From 625aae74a5f45d5647a86191d53f3ac260680c01 Mon Sep 17 00:00:00 2001
From: Nicholas Gates <nick@nickgates.com>
Date: Fri, 10 Jan 2025 22:29:50 +0000
Subject: [PATCH] Better buffer debug

---
 vortex-buffer/src/buffer.rs          | 29 +++++++++++++++++++---------
 vortex-buffer/src/lib.rs             |  1 +
 vortex-file/src/v2/file.rs           |  2 ++
 vortex-file/src/v2/segments/cache.rs |  2 ++
 vortex-layout/src/segments/mod.rs    |  7 +++++++
 5 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/vortex-buffer/src/buffer.rs b/vortex-buffer/src/buffer.rs
index 74530f55b..13ad4f874 100644
--- a/vortex-buffer/src/buffer.rs
+++ b/vortex-buffer/src/buffer.rs
@@ -1,3 +1,4 @@
+use std::any::type_name;
 use std::collections::Bound;
 use std::fmt::{Debug, Formatter};
 use std::ops::{Deref, RangeBounds};
@@ -281,21 +282,31 @@ impl<T> Buffer<T> {
     }
 }
 
-impl<T> Debug for Buffer<T> {
+impl<T> Debug for Buffer<T>
+where
+    T: Debug,
+{
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        const TRUNC_SIZE: usize = 512;
-        let mut binding = f.debug_struct("Buffer");
-        let mut fields = binding
+        let mut binding = f.debug_struct(&format!("Buffer<{}>", type_name::<T>()));
+        let fields = binding
             .field("length", &self.length)
             .field("alignment", &self.alignment);
 
-        let mut bytes = self.bytes.clone();
-        if bytes.len() > TRUNC_SIZE {
-            fields = fields.field("truncated", &true);
+        const TRUNC_SIZE: usize = 16;
+        if self.len() <= TRUNC_SIZE {
+            fields.field("as_slice", &self.as_slice());
+        } else {
+            fields.field_with(&"as_slice", |f| {
+                write!(f, "[")?;
+                for elem in self.as_slice().iter().take(TRUNC_SIZE) {
+                    write!(f, "{:?}, ", *elem)?;
+                }
+                write!(f, "...")?;
+                write!(f, "]")
+            });
         }
 
-        bytes.truncate(TRUNC_SIZE);
-        fields.field("bytes", &bytes).finish()
+        fields.finish()
     }
 }
 
diff --git a/vortex-buffer/src/lib.rs b/vortex-buffer/src/lib.rs
index 641bcd410..e2263c4fd 100644
--- a/vortex-buffer/src/lib.rs
+++ b/vortex-buffer/src/lib.rs
@@ -1,4 +1,5 @@
 #![feature(unsigned_is_multiple_of)]
+#![feature(debug_closure_helpers)]
 #![deny(missing_docs)]
 
 //! A library for working with custom aligned buffers of sized values.
diff --git a/vortex-file/src/v2/file.rs b/vortex-file/src/v2/file.rs
index 8cf5f97f5..fe65ffc65 100644
--- a/vortex-file/src/v2/file.rs
+++ b/vortex-file/src/v2/file.rs
@@ -48,6 +48,8 @@ impl<R: VortexReadAt + Unpin> VortexFile<R> {
 
     /// Performs a scan operation over the file.
     pub fn scan(self, scan: Arc<Scan>) -> VortexResult<impl ArrayStream + 'static> {
+        println!("File Layout: {:#?}", self.file_layout);
+
         // Create a shared reader for the scan.
         let reader: Arc<dyn LayoutReader> = self
             .file_layout()
diff --git a/vortex-file/src/v2/segments/cache.rs b/vortex-file/src/v2/segments/cache.rs
index bb04b6b5a..0fc75b478 100644
--- a/vortex-file/src/v2/segments/cache.rs
+++ b/vortex-file/src/v2/segments/cache.rs
@@ -69,10 +69,12 @@ impl<R: VortexReadAt + Unpin> SegmentCache<R> {
                 let segments = self.segments.clone();
                 async move {
                     let segment = &segments[*request.id as usize];
+                    println!("Reading segment {} {:?}", *request.id, segment);
                     let bytes = read
                         .read_byte_range(segment.offset, segment.length as u64)
                         .map_ok(|bytes| ByteBuffer::from(bytes).aligned(segment.alignment))
                         .await?;
+                    println!("Completed segment {} read", *request.id);
                     request
                         .callback
                         .send(bytes)
diff --git a/vortex-layout/src/segments/mod.rs b/vortex-layout/src/segments/mod.rs
index 143b0fa47..7b66f4c8d 100644
--- a/vortex-layout/src/segments/mod.rs
+++ b/vortex-layout/src/segments/mod.rs
@@ -1,3 +1,4 @@
+use std::fmt::Display;
 use std::ops::Deref;
 
 use async_trait::async_trait;
@@ -9,6 +10,12 @@ use vortex_error::VortexResult;
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct SegmentId(u32);
 
+impl Display for SegmentId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "SegmentId({})", self.0)
+    }
+}
+
 impl From<u32> for SegmentId {
     fn from(value: u32) -> Self {
         Self(value)