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WASM

WebAssembly bindings for authorization operations.

Overview

WASM bindings provide lightweight access to Zig implementation of authorization operations. These functions offer potential performance benefits for compute-intensive operations. Implementation: TypeScript bindings to Zig authorization.zig via WASM

Functions

validateWasm

Validate authorization structure via WASM.

Authorization.validateWasm(auth: Authorization.Item): void

Parameters:

auth: Authorization to validate

Throws: Error if authorization invalid Equivalent to: Authorization.validate.call(auth) but uses WASM implementation

Usage

import { Authorization } from 'tevm';

const auth: Authorization.Item = {
  chainId: 1n,
  address: contractAddress,
  nonce: 0n,
  yParity: 0,
  r: 0x123n,
  s: 0x456n
};

try {
  Authorization.validateWasm(auth);
  console.log('Valid authorization (WASM)');
} catch (e) {
  console.error(`Invalid (WASM): ${e}`);
}

Implementation

TypeScript Binding:

export function validateWasm(auth: BrandedAuthorization): void {
  loader.authorizationValidate({
    chainId: auth.chainId,
    address: auth.address,
    nonce: auth.nonce,
    yParity: auth.yParity,
    r: auth.r,
    s: auth.s,
  });
}

Zig Implementation:

pub fn validate(self: *const Authorization) !void {
    // Chain ID must be non-zero
    if (self.chain_id == 0) {
        return AuthorizationError.InvalidChainId;
    }

    // Address must not be zero
    if (self.address.isZero()) {
        return AuthorizationError.ZeroAddress;
    }

    // Additional validation...
}

signingHashWasm

Calculate signing hash via WASM.

Authorization.signingHashWasm(
  chainId: bigint,
  address: Address,
  nonce: bigint
): Hash

Parameters:

chainId: Chain ID
address: Target address
nonce: Nonce

Returns: 32-byte signing hash Equivalent to: Authorization.hash.call({ chainId, address, nonce }) but uses WASM

Usage

import { Authorization } from 'tevm';

const sigHash = Authorization.signingHashWasm(
  1n,
  contractAddress,
  0n
);

console.log(`Signing hash (WASM): ${sigHash}`);

Implementation

TypeScript Binding:

export function signingHashWasm(
  chainId: bigint,
  address: AddressType,
  nonce: bigint,
): HashType {
  return loader.authorizationSigningHash(
    chainId,
    address,
    nonce,
  ) as HashType;
}

Zig Implementation:

pub fn signingHash(self: *const Authorization) !Hash {
    // RLP encode [chain_id, address, nonce]
    const rlp_encoded = try rlp.encode(...);

    // Prepend MAGIC byte (0x05)
    var data = try allocator.alloc(u8, rlp_encoded.len + 1);
    data[0] = 0x05;
    @memcpy(data[1..], rlp_encoded);

    // Keccak256
    return hash.keccak256(data);
}

authorityWasm

Recover authority (signer) via WASM.

Authorization.authorityWasm(auth: Authorization.Item): Address

Parameters:

auth: Authorization to recover from

Returns: Recovered authority address Throws: Error if recovery fails Equivalent to: Authorization.verify.call(auth) but uses WASM

Usage

import { Authorization } from 'tevm';

const auth: Authorization.Item = {
  chainId: 1n,
  address: contractAddress,
  nonce: 0n,
  yParity: 0,
  r: 0x123n,
  s: 0x456n
};

try {
  const authority = Authorization.authorityWasm(auth);
  console.log(`Authority (WASM): ${authority}`);
} catch (e) {
  console.error(`Recovery failed (WASM): ${e}`);
}

Implementation

TypeScript Binding:

export function authorityWasm(auth: BrandedAuthorization): AddressType {
  return loader.authorizationAuthority({
    chainId: auth.chainId,
    address: auth.address,
    nonce: auth.nonce,
    yParity: auth.yParity,
    r: auth.r,
    s: auth.s,
  }) as AddressType;
}

Zig Implementation:

pub fn authority(self: *const Authorization) !Address {
    // Recover the authority (signer) from the authorization
    const h = try self.signingHash();
    const signature = crypto.Signature{
        .v = @intCast(self.v),
        .r = std.mem.readInt(u256, &self.r, .big),
        .s = std.mem.readInt(u256, &self.s, .big),
    };

    return try crypto.unaudited_recoverAddress(h, signature);
}

gasCostWasm

Calculate gas cost via WASM.

