Crate nostd_multipart 

Heap-free, panic-free, streaming multipart/form-data parser and encoder for #![no_std].

The crate is sans-IO: you feed bytes to Parser::parse and get back at most one Event per call plus the number of bytes consumed. Part data is yielded as sub-slices of your own input buffer (zero-copy). Only part headers are copied, into a line buffer whose size is the const generic LINE.

The normative specification is DESIGN.md in the repository; the rule numbers referenced in the source (rule 3, …) point there.

use nostd_multipart::{Event, Parser};

let body = b"--xyz\r\nContent-Disposition: form-data; name=\"f\"\r\n\r\nhello\r\n--xyz--";
let mut p: Parser<'_> = Parser::new(b"xyz").unwrap();
let mut pos = 0;
let mut data = Vec::new();
loop {
    let (used, ev) = p.parse(&body[pos..], true).unwrap();
    pos += used;
    match ev {
        Some(Event::Data(d)) => data.extend_from_slice(d),
        Some(Event::Finished) => break,
        _ => {}
    }
}
assert_eq!(data, b"hello");

Structs

ContentDisposition

A parsed Content-Disposition header value.

Decoded

Iterator over the decoded bytes of a ParamValue.

Encoder

Streaming multipart/form-data encoder.

MultipartReader

Drives a Parser from a blocking embedded_io::Read with a BUF-byte buffer (BUF >= parser.min_buffer()).

MultipartReaderAsync

Drives a Parser from an embedded_io_async::Read with a BUF-byte buffer (BUF >= parser.min_buffer()).

ParamValue

A parameter value: the raw bytes plus lazy decoding of RFC 822 quoted-pairs (\x → x) and the WHATWG escapes %22, %0D, %0A (→ ", CR, LF). Other % sequences are left as they are.

Parser

Streaming, zero-copy multipart/form-data parser.

Part

Description of one part for the Encoder.

Enums

Error

Every failure the crate can report. See DESIGN.md §12.

Event

One parse event. 'i is the lifetime of the input slice passed to Parser::parse, 'p the borrow of the parser.

ReadError

Error of the reader adapters.

Constants

MAX_PADDING

Maximum number of SP/HTAB transport-padding bytes accepted between the boundary and the CRLF of a part delimiter (rule 3). More padding means “not a delimiter”.

Functions

boundary_from_random

Maps N random bytes (e.g. from a hardware RNG) to a valid boundary of N bchars from A–Z a–z 0–9 - _ (6 bits of entropy per byte).

content_disposition

Parses a Content-Disposition header value (rule 8).