feat(tvix/castore/blob/naive_seeker): add some more tracing r/7947

Change-Id: Iecf4a82a7d84008a8620825570b34e9094e6d590
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11445
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI

1 files changed, 17 insertions, 10 deletions

diff --git a/tvix/castore/src/blobservice/naive_seeker.rs b/tvix/castore/src/blobservice/naive_seeker.rs
index 5c943b9870b4..f5a530715093 100644
--- a/tvix/castore/src/blobservice/naive_seeker.rs
+++ b/tvix/castore/src/blobservice/naive_seeker.rs
@@ -4,7 +4,7 @@ use pin_project_lite::pin_project;
 use std::io;
 use std::task::Poll;
 use tokio::io::AsyncRead;
-use tracing::{debug, instrument};
+use tracing::{debug, instrument, trace, warn};
 
 pin_project! {
     /// This implements [tokio::io::AsyncSeek] for and [tokio::io::AsyncRead] by
@@ -79,6 +79,7 @@ impl<R: tokio::io::AsyncRead> NaiveSeeker<R> {
 }
 
 impl<R: tokio::io::AsyncRead> tokio::io::AsyncRead for NaiveSeeker<R> {
+    #[instrument(level = "trace", skip_all)]
     fn poll_read(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
@@ -90,9 +91,12 @@ impl<R: tokio::io::AsyncRead> tokio::io::AsyncRead for NaiveSeeker<R> {
 
         let this = self.project();
         ready!(this.r.poll_read(cx, buf))?;
+
         let bytes_read = buf.filled().len() - filled_before;
         *this.pos += bytes_read as u64;
 
+        trace!(bytes_read = bytes_read, new_pos = this.pos, "poll_read");
+
         Ok(()).into()
     }
 }
@@ -105,16 +109,18 @@ impl<R: tokio::io::AsyncRead> tokio::io::AsyncBufRead for NaiveSeeker<R> {
         self.project().r.poll_fill_buf(cx)
     }
 
+    #[instrument(level = "trace", skip(self))]
     fn consume(self: std::pin::Pin<&mut Self>, amt: usize) {
         let this = self.project();
         this.r.consume(amt);
-        let pos: &mut u64 = this.pos;
-        *pos += amt as u64;
+        *this.pos += amt as u64;
+
+        trace!(new_pos = this.pos, "consume");
     }
 }
 
 impl<R: tokio::io::AsyncRead> tokio::io::AsyncSeek for NaiveSeeker<R> {
-    #[instrument(skip(self), err(Debug))]
+    #[instrument(level="trace", skip(self), fields(inner_pos=%self.pos), err(Debug))]
     fn start_seek(
         self: std::pin::Pin<&mut Self>,
         position: std::io::SeekFrom,
@@ -149,23 +155,24 @@ impl<R: tokio::io::AsyncRead> tokio::io::AsyncSeek for NaiveSeeker<R> {
             }
         };
 
-        debug!(absolute_offset=?absolute_offset, "seek");
-
-        // we already know absolute_offset is larger than self.pos
+        // we already know absolute_offset is >= self.pos
         debug_assert!(
             absolute_offset >= self.pos,
-            "absolute_offset {} is larger than self.pos {}",
+            "absolute_offset {} must be >= self.pos {}",
             absolute_offset,
             self.pos
         );
 
         // calculate bytes to skip
-        *self.project().bytes_to_skip = absolute_offset - self.pos;
+        let this = self.project();
+        *this.bytes_to_skip = absolute_offset - *this.pos;
+
+        debug!(bytes_to_skip = *this.bytes_to_skip, "seek");
 
         Ok(())
     }
 
-    #[instrument(skip(self))]
+    #[instrument(skip_all)]
     fn poll_complete(
         mut self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,