From 82f5a9766b168637788595a35bf205be2fa89f43 Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Fri, 26 Apr 2019 18:16:40 -0400
Subject: [PATCH 01/16] Adding 128 bit traceId support Signed-off-by: Paul
 Biccherai <paul.biccherai@chronwell.com>

---
 .gitignore           |  1 +
 src/_flow/tracer.js  |  1 +
 src/span_context.js  | 71 ++++++++++++++++++++++++++++++++++----------
 src/thrift.js        |  9 +++---
 src/tracer.js        | 12 ++++++--
 test/span.js         |  1 +
 test/span_context.js | 51 +++++++++++++++++++++++++++----
 test/thrift.js       | 19 ++++++++++++
 test/tracer.js       | 31 +++++++++++++------
 9 files changed, 160 insertions(+), 36 deletions(-)

diff --git a/.gitignore b/.gitignore
index dc9c88d0a..ca1545c45 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@ npm-debug.log
 dist/
 
 .idea/
+.vscode/
 *.iml
 
 crossdock/jaeger-docker-compose.yml
diff --git a/src/_flow/tracer.js b/src/_flow/tracer.js
index 4334332e4..4d4f9d666 100644
--- a/src/_flow/tracer.js
+++ b/src/_flow/tracer.js
@@ -20,4 +20,5 @@ declare type startSpanOptions = {
   references?: Array<Reference>,
   tags?: any,
   startTime?: number,
+  traceId128bit?: boolean,
 };
diff --git a/src/span_context.js b/src/span_context.js
index 64d6d1d7b..346befd10 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -15,7 +15,8 @@ import * as constants from './constants.js';
 import Utils from './util.js';
 
 export default class SpanContext {
-  _traceId: any;
+  _traceIdLow: any;
+  _traceIdHigh: any;
   _spanId: any;
   _parentId: any;
   _traceIdStr: ?string;
@@ -43,7 +44,8 @@ export default class SpanContext {
   _samplingFinalized: boolean;
 
   constructor(
-    traceId: any,
+    traceIdLow: any,
+    traceIdHigh: any,
     spanId: any,
     parentId: any,
     traceIdStr: ?string,
@@ -54,7 +56,8 @@ export default class SpanContext {
     debugId: ?string = '',
     samplingFinalized: boolean = false
   ) {
-    this._traceId = traceId;
+    this._traceIdLow = traceIdLow;
+    this._traceIdHigh = traceIdHigh;
     this._spanId = spanId;
     this._parentId = parentId;
     this._traceIdStr = traceIdStr;
@@ -66,11 +69,32 @@ export default class SpanContext {
     this._samplingFinalized = samplingFinalized;
   }
 
-  get traceId(): any {
-    if (this._traceId == null && this._traceIdStr != null) {
-      this._traceId = Utils.encodeInt64(this._traceIdStr);
+  get traceIdLow(): any {
+    this._tryParseTraceIdStr();
+    return this._traceIdLow;
+  }
+
+  get traceIdHigh(): any {
+    this._tryParseTraceIdStr();
+    return this._traceIdHigh;
+  }
+
+  _tryParseTraceIdStr() {
+    if (this._traceIdLow == null && this._traceIdHigh == null && this._traceIdStr != null) {
+      if (this._traceIdStr.length > 16) {
+        const safeTraceIdStr = this._traceIdStr.length % 2 == 0 ? this._traceIdStr : '0' + this._traceIdStr;
+        const traceId = Buffer.from(safeTraceIdStr, 'hex');
+        this._traceIdHigh = traceId.slice(-16, -8);
+        if (this._traceIdHigh.length != 8) {
+          const tmpBuffer = Buffer.alloc(8);
+          this._traceIdHigh.copy(tmpBuffer, 8 - this._traceIdHigh.length);
+          this._traceIdHigh = tmpBuffer;
+        }
+        this._traceIdLow = traceId.slice(-8);
+      } else {
+        this._traceIdLow = Utils.encodeInt64(this._traceIdStr);
+      }
     }
-    return this._traceId;
   }
 
   get spanId(): any {
@@ -88,8 +112,14 @@ export default class SpanContext {
   }
 
   get traceIdStr(): ?string {
-    if (this._traceIdStr == null && this._traceId != null) {
-      this._traceIdStr = Utils.removeLeadingZeros(this._traceId.toString('hex'));
+    if (this._traceIdStr == null && this._traceIdLow != null) {
+      if (this._traceIdHigh != null) {
+        this._traceIdStr = Utils.removeLeadingZeros(
+          this._traceIdHigh.toString('hex') + this._traceIdLow.toString('hex')
+        );
+      } else {
+        this._traceIdStr = Utils.removeLeadingZeros(this._traceIdLow.toString('hex'));
+      }
     }
     return this._traceIdStr;
   }
@@ -124,8 +154,13 @@ export default class SpanContext {
     return this._samplingFinalized;
   }
 
-  set traceId(traceId: Buffer): void {
-    this._traceId = traceId;
+  set traceIdLow(traceIdLow: Buffer): void {
+    this._traceIdLow = traceIdLow;
+    this._traceIdStr = null;
+  }
+
+  set traceIdHigh(traceIdHigh: Buffer): void {
+    this._traceIdHigh = traceIdHigh;
     this._traceIdStr = null;
   }
 
@@ -152,7 +187,7 @@ export default class SpanContext {
   }
 
   get isValid(): boolean {
-    return !!((this._traceId || this._traceIdStr) && (this._spanId || this._spanIdStr));
+    return !!((this._traceIdLow || this._traceIdStr) && (this._spanId || this._spanIdStr));
   }
 
   finalizeSampling(): void {
@@ -181,7 +216,8 @@ export default class SpanContext {
     let newBaggage = Utils.clone(this._baggage);
     newBaggage[key] = value;
     return new SpanContext(
-      this._traceId,
+      this._traceIdLow,
+      this._traceIdHigh,
       this._spanId,
       this._parentId,
       this._traceIdStr,
@@ -238,7 +274,8 @@ export default class SpanContext {
   }
 
   static withBinaryIds(
-    traceId: any,
+    traceIdLow: any,
+    traceIdHigh: any,
     spanId: any,
     parentId: any,
     flags: number,
@@ -246,7 +283,8 @@ export default class SpanContext {
     debugId: ?string = ''
   ): SpanContext {
     return new SpanContext(
-      traceId,
+      traceIdLow,
+      traceIdHigh,
       spanId,
       parentId,
       null, // traceIdStr: string,
@@ -267,7 +305,8 @@ export default class SpanContext {
     debugId: ?string = ''
   ): SpanContext {
     return new SpanContext(
-      null, // traceId,
+      null, // traceIdLow,
+      null, // traceIdHigh,
       null, // spanId,
       null, // parentId,
       traceIdStr,
diff --git a/src/thrift.js b/src/thrift.js
index c0d83a2d6..bd1028261 100644
--- a/src/thrift.js
+++ b/src/thrift.js
@@ -104,8 +104,8 @@ export default class ThriftUtils {
 
       thriftRefs.push({
         refType: refEnum,
-        traceIdLow: context.traceId,
-        traceIdHigh: ThriftUtils.emptyBuffer,
+        traceIdLow: context.traceIdLow,
+        traceIdHigh: context.traceIdHigh == null ? ThriftUtils.emptyBuffer : context.traceIdHigh,
         spanId: context.spanId,
       });
     }
@@ -119,8 +119,9 @@ export default class ThriftUtils {
     let unsigned = true;
 
     return {
-      traceIdLow: span._spanContext.traceId,
-      traceIdHigh: ThriftUtils.emptyBuffer, // TODO(oibe) implement 128 bit ids
+      traceIdLow: span._spanContext.traceIdLow,
+      traceIdHigh:
+        span._spanContext.traceIdHigh == null ? ThriftUtils.emptyBuffer : span._spanContext.traceIdHigh,
       spanId: span._spanContext.spanId,
       parentSpanId: span._spanContext.parentId || ThriftUtils.emptyBuffer,
       operationName: span._operationName,
diff --git a/src/tracer.js b/src/tracer.js
index 6f11c7aba..6aa0b671c 100644
--- a/src/tracer.js
+++ b/src/tracer.js
@@ -188,6 +188,8 @@ export default class Tracer {
    *        the created Span object. The time should be specified in
    *        milliseconds as Unix timestamp. Decimal value are supported
    *        to represent time values with sub-millisecond accuracy.
+   * @param {number} [options.traceId128bit] - generate root span with a
+   *        128bit traceId.
    * @return {Span} - a new Span object.
    **/
   startSpan(operationName: string, options: ?startSpanOptions): Span {
@@ -239,12 +241,18 @@ export default class Tracer {
         ctx.baggage = parent.baggage;
       }
 
-      ctx.traceId = randomId;
+      if (options.traceId128bit) {
+        ctx.traceIdLow = randomId;
+        ctx.traceIdHigh = Utils.getRandom64();
+      } else {
+        ctx.traceIdLow = randomId;
+      }
       ctx.spanId = randomId;
       ctx.parentId = null;
       ctx.flags = flags;
     } else {
-      ctx.traceId = parent.traceId;
+      ctx.traceIdLow = parent.traceIdLow;
+      ctx.traceIdHigh = parent.traceIdHigh;
       ctx.spanId = Utils.getRandom64();
       ctx.parentId = parent.spanId;
       ctx.flags = parent.flags;
diff --git a/test/span.js b/test/span.js
index 779b64196..59665ffbe 100644
--- a/test/span.js
+++ b/test/span.js
@@ -35,6 +35,7 @@ describe('span should', () => {
 
     spanContext = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
+      null,
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       constants.SAMPLED_MASK
diff --git a/test/span_context.js b/test/span_context.js
index 96208dc31..e051577d1 100644
--- a/test/span_context.js
+++ b/test/span_context.js
@@ -24,14 +24,31 @@ describe('SpanContext should', () => {
   });
 
   it('return given values as they were set', () => {
-    let traceId = Utils.encodeInt64(1);
+    let traceIdLow = Utils.encodeInt64(1);
     let spanId = Utils.encodeInt64(2);
     let parentId = Utils.encodeInt64(3);
     let flags = 1;
 
