[clone] as_read() support for packet lines

Author: Byron

git-packetline/src/read.rs

@@ -11,7 +11,6 @@ use std::io;
 /// Read pack lines one after another, without consuming more than needed from the underlying
 /// `Read`. `Flush` lines cause the reader to stop producing lines forever, leaving `Read` at the
 /// start of whatever comes next.
-/// It signals encountering a flush line with `UnexpectedEof`
 pub struct Reader<T> {
     pub inner: T,
     buf: Vec<u8>,
@@ -54,22 +53,16 @@ where
         }
     }
 
-    pub fn read_line(&mut self) -> io::Result<Result<PacketLine, decode::Error>> {
-        let eof = || {
-            Err(io::Error::new(
-                io::ErrorKind::UnexpectedEof,
-                "attempt to read past flush line",
-            ))
-        };
+    pub fn read_line(&mut self) -> Option<io::Result<Result<PacketLine, decode::Error>>> {
         if self.is_done {
-            return eof();
+            return None;
         }
         match Self::read_line_inner(&mut self.inner, &mut self.buf) {
             Ok(Ok(line)) if line == self.delimiter => {
                 self.is_done = true;
-                eof()
+                None
             }
-            err => err,
+            res => Some(res),
         }
     }
 
@@ -139,10 +132,10 @@ where
         if self.pos >= self.cap {
             debug_assert!(self.pos == self.cap);
             self.cap = loop {
-                let line = self
-                    .parent
-                    .read_line()?
-                    .map_err(|err| io::Error::new(io::ErrorKind::Other, err))?;
+                let line = match self.parent.read_line() {
+                    Some(line) => line?.map_err(|err| io::Error::new(io::ErrorKind::Other, err))?,
+                    None => break 0,
+                };
                 match self.progress_and_parse.as_mut() {
                     Some((progress, parse_progress)) => {
                         let mut band = line

git-packetline/tests/packet_line/read.rs

@@ -1,5 +1,6 @@
 use git_packetline::PacketLine;
-use std::{io, path::PathBuf};
+use std::io;
+use std::path::PathBuf;
 
 fn fixture_path(path: &str) -> PathBuf {
     PathBuf::from("tests/fixtures").join(path)
@@ -10,7 +11,7 @@ fn fixture_bytes(path: &str) -> Vec<u8> {
 }
 
 mod to_read {
-    use crate::packet_line::read::{exhaust, fixture_bytes};
+    use crate::packet_line::read::fixture_bytes;
     use bstr::ByteSlice;
     use git_odb::pack;
     use git_packetline::RemoteProgress;
@@ -21,13 +22,13 @@ mod to_read {
         let buf = fixture_bytes("v1/01-clone.combined-output");
         let mut rd = git_packetline::Reader::new(&buf[..], None);
 
+        // Read without sideband decoding
         let mut out = Vec::new();
         rd.as_read().read_to_end(&mut out)?;
-        assert_eq!(out.as_bstr(), b"foo".as_bstr());
+        assert_eq!(out.as_bstr(), b"808e50d724f604f69ab93c6da2919c014667bedb HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow deepen-since deepen-not deepen-relative no-progress include-tag multi_ack_detailed symref=HEAD:refs/heads/master object-format=sha1 agent=git/2.28.0\n808e50d724f604f69ab93c6da2919c014667bedb refs/heads/master\n".as_bstr());
 
-        assert_eq!(exhaust(&mut rd), 2);
         rd.reset();
-        assert_eq!(rd.read_line()??.to_text().0.as_bstr(), b"NAK".as_bstr());
+        assert_eq!(rd.read_line().expect("line")??.to_text().0.as_bstr(), b"NAK".as_bstr());
         fn no_parsing(_: &[u8]) -> Option<RemoteProgress> {
             None
         }
@@ -55,7 +56,7 @@ fn read_from_file_and_reader_advancement() -> crate::Result {
     bytes.extend(fixture_bytes("v1/fetch/01-many-refs.response").into_iter());
     let mut rd = git_packetline::Reader::new(&bytes[..], None);
     assert_eq!(
-        rd.read_line()??.as_bstr(),
+        rd.read_line().expect("line")??.as_bstr(),
         PacketLine::Data(b"7814e8a05a59c0cf5fb186661d1551c75d1299b5 HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow deepen-since deepen-not deepen-relative no-progress include-tag multi_ack_detailed symref=HEAD:refs/heads/master object-format=sha1 agent=git/2.28.0\n").as_bstr()
     );
     assert_eq!(exhaust(&mut rd) + 1, 1561, "it stops after seeing the flush byte");
@@ -65,18 +66,20 @@ fn read_from_file_and_reader_advancement() -> crate::Result {
         1561,
         "it should read the second part of the identical file from the previously advanced reader"
     );
+
+    // this reset is will cause actual io::Errors to occour
     rd.reset();
     assert_eq!(
-        rd.read_line().unwrap_err().kind(),
+        rd.read_line().expect("some error").unwrap_err().kind(),
         io::ErrorKind::UnexpectedEof,
-        "trying to keep reading from exhausted input propagates the error"
+        "trying to keep reading from exhausted input results in Some() containing the original error"
     );
     Ok(())
 }
 
 fn exhaust(rd: &mut git_packetline::Reader<&[u8]>) -> i32 {
     let mut count = 0;
-    while let Ok(_) = rd.read_line() {
+    while let Some(_) = rd.read_line() {
         count += 1;
     }
     count

tasks.md

@@ -1,14 +1,16 @@
 ### Cloning
 * **gixp-pack-receive**
   * _a program to (initially only) clone from a given URL_, storing a full pack with index only. No support for `git-refs`.
-  * [x] pkt-lines support
-  * [x] Don't forcibly remove newlines at the end of pack lines, but make that an extra step.
-  * [x] decode band should be able to fail
-  * [x] PacketLine 'Iterator' from `Read`
-  * [x] `Read` from packet lines with sideband
-    * [x] Progress parsing, with 'info(…)' fallback if that fails
-    * [x] SetName in Progress trait (to allow setting the correct progress information)
-    * [ ] Disable sideband support (e.g. github http V2 doesn't have it)
+  * **git-packetline**
+    * [x] pkt-lines support
+    * [x] Don't forcibly remove newlines at the end of pack lines, but make that an extra step.
+    * [x] decode band should be able to fail
+    * [x] PacketLine 'Iterator' from `Read`
+    * [x] `Read` from packet lines with sideband
+      * [x] Progress parsing, with 'info(…)' fallback if that fails
+      * [x] SetName in Progress trait (to allow setting the correct progress information)
+      * [x] Disable sideband support (e.g. github http V2 doesn't have it)
+    * [ ] don't coerce line delimiters into empty slices.
   * **git-url**
     * [ ] parse into components to make them easy to understand
   * **connect**