body.as_bstr()), | |
| 36 | + ), | |
| 37 | + )); | |
| 38 | + } | |
| 39 | + Err(_) => match i1.get(1..) { | |
| 40 | + Some(next) => next, | |
| 41 | + None => break, | |
| 42 | + }, | |
| 43 | + }, | |
| 44 | + Err(_) => match c.get(1..) { | |
| 45 | + Some(next) => next, | |
| 46 | + None => break, | |
| 47 | + }, | |
| 48 | + }; | |
| 49 | + } | |
| 50 | + Ok((&[], (i.as_bstr(), None))) | |
| 58 | 51 | } |
| 59 | 52 | |
| 60 | 53 | /// Returns title and body, without separator |
| 61 | 54 | pub fn bytes(message: &[u8]) -> (&BStr, Option<&BStr>) { |
| 62 | 55 | all_consuming(nomfoo::<()>)(message).expect("cannot fail").1 |
| 63 | − // match message | |
| 64 | − // .find(b"\n\n") | |
| 65 | − // .map(|pos| (2, pos)) | |
| 66 | − // .or_else(|| message.find(b"\r\n\r\n").map(|pos| (4, pos))) | |
| 67 | − // { | |
| 68 | − // Some((sep_len, end_of_title)) => { | |
| 69 | − // let body = &message[end_of_title + sep_len..]; | |
| 70 | − // ( | |
| 71 | − // message[..end_of_title].as_bstr(), | |
| 72 | − // if body.is_empty() { None } else { Some(body.as_bstr()) }, | |
| 73 | − // ) | |
| 74 | − // } | |
| 75 | − // None => (message.as_bstr(), None), | |
| 76 | − // } | |
| 77 | 56 | } |
| 78 | 57 | } |
| 79 | 58 | |