-    let context = SpanContext.withBinaryIds(traceId, spanId, parentId, flags);
+    let context = SpanContext.withBinaryIds(traceIdLow, null, spanId, parentId, flags);
 
-    assert.deepEqual(traceId, context.traceId);
+    assert.deepEqual(traceIdLow, context.traceIdLow);
+    assert.deepEqual(spanId, context.spanId);
+    assert.deepEqual(parentId, context.parentId);
+    assert.equal(flags, context.flags);
+  });
+
+  it('return given values as they were set 128 bit', () => {
+    let traceIdLow = Utils.encodeInt64(1);
+    let traceIdHigh = Utils.encodeInt64(2);
+    let spanId = Utils.encodeInt64(3);
+    let parentId = Utils.encodeInt64(4);
+    let flags = 1;
+
+    let context = SpanContext.withBinaryIds(traceIdLow, traceIdHigh, spanId, parentId, flags);
+
+    assert.deepEqual(traceIdLow, context.traceIdLow);
+    assert.deepEqual(traceIdHigh, context.traceIdHigh);
+    assert.deepEqual('20000000000000001', context.traceIdStr);
     assert.deepEqual(spanId, context.spanId);
     assert.deepEqual(parentId, context.parentId);
     assert.equal(flags, context.flags);
@@ -40,6 +57,7 @@ describe('SpanContext should', () => {
   it('return IsSampled properly', () => {
     let context = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
+      null,
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       3
@@ -53,11 +71,12 @@ describe('SpanContext should', () => {
   });
 
   it('format strings properly with toString', () => {
-    let ctx1 = SpanContext.withBinaryIds(Utils.encodeInt64(0x100), Utils.encodeInt64(0x7f), null, 1);
+    let ctx1 = SpanContext.withBinaryIds(Utils.encodeInt64(0x100), null, Utils.encodeInt64(0x7f), null, 1);
     assert.equal(ctx1.toString(), '100:7f:0:1');
 
     let ctx2 = SpanContext.withBinaryIds(
       Utils.encodeInt64(255 << 4),
+      null,
       Utils.encodeInt64(127),
       Utils.encodeInt64(256),
       0
@@ -65,7 +84,7 @@ describe('SpanContext should', () => {
     assert.equal(ctx2.toString(), 'ff0:7f:100:0');
 
     // test large numbers
-    let ctx3 = SpanContext.withBinaryIds(LARGEST_64_BUFFER, LARGEST_64_BUFFER, LARGEST_64_BUFFER, 0);
+    let ctx3 = SpanContext.withBinaryIds(LARGEST_64_BUFFER, null, LARGEST_64_BUFFER, LARGEST_64_BUFFER, 0);
     assert.equal(ctx3.toString(), 'ffffffffffffffff:ffffffffffffffff:ffffffffffffffff:0');
     assert.equal('ffffffffffffffff', ctx3.traceIdStr);
     assert.equal('ffffffffffffffff', ctx3.spanIdStr);
@@ -90,6 +109,28 @@ describe('SpanContext should', () => {
     assert.equal(context.flags, 0x1);
   });
 
+  it('turn properly formatted strings into correct span contexts 128 bit', () => {
+    let context = SpanContext.fromString('20000000000000100:7f:0:1');
+
+    assert.deepEqual('20000000000000100', context.traceIdStr);
+    assert.deepEqual(Utils.encodeInt64(0x100), context.traceIdLow);
+    assert.deepEqual(Utils.encodeInt64(0x2), context.traceIdHigh);
+    assert.deepEqual(Utils.encodeInt64(0x7f), context.spanId);
+    assert.equal(null, context.parentId);
+    assert.equal(1, context.flags);
+
+    // test large numbers
+    context = SpanContext.fromString('ffffffffffffffffffffffffffffffff:ffffffffffffffff:5:1');
+    assert.equal('ffffffffffffffffffffffffffffffff', context.traceIdStr);
+    assert.equal('ffffffffffffffff', context.spanIdStr);
+    assert.deepEqual(LARGEST_64_BUFFER, context.traceIdLow);
+    assert.deepEqual(LARGEST_64_BUFFER, context.traceIdHigh);
+    assert.deepEqual(LARGEST_64_BUFFER, context.spanId);
+    assert.deepEqual(LARGEST_64_BUFFER, context.spanId);
+    assert.deepEqual(Utils.encodeInt64(0x5), context.parentId);
+    assert.equal(context.flags, 0x1);
+  });
+
   it('return null on malformed traces', () => {
     assert.equal(SpanContext.fromString('bad value'), null);
     assert.equal(SpanContext.fromString('1:1:1:1:1'), null, 'Too many colons');
diff --git a/test/thrift.js b/test/thrift.js
index ec1b0f3cf..3f1829130 100644
--- a/test/thrift.js
+++ b/test/thrift.js
@@ -11,6 +11,7 @@
 // the License.
 
 import { assert } from 'chai';
+import opentracing from 'opentracing';
 import ConstSampler from '../src/samplers/const_sampler.js';
 import InMemoryReporter from '../src/reporters/in_memory_reporter.js';
 import Tracer from '../src/tracer.js';
@@ -64,4 +65,22 @@ describe('ThriftUtils', () => {
     assert.deepEqual(tSpan.duration, Utils.encodeInt64((123.678 - 123.456) * 1000));
     assert.deepEqual(tSpan.logs[0].timestamp, Utils.encodeInt64(123567));
   });
+
+  it('should convert span with 128 bit traceId', () => {
+    let reporter = new InMemoryReporter();
+    let tracer = new Tracer('test-service-name', reporter, new ConstSampler(true));
+    let span = tracer.startSpan('some operation', { traceId128bit: true });
+    let childOfRef = new opentracing.Reference(opentracing.REFERENCE_CHILD_OF, span.context());
+    let childSpan = tracer.startSpan('some child operation', { references: [childOfRef] });
+    childSpan.finish();
+    span.finish();
+    tracer.close();
+    let tSpan = ThriftUtils.spanToThrift(childSpan);
+    assert.deepEqual(tSpan.traceIdLow, childSpan.context().traceIdLow);
+    assert.deepEqual(tSpan.traceIdHigh, childSpan.context().traceIdHigh);
+    assert.deepEqual(tSpan.spanId, childSpan.context().spanId);
+    assert.deepEqual(tSpan.references[0].traceIdLow, span.context().traceIdLow);
+    assert.deepEqual(tSpan.references[0].traceIdHigh, span.context().traceIdHigh);
+    assert.deepEqual(tSpan.references[0].spanId, span.context().spanId);
+  });
 });
diff --git a/test/tracer.js b/test/tracer.js
index ac65b2c39..92fa77566 100644
--- a/test/tracer.js
+++ b/test/tracer.js
@@ -89,7 +89,7 @@ describe('tracer should', () => {
     let spanContext = tracer.extract(opentracing.FORMAT_TEXT_MAP, headers);
     let rootSpan = tracer.startSpan('fry', { childOf: spanContext });
 
-    assert.isOk(rootSpan.context().traceId);
+    assert.isOk(rootSpan.context().traceIdLow);
     assert.isNotOk(rootSpan.context().parentId);
     assert.equal(rootSpan.context().flags, 1);
     assert.equal('Bender', rootSpan.getBaggageItem('robot'));
@@ -98,11 +98,11 @@ describe('tracer should', () => {
   });
 
   it('create a span correctly through _startInternalSpan', () => {
-    let traceId = Utils.encodeInt64(1);
+    let traceIdLow = Utils.encodeInt64(1);
     let spanId = Utils.encodeInt64(2);
     let parentId = Utils.encodeInt64(3);
     let flags = 1;
-    let context = SpanContext.withBinaryIds(traceId, spanId, parentId, flags);
+    let context = SpanContext.withBinaryIds(traceIdLow, null, spanId, parentId, flags);
     let start = 123.456;
     let rpcServer = false;
     let internalTags = [];
@@ -122,7 +122,7 @@ describe('tracer should', () => {
       references
     );
 
-    assert.deepEqual(span.context().traceId, traceId);
+    assert.deepEqual(span.context().traceIdLow, traceIdLow);
     assert.deepEqual(span.context().spanId, spanId);
     assert.deepEqual(span.context().parentId, parentId);
     assert.equal(span.context().flags, flags);
@@ -151,7 +151,7 @@ describe('tracer should', () => {
       startTime: startTime,
     });
 
-    assert.equal(span.context().traceId, span.context().spanId);
+    assert.equal(span.context().traceIdLow, span.context().spanId);
     assert.isNotOk(span.context().parentId);
     assert.isOk(span.context().isSampled());
     assert.equal(span._startTime, startTime);
@@ -160,13 +160,13 @@ describe('tracer should', () => {
   describe('start a child span represented as a separate span from parent, using childOf and references', () => {
     let nextId = 0;
     const getId = () => Utils.encodeInt64(nextId++);
-    const traceId = getId();
+    const traceIdLow = getId();
     const flags = 1;
 
