add bark-alloc crate for bark-protocol packet allocation

Cargo.lock

@@ -63,6 +63,7 @@ checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 name = "bark"
 version = "0.1.0"
 dependencies = [
+ "bark-alloc",
  "bark-protocol",
  "bitflags 2.4.0",
  "bytemuck",
@@ -81,10 +82,19 @@ dependencies = [
  "xdg",
 ]
 
+[[package]]
+name = "bark-alloc"
+version = "0.1.0"
+dependencies = [
+ "bytemuck",
+ "derive_more",
+]
+
 [[package]]
 name = "bark-protocol"
 version = "0.1.0"
 dependencies = [
+ "bark-alloc",
  "bitflags 2.4.0",
  "bytemuck",
  "derive_more",

Cargo.toml

@@ -2,10 +2,12 @@
 resolver = "2"
 members = [
     "bark",
+    "bark-alloc",
     "bark-protocol",
 ]
 
 [workspace.dependencies]
+bark-alloc = { path = "bark-alloc" }
 bark-protocol = { path = "bark-protocol" }
 
 bitflags = { version = "2.4.0", features = ["bytemuck"] }

bark-alloc/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "bark-alloc"
+version = "0.1.0"
+edition = "2021"
+
+[features]
+alloc = ["bytemuck/extern_crate_alloc"]
+
+[dependencies]
+bytemuck = { workspace = true, optional = true }
+derive_more = { workspace = true }

bark-alloc/src/lib.rs

@@ -0,0 +1,24 @@
+#![no_std]
+
+#[cfg(not(feature = "alloc"))]
+compile_error!("must enable alloc feature!");
+
+#[cfg(feature = "alloc")]
+mod impl_ {
+    extern crate alloc;
+
+    use derive_more::{Deref, DerefMut};
+
+    #[repr(transparent)]
+    #[derive(Deref, DerefMut)]
+    #[deref(forward)]
+    pub struct FixedBuffer<const N: usize>(alloc::boxed::Box<[u8]>);
+
+    impl<const N: usize> FixedBuffer<N> {
+        pub fn alloc_zeroed() -> Self {
+            FixedBuffer(bytemuck::allocation::zeroed_slice_box(N))
+        }
+    }
+}
+
+pub use impl_::*;

bark-protocol/Cargo.toml

@@ -4,6 +4,8 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+bark-alloc = { workspace = true }
+
 bitflags = { workspace = true }
 bytemuck = { workspace = true }
 derive_more = { workspace = true }

bark-protocol/src/lib.rs

@@ -1,5 +1,4 @@
 #![no_std]
-extern crate alloc;
 
 pub mod time;
 pub mod types;

bark-protocol/src/packet.rs

@@ -18,7 +18,7 @@ pub const MAX_PACKET_SIZE: usize =
     size_of::<types::AudioPacketBuffer>();
 
 pub struct PacketBuffer {
-    raw: alloc::boxed::Box<[u8]>,
+    raw: bark_alloc::FixedBuffer<MAX_PACKET_SIZE>,
     len: usize,
 }
 
@@ -31,7 +31,7 @@ impl Debug for PacketBuffer {
 impl PacketBuffer {
     pub fn allocate() -> Self {
         PacketBuffer {
-            raw: bytemuck::allocation::zeroed_slice_box(MAX_PACKET_SIZE),
+            raw: bark_alloc::FixedBuffer::alloc_zeroed(),
             len: 0,
         }
     }

bark/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+bark-alloc = { workspace = true, features = ["alloc"] }
 bark-protocol = { workspace = true }
 
 bitflags = { workspace = true }