Wire up safety limiter to destination node

 * Migrate destination node to proper full-featured `ForeignNode`
 * Finish up `SafetyLimiterAWP` with full-featured wasm loading, io handling, etc.
 * Setup dynamic dis/connect for safety limiter enabled and disabled cases

backend/Cargo.toml

@@ -44,7 +44,7 @@ tokio = { version = "1.24", features = ["macros", "rt-multi-thread"] }
 scrypt = "0.11.0"
 base64 = "0.22"
 
-rust-s3 = { version = "0.34", features = [] }
+rust-s3 = { version = "0.35", features = [] }
 aws-region = { version = "0.25.0", features = ["serde"] }
 urlencoding = "2.1"
 

engine/safety_limiter/src/lib.rs

@@ -76,6 +76,9 @@ fn process(envelope: &mut f32, sample: f32) -> f32 {
   dsp::clamp(-4., 4., sample)
 }
 
+#[no_mangle]
+pub extern "C" fn safety_limiter_get_io_buffer_ptr() -> *mut f32 { io_buf().as_mut_ptr() }
+
 #[no_mangle]
 pub extern "C" fn safety_limiter_process() {
   let state = state();

public/SafetyLimiterAWP.js

@@ -0,0 +1,74 @@
+class SafetyLimiterAWP extends AudioWorkletProcessor {
+  constructor() {
+    super();
+
+    this.isShutdown = false;
+    this.wasmInstance = null;
+    this.ioBufPtr = 0;
+    this.wasmMemoryBuffer = null;
+
+    this.port.onmessage = evt => this.handleMessage(evt.data);
+  }
+
+  handleMessage(data) {
+    switch (data.type) {
+      case 'setWasmBytes': {
+        this.initWasm(data.wasmBytes);
+        break;
+      }
+      default: {
+        console.error('Unhandled message type in safety limiter AWP: ', evt.data.type);
+      }
+    }
+  }
+
+  /**
+   * @param {ArrayBuffer} wasmBytes
+   */
+  async initWasm(wasmBytes) {
+    const compiledModule = await WebAssembly.compile(wasmBytes);
+    this.wasmInstance = await WebAssembly.instantiate(compiledModule, { env: {} });
+    this.ioBufPtr = this.wasmInstance.exports.safety_limiter_get_io_buffer_ptr();
+    this.wasmMemoryBuffer = new Float32Array(this.wasmInstance.exports.memory.buffer);
+  }
+
+  getWasmMemoryBuffer() {
+    if (this.wasmMemoryBuffer?.buffer !== this.wasmInstance.exports.memory.buffer) {
+      this.wasmMemoryBuffer = new Float32Array(this.wasmInstance.exports.memory.buffer);
+    }
+    return this.wasmMemoryBuffer;
+  }
+
+  process(inputs, outputs, _params) {
+    if (!this.ioBufPtr || this.isShutdown) {
+      return false;
+    }
+
+    const input = inputs[0]?.[0];
+    const output = outputs[0]?.[0];
+    if (!input || !output) {
+      return true;
+    }
+
+    const wasmMemory = this.getWasmMemoryBuffer();
+    const sampleCount = input.length;
+    let ioBuf = wasmMemory.subarray(
+      this.ioBufPtr / Float32Array.BYTES_PER_ELEMENT,
+      this.ioBufPtr / Float32Array.BYTES_PER_ELEMENT + sampleCount
+    );
+    ioBuf.set(input);
+
+    this.wasmInstance.exports.safety_limiter_process();
+
+    if (ioBuf.length === 0) {
+      ioBuf = this.getWasmMemoryBuffer().subarray(
+        this.ioBufPtr / Float32Array.BYTES_PER_ELEMENT,
+        this.ioBufPtr / Float32Array.BYTES_PER_ELEMENT + sampleCount
+      );
+    }
+
+    return true;
+  }
+}
+
+registerProcessor('safety-limiter-awp', SafetyLimiterAWP);

src/graphEditor/nodes/CustomAudio/CustomAudio.ts

@@ -45,7 +45,7 @@ import { LGAudioConnectables } from '../AudioConnectablesNode';
 import { FMSynthFxNode } from './FMSynthFx/FMSynthFxNode';
 import { SubgraphPortalNode } from 'src/graphEditor/nodes/CustomAudio/Subgraph/SubgraphPortalNode';
 import { BPMNode } from 'src/graphEditor/nodes/CustomAudio/BPM/BPMNode';
-import { DestinationNodeSmallViewShim } from 'src/graphEditor/nodes/CustomAudio/Destination/DestinationNodeSmallView';
+import { CustomDestinationNode } from 'src/graphEditor/nodes/CustomAudio/Destination/CustomDestinationNode';
 
 const ctx = new AudioContext();
 
@@ -336,30 +336,6 @@ const CustomBiquadFilterNode = enhanceAudioNode({
   ),
 });
 
-export class CustomAudioDestinationNode extends GainNode {
-  constructor(ctx: AudioContext) {
-    super(ctx);
-    return (ctx as any).globalVolume as GainNode;
-  }
-}
-
-const CustomDestinationNode = enhanceAudioNode({
-  AudioNodeClass: CustomAudioDestinationNode,
-  nodeType: 'customAudio/destination',
-  name: 'Destination',
-  buildConnectables: (foreignNode: ForeignNode<GainNode> & { node: GainNode }) => ({
-    inputs: Map<string, ConnectableInput>().set('input', {
-      node: foreignNode.node,
-      type: 'customAudio',
-    }),
-    outputs: Map<string, ConnectableOutput>(),
-    node: foreignNode,
-  }),
-  SmallViewRenderer: DestinationNodeSmallViewShim,
-  getOverridableParams: () => [],
-  paramKeys: [],
-});
-
 const NativeCompressorNode = enhanceAudioNode({
   AudioNodeClass: DynamicsCompressorNode,
   nodeType: 'customAudio/nativeCompressor',