-    const parentContext = SpanContext.withBinaryIds(traceId, getId(), null, flags);
-    const childOfContext = SpanContext.withBinaryIds(traceId, getId(), null, flags);
+    const parentContext = SpanContext.withBinaryIds(traceIdLow, getId(), null, flags);
+    const childOfContext = SpanContext.withBinaryIds(traceIdLow, getId(), null, flags);
     const childOfRef = new opentracing.Reference(opentracing.REFERENCE_CHILD_OF, childOfContext);
-    const followsFromContext = SpanContext.withBinaryIds(traceId, getId(), null, flags);
+    const followsFromContext = SpanContext.withBinaryIds(traceIdLow, getId(), null, flags);
     const followsFromRef = new opentracing.Reference(opentracing.REFERENCE_FOLLOWS_FROM, followsFromContext);
 
     const testCases = [
@@ -264,6 +264,7 @@ describe('tracer should', () => {
     };
     let savedContext = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
+      null,
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       constants.SAMPLED_MASK,
@@ -293,6 +294,7 @@ describe('tracer should', () => {
     };
     let savedContext = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
+      null,
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       constants.SAMPLED_MASK,
@@ -418,6 +420,17 @@ describe('tracer should', () => {
     });
   });
 
+  it('start a root span with 128 bit traceId', () => {
+    let span = tracer.startSpan('test-name', {
+      traceId128bit: true,
+    });
+
+    assert.equal(span.context().traceIdLow, span.context().spanId);
+    assert.isOk(span.context().traceIdHigh);
+    assert.isNotOk(span.context().parentId);
+    assert.isOk(span.context().isSampled());
+  });
+
   it('should NOT mutate tags', () => {
     const tags = {
       robot: 'bender',

From 678561f46251f2830af9ed06f7d4676dcf483186 Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Fri, 26 Apr 2019 19:38:01 -0400
Subject: [PATCH 02/16] fix node 0.10 issue Signed-off-by: Paul Biccherai
 <paul.biccherai@chronwell.com>

---
 src/span_context.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/span_context.js b/src/span_context.js
index 346befd10..be4e8731e 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -83,10 +83,11 @@ export default class SpanContext {
     if (this._traceIdLow == null && this._traceIdHigh == null && this._traceIdStr != null) {
       if (this._traceIdStr.length > 16) {
         const safeTraceIdStr = this._traceIdStr.length % 2 == 0 ? this._traceIdStr : '0' + this._traceIdStr;
-        const traceId = Buffer.from(safeTraceIdStr, 'hex');
+        const traceId = new Buffer(safeTraceIdStr, 'hex');
         this._traceIdHigh = traceId.slice(-16, -8);
         if (this._traceIdHigh.length != 8) {
-          const tmpBuffer = Buffer.alloc(8);
+          const tmpBuffer = new Buffer(8);
+          tmpBuffer.fill(0);
           this._traceIdHigh.copy(tmpBuffer, 8 - this._traceIdHigh.length);
           this._traceIdHigh = tmpBuffer;
         }

From cd7cf056b9d9aba4f28bd9b38517d1e4405d258a Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Thu, 9 May 2019 11:21:29 -0400
Subject: [PATCH 03/16] Replace node latest to lts in the travis config
 Signed-off-by: Paul Biccherai <paul.biccherai@chronwell.com>

---
 .travis.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.travis.yml b/.travis.yml
index a06341e18..a3a30b7c2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,6 +21,8 @@ matrix:
       - docker
   - env: TEST_NODE_VERSION=6 LINT=1 COVER=1
   - env: TEST_NODE_VERSION=4
+  - env: TEST_NODE_VERSION=--lts
+  allow_failures:
   - env: TEST_NODE_VERSION=node
 
 env:

From 0c23d6fb140928141d5d3416c9c2d383956cf3dd Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Thu, 9 May 2019 12:54:31 -0400
Subject: [PATCH 04/16] Fix travis file, adding back build for node latest
 Signed-off-by: Paul Biccherai <paul.biccherai@chronwell.com>

---
 .travis.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.travis.yml b/.travis.yml
index a3a30b7c2..e8abda726 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,6 +22,7 @@ matrix:
   - env: TEST_NODE_VERSION=6 LINT=1 COVER=1
   - env: TEST_NODE_VERSION=4
   - env: TEST_NODE_VERSION=--lts
+  - env: TEST_NODE_VERSION=node
   allow_failures:
   - env: TEST_NODE_VERSION=node
 

From 16e1d9156a8b81a8f7ab9ad71279cfd022405bf5 Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Wed, 15 May 2019 19:03:20 -0400
Subject: [PATCH 05/16] Refactoring traceId Signed-off-by: Paul Biccherai
 <paul.biccherai@chronwell.com>

---
 src/span_context.js  | 77 ++++++++++++--------------------------------
 src/thrift.js        | 25 +++++++++++---
 src/tracer.js        |  8 ++---
 test/span.js         |  1 -
 test/span_context.js | 27 +++++++---------
 test/thrift.js       |  8 ++---
 test/tracer.js       | 56 ++++++++++++++++++++++++--------
 7 files changed, 102 insertions(+), 100 deletions(-)

diff --git a/src/span_context.js b/src/span_context.js
index be4e8731e..3451848fb 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -15,8 +15,7 @@ import * as constants from './constants.js';
 import Utils from './util.js';
 
 export default class SpanContext {
-  _traceIdLow: any;
-  _traceIdHigh: any;
+  _traceId: any;
   _spanId: any;
   _parentId: any;
   _traceIdStr: ?string;
@@ -44,8 +43,7 @@ export default class SpanContext {
   _samplingFinalized: boolean;
 
   constructor(
-    traceIdLow: any,
-    traceIdHigh: any,
+    traceId: any,
     spanId: any,
     parentId: any,
     traceIdStr: ?string,
@@ -56,8 +54,7 @@ export default class SpanContext {
     debugId: ?string = '',
     samplingFinalized: boolean = false
   ) {
-    this._traceIdLow = traceIdLow;
-    this._traceIdHigh = traceIdHigh;
+    this._traceId = traceId;
     this._spanId = spanId;
     this._parentId = parentId;
     this._traceIdStr = traceIdStr;
@@ -69,33 +66,16 @@ export default class SpanContext {
     this._samplingFinalized = samplingFinalized;
   }
 
-  get traceIdLow(): any {
-    this._tryParseTraceIdStr();
-    return this._traceIdLow;
-  }
-
-  get traceIdHigh(): any {
-    this._tryParseTraceIdStr();
-    return this._traceIdHigh;
-  }
-
-  _tryParseTraceIdStr() {
-    if (this._traceIdLow == null && this._traceIdHigh == null && this._traceIdStr != null) {
-      if (this._traceIdStr.length > 16) {
-        const safeTraceIdStr = this._traceIdStr.length % 2 == 0 ? this._traceIdStr : '0' + this._traceIdStr;
-        const traceId = new Buffer(safeTraceIdStr, 'hex');
-        this._traceIdHigh = traceId.slice(-16, -8);
-        if (this._traceIdHigh.length != 8) {
-          const tmpBuffer = new Buffer(8);
-          tmpBuffer.fill(0);
-          this._traceIdHigh.copy(tmpBuffer, 8 - this._traceIdHigh.length);
-          this._traceIdHigh = tmpBuffer;
-        }
-        this._traceIdLow = traceId.slice(-8);
-      } else {
-        this._traceIdLow = Utils.encodeInt64(this._traceIdStr);
-      }
+  get traceId(): any {
+    if (this._traceId == null && this._traceIdStr != null) {
+      const safeTraceIdStr = this._traceIdStr.length % 2 == 0 ? this._traceIdStr : '0' + this._traceIdStr;
+      const tmpBuffer = new Buffer(safeTraceIdStr, 'hex');
+      const size = tmpBuffer.length > 8 ? 16 : 8;
+      this._traceId = new Buffer(size);
+      this._traceId.fill(0);
+      tmpBuffer.copy(this._traceId, size - tmpBuffer.length);
     }
+    return this._traceId;
   }
 
   get spanId(): any {
@@ -113,14 +93,8 @@ export default class SpanContext {
   }
 
   get traceIdStr(): ?string {
-    if (this._traceIdStr == null && this._traceIdLow != null) {
-      if (this._traceIdHigh != null) {
-        this._traceIdStr = Utils.removeLeadingZeros(
-          this._traceIdHigh.toString('hex') + this._traceIdLow.toString('hex')
-        );
-      } else {
-        this._traceIdStr = Utils.removeLeadingZeros(this._traceIdLow.toString('hex'));
-      }
+    if (this._traceIdStr == null && this._traceId != null) {
+      this._traceIdStr = Utils.removeLeadingZeros(this._traceId.toString('hex'));
     }
     return this._traceIdStr;
   }
@@ -155,13 +129,8 @@ export default class SpanContext {
     return this._samplingFinalized;
   }
 
-  set traceIdLow(traceIdLow: Buffer): void {
-    this._traceIdLow = traceIdLow;
-    this._traceIdStr = null;
-  }
-
-  set traceIdHigh(traceIdHigh: Buffer): void {
-    this._traceIdHigh = traceIdHigh;
+  set traceId(traceId: Buffer): void {
+    this._traceId = traceId;
     this._traceIdStr = null;
   }
 
