From f0a67c407121be749a41895dbc33d9120ca15b95 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <christian@neon.tech>
Date: Thu, 14 Mar 2024 17:19:15 +0000
Subject: [PATCH] WIP: page_cache_priming_writer: clippy

---
 pageserver/src/tenant/ephemeral_file.rs                      | 2 +-
 .../owned_buffers_io/util/size_tracking_writer.rs            | 1 +
 pageserver/src/virtual_file/owned_buffers_io/write.rs        | 5 +++--
 .../owned_buffers_io/write/zero_initialized_buffer.rs        | 1 +
 4 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/pageserver/src/tenant/ephemeral_file.rs b/pageserver/src/tenant/ephemeral_file.rs
index 179239a621..fda724dfe5 100644
--- a/pageserver/src/tenant/ephemeral_file.rs
+++ b/pageserver/src/tenant/ephemeral_file.rs
@@ -202,7 +202,7 @@ impl EphemeralFile {
         }
 
         // Write the payload
-        self.file.write_all_borrowed(&srcbuf, ctx).await?;
+        self.file.write_all_borrowed(srcbuf, ctx).await?;
 
         Ok(pos)
     }
diff --git a/pageserver/src/virtual_file/owned_buffers_io/util/size_tracking_writer.rs b/pageserver/src/virtual_file/owned_buffers_io/util/size_tracking_writer.rs
index dcde4e3ced..92d75e396e 100644
--- a/pageserver/src/virtual_file/owned_buffers_io/util/size_tracking_writer.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/util/size_tracking_writer.rs
@@ -21,6 +21,7 @@ impl<W> Writer<W> {
     }
     /// Returns the wrapped `VirtualFile` object as well as the number
     /// of bytes that were written to it through this object.
+    #[allow(dead_code)]
     pub fn into_inner(self) -> (u64, W) {
         (self.bytes_amount, self.dst)
     }
diff --git a/pageserver/src/virtual_file/owned_buffers_io/write.rs b/pageserver/src/virtual_file/owned_buffers_io/write.rs
index cfa5921e18..7243c11a94 100644
--- a/pageserver/src/virtual_file/owned_buffers_io/write.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/write.rs
@@ -73,6 +73,7 @@ where
             .as_zero_padded_slice()
     }
 
+    #[allow(dead_code)]
     pub async fn flush_and_into_inner(mut self, ctx: &RequestContext) -> std::io::Result<W> {
         self.flush(ctx).await?;
         let Self { buf, writer } = self;
@@ -215,7 +216,7 @@ impl OwnedAsyncWriter for Vec<u8> {
         buf: &[u8],
         _ctx: &RequestContext,
     ) -> std::io::Result<usize> {
-        self.extend_from_slice(&buf[..]);
+        self.extend_from_slice(buf);
         Ok(buf.len())
     }
 }
@@ -341,7 +342,7 @@ mod tests {
                 let expect: &[&[u8]] = &[b"ab", b"cd", b"ef", b"gh", b"ij", b"kl", b"mn", b"o"];
                 expect
             }
-            .into_iter()
+            .iter()
             .map(|v| v[..].to_vec())
             .collect::<Vec<_>>()
         );
diff --git a/pageserver/src/virtual_file/owned_buffers_io/write/zero_initialized_buffer.rs b/pageserver/src/virtual_file/owned_buffers_io/write/zero_initialized_buffer.rs
index 90b7e9182a..12607c1fcf 100644
--- a/pageserver/src/virtual_file/owned_buffers_io/write/zero_initialized_buffer.rs
+++ b/pageserver/src/virtual_file/owned_buffers_io/write/zero_initialized_buffer.rs
@@ -54,6 +54,7 @@ impl<const N: usize> Buf<N> {
     }
 }
 
+/// SAFETY: the Box<> has a stable location in memory.
 unsafe impl<const N: usize> tokio_epoll_uring::IoBuf for Buf<N> {
     fn stable_ptr(&self) -> *const u8 {
         self.allocation.as_ptr()