Add support for Opencensus Span links to Thrift Span references (#473)

* Add support for Opencensus Span links to Thrift Span references

* fix review comments

Author: mayurkale22

CHANGELOG.md

@@ -5,6 +5,7 @@ All notable changes to this project will be documented in this file.
 ## Unreleased
 
 - Gauge: Add support for constant labels.
+- Add support for Opencensus Span links to Thrift Span references.
 
 ## 0.0.10 - 2019-04-03
 - Add optional `compressedSize` and `uncompressedSize` params to `Span.addMessageEvent`

packages/opencensus-exporter-jaeger/src/jaeger-driver/index.ts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import {Span} from '@opencensus/core';
+import {Link, LinkType, Span} from '@opencensus/core';
 
 // tslint:disable-next-line:variable-name
 export const UDPSender =
@@ -139,7 +139,7 @@ export function spanToThrift(span: Span): ThriftSpan {
     spanId: Utils.encodeInt64(span.spanContext.spanId),
     parentSpanId: parentSpan,
     operationName: span.name,
-    references: [],
+    references: getThriftReference(span.links),
     flags: span.spanContext.options || 0x1,
     startTime:
         Utils.encodeInt64(span.startTime.getTime() * 1000),  // to microseconds
@@ -148,3 +148,33 @@ export function spanToThrift(span: Span): ThriftSpan {
     logs: spanLogs,
   };
 }
+
+function getThriftReference(links: Link[]): ThriftReference[] {
+  return links
+             .map(
+                 (link):
+                     ThriftReference|
+                 null => {
+                   const refType = getThriftType(link.type);
+                   if (!refType) return null;
+
+                   const traceId =
+                       `00000000000000000000000000000000${link.traceId}`.slice(
+                           -32);
+                   const traceIdHigh = Utils.encodeInt64(traceId.slice(0, 16));
+                   const traceIdLow = Utils.encodeInt64(traceId.slice(16));
+                   const spanId = Utils.encodeInt64(link.spanId);
+                   return {traceIdLow, traceIdHigh, spanId, refType};
+                 })
+             .filter(ref => !!ref) as ThriftReference[];
+}
+
+function getThriftType(type: number): ThriftReferenceType|null {
+  if (type === LinkType.CHILD_LINKED_SPAN) {
+    return ThriftReferenceType.CHILD_OF;
+  }
+  if (type === LinkType.PARENT_LINKED_SPAN) {
+    return ThriftReferenceType.FOLLOWS_FROM;
+  }
+  return null;
+}

packages/opencensus-exporter-jaeger/test/test-jaeger.ts

@@ -14,16 +14,15 @@
  * limitations under the License.
  */
 
-import {CoreTracer, logger} from '@opencensus/core';
+import {CoreTracer, LinkType, logger} from '@opencensus/core';
 import * as assert from 'assert';
-import {JaegerTraceExporter, JaegerTraceExporterOptions} from '../src/';
-import {spanToThrift, ThriftUtils, UDPSender} from '../src/jaeger-driver';
-
-const DEFAULT_BUFFER_TIMEOUT = 10;  // time in milliseconds
 
+import {JaegerTraceExporter, JaegerTraceExporterOptions,} from '../src/';
+import {spanToThrift, ThriftReferenceType, ThriftUtils, UDPSender} from '../src/jaeger-driver';
 import {ThriftProcess} from '../src/jaeger-driver';
 import {SenderCallback} from '../src/jaeger-driver';
 
+const DEFAULT_BUFFER_TIMEOUT = 10;  // time in milliseconds
 
 /**
  * Controls if the tests will use a real network or not
@@ -116,6 +115,13 @@ describe('Jaeger Exporter', () => {
         span.addAnnotation('something happened', {
           'error': true,
         });
+        const traceIdHigh = '6e0c63257de34c92';
+        const traceIdLow = 'bf9efcd03927272e';
+        const traceId = traceIdHigh + traceIdLow;
+        const spanId = '6e0c63257de34c92';
+        span.addLink(traceId, spanId, LinkType.CHILD_LINKED_SPAN);
+        span.addLink(traceId, spanId, LinkType.PARENT_LINKED_SPAN);
+        span.addLink(traceId, spanId, LinkType.UNSPECIFIED);
         span.end();
         rootSpan.end();
         const thriftSpan = spanToThrift(span);
@@ -146,6 +152,22 @@ describe('Jaeger Exporter', () => {
 
         assert.ok(testBoolSeen && testStringSeen && testNumSeen);
 
+        assert.equal(thriftSpan.references.length, 2);
+        assert.deepEqual(thriftSpan.references, [
+          {
+            refType: ThriftReferenceType.CHILD_OF,
+            traceIdHigh: Buffer.from([110, 12, 99, 37, 125, 227, 76, 146]),
+            traceIdLow: Buffer.from([191, 158, 252, 208, 57, 39, 39, 46]),
+            spanId: Buffer.from([110, 12, 99, 37, 125, 227, 76, 146])
+          },
+          {
+            refType: ThriftReferenceType.FOLLOWS_FROM,
+            traceIdHigh: Buffer.from([110, 12, 99, 37, 125, 227, 76, 146]),
+            traceIdLow: Buffer.from([191, 158, 252, 208, 57, 39, 39, 46]),
+            spanId: Buffer.from([110, 12, 99, 37, 125, 227, 76, 146])
+          }
+        ]);
+
         assert.strictEqual(thriftSpan.logs.length, 1);
         thriftSpan.logs.forEach((log) => {
           let descriptionSeen = false;