@@ -188,7 +157,7 @@ export default class SpanContext {
   }
 
   get isValid(): boolean {
-    return !!((this._traceIdLow || this._traceIdStr) && (this._spanId || this._spanIdStr));
+    return !!((this._traceId || this._traceIdStr) && (this._spanId || this._spanIdStr));
   }
 
   finalizeSampling(): void {
@@ -217,8 +186,7 @@ export default class SpanContext {
     let newBaggage = Utils.clone(this._baggage);
     newBaggage[key] = value;
     return new SpanContext(
-      this._traceIdLow,
-      this._traceIdHigh,
+      this._traceId,
       this._spanId,
       this._parentId,
       this._traceIdStr,
@@ -275,8 +243,7 @@ export default class SpanContext {
   }
 
   static withBinaryIds(
-    traceIdLow: any,
-    traceIdHigh: any,
+    traceId: any,
     spanId: any,
     parentId: any,
     flags: number,
@@ -284,8 +251,7 @@ export default class SpanContext {
     debugId: ?string = ''
   ): SpanContext {
     return new SpanContext(
-      traceIdLow,
-      traceIdHigh,
+      traceId,
       spanId,
       parentId,
       null, // traceIdStr: string,
@@ -306,8 +272,7 @@ export default class SpanContext {
     debugId: ?string = ''
   ): SpanContext {
     return new SpanContext(
-      null, // traceIdLow,
-      null, // traceIdHigh,
+      null, // traceId,
       null, // spanId,
       null, // parentId,
       traceIdStr,
diff --git a/src/thrift.js b/src/thrift.js
index bd1028261..1aa0a95f8 100644
--- a/src/thrift.js
+++ b/src/thrift.js
@@ -104,8 +104,8 @@ export default class ThriftUtils {
 
       thriftRefs.push({
         refType: refEnum,
-        traceIdLow: context.traceIdLow,
-        traceIdHigh: context.traceIdHigh == null ? ThriftUtils.emptyBuffer : context.traceIdHigh,
+        traceIdLow: ThriftUtils.getTraceIdLow(context.traceId),
+        traceIdHigh: ThriftUtils.getTraceIdHigh(context.traceId),
         spanId: context.spanId,
       });
     }
@@ -113,15 +113,30 @@ export default class ThriftUtils {
     return thriftRefs;
   }
 
+  static getTraceIdLow(traceId: Buffer) {
+    if (traceId != null) {
+      return traceId.slice(-8);
+    }
+
+    return ThriftUtils.emptyBuffer;
+  }
+
+  static getTraceIdHigh(traceId: Buffer) {
+    if (traceId != null && traceId.length > 8) {
+      return traceId.slice(-16, -8);
+    }
+
+    return ThriftUtils.emptyBuffer;
+  }
+
   static spanToThrift(span: Span): any {
     let tags = ThriftUtils.getThriftTags(span._tags);
     let logs = ThriftUtils.getThriftLogs(span._logs);
     let unsigned = true;
 
     return {
-      traceIdLow: span._spanContext.traceIdLow,
-      traceIdHigh:
-        span._spanContext.traceIdHigh == null ? ThriftUtils.emptyBuffer : span._spanContext.traceIdHigh,
+      traceIdLow: ThriftUtils.getTraceIdLow(span._spanContext.traceId),
+      traceIdHigh: ThriftUtils.getTraceIdHigh(span._spanContext.traceId),
       spanId: span._spanContext.spanId,
       parentSpanId: span._spanContext.parentId || ThriftUtils.emptyBuffer,
       operationName: span._operationName,
diff --git a/src/tracer.js b/src/tracer.js
index 6aa0b671c..fecaba638 100644
--- a/src/tracer.js
+++ b/src/tracer.js
@@ -242,17 +242,15 @@ export default class Tracer {
       }
 
       if (options.traceId128bit) {
-        ctx.traceIdLow = randomId;
-        ctx.traceIdHigh = Utils.getRandom64();
+        ctx.traceId = new Buffer.concat([Utils.getRandom64(), randomId]);
       } else {
-        ctx.traceIdLow = randomId;
+        ctx.traceId = randomId;
       }
       ctx.spanId = randomId;
       ctx.parentId = null;
       ctx.flags = flags;
     } else {
-      ctx.traceIdLow = parent.traceIdLow;
-      ctx.traceIdHigh = parent.traceIdHigh;
+      ctx.traceId = parent.traceId;
       ctx.spanId = Utils.getRandom64();
       ctx.parentId = parent.spanId;
       ctx.flags = parent.flags;
diff --git a/test/span.js b/test/span.js
index 59665ffbe..779b64196 100644
--- a/test/span.js
+++ b/test/span.js
@@ -35,7 +35,6 @@ describe('span should', () => {
 
     spanContext = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
-      null,
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       constants.SAMPLED_MASK
diff --git a/test/span_context.js b/test/span_context.js
index e051577d1..954d33c95 100644
--- a/test/span_context.js
+++ b/test/span_context.js
@@ -24,30 +24,28 @@ describe('SpanContext should', () => {
   });
 
   it('return given values as they were set', () => {
-    let traceIdLow = Utils.encodeInt64(1);
+    let traceId = Utils.encodeInt64(1);
     let spanId = Utils.encodeInt64(2);
     let parentId = Utils.encodeInt64(3);
     let flags = 1;
 
-    let context = SpanContext.withBinaryIds(traceIdLow, null, spanId, parentId, flags);
+    let context = SpanContext.withBinaryIds(traceId, spanId, parentId, flags);
 
-    assert.deepEqual(traceIdLow, context.traceIdLow);
+    assert.deepEqual(traceId, context.traceId);
     assert.deepEqual(spanId, context.spanId);
     assert.deepEqual(parentId, context.parentId);
     assert.equal(flags, context.flags);
   });
 
   it('return given values as they were set 128 bit', () => {
-    let traceIdLow = Utils.encodeInt64(1);
-    let traceIdHigh = Utils.encodeInt64(2);
+    let traceId = Buffer.concat([Utils.encodeInt64(2), Utils.encodeInt64(1)]);
     let spanId = Utils.encodeInt64(3);
     let parentId = Utils.encodeInt64(4);
     let flags = 1;
 
-    let context = SpanContext.withBinaryIds(traceIdLow, traceIdHigh, spanId, parentId, flags);
+    let context = SpanContext.withBinaryIds(traceId, spanId, parentId, flags);
 
-    assert.deepEqual(traceIdLow, context.traceIdLow);
-    assert.deepEqual(traceIdHigh, context.traceIdHigh);
+    assert.deepEqual(traceId, context.traceId);
     assert.deepEqual('20000000000000001', context.traceIdStr);
     assert.deepEqual(spanId, context.spanId);
     assert.deepEqual(parentId, context.parentId);
@@ -57,7 +55,6 @@ describe('SpanContext should', () => {
   it('return IsSampled properly', () => {
     let context = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
-      null,
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       3
@@ -71,12 +68,11 @@ describe('SpanContext should', () => {
   });
 
   it('format strings properly with toString', () => {
-    let ctx1 = SpanContext.withBinaryIds(Utils.encodeInt64(0x100), null, Utils.encodeInt64(0x7f), null, 1);
+    let ctx1 = SpanContext.withBinaryIds(Utils.encodeInt64(0x100), Utils.encodeInt64(0x7f), null, 1);
     assert.equal(ctx1.toString(), '100:7f:0:1');
 
     let ctx2 = SpanContext.withBinaryIds(
       Utils.encodeInt64(255 << 4),
-      null,
       Utils.encodeInt64(127),
       Utils.encodeInt64(256),
       0
@@ -84,7 +80,7 @@ describe('SpanContext should', () => {
     assert.equal(ctx2.toString(), 'ff0:7f:100:0');
 
     // test large numbers
-    let ctx3 = SpanContext.withBinaryIds(LARGEST_64_BUFFER, null, LARGEST_64_BUFFER, LARGEST_64_BUFFER, 0);
+    let ctx3 = SpanContext.withBinaryIds(LARGEST_64_BUFFER, LARGEST_64_BUFFER, LARGEST_64_BUFFER, 0);
     assert.equal(ctx3.toString(), 'ffffffffffffffff:ffffffffffffffff:ffffffffffffffff:0');
     assert.equal('ffffffffffffffff', ctx3.traceIdStr);
     assert.equal('ffffffffffffffff', ctx3.spanIdStr);
@@ -95,6 +91,7 @@ describe('SpanContext should', () => {
     let context = SpanContext.fromString('100:7f:0:1');
 
     assert.deepEqual('100', context.traceIdStr);
+    assert.deepEqual(Utils.encodeInt64(0x100), context.traceId);
     assert.deepEqual(Utils.encodeInt64(0x7f), context.spanId);
     assert.equal(null, context.parentId);
     assert.equal(1, context.flags);
@@ -113,8 +110,7 @@ describe('SpanContext should', () => {
     let context = SpanContext.fromString('20000000000000100:7f:0:1');
 