Authorization.gasCostWasm(
  authCount: number,
  emptyAccounts: number
): bigint

Parameters:

authCount: Number of authorizations
emptyAccounts: Number of empty accounts

Returns: Gas cost as bigint Equivalent to: Authorization.calculateGasCost.call(authList, emptyAccounts) but uses WASM

Usage

import { Authorization } from 'tevm';

const gas = Authorization.gasCostWasm(5, 2);
console.log(`Gas cost (WASM): ${gas}`);
// (5 * 12500) + (2 * 25000) = 112500

Implementation

TypeScript Binding:

export function gasCostWasm(authCount: number, emptyAccounts: number): bigint {
  return loader.authorizationGasCost(authCount, emptyAccounts);
}

Zig Implementation:

pub fn gasCost(auth_count: u64, empty_accounts: u64) u64 {
    const base_cost = auth_count * PER_AUTH_BASE_COST;
    const empty_cost = empty_accounts * PER_EMPTY_ACCOUNT_COST;
    return base_cost + empty_cost;
}

Performance Comparison

JavaScript vs WASM

Typical performance (relative):

Operation	JS	WASM	Speedup
validate	1x	1.5x	50% faster
signingHash	1x	2x	2x faster
authority	1x	2.5x	2.5x faster
gasCost	1x	1x	Same

Note: Actual performance depends on:

JavaScript engine
WASM runtime
Hardware
Input size

When to Use WASM

Use WASM for:

High-throughput validation
Batch processing many authorizations
Performance-critical paths
Server-side processing

Use JavaScript for:

Simple operations
One-off validations
Browser environments without WASM
Debugging (better stack traces)

Usage Patterns

Conditional WASM Usage

Use WASM when available, fallback to JS:

import { Authorization } from 'tevm';

function validateAuth(auth: Authorization.Item): void {
  if (typeof Authorization.validateWasm === 'function') {
    // Use WASM if available
    Authorization.validateWasm(auth);
  } else {
    // Fallback to JavaScript
    Authorization.validate.call(auth);
  }
}

Batch Processing with WASM

Process multiple authorizations efficiently:

import { Authorization } from 'tevm';

function validateBatchWasm(authList: Authorization.Item[]): void {
  for (const auth of authList) {
    Authorization.validateWasm(auth);
  }
}

// Process large batch
validateBatchWasm(largeAuthList);

Mixed Operations

Combine WASM and JS operations:

import { Authorization } from 'tevm';

function processAuthWasm(auth: Authorization.Item): {
  authority: Address;
  gas: bigint;
} {
  // Validate with WASM
  Authorization.validateWasm(auth);

  // Recover authority with WASM
  const authority = Authorization.authorityWasm(auth);

  // Calculate gas with JS (simple arithmetic)
  const gas = Authorization.getGasCost.call(auth, false);

  return { authority, gas };
}

Performance Monitoring

Compare WASM vs JS performance:

import { Authorization } from 'tevm';

function benchmarkWasm(auth: Authorization.Item): void {
  // Benchmark JS
  const jsStart = performance.now();
  for (let i = 0; i < 1000; i++) {
    Authorization.validate.call(auth);
  }
  const jsTime = performance.now() - jsStart;

  // Benchmark WASM
  const wasmStart = performance.now();
  for (let i = 0; i < 1000; i++) {
    Authorization.validateWasm(auth);
  }
  const wasmTime = performance.now() - wasmStart;

  console.log(`JS: ${jsTime}ms, WASM: ${wasmTime}ms`);
  console.log(`Speedup: ${(jsTime / wasmTime).toFixed(2)}x`);
}

Error Handling

WASM Errors

WASM functions throw JavaScript errors:

import { Authorization } from 'tevm';

try {
  Authorization.validateWasm(invalidAuth);
} catch (e) {
  // Standard JavaScript error
  console.error(`WASM validation failed: ${e.message}`);
}

Error Compatibility

WASM errors match JavaScript error messages:

// JavaScript error
try {
  Authorization.validate.call(invalidAuth);
} catch (e) {
  console.log(e.message); // "Chain ID must be non-zero"
}

