Replace rental with ouroboros

rental is not maintained any more and users
are encouraged to switch to alternatives.

Author: est31

Cargo.toml

@@ -30,7 +30,7 @@ async-native-tls = { version = "0.3.3" }
 async-std = { version = "1.8.0", default-features = false, features = ["std"] }
 pin-utils = "0.1.0-alpha.4"
 futures = "0.3.15"
-rental = "0.5.5"
+ouroboros = "0.9"
 stop-token = "0.2"
 byte-pool = "0.2.2"
 lazy_static = "1.4.0"

examples/idle.rs

@@ -73,7 +73,7 @@ async fn fetch_and_idle(imap_server: &str, login: &str, password: &str) -> Resul
             println!("-- IDLE timed out");
         }
         NewData(data) => {
-            let s = String::from_utf8(data.head().to_vec()).unwrap();
+            let s = String::from_utf8(data.borrow_raw().to_vec()).unwrap();
             println!("-- IDLE data:\n{}", s);
         }
     }

src/imap_stream.rs

@@ -108,7 +108,7 @@ impl<R: Read + Write + Unpin> ImapStream<R> {
         let block: Block<'static> = self.buffer.take_block();
         // Be aware, now self.buffer is invalid until block is returned or reset!
 
-        let res = ResponseData::try_new(block, |buf| {
+        let res = ResponseData::try_new_or_recover(block, |buf| {
             let buf = &buf[..self.buffer.used()];
             log::trace!("decode: input: {:?}", std::str::from_utf8(buf));
             match imap_proto::parser::parse_response(buf) {
@@ -139,8 +139,8 @@ impl<R: Read + Write + Unpin> ImapStream<R> {
         });
         match res {
             Ok(response) => Ok(Some(response)),
-            Err(rental::RentalError(err, block)) => {
-                self.buffer.return_block(block);
+            Err((err, heads)) => {
+                self.buffer.return_block(heads.raw);
                 match err {
                     Some(err) => Err(err),
                     None => Ok(None),

src/lib.rs

@@ -65,9 +65,6 @@
 #[macro_use]
 extern crate pin_utils;
 
-#[macro_use]
-extern crate rental;
-
 // Reexport imap_proto for easier access.
 pub use imap_proto;
 

src/parse.rs

@@ -342,7 +342,6 @@ mod tests {
                     assert_eq!(remaining.len(), 0);
                     Ok(response)
                 })
-                .map_err(|err: rental::RentalError<io::Error, _>| err.0)
             })
             .collect()
     }

src/types/name.rs

@@ -4,17 +4,13 @@ use imap_proto::{MailboxDatum, Response};
 
 use crate::types::ResponseData;
 
-rental! {
-    pub mod rents {
-        use super::*;
-
-        /// A name that matches a `LIST` or `LSUB` command.
-        #[rental(debug, covariant)]
-        pub struct Name {
-            response: Box<ResponseData>,
-            inner: InnerName<'response>,
-        }
-    }
+/// A name that matches a `LIST` or `LSUB` command.
+#[ouroboros::self_referencing(pub_extras)]
+pub struct Name {
+    response: Box<ResponseData>,
+    #[borrows(response)]
+    #[covariant]
+    inner: InnerName<'this>,
 }
 
 #[derive(PartialEq, Eq, Debug)]
@@ -24,8 +20,6 @@ pub struct InnerName<'a> {
     name: &'a str,
 }
 
-pub use rents::Name;
-
 /// An attribute set for an IMAP name.
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub enum NameAttribute<'a> {
@@ -103,22 +97,22 @@ impl Name {
 
     /// Attributes of this name.
     pub fn attributes(&self) -> &[NameAttribute<'_>] {
-        &self.suffix().attributes[..]
+        &self.borrow_inner().attributes[..]
     }
 
     /// The hierarchy delimiter is a character used to delimit levels of hierarchy in a mailbox
     /// name.  A client can use it to create child mailboxes, and to search higher or lower levels
     /// of naming hierarchy.  All children of a top-level hierarchy node use the same
     /// separator character.  `None` means that no hierarchy exists; the name is a "flat" name.
     pub fn delimiter(&self) -> Option<&str> {
-        self.suffix().delimiter
+        self.borrow_inner().delimiter
     }
 
     /// The name represents an unambiguous left-to-right hierarchy, and are valid for use as a
     /// reference in `LIST` and `LSUB` commands. Unless [`NameAttribute::NoSelect`] is indicated,
     /// the name is also valid as an argument for commands, such as `SELECT`, that accept mailbox
     /// names.
     pub fn name(&self) -> &str {
-        self.suffix().name
+        self.borrow_inner().name
     }
 }

src/types/response_data.rs

@@ -3,20 +3,14 @@ use std::fmt;
 use byte_pool::Block;
 use imap_proto::{RequestId, Response};
 
-rental! {
-    pub mod rents {
-        use super::*;
-
-        #[rental(covariant)]
-        pub struct ResponseData {
-            raw: Block<'static>,
-            response: Response<'raw>,
-        }
-    }
+#[ouroboros::self_referencing(pub_extras)]
+pub struct ResponseData {
+    pub raw: Block<'static>,
+    #[borrows(raw)]
+    #[covariant]
+    response: Response<'this>,
 }
 
-pub use rents::ResponseData;
-
 impl std::cmp::PartialEq for ResponseData {
     fn eq(&self, other: &Self) -> bool {
         self.parsed() == other.parsed()
@@ -28,21 +22,21 @@ impl std::cmp::Eq for ResponseData {}
 impl fmt::Debug for ResponseData {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("ResponseData")
-            .field("raw", &self.head().len())
-            .field("response", self.suffix())
+            .field("raw", &self.borrow_raw().len())
+            .field("response", self.borrow_response())
             .finish()
     }
 }
 
 impl ResponseData {
     pub fn request_id(&self) -> Option<&RequestId> {
-        match self.suffix() {
+        match self.borrow_response() {
             Response::Done { ref tag, .. } => Some(tag),
             _ => None,
         }
     }
 
     pub fn parsed(&self) -> &Response<'_> {
-        self.suffix()
+        self.borrow_response()
     }
 }