     assert.deepEqual('20000000000000100', context.traceIdStr);
-    assert.deepEqual(Utils.encodeInt64(0x100), context.traceIdLow);
-    assert.deepEqual(Utils.encodeInt64(0x2), context.traceIdHigh);
+    assert.deepEqual(Buffer.concat([Utils.encodeInt64(0x2), Utils.encodeInt64(0x100)]), context.traceId);
     assert.deepEqual(Utils.encodeInt64(0x7f), context.spanId);
     assert.equal(null, context.parentId);
     assert.equal(1, context.flags);
@@ -123,8 +119,7 @@ describe('SpanContext should', () => {
     context = SpanContext.fromString('ffffffffffffffffffffffffffffffff:ffffffffffffffff:5:1');
     assert.equal('ffffffffffffffffffffffffffffffff', context.traceIdStr);
     assert.equal('ffffffffffffffff', context.spanIdStr);
-    assert.deepEqual(LARGEST_64_BUFFER, context.traceIdLow);
-    assert.deepEqual(LARGEST_64_BUFFER, context.traceIdHigh);
+    assert.deepEqual(Buffer.concat([LARGEST_64_BUFFER, LARGEST_64_BUFFER]), context.traceId);
     assert.deepEqual(LARGEST_64_BUFFER, context.spanId);
     assert.deepEqual(LARGEST_64_BUFFER, context.spanId);
     assert.deepEqual(Utils.encodeInt64(0x5), context.parentId);
diff --git a/test/thrift.js b/test/thrift.js
index 3f1829130..47087b2ee 100644
--- a/test/thrift.js
+++ b/test/thrift.js
@@ -76,11 +76,11 @@ describe('ThriftUtils', () => {
     span.finish();
     tracer.close();
     let tSpan = ThriftUtils.spanToThrift(childSpan);
-    assert.deepEqual(tSpan.traceIdLow, childSpan.context().traceIdLow);
-    assert.deepEqual(tSpan.traceIdHigh, childSpan.context().traceIdHigh);
+    assert.deepEqual(tSpan.traceIdLow, childSpan.context().traceId.slice(-8));
+    assert.deepEqual(tSpan.traceIdHigh, childSpan.context().traceId.slice(-16, -8));
     assert.deepEqual(tSpan.spanId, childSpan.context().spanId);
-    assert.deepEqual(tSpan.references[0].traceIdLow, span.context().traceIdLow);
-    assert.deepEqual(tSpan.references[0].traceIdHigh, span.context().traceIdHigh);
+    assert.deepEqual(tSpan.references[0].traceIdLow, span.context().traceId.slice(-8));
+    assert.deepEqual(tSpan.references[0].traceIdHigh, span.context().traceId.slice(-16, -8));
     assert.deepEqual(tSpan.references[0].spanId, span.context().spanId);
   });
 });
diff --git a/test/tracer.js b/test/tracer.js
index 92fa77566..7659e7897 100644
--- a/test/tracer.js
+++ b/test/tracer.js
@@ -89,7 +89,7 @@ describe('tracer should', () => {
     let spanContext = tracer.extract(opentracing.FORMAT_TEXT_MAP, headers);
     let rootSpan = tracer.startSpan('fry', { childOf: spanContext });
 
-    assert.isOk(rootSpan.context().traceIdLow);
+    assert.isOk(rootSpan.context().traceId);
     assert.isNotOk(rootSpan.context().parentId);
     assert.equal(rootSpan.context().flags, 1);
     assert.equal('Bender', rootSpan.getBaggageItem('robot'));
@@ -98,11 +98,11 @@ describe('tracer should', () => {
   });
 
   it('create a span correctly through _startInternalSpan', () => {
-    let traceIdLow = Utils.encodeInt64(1);
+    let traceId = Utils.encodeInt64(1);
     let spanId = Utils.encodeInt64(2);
     let parentId = Utils.encodeInt64(3);
     let flags = 1;
-    let context = SpanContext.withBinaryIds(traceIdLow, null, spanId, parentId, flags);
+    let context = SpanContext.withBinaryIds(traceId, spanId, parentId, flags);
     let start = 123.456;
     let rpcServer = false;
     let internalTags = [];
@@ -122,7 +122,7 @@ describe('tracer should', () => {
       references
     );
 
-    assert.deepEqual(span.context().traceIdLow, traceIdLow);
+    assert.deepEqual(span.context().traceId, traceId);
     assert.deepEqual(span.context().spanId, spanId);
     assert.deepEqual(span.context().parentId, parentId);
     assert.equal(span.context().flags, flags);
@@ -151,7 +151,7 @@ describe('tracer should', () => {
       startTime: startTime,
     });
 
-    assert.equal(span.context().traceIdLow, span.context().spanId);
+    assert.equal(span.context().traceId, span.context().spanId);
     assert.isNotOk(span.context().parentId);
     assert.isOk(span.context().isSampled());
     assert.equal(span._startTime, startTime);
@@ -160,13 +160,13 @@ describe('tracer should', () => {
   describe('start a child span represented as a separate span from parent, using childOf and references', () => {
     let nextId = 0;
     const getId = () => Utils.encodeInt64(nextId++);
-    const traceIdLow = getId();
+    const traceId = getId();
     const flags = 1;
 
-    const parentContext = SpanContext.withBinaryIds(traceIdLow, getId(), null, flags);
-    const childOfContext = SpanContext.withBinaryIds(traceIdLow, getId(), null, flags);
+    const parentContext = SpanContext.withBinaryIds(traceId, getId(), null, flags);
+    const childOfContext = SpanContext.withBinaryIds(traceId, getId(), null, flags);
     const childOfRef = new opentracing.Reference(opentracing.REFERENCE_CHILD_OF, childOfContext);
-    const followsFromContext = SpanContext.withBinaryIds(traceIdLow, getId(), null, flags);
+    const followsFromContext = SpanContext.withBinaryIds(traceId, getId(), null, flags);
     const followsFromRef = new opentracing.Reference(opentracing.REFERENCE_FOLLOWS_FROM, followsFromContext);
 
     const testCases = [
@@ -264,7 +264,38 @@ describe('tracer should', () => {
     };
     let savedContext = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
-      null,
+      Utils.encodeInt64(2),
+      Utils.encodeInt64(3),
+      constants.SAMPLED_MASK,
+      baggage
+    );
+
+    let assertByFormat = format => {
+      let carrier = {};
+      tracer.inject(savedContext, format, carrier);
+      let extractedContext = tracer.extract(format, carrier);
+
+      assert.deepEqual(savedContext.traceId, extractedContext.traceId);
+      assert.deepEqual(savedContext.spanId, extractedContext.spanId);
+      assert.deepEqual(savedContext.parentId, extractedContext.parentId);
+      assert.equal(savedContext.flags, extractedContext.flags);
+      assert.equal(savedContext.baggage[keyOne], extractedContext.baggage[keyOne]);
+      assert.equal(savedContext.baggage[keyTwo], extractedContext.baggage[keyTwo]);
+    };
+
+    assertByFormat(opentracing.FORMAT_TEXT_MAP);
+    assertByFormat(opentracing.FORMAT_HTTP_HEADERS);
+  });
+
+  it('inject plain text headers into carrier, and extract span context with the same value 128bits', () => {
+    let keyOne = 'keyOne';
+    let keyTwo = 'keyTwo';
+    let baggage = {
+      keyOne: 'leela',
+      keyTwo: 'bender',
+    };
+    let savedContext = SpanContext.withBinaryIds(
+      Buffer.concat([Utils.encodeInt64(1), Utils.encodeInt64(2)]),
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       constants.SAMPLED_MASK,
@@ -294,7 +325,6 @@ describe('tracer should', () => {
     };
     let savedContext = SpanContext.withBinaryIds(
       Utils.encodeInt64(1),
-      null,
       Utils.encodeInt64(2),
       Utils.encodeInt64(3),
       constants.SAMPLED_MASK,
@@ -425,8 +455,8 @@ describe('tracer should', () => {
       traceId128bit: true,
     });
 
-    assert.equal(span.context().traceIdLow, span.context().spanId);
-    assert.isOk(span.context().traceIdHigh);
+    assert.deepEqual(span.context().traceId.slice(-8), span.context().spanId);
+    assert.isOk(span.context().traceId);
     assert.isNotOk(span.context().parentId);
     assert.isOk(span.context().isSampled());
   });

From d5aa139cc9b12b6734ff1efb0d0556fc7a3c9bbe Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Thu, 16 May 2019 10:03:13 -0400
Subject: [PATCH 06/16] Adding unit test Signed-off-by: Paul Biccherai
 <paul.biccherai@chronwell.com>

---
 test/thrift.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/test/thrift.js b/test/thrift.js
index 47087b2ee..ac5446044 100644
--- a/test/thrift.js
+++ b/test/thrift.js
@@ -83,4 +83,16 @@ describe('ThriftUtils', () => {
     assert.deepEqual(tSpan.references[0].traceIdHigh, span.context().traceId.slice(-16, -8));
     assert.deepEqual(tSpan.references[0].spanId, span.context().spanId);
   });
+
+  it('should convert extract traceIdLow and traceIdHigh', () => {
+    let traceIdLow = Utils.encodeInt64(1);
+    let traceIdHigh = Utils.encodeInt64(2);
+    let traceId = Buffer.concat([traceIdHigh, traceIdLow]);
+
+    assert.deepEqual(ThriftUtils.getTraceIdLow(traceId), traceIdLow);
+    assert.deepEqual(ThriftUtils.getTraceIdHigh(traceId), traceIdHigh);
+
+    assert.deepEqual(ThriftUtils.getTraceIdLow(null), ThriftUtils.emptyBuffer);
+    assert.deepEqual(ThriftUtils.getTraceIdHigh(null), ThriftUtils.emptyBuffer);
+  });
 });

From eb918d36bfe4fd6664c927eac9e6a97b2a0d2c59 Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Wed, 12 Jun 2019 19:13:09 -0400
Subject: [PATCH 07/16] Fixed issues Signed-off-by: Paul Biccherai
 <paul.biccherai@chronwell.com>

