feat: add precomputed-tables for improved performance

- Add k256 precomputed-tables feature for faster elliptic curve operations
- Provide custom critical-section implementation for WASM (single-threaded no-op)
- Restore benchmark test to 1000 iterations

Performance improvements:
- derivePath from xpub: ~2x faster than utxo-lib
- derive single child: ~2.2x faster than utxo-lib
- fromBase58 (xpub): ~3x faster than utxo-lib

Author: OttoAllmendinger

packages/wasm-bip32/Cargo.lock

@@ -20,6 +20,8 @@ k256 = { version = "0.13", default-features = false, features = [
     "ecdsa",
     "sha256",
     "alloc",
+    "precomputed-tables",
+    "critical-section",
 ] }
 sha2 = { version = "0.10", default-features = false }
 ripemd = { version = "0.1", default-features = false }
@@ -28,6 +30,8 @@ bs58 = { version = "0.5", default-features = false, features = [
     "alloc",
 ] }
 getrandom = { version = "0.2", features = ["js"] }
+# Provide critical-section implementation for WASM (single-threaded, so no-op)
+critical-section = "1.2"
 
 [dev-dependencies]
 wasm-bindgen-test = "0.3"

packages/wasm-bip32/Cargo.toml

@@ -6,3 +6,19 @@ mod message;
 pub use bip32::WasmBIP32;
 pub use ecpair::WasmECPair;
 pub use error::WasmBip32Error;
+
+// Provide a no-op critical section implementation for single-threaded WASM
+use critical_section::RawRestoreState;
+
+struct SingleThreadedCs;
+critical_section::set_impl!(SingleThreadedCs);
+
+unsafe impl critical_section::Impl for SingleThreadedCs {
+    unsafe fn acquire() -> RawRestoreState {
+        // WASM is single-threaded, no actual locking needed
+    }
+
+    unsafe fn release(_restore_state: RawRestoreState) {
+        // WASM is single-threaded, no actual unlocking needed
+    }
+}

packages/wasm-bip32/src/lib.rs

@@ -138,10 +138,8 @@ describe("WasmBIP32", () => {
   });
 });
 
-describe("BIP32 Benchmarks: wasm-bip32 vs utxo-lib", function () {
-  // Increase timeout for benchmark tests (default mocha timeout is 2000ms)
-  this.timeout(30000);
-  const ops = 100;
+describe("BIP32 Benchmarks: wasm-bip32 vs utxo-lib", () => {
+  const ops = 1000;
   const seed = new Uint8Array(32).fill(1);
   const xprv =
     "xprv9s21ZrQH143K3QTDL4LXw2F7HEK3wJUD2nW2nRk4stbPy6cq3jPPqjiChkVvvNKmPGJxWUtg6LnF5kejMRNNU3TGtRBeJgk33yuGBxrMPHi";