feat: fast span and trace id generation

packages/opentelemetry-core/src/platform/browser/id.ts

@@ -13,44 +13,26 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-declare type WindowWithMsCrypto = Window & {
-  msCrypto?: Crypto;
-};
-const cryptoLib = window.crypto || (window as WindowWithMsCrypto).msCrypto;
 
 const SPAN_ID_BYTES = 8;
 const TRACE_ID_BYTES = 16;
-const randomBytesArray = new Uint8Array(TRACE_ID_BYTES);
 
 /** Returns a random 16-byte trace ID formatted as a 32-char hex string. */
-export function randomTraceId(): string {
-  cryptoLib.getRandomValues(randomBytesArray);
-  return toHex(randomBytesArray.slice(0, TRACE_ID_BYTES));
-}
+export const randomTraceId = getIdGenerator(TRACE_ID_BYTES);
 
 /** Returns a random 8-byte span ID formatted as a 16-char hex string. */
-export function randomSpanId(): string {
-  cryptoLib.getRandomValues(randomBytesArray);
-  return toHex(randomBytesArray.slice(0, SPAN_ID_BYTES));
-}
-
-/**
- * Get the hex string representation of a byte array
- *
- * @param byteArray
- */
-function toHex(byteArray: Uint8Array) {
-  const chars: number[] = new Array(byteArray.length * 2);
-  const alpha = 'a'.charCodeAt(0) - 10;
-  const digit = '0'.charCodeAt(0);
+export const randomSpanId = getIdGenerator(SPAN_ID_BYTES);
 
-  let p = 0;
-  for (let i = 0; i < byteArray.length; i++) {
-    let nibble = (byteArray[i] >>> 4) & 0xf;
-    chars[p++] = nibble > 9 ? nibble + alpha : nibble + digit;
-    nibble = byteArray[i] & 0xf;
-    chars[p++] = nibble > 9 ? nibble + alpha : nibble + digit;
+const SHARED_CHAR_CODES_ARRAY = Array(32);
+function getIdGenerator(bytes: number): () => string {
+  return function generateId() {
+    for (let i = 0; i < bytes * 2; i++) {
+      SHARED_CHAR_CODES_ARRAY[i] = (Math.floor(Math.random() * 16)) + 48;
+      // valid hex characters in the range 48-57 and 97-102
+      if (SHARED_CHAR_CODES_ARRAY[i] >= 58) { 
+        SHARED_CHAR_CODES_ARRAY[i] += 39
+      }
+    }
+    return String.fromCharCode.apply(null, SHARED_CHAR_CODES_ARRAY.slice(0, bytes * 2));
   }
-
-  return String.fromCharCode.apply(null, chars);
 }

packages/opentelemetry-core/src/platform/node/id.ts

@@ -14,23 +14,27 @@
  * limitations under the License.
  */
 
-import * as crypto from 'crypto';
-
 const SPAN_ID_BYTES = 8;
 const TRACE_ID_BYTES = 16;
 
 /**
  * Returns a random 16-byte trace ID formatted/encoded as a 32 lowercase hex
  * characters corresponding to 128 bits.
  */
-export function randomTraceId(): string {
-  return crypto.randomBytes(TRACE_ID_BYTES).toString('hex');
-}
+export const randomTraceId = getIdGenerator(TRACE_ID_BYTES);
 
 /**
  * Returns a random 8-byte span ID formatted/encoded as a 16 lowercase hex
  * characters corresponding to 64 bits.
  */
-export function randomSpanId(): string {
-  return crypto.randomBytes(SPAN_ID_BYTES).toString('hex');
+export const randomSpanId = getIdGenerator(SPAN_ID_BYTES);
+
+const SHARED_BUFFER = Buffer.allocUnsafe(TRACE_ID_BYTES);
+function getIdGenerator(bytes: number): () => string {
+  return function generateId() {
+    for (let i = 0; i < bytes; i++) {
+      SHARED_BUFFER[i] = Math.floor(Math.random() * 256);
+    }
+    return SHARED_BUFFER.slice(0, bytes).toString('hex');
+  }
 }

packages/opentelemetry-core/test/platform/id.test.ts

@@ -20,6 +20,7 @@ import { randomSpanId, randomTraceId } from '../../src/platform';
 describe('randomTraceId', () => {
   it('returns 32 character hex strings', () => {
     const traceId = randomTraceId();
+    console.log(traceId);
     assert.ok(traceId.match(/[a-f0-9]{32}/));
     assert.ok(!traceId.match(/^0+$/));
   });