---
 src/span_context.js  |  5 ++---
 src/tracer.js        |  4 ++--
 src/util.js          | 35 +++++++++++++++++++++++++++++++++++
 test/span_context.js |  1 -
 test/util.js         | 20 ++++++++++++++++++++
 5 files changed, 59 insertions(+), 6 deletions(-)

diff --git a/src/span_context.js b/src/span_context.js
index 3451848fb..45416c17e 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -69,10 +69,9 @@ export default class SpanContext {
   get traceId(): any {
     if (this._traceId == null && this._traceIdStr != null) {
       const safeTraceIdStr = this._traceIdStr.length % 2 == 0 ? this._traceIdStr : '0' + this._traceIdStr;
-      const tmpBuffer = new Buffer(safeTraceIdStr, 'hex');
+      const tmpBuffer = Utils.newBuffer(safeTraceIdStr, 'hex');
       const size = tmpBuffer.length > 8 ? 16 : 8;
-      this._traceId = new Buffer(size);
-      this._traceId.fill(0);
+      this._traceId = Utils.newBuffer(size);
       tmpBuffer.copy(this._traceId, size - tmpBuffer.length);
     }
     return this._traceId;
diff --git a/src/tracer.js b/src/tracer.js
index fecaba638..ff7306ca6 100644
--- a/src/tracer.js
+++ b/src/tracer.js
@@ -188,7 +188,7 @@ export default class Tracer {
    *        the created Span object. The time should be specified in
    *        milliseconds as Unix timestamp. Decimal value are supported
    *        to represent time values with sub-millisecond accuracy.
-   * @param {number} [options.traceId128bit] - generate root span with a
+   * @param {boolean} [options.traceId128bit] - generate root span with a
    *        128bit traceId.
    * @return {Span} - a new Span object.
    **/
@@ -242,7 +242,7 @@ export default class Tracer {
       }
 
       if (options.traceId128bit) {
-        ctx.traceId = new Buffer.concat([Utils.getRandom64(), randomId]);
+        ctx.traceId = Buffer.concat([Utils.getRandom64(), randomId]);
       } else {
         ctx.traceId = randomId;
       }
diff --git a/src/util.js b/src/util.js
index a46594c17..bc8e98393 100644
--- a/src/util.js
+++ b/src/util.js
@@ -16,6 +16,17 @@ import Int64 from 'node-int64';
 import os from 'os';
 import http from 'http';
 
+type BufferEncoding =
+  | 'ascii'
+  | 'utf8'
+  | 'utf-8'
+  | 'utf16le'
+  | 'ucs2'
+  | 'ucs-2'
+  | 'base64'
+  | 'latin1'
+  | 'binary'
+  | 'hex';
 export default class Utils {
   /**
    * Determines whether a string contains a given prefix.
@@ -148,4 +159,28 @@ export default class Utils {
         error(err);
       });
   }
+
+  /**
+   * @param {string|number} input - a string to store in the buffer
+   * or a number of octets to allocate.
+   * @param {string} encoding - identifies the character encoding. Default is 'utf8'.
+   * @return {Buffer} - returns a buffer representing the encoded string, or an empty buffer.
+   **/
+  static newBuffer(input: string | number, encoding?: BufferEncoding): Buffer {
+    if (typeof input === 'string') {
+      if (Buffer.from && Buffer.from !== Uint8Array.from) {
+        return Buffer.from(input, encoding);
+      }
+      return new Buffer(input, encoding);
+    } else if (typeof input === 'number') {
+      if (Buffer.alloc) {
+        return Buffer.alloc(input);
+      }
+      const buffer = new Buffer(input);
+      buffer.fill(0);
+      return buffer;
+    } else {
+      throw new Error('The "input" argument must be a number or a string');
+    }
+  }
 }
diff --git a/test/span_context.js b/test/span_context.js
index 954d33c95..a1ba592d0 100644
--- a/test/span_context.js
+++ b/test/span_context.js
@@ -121,7 +121,6 @@ describe('SpanContext should', () => {
     assert.equal('ffffffffffffffff', context.spanIdStr);
     assert.deepEqual(Buffer.concat([LARGEST_64_BUFFER, LARGEST_64_BUFFER]), context.traceId);
     assert.deepEqual(LARGEST_64_BUFFER, context.spanId);
-    assert.deepEqual(LARGEST_64_BUFFER, context.spanId);
     assert.deepEqual(Utils.encodeInt64(0x5), context.parentId);
     assert.equal(context.flags, 0x1);
   });
diff --git a/test/util.js b/test/util.js
index d6d077de1..8eb99969c 100644
--- a/test/util.js
+++ b/test/util.js
@@ -44,4 +44,24 @@ describe('utils', () => {
     ];
     assert.deepEqual(expectedTags, results);
   });
+
+  it('should create new empty buffer', () => {
+    let results = Utils.newBuffer(8);
+    assert.isNotNull(results);
+    assert.equal(results.length, 8);
+    assert.deepEqual(new Buffer([0, 0, 0, 0, 0, 0, 0, 0]), results);
+  });
+
+  it('should create new buffer from text', () => {
+    let expectedValue = 'test';
+    let results = Utils.newBuffer(expectedValue, 'utf-8');
+    assert.isNotNull(results);
+    assert.equal(expectedValue, results.toString('utf-8'));
+  });
+
+  it('should fail to create new buffer', () => {
+    assert.throw(() => {
+      Utils.newBuffer((undefined: any));
+    }, 'The "input" argument must be a number or a string');
+  });
 });

From 4ec48e6f199b0e55a149eef97fa3ec5689d2a4ce Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Mon, 17 Jun 2019 16:32:34 -0400
Subject: [PATCH 08/16] Force travis to use ubuntu trusty Signed-off-by: Paul
 Biccherai <paul.biccherai@chronwell.com>

---
 .travis.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.travis.yml b/.travis.yml
index 65350386b..c63ddb955 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 sudo: required
+dist: trusty
 
 # Travis will use .nvmrc, by default
 language: node_js

From a00710ef336e049a85daf0f9861b854cfa1c37c1 Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Mon, 24 Jun 2019 19:28:32 -0400
Subject: [PATCH 09/16] Fix issues Signed-off-by: Paul Biccherai
 <paul.biccherai@chronwell.com>

---
 src/_flow/tracer.js |  1 -
 src/span_context.js |  4 ++-
 src/tracer.js       | 17 +++++++----
 src/util.js         | 69 +++++++++++++++++++++++++--------------------
 test/thrift.js      |  4 +--
 test/tracer.js      |  5 ++--
 test/util.js        | 14 +++------
 7 files changed, 60 insertions(+), 54 deletions(-)

diff --git a/src/_flow/tracer.js b/src/_flow/tracer.js
index 4d4f9d666..4334332e4 100644
--- a/src/_flow/tracer.js
+++ b/src/_flow/tracer.js
@@ -20,5 +20,4 @@ declare type startSpanOptions = {
   references?: Array<Reference>,
   tags?: any,
   startTime?: number,
-  traceId128bit?: boolean,
 };
diff --git a/src/span_context.js b/src/span_context.js
index 45416c17e..bed019376 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -68,8 +68,10 @@ export default class SpanContext {
 
   get traceId(): any {
     if (this._traceId == null && this._traceIdStr != null) {
+      // make sure that the HEX has an even number of digits, node is expecting 2 HEX character per byte
+      // https://github.com/nodejs/node/issues/21242
       const safeTraceIdStr = this._traceIdStr.length % 2 == 0 ? this._traceIdStr : '0' + this._traceIdStr;
-      const tmpBuffer = Utils.newBuffer(safeTraceIdStr, 'hex');
+      const tmpBuffer = Utils.newBufferFromHex(safeTraceIdStr);
       const size = tmpBuffer.length > 8 ? 16 : 8;
       this._traceId = Utils.newBuffer(size);
       tmpBuffer.copy(this._traceId, size - tmpBuffer.length);
diff --git a/src/tracer.js b/src/tracer.js
index ff7306ca6..ad10b1186 100644
--- a/src/tracer.js
+++ b/src/tracer.js
@@ -43,6 +43,7 @@ export default class Tracer {
   _baggageSetter: BaggageSetter;
   _debugThrottler: Throttler & ProcessSetter;
   _process: Process;
+  _traceId128bit: boolean;
 
   /**
    * @param {String} [serviceName] - name of the current service or application.
@@ -56,6 +57,7 @@ export default class Tracer {
    * @param {Object} [options.baggageRestrictionManager] - a baggageRestrictionManager matching
    * @param {Object} [options.contextKey] - a name of the key to extract/inject context from headers
    * @param {Object} [options.baggagePrefix] - a name of the context baggage key prefix
+   * @param {boolean} [options.traceId128bit] - generate root span with a 128bit traceId.
    * BaggageRestrictionManager API from ./baggage.js.
    */
   constructor(
@@ -115,6 +117,8 @@ export default class Tracer {
     this._debugThrottler.setProcess(this._process);
     // TODO update reporter to implement ProcessSetter
     this._reporter.setProcess(this._process.serviceName, this._process.tags);
+
+    this._traceId128bit = options.traceId128bit;
   }
 
   _startInternalSpan(
@@ -188,8 +192,6 @@ export default class Tracer {
    *        the created Span object. The time should be specified in
    *        milliseconds as Unix timestamp. Decimal value are supported
    *        to represent time values with sub-millisecond accuracy.
-   * @param {boolean} [options.traceId128bit] - generate root span with a
-   *        128bit traceId.
    * @return {Span} - a new Span object.
    **/
   startSpan(operationName: string, options: ?startSpanOptions): Span {
@@ -226,7 +228,6 @@ export default class Tracer {
     let ctx: SpanContext = new SpanContext();
     let internalTags: any = {};
     if (!parent || !parent.isValid) {
-      let randomId = Utils.getRandom64();
       let flags = 0;
       if (this._sampler.isSampled(operationName, internalTags)) {
         flags |= constants.SAMPLED_MASK;
@@ -241,12 +242,16 @@ export default class Tracer {
         ctx.baggage = parent.baggage;
       }
 
-      if (options.traceId128bit) {
-        ctx.traceId = Buffer.concat([Utils.getRandom64(), randomId]);
+      if (this._traceId128bit) {
+        let randomId = Utils.getRandom128();
+        ctx.traceId = randomId;
+        ctx.spanId = randomId.slice(-8);
       } else {
+        let randomId = Utils.getRandom64();
         ctx.traceId = randomId;
+        ctx.spanId = randomId;
       }
-      ctx.spanId = randomId;
+
       ctx.parentId = null;
       ctx.flags = flags;
     } else {
diff --git a/src/util.js b/src/util.js
index bc8e98393..6bbc520ec 100644
--- a/src/util.js
+++ b/src/util.js
@@ -16,17 +16,6 @@ import Int64 from 'node-int64';
 import os from 'os';
 import http from 'http';
 
