From f508ec842da225f4946c40953bf24b424f52512d Mon Sep 17 00:00:00 2001
From: metamuffin <metamuffin@disroot.org>
Date: Mon, 16 Feb 2026 19:29:28 +0100
Subject: handle unaligned vecs/slices

---
 common/object/src/buffer.rs | 44 +++++++++++++++++++++++++++++++-------------
 common/object/src/lib.rs    |  2 +-
 2 files changed, 32 insertions(+), 14 deletions(-)

(limited to 'common/object')

diff --git a/common/object/src/buffer.rs b/common/object/src/buffer.rs
index f73b22e..1792d73 100644
--- a/common/object/src/buffer.rs
+++ b/common/object/src/buffer.rs
@@ -5,7 +5,9 @@
 */
 
 use crate::{Object, Tag, ValueStore};
-use bytemuck::try_cast_vec;
+use bytemuck::{try_cast_slice, try_cast_vec};
+use log::trace;
+use std::borrow::Cow;
 
 #[derive(PartialEq, Eq, Hash)]
 pub struct ObjectBuffer(pub Vec<u32>);
@@ -32,13 +34,9 @@ impl ObjectBuffer {
             } else {
                 temp.clear();
                 val.store_unaligned(&mut temp);
-                let mut pad = 0;
-                while temp.len() % 4 != 0 {
-                    pad += 1;
-                    temp.push(0);
-                }
+                let pad = pad_vec(&mut temp);
                 offsets.push(off | pad);
-                values.extend(bytemuck::cast_slice(&temp)); // ok bc. temp length is a whole number of dwords
+                values.extend(&*slice_u8_to_u32(&temp));
             }
         }
         ObjectBuffer(
@@ -54,12 +52,7 @@ impl ObjectBuffer {
 
 impl From<Vec<u8>> for ObjectBuffer {
     fn from(value: Vec<u8>) -> Self {
-        ObjectBuffer(try_cast_vec(value).unwrap_or_else(|(_, v)| {
-            v.into_iter()
-                .array_chunks()
-                .map(u32::from_ne_bytes)
-                .collect()
-        }))
+        ObjectBuffer(vec_u8_to_u32(value))
     }
 }
 
@@ -72,3 +65,28 @@ pub(super) fn pad_vec(temp: &mut Vec<u8>) -> u32 {
     }
     pad
 }
+
+pub fn vec_u8_to_u32(value: Vec<u8>) -> Vec<u32> {
+    try_cast_vec(value).unwrap_or_else(|(_, v)| {
+        trace!("encountered unalined vec");
+        v.into_iter()
+            .array_chunks()
+            .map(u32::from_ne_bytes)
+            .collect()
+    })
+}
+pub fn slice_u8_to_u32<'a>(value: &'a [u8]) -> Cow<'a, [u32]> {
+    try_cast_slice(value)
+        .map(Cow::Borrowed)
+        .unwrap_or_else(|_| {
+            trace!("encountered unalined slice");
+            Cow::Owned(
+                value
+                    .into_iter()
+                    .copied()
+                    .array_chunks()
+                    .map(u32::from_ne_bytes)
+                    .collect(),
+            )
+        })
+}
diff --git a/common/object/src/lib.rs b/common/object/src/lib.rs
index 9af4f85..771dd94 100644
--- a/common/object/src/lib.rs
+++ b/common/object/src/lib.rs
@@ -237,7 +237,7 @@ impl<'a> Object<'a> {
                 val.store_unaligned(&mut temp);
                 let pad = pad_vec(&mut temp);
                 buf[new_offs + i] = off | pad;
-                buf.extend(bytemuck::cast_slice(&temp));
+                buf.extend(&*slice_u8_to_u32(&temp));
             }
         }
         let values_insert_size = buf.len() - values_new;
-- 
cgit v1.3