core: span allocation with shared free list and geometric growth

Amp-Thread-ID: https://ampcode.com/threads/T-01a0b2dd-db32-712d-99ce-12ce4a86d979
Co-authored-by: Heaust Azure <heaust.azure@gmail.com>

core/lib.rs

@@ -1,28 +1,46 @@
+//! The arena and allocator compile natively for `cargo test`; everything touching WebGPU is wasm-only.
+#![cfg_attr(not(target_arch = "wasm32"), allow(dead_code))]
+
+#[cfg(target_arch = "wasm32")]
 use std::cell::RefCell;
+#[cfg(target_arch = "wasm32")]
 use std::rc::Rc;
 
+#[cfg(target_arch = "wasm32")]
 use serde::Deserialize;
+#[cfg(target_arch = "wasm32")]
 use wasm_bindgen::prelude::*;
 
+#[cfg(target_arch = "wasm32")]
 #[path = "render_graph/compiler.rs"]
 mod compiler;
+#[cfg(target_arch = "wasm32")]
 #[path = "renderer/wgpu.rs"]
 mod gpu;
+#[cfg(target_arch = "wasm32")]
 #[path = "render_graph/gpu_resource.rs"]
 mod gpu_resource;
+#[cfg(target_arch = "wasm32")]
 #[path = "render_graph/render_graph.rs"]
 mod graph;
+#[cfg(target_arch = "wasm32")]
 #[path = "renderer/render.rs"]
 mod render;
 mod render_data;
+#[cfg(target_arch = "wasm32")]
 #[path = "render_graph/store.rs"]
 mod store;
 
+#[cfg(target_arch = "wasm32")]
 use gpu::Wgpu;
+#[cfg(target_arch = "wasm32")]
 use render::RenderLoop;
+#[cfg(target_arch = "wasm32")]
 use render_data::RenderData;
+#[cfg(target_arch = "wasm32")]
 use store::Store;
 
+#[cfg(target_arch = "wasm32")]
 #[derive(Deserialize)]
 struct RowRequest {
     name: String,
@@ -31,6 +49,7 @@ struct RowRequest {
     format: String,
 }
 
+#[cfg(target_arch = "wasm32")]
 #[wasm_bindgen]
 pub struct Core {
     data: Rc<RefCell<RenderData>>,
@@ -39,6 +58,7 @@ pub struct Core {
     render: Rc<RenderLoop>,
 }
 
+#[cfg(target_arch = "wasm32")]
 #[wasm_bindgen]
 impl Core {
     #[wasm_bindgen(constructor)]
@@ -128,11 +148,11 @@ impl Core {
             .map_err(JsError::new)
     }
 
-    pub fn allocate_object(&self, name: &str) -> Result<String, JsError> {
+    pub fn allocate_object(&self, name: &str, count: u32) -> Result<String, JsError> {
         let (id, grew) = self
             .data
             .borrow_mut()
-            .allocate_object(name)
+            .allocate_object(name, count)
             .map_err(JsError::new)?;
         let rows = self
             .data