-type BufferEncoding =
-  | 'ascii'
-  | 'utf8'
-  | 'utf-8'
-  | 'utf16le'
-  | 'ucs2'
-  | 'ucs-2'
-  | 'base64'
-  | 'latin1'
-  | 'binary'
-  | 'hex';
 export default class Utils {
   /**
    * Determines whether a string contains a given prefix.
@@ -53,7 +42,7 @@ export default class Utils {
   }
 
   /**
-   * Determines whether a string contains a given prefix.
+   * Get a random buffer representing a random 64 bit.
    *
    * @return {Buffer}  - returns a buffer representing a random 64 bit
    * number.
@@ -66,6 +55,23 @@ export default class Utils {
     return buf;
   }
 
+  /**
+   * Get a random buffer representing a random 128 bit.
+   *
+   * @return {Buffer}  - returns a buffer representing a random 128 bit
+   * number.
+   **/
+  static getRandom128(): Buffer {
+    let randint1 = xorshift.randomint();
+    let randint2 = xorshift.randomint();
+    let buf = new Buffer(16);
+    buf.writeUInt32BE(randint1[0], 0);
+    buf.writeUInt32BE(randint1[1], 4);
+    buf.writeUInt32BE(randint2[0], 8);
+    buf.writeUInt32BE(randint2[1], 12);
+    return buf;
+  }
+
   /**
    * @param {string|number} numberValue - a string or number to be encoded
    * as a 64 bit byte array.
@@ -161,26 +167,27 @@ export default class Utils {
   }
 
   /**
-   * @param {string|number} input - a string to store in the buffer
-   * or a number of octets to allocate.
-   * @param {string} encoding - identifies the character encoding. Default is 'utf8'.
-   * @return {Buffer} - returns a buffer representing the encoded string, or an empty buffer.
+   * @param {string|number} input - a hex encoded string to store in the buffer.
+   * @return {Buffer} - returns a buffer representing the hex encoded string.
    **/
-  static newBuffer(input: string | number, encoding?: BufferEncoding): Buffer {
-    if (typeof input === 'string') {
-      if (Buffer.from && Buffer.from !== Uint8Array.from) {
-        return Buffer.from(input, encoding);
-      }
-      return new Buffer(input, encoding);
-    } else if (typeof input === 'number') {
-      if (Buffer.alloc) {
-        return Buffer.alloc(input);
-      }
-      const buffer = new Buffer(input);
-      buffer.fill(0);
-      return buffer;
-    } else {
-      throw new Error('The "input" argument must be a number or a string');
+  static newBufferFromHex(input: string): Buffer {
+    const encoding = 'hex';
+    if (Buffer.from && Buffer.from !== Uint8Array.from) {
+      return Buffer.from(input, encoding);
+    }
+    return new Buffer(input, encoding);
+  }
+
+  /**
+   * @param {number} input - a number of octets to allocate.
+   * @return {Buffer} - returns an empty buffer.
+   **/
+  static newBuffer(size: number): Buffer {
+    if (Buffer.alloc) {
+      return Buffer.alloc(size);
     }
+    const buffer = new Buffer(size);
+    buffer.fill(0);
+    return buffer;
   }
 }
diff --git a/test/thrift.js b/test/thrift.js
index ac5446044..68b80499a 100644
--- a/test/thrift.js
+++ b/test/thrift.js
@@ -68,8 +68,8 @@ describe('ThriftUtils', () => {
 
   it('should convert span with 128 bit traceId', () => {
     let reporter = new InMemoryReporter();
-    let tracer = new Tracer('test-service-name', reporter, new ConstSampler(true));
-    let span = tracer.startSpan('some operation', { traceId128bit: true });
+    let tracer = new Tracer('test-service-name', reporter, new ConstSampler(true), { traceId128bit: true });
+    let span = tracer.startSpan('some operation');
     let childOfRef = new opentracing.Reference(opentracing.REFERENCE_CHILD_OF, span.context());
     let childSpan = tracer.startSpan('some child operation', { references: [childOfRef] });
     childSpan.finish();
diff --git a/test/tracer.js b/test/tracer.js
index 7659e7897..f0814961b 100644
--- a/test/tracer.js
+++ b/test/tracer.js
@@ -451,9 +451,8 @@ describe('tracer should', () => {
   });
 
   it('start a root span with 128 bit traceId', () => {
-    let span = tracer.startSpan('test-name', {
-      traceId128bit: true,
-    });
+    tracer = new Tracer('test-service-name', reporter, new ConstSampler(true), { traceId128bit: true });
+    let span = tracer.startSpan('test-name');
 
     assert.deepEqual(span.context().traceId.slice(-8), span.context().spanId);
     assert.isOk(span.context().traceId);
diff --git a/test/util.js b/test/util.js
index 8eb99969c..63907832c 100644
--- a/test/util.js
+++ b/test/util.js
@@ -52,16 +52,10 @@ describe('utils', () => {
     assert.deepEqual(new Buffer([0, 0, 0, 0, 0, 0, 0, 0]), results);
   });
 
-  it('should create new buffer from text', () => {
-    let expectedValue = 'test';
-    let results = Utils.newBuffer(expectedValue, 'utf-8');
+  it('should create new buffer from hex', () => {
+    let expectedValue = 'deadbeef';
+    let results = Utils.newBufferFromHex(expectedValue);
     assert.isNotNull(results);
-    assert.equal(expectedValue, results.toString('utf-8'));
-  });
-
-  it('should fail to create new buffer', () => {
-    assert.throw(() => {
-      Utils.newBuffer((undefined: any));
-    }, 'The "input" argument must be a number or a string');
+    assert.equal(expectedValue, results.toString('hex'));
   });
 });

From 5059f19a405ead67a6b2edf81765fa8b5b0dc77b Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Mon, 8 Jul 2019 18:46:25 -0400
Subject: [PATCH 10/16] Refactoring Signed-off-by: Paul Biccherai
 <paul.biccherai@chronwell.com>

---
 src/span_context.js | 16 ++++++++++------
 src/util.js         |  2 ++
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/span_context.js b/src/span_context.js
index bed019376..3b034949f 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -68,13 +68,17 @@ export default class SpanContext {
 
   get traceId(): any {
     if (this._traceId == null && this._traceIdStr != null) {
-      // make sure that the HEX has an even number of digits, node is expecting 2 HEX character per byte
+      // make sure that the string is 32 or 16 characters long to generate the
+      // corresponding 64 or 128 bits buffer by padding the start with zeros if necessary
+      // https://github.com/jaegertracing/jaeger/issues/1657
+      // At the same time this will enforce that the HEX has an even number of digits, node is expecting 2 HEX characters per byte
       // https://github.com/nodejs/node/issues/21242
-      const safeTraceIdStr = this._traceIdStr.length % 2 == 0 ? this._traceIdStr : '0' + this._traceIdStr;
-      const tmpBuffer = Utils.newBufferFromHex(safeTraceIdStr);
-      const size = tmpBuffer.length > 8 ? 16 : 8;
-      this._traceId = Utils.newBuffer(size);
-      tmpBuffer.copy(this._traceId, size - tmpBuffer.length);
+      const traceIdExactLength = this._traceIdStr.length > 16 ? 32 : 16;
+      const safeTraceIdStr =
+        this._traceIdStr.length === traceIdExactLength
+          ? this._traceIdStr
+          : this._traceIdStr.padStart(traceIdExactLength, '0');
+      this._traceId = Utils.newBufferFromHex(safeTraceIdStr);
     }
     return this._traceId;
   }
diff --git a/src/util.js b/src/util.js
index 6bbc520ec..2ccf04dcb 100644
--- a/src/util.js
+++ b/src/util.js
@@ -172,6 +172,8 @@ export default class Utils {
    **/
   static newBufferFromHex(input: string): Buffer {
     const encoding = 'hex';
+    // check that 'Buffer.from' exists based on node's documentation
+    // https://nodejs.org/en/docs/guides/buffer-constructor-deprecation/#variant-3
     if (Buffer.from && Buffer.from !== Uint8Array.from) {
       return Buffer.from(input, encoding);
     }

From 69ac16c0a5ada6e63d46efc60fd202316ce47a4b Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Mon, 8 Jul 2019 20:10:52 -0400
Subject: [PATCH 11/16] Fix node 0.10 compatibility Signed-off-by: Paul
 Biccherai <paul.biccherai@chronwell.com>

---
 src/span_context.js | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/span_context.js b/src/span_context.js
index 3b034949f..2eaaede6c 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -74,11 +74,14 @@ export default class SpanContext {
       // At the same time this will enforce that the HEX has an even number of digits, node is expecting 2 HEX characters per byte
       // https://github.com/nodejs/node/issues/21242
       const traceIdExactLength = this._traceIdStr.length > 16 ? 32 : 16;
-      const safeTraceIdStr =
-        this._traceIdStr.length === traceIdExactLength
-          ? this._traceIdStr
-          : this._traceIdStr.padStart(traceIdExactLength, '0');
-      this._traceId = Utils.newBufferFromHex(safeTraceIdStr);
+      if (this._traceIdStr.length === traceIdExactLength) {
+        this._traceId = Utils.newBufferFromHex(this._traceIdStr);
+      } else {
+        const paddings = ['0000000000000000', '00000000000000000000000000000000'];
+        const paddingIndex = traceIdExactLength === 16 ? 0 : 1;
+        const safeTraceIdStr = (paddings[paddingIndex] + this._traceIdStr).slice(-traceIdExactLength);
+        this._traceId = Utils.newBufferFromHex(safeTraceIdStr);
+      }
     }
     return this._traceId;
   }