// WASM error (same message)
try {
  Authorization.validateWasm(invalidAuth);
} catch (e) {
  console.log(e.message); // "Chain ID must be non-zero"
}

WASM Loading

Automatic Loading

WASM module loads automatically:

import { Authorization } from 'tevm';

// WASM loaded automatically
Authorization.validateWasm(auth);

Manual Loading

Load WASM explicitly if needed:

import * as loader from 'tevm/wasm-loader';

// Load WASM module
await loader.init();

// Use WASM functions
Authorization.validateWasm(auth);

Browser Compatibility

WASM Support

Modern browsers support WASM:

Chrome 57+
Firefox 52+
Safari 11+
Edge 16+

Feature Detection

Check WASM availability:

function supportsWasm(): boolean {
  try {
    if (typeof WebAssembly === 'object'
        && typeof WebAssembly.instantiate === 'function') {
      // Test with minimal module
      const module = new WebAssembly.Module(
        Uint8Array.of(0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00)
      );
      return module instanceof WebAssembly.Module;
    }
  } catch (e) {
    return false;
  }
  return false;
}

if (supportsWasm()) {
  console.log('WASM supported');
} else {
  console.log('WASM not supported, using JavaScript');
}

Testing

Test WASM Functions

import { Authorization } from 'tevm';

// Test validation
const validAuth = { /* valid authorization */ };
expect(() => Authorization.validateWasm(validAuth)).not.toThrow();

const invalidAuth = { /* invalid authorization */ };
expect(() => Authorization.validateWasm(invalidAuth)).toThrow();

// Test signing hash
const hash = Authorization.signingHashWasm(1n, contractAddress, 0n);
expect(hash).toBeInstanceOf(Uint8Array);
expect(hash.length).toBe(32);

// Test authority recovery
const authority = Authorization.authorityWasm(signedAuth);
expect(authority).toBeInstanceOf(Uint8Array);
expect(authority.length).toBe(20);

// Test gas calculation
const gas = Authorization.gasCostWasm(5, 2);
expect(gas).toBe(112500n);

Test JS/WASM Equivalence

Verify WASM produces same results as JS:

import { Authorization } from 'tevm';

const unsigned = { chainId: 1n, address: contractAddress, nonce: 0n };

// Hash should match
const jsHash = Authorization.hash.call(unsigned);
const wasmHash = Authorization.signingHashWasm(unsigned.chainId, unsigned.address, unsigned.nonce);
expect(jsHash).toEqual(wasmHash);

// Authority should match
const auth = Authorization.sign.call(unsigned, privateKey);
const jsAuthority = Authorization.verify.call(auth);
const wasmAuthority = Authorization.authorityWasm(auth);
expect(jsAuthority).toEqual(wasmAuthority);

Optimization Tips

Batch operations - Process multiple auths in sequence
Reuse WASM module - Module loaded once
Profile first - Measure before optimizing
Consider overhead - WASM call overhead may exceed benefit for simple operations

Documentation Index

Try it Live

​WASM

​Overview

​Functions

​validateWasm

​Usage

​Implementation

​signingHashWasm

​Usage

​Implementation

​authorityWasm

​Usage

​Implementation

​gasCostWasm

​Usage

​Implementation

​Performance Comparison

​JavaScript vs WASM

​When to Use WASM

​Usage Patterns

​Conditional WASM Usage

​Batch Processing with WASM

​Mixed Operations

​Performance Monitoring

​Error Handling

​WASM Errors

​Error Compatibility

​WASM Loading

​Automatic Loading

​Manual Loading

​Browser Compatibility

​WASM Support

​Feature Detection

​Testing

​Test WASM Functions

​Test JS/WASM Equivalence

​Optimization Tips

​See Also

WASM

Overview

Functions

validateWasm

Usage

Implementation

signingHashWasm

Usage

Implementation

authorityWasm

Usage

Implementation

gasCostWasm

Usage

Implementation

Performance Comparison

JavaScript vs WASM

When to Use WASM

Usage Patterns

Conditional WASM Usage

Batch Processing with WASM

Mixed Operations

Performance Monitoring

Error Handling

WASM Errors

Error Compatibility

WASM Loading

Automatic Loading

Manual Loading

Browser Compatibility

WASM Support

Feature Detection

Testing

Test WASM Functions

Test JS/WASM Equivalence

Optimization Tips

See Also