From ffa6b5c4ae2cdd3e07426ed0330f3f66e90ee57b Mon Sep 17 00:00:00 2001
From: metamuffin <metamuffin@disroot.org>
Date: Tue, 6 Jan 2026 19:10:37 +0100
Subject: tag registry

---
 common/object/src/buffer.rs   | 12 ++++++++++++
 common/object/src/lib.rs      |  5 ++++-
 common/object/src/registry.rs | 27 +++++++++++++++++++++++++++
 common/object/src/tests.rs    | 12 ++++++++++++
 common/object/src/value.rs    | 34 ++++++++++++++++++++++++++++++++++
 5 files changed, 89 insertions(+), 1 deletion(-)
 create mode 100644 common/object/src/registry.rs

(limited to 'common/object/src')

diff --git a/common/object/src/buffer.rs b/common/object/src/buffer.rs
index 56b8caf..dbde833 100644
--- a/common/object/src/buffer.rs
+++ b/common/object/src/buffer.rs
@@ -5,6 +5,7 @@
 */
 
 use crate::{Object, Tag, ValueStore};
+use bytemuck::try_cast_vec;
 
 pub struct ObjectBuffer(pub Vec<u32>);
 
@@ -48,3 +49,14 @@ 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()
+        }))
+    }
+}
diff --git a/common/object/src/lib.rs b/common/object/src/lib.rs
index 831dee7..522b6c1 100644
--- a/common/object/src/lib.rs
+++ b/common/object/src/lib.rs
@@ -3,12 +3,15 @@
     which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
     Copyright (C) 2026 metamuffin <metamuffin.org>
 */
+#![feature(iter_array_chunks)]
 
 mod buffer;
+mod registry;
 #[cfg(test)]
 mod tests;
 mod value;
 pub use buffer::*;
+pub use registry::*;
 pub use value::*;
 
 use std::marker::PhantomData;
@@ -18,7 +21,7 @@ use std::marker::PhantomData;
 pub struct Tag(pub u32);
 pub struct TypedTag<T>(pub Tag, pub PhantomData<T>);
 
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 pub struct Object<'a> {
     tags: &'a [u32],
     offsets: &'a [u32],
diff --git a/common/object/src/registry.rs b/common/object/src/registry.rs
new file mode 100644
index 0000000..7148efd
--- /dev/null
+++ b/common/object/src/registry.rs
@@ -0,0 +1,27 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2026 metamuffin <metamuffin.org>
+*/
+
+use crate::Tag;
+use log::error;
+use std::{any::TypeId, collections::BTreeMap};
+
+#[derive(Default)]
+pub struct Registry {
+    tags: BTreeMap<Tag, TagInfo>,
+}
+impl Registry {
+    pub fn add(&mut self, tag: Tag, info: TagInfo) {
+        if let Some(other) = self.tags.get(&tag) {
+            error!("Tag conflict: {:?} vs {:?}", info.name, other.name)
+        }
+        self.tags.insert(tag, info);
+    }
+}
+
+pub struct TagInfo {
+    pub name: &'static str,
+    pub r#type: Option<TypeId>,
+}
diff --git a/common/object/src/tests.rs b/common/object/src/tests.rs
index 35a29ba..143782c 100644
--- a/common/object/src/tests.rs
+++ b/common/object/src/tests.rs
@@ -37,3 +37,15 @@ fn read_multi_field() {
     assert_eq!(friends.next(), Some("Charlie"));
     assert_eq!(friends.next(), None);
 }
+
+#[test]
+fn vec_align_test() {
+    let mut c = 0;
+    for _ in 0..10_000 {
+        let x = Vec::<u8>::with_capacity(16);
+        if x.as_ptr().align_offset(4) == 0 {
+            c += 1;
+        }
+    }
+    assert_eq!(c, 10_000, "correctly aligned vecs by system allocator")
+}
diff --git a/common/object/src/value.rs b/common/object/src/value.rs
index d77d53a..1b24e79 100644
--- a/common/object/src/value.rs
+++ b/common/object/src/value.rs
@@ -107,3 +107,37 @@ impl ValueStore for ObjectBuffer {
         self.0.len() * 4
     }
 }
+impl<'a> Value<'a> for &'a [u8] {
+    const ALIGNED: bool = false;
+    fn load_unaligned(buf: &'a [u8]) -> Option<Self> {
+        Some(buf)
+    }
+}
+impl ValueStore for &[u8] {
+    fn is_aligned(&self) -> bool {
+        false
+    }
+    fn store_unaligned(&self, buf: &mut Vec<u8>) {
+        buf.extend(*self);
+    }
+    fn size(&self) -> usize {
+        self.len()
+    }
+}
+impl<'a> Value<'a> for &'a [u32] {
+    const ALIGNED: bool = true;
+    fn load_aligned(buf: &'a [u32]) -> Option<Self> {
+        Some(buf)
+    }
+}
+impl ValueStore for &[u32] {
+    fn is_aligned(&self) -> bool {
+        true
+    }
+    fn store_aligned(&self, buf: &mut Vec<u32>) {
+        buf.extend(*self);
+    }
+    fn size(&self) -> usize {
+        self.len() * 4
+    }
+}
-- 
cgit v1.3