From 50b49feebc25cdc442c1c3d77483b0d8f31e4bcd Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Thu, 11 Jul 2019 19:33:36 -0400
Subject: [PATCH 12/16] Increase timeout on some unit tests Signed-off-by: Paul
 Biccherai <paul.biccherai@chronwell.com>

---
 src/util.js         | 4 ++--
 test/http_sender.js | 2 +-
 test/udp_sender.js  | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/util.js b/src/util.js
index 2ccf04dcb..432334f5e 100644
--- a/src/util.js
+++ b/src/util.js
@@ -49,7 +49,7 @@ export default class Utils {
    **/
   static getRandom64(): Buffer {
     let randint = xorshift.randomint();
-    let buf = new Buffer(8);
+    let buf = this.newBuffer(8);
     buf.writeUInt32BE(randint[0], 0);
     buf.writeUInt32BE(randint[1], 4);
     return buf;
@@ -64,7 +64,7 @@ export default class Utils {
   static getRandom128(): Buffer {
     let randint1 = xorshift.randomint();
     let randint2 = xorshift.randomint();
-    let buf = new Buffer(16);
+    let buf = this.newBuffer(16);
     buf.writeUInt32BE(randint1[0], 0);
     buf.writeUInt32BE(randint1[1], 4);
     buf.writeUInt32BE(randint2[0], 8);
diff --git a/test/http_sender.js b/test/http_sender.js
index eff9663f6..7016ad8aa 100644
--- a/test/http_sender.js
+++ b/test/http_sender.js
@@ -253,7 +253,7 @@ describe('http sender', () => {
       expect(err).to.have.string('error sending spans over HTTP: Error: getaddrinfo ENOTFOUND');
       tracer.close(done);
     });
-  });
+  }).timeout(5000);
 
   it('should handle HTTPS collectors', done => {
     // Make it ignore the fact that our cert isn't valid.
diff --git a/test/udp_sender.js b/test/udp_sender.js
index f4686bfc3..88b34bb7b 100644
--- a/test/udp_sender.js
+++ b/test/udp_sender.js
@@ -273,4 +273,4 @@ describe('udp sender', () => {
       }
     });
   });
-});
+}).timeout(5000);

From cfd324c8c25c8edbf4eaadaf272df7fe0d8e59d4 Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Thu, 11 Jul 2019 19:49:41 -0400
Subject: [PATCH 13/16] Increase timeout on some unit tests Signed-off-by: Paul
 Biccherai <paul.biccherai@chronwell.com>

---
 test/udp_sender.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/udp_sender.js b/test/udp_sender.js
index 88b34bb7b..2255e70ba 100644
--- a/test/udp_sender.js
+++ b/test/udp_sender.js
@@ -272,5 +272,5 @@ describe('udp sender', () => {
         tracer.close(done);
       }
     });
-  });
-}).timeout(5000);
+  }).timeout(5000);
+});

From 1f02e9cd1dde8464d7787f1461f13a20ee172545 Mon Sep 17 00:00:00 2001
From: Paul Biccherai <paul.biccherai@chronwell.com>
Date: Wed, 4 Sep 2019 10:56:49 -0400
Subject: [PATCH 14/16] Small refactor Signed-off-by: Paul Biccherai
 <paul.biccherai@chronwell.com>

---
 src/span_context.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/span_context.js b/src/span_context.js
index 656cd97a4..9c1654fc4 100644
--- a/src/span_context.js
+++ b/src/span_context.js
@@ -60,9 +60,8 @@ export default class SpanContext {
       if (this._traceIdStr.length === traceIdExactLength) {
         this._traceId = Utils.newBufferFromHex(this._traceIdStr);
       } else {
-        const paddings = ['0000000000000000', '00000000000000000000000000000000'];
-        const paddingIndex = traceIdExactLength === 16 ? 0 : 1;
-        const safeTraceIdStr = (paddings[paddingIndex] + this._traceIdStr).slice(-traceIdExactLength);
+        const padding = traceIdExactLength === 16 ? '0000000000000000' : '00000000000000000000000000000000';
+        const safeTraceIdStr = (padding + this._traceIdStr).slice(-traceIdExactLength);
         this._traceId = Utils.newBufferFromHex(safeTraceIdStr);
       }
     }

From eee5ab63f61c77451e5d781d7fd69fe065faff01 Mon Sep 17 00:00:00 2001
From: Yuri Shkuro <ys@uber.com>
Date: Sun, 8 Sep 2019 19:43:26 -0400
Subject: [PATCH 15/16] Add one more test; create Buffer via Utils

Signed-off-by: Yuri Shkuro <ys@uber.com>
---
 src/reporters/udp_sender.js |  7 ++++---
 src/thrift.js               |  2 +-
 test/tracer.js              | 25 ++++++++++++++++++++++---
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/reporters/udp_sender.js b/src/reporters/udp_sender.js
index 999b01677..30bd7edc0 100644
--- a/src/reporters/udp_sender.js
+++ b/src/reporters/udp_sender.js
@@ -15,8 +15,9 @@ import dgram from 'dgram';
 import fs from 'fs';
 import path from 'path';
 import { Thrift } from 'thriftrw';
-import NullLogger from '../logger.js';
-import SenderUtils from './sender_utils.js';
+import NullLogger from '../logger';
+import SenderUtils from './sender_utils';
+import Utils from '../util';
 
 const HOST = 'localhost';
 const PORT = 6832;
@@ -128,7 +129,7 @@ export default class UDPSender {
     }
 
     const bufferLen = this._totalSpanBytes + this._emitSpanBatchOverhead;
-    const thriftBuffer = new Buffer(bufferLen);
+    const thriftBuffer = Utils.newBuffer(bufferLen);
     const writeResult = this._agentThrift.Agent.emitBatch.argumentsMessageRW.writeInto(
       this._convertBatchToThriftMessage(),
       thriftBuffer,
diff --git a/src/thrift.js b/src/thrift.js
index 1aa0a95f8..6fe116b1e 100644
--- a/src/thrift.js
+++ b/src/thrift.js
@@ -22,7 +22,7 @@ export default class ThriftUtils {
     source: fs.readFileSync(path.join(__dirname, './jaeger-idl/thrift/jaeger.thrift'), 'ascii'),
     allowOptionalArguments: true,
   });
-  static emptyBuffer: Buffer = new Buffer([0, 0, 0, 0, 0, 0, 0, 0]);
+  static emptyBuffer: Buffer = Utils.newBuffer(8).fill(0);
 
   static getThriftTags(initialTags: Array<Tag>): Array<any> {
     let thriftTags = [];
diff --git a/test/tracer.js b/test/tracer.js
index f924a9fd4..ed1a3ed3b 100644
--- a/test/tracer.js
+++ b/test/tracer.js
@@ -467,9 +467,28 @@ describe('tracer should', () => {
     let span = tracer.startSpan('test-name');
 
     assert.deepEqual(span.context().traceId.slice(-8), span.context().spanId);
-    assert.isOk(span.context().traceId);
-    assert.isNotOk(span.context().parentId);
-    assert.isOk(span.context().isSampled());
+    assert.equal(16, span.context().traceId.length);
+  });
+
+  it('preserve 64bit traceId even when in 128bit mode', () => {
+    // NB: because we currently trim leading zeros, this test is not as effective as it could be.
+    // But once https://github.com/jaegertracing/jaeger-client-node/issues/391 is fixed, this test
+    // will be more useful as it can catch regression.
+    tracer = new Tracer('test-service-name', reporter, new ConstSampler(true), { traceId128bit: true });
+    let span = tracer.startSpan('test-name');
+    assert.equal(16, span.context().traceId.length, 'new traces use 128bit IDs');
+
+    let parent = SpanContext.fromString('100:7f:0:1');
+    assert.equal(8, parent.traceId.length, 'respect 64bit length');
+
+    let child = tracer.startSpan('test-name', { childOf: parent });
+    assert.equal(8, child.context().traceId.length, 'preserve 64bit length');
+
+    let carrier = {};
+    tracer.inject(child.context(), opentracing.FORMAT_TEXT_MAP, carrier);
+    // Once https://github.com/jaegertracing/jaeger-client-node/issues/391 is fixed, the following
+    // asset will fail and will need to be changed to compare against '0000000000000100' string.
+    assert.equal('100:', carrier['uber-trace-id'].substring(0, 4), 'preserve 64bit length');
   });
 
   it('should NOT mutate tags', () => {

From fb29d6936db1a108347a433cce3006ce948a9071 Mon Sep 17 00:00:00 2001
From: Yuri Shkuro <ys@uber.com>
Date: Sun, 8 Sep 2019 20:27:50 -0400
Subject: [PATCH 16/16] Avoid Buffer.fill() which is void on Node 0.10

Signed-off-by: Yuri Shkuro <ys@uber.com>
---
 src/thrift.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/thrift.js b/src/thrift.js
index 6fe116b1e..0769808a7 100644
--- a/src/thrift.js
+++ b/src/thrift.js
@@ -22,7 +22,7 @@ export default class ThriftUtils {
     source: fs.readFileSync(path.join(__dirname, './jaeger-idl/thrift/jaeger.thrift'), 'ascii'),
     allowOptionalArguments: true,
   });
-  static emptyBuffer: Buffer = Utils.newBuffer(8).fill(0);
+  static emptyBuffer: Buffer = Utils.newBuffer(8);
 
   static getThriftTags(initialTags: Array<Tag>): Array<any> {
     let thriftTags = [];