feat(stream): implement LendingIterator for MultipartStream

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "multipart_async_stream"
-version = "0.1.1"
+version = "0.2.2"
 edition = "2024"
 license = "MIT OR Apache-2.0"
 description = "An easy-to-use, efficient, and asynchronous multipart stream parser."
@@ -14,12 +14,14 @@ categories = [
 ]
 
 [dependencies]
+async-iterator = "2.3.0"
 bytes = "1.10.1"
+constcat = "0.6.1"
 futures-util = { version = "0.3.31", features = ["tokio-io"] }
 http = "1.3.1"
 httparse = "1.10.1"
 memchr = "2.7.5"
-thiserror = "2.0.15"
+thiserror = "2.0.16"
 
 [dev-dependencies]
 reqwest = { version = "0.12.23", features = ["stream"] }

README.md

@@ -1,30 +1,20 @@
 # Multipart Stream
 
-![alt text](https://img.shields.io/crates/v/multipart_async_stream.svg)
-
-
-![alt text](https://docs.rs/multipart_async_stream/badge.svg)
-
-
-![alt text](https://github.com/OpenTritium/multipart_stream/actions/workflows/ci.yaml/badge.svg)
+![alt text](https://img.shields.io/crates/v/multipart_async_stream.svg) ![alt text](https://docs.rs/multipart_async_stream/badge.svg) ![alt text](https://github.com/OpenTritium/multipart_stream/actions/workflows/ci.yaml/badge.svg)
 
 This library is designed as an adapter for `futures_util::TryStream`, allowing for easy parsing of an incoming byte stream (such as from an HTTP response) and splitting it into multiple parts (`Part`). It is especially useful for handling `multipart/byteranges` HTTP responses.
 
 A common use case is sending an HTTP Range request to a server and then parsing the resulting `multipart/byteranges` response body.
 The example below demonstrates how to use reqwest to download multiple ranges of a file and parse the individual parts using multipart_stream.
 
 ```rust
-use http::header::CONTENT_TYPE;
+use multipart_async_stream::{LendingIterator, MultipartStream, TryStreamExt, header::CONTENT_TYPE};
 
 #[tokio::main]
 async fn main() {
     const URL: &str = "https://mat1.gtimg.com/pingjs/ext2020/newom/build/static/images/new_logo.png";
     let client = reqwest::Client::new();
-    let response = client
-        .get(URL)
-        .header("Range", "bytes=0-32,64-128")
-        .send()
-        .await.unwrap();
+    let response = client.get(URL).header("Range", "bytes=0-31,64-127").send().await.unwrap();
     let boundary = response
         .headers()
         .get(CONTENT_TYPE)
@@ -33,9 +23,23 @@ async fn main() {
         .and_then(|s| s.split("boundary=").nth(1))
         .map(|s| s.trim().as_bytes().to_vec().into_boxed_slice());
     let s = response.bytes_stream();
-    let mut m = multipart_async_stream::MultipartStream::new(s, &boundary.unwrap());
-    while let Ok(x) = m.try_next().await {
-        println!("Part: {x:?}");
+    let mut m = MultipartStream::new(s, &boundary.unwrap());
+
+    while let Some(Ok(part)) = m.next().await {
+        println!("{:?}", part.headers());
+        let mut body = part.body();
+        while let Ok(Some(b)) = body.try_next().await {
+            println!("{:?}", b);
+        }
     }
 }
+```
+
+The output of the program above is:
+
+```bash
+{"content-type": "image/png", "content-range": "bytes 0-31/10845"}
+b"\x89PNG\r\n\x1a\n\0\0\0\rIHDR\0\0\0\xf4\0\0\0B\x08\x06\0\0\0`\xbc\xfb"
+{"content-type": "image/png", "content-range": "bytes 64-127/10845"}
+b"L:com.adobe.xmp\0\0\0\0\0<?xpacket begin=\"\xef\xbb\xbf\" id=\"W5M0MpCehiHzreSzNT"
 ```

examples/demo.rs

@@ -1,4 +1,4 @@
-use http::header::CONTENT_TYPE;
+use multipart_async_stream::{LendingIterator, MultipartStream, TryStreamExt, header::CONTENT_TYPE};
 
 #[tokio::main]
 async fn main() {
@@ -13,8 +13,13 @@ async fn main() {
         .and_then(|s| s.split("boundary=").nth(1))
         .map(|s| s.trim().as_bytes().to_vec().into_boxed_slice());
     let s = response.bytes_stream();
-    let mut m = multipart_async_stream::MultipartStream::new(s, &boundary.unwrap());
-    while let Ok(x) = m.try_next().await {
-        println!("Part: {x:?}");
+    let mut m = MultipartStream::new(s, &boundary.unwrap());
+
+    while let Some(Ok(part)) = m.next().await {
+        println!("{:?}", part.headers());
+        let mut body = part.body();
+        while let Ok(Some(b)) = body.try_next().await {
+            println!("{:?}", b);
+        }
     }
 }

fuzz/fuzz_targets/parse_stream.rs

@@ -1,9 +1,8 @@
 #![no_main]
-
 use bytes::Bytes;
-use futures_util::{TryStream, stream};
+use futures_util::stream;
 use libfuzzer_sys::fuzz_target;
-use multipart_async_stream::MultipartStream;
+use multipart_async_stream::{LendingIterator, MultipartStream, TryStream, TryStreamExt};
 use std::convert::Infallible;
 use tokio::runtime::Builder;
 
@@ -26,9 +25,9 @@ fn do_fuzz(data: &[u8]) {
 
     rt.block_on(async {
         let s = create_stream_from_chunks(body, 32);
-        let mut stream = MultipartStream::new(s, boundary);
+        let mut m = MultipartStream::new(s, boundary);
         loop {
-            if stream.try_next().await.is_err() {
+            if m.next().await.is_some_and(|result| result.is_err()) {
                 break;
             }
         }