Merge pull request #23 from ExpediaDotCom/allow-idgenerate-func

allow id generation to be client driven

Author: Kapil Rastogi

src/generators/id-generator.ts

@@ -0,0 +1,19 @@
+/*
+ *  Copyright 2018 Expedia, Inc.
+ *
+ *       Licensed under the Apache License, Version 2.0 (the "License");
+ *       you may not use this file except in compliance with the License.
+ *      You may obtain a copy of the License at
+ *
+ *           http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *       Unless required by applicable law or agreed to in writing, software
+ *       distributed under the License is distributed on an "AS IS" BASIS,
+ *       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *       See the License for the specific language governing permissions and
+ *       limitations under the License.
+ */
+
+export interface Generator {
+    generate(): string;
+}

src/generators/index.ts

@@ -0,0 +1,18 @@
+/*
+ *  Copyright 2018 Expedia, Inc.
+ *
+ *       Licensed under the Apache License, Version 2.0 (the "License");
+ *       you may not use this file except in compliance with the License.
+ *      You may obtain a copy of the License at
+ *
+ *           http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *       Unless required by applicable law or agreed to in writing, software
+ *       distributed under the License is distributed on an "AS IS" BASIS,
+ *       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *       See the License for the specific language governing permissions and
+ *       limitations under the License.
+ */
+
+export * from './id-generator';
+export * from './uuid-generator';

src/generators/uuid-generator.ts

@@ -0,0 +1,24 @@
+/*
+ *  Copyright 2018 Expedia, Inc.
+ *
+ *       Licensed under the Apache License, Version 2.0 (the "License");
+ *       you may not use this file except in compliance with the License.
+ *      You may obtain a copy of the License at
+ *
+ *           http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *       Unless required by applicable law or agreed to in writing, software
+ *       distributed under the License is distributed on an "AS IS" BASIS,
+ *       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *       See the License for the specific language governing permissions and
+ *       limitations under the License.
+ */
+
+import { Generator } from './id-generator';
+import Utils from '../utils';
+
+export class UUIDGenerator implements Generator {
+    generate(): string {
+        return Utils.randomUUID();
+    }
+}

src/tracer-config.ts

@@ -15,6 +15,7 @@
  */
 
 import { Logger } from './logger';
+import { Generator } from './generators';
 import { DispatcherConfig } from './dispatchers/dispatcher-config';
 
 export interface TracerConfig {
@@ -23,4 +24,5 @@ export interface TracerConfig {
     logger?: Logger;
     commonTags?: { [key: string]: any };
     dispatcher?: DispatcherConfig;
+    idGenerator?: Generator;
 }

src/tracer.ts

@@ -29,18 +29,21 @@ import URLCodex from './propagators/url_codex';
 import StartSpanFields from './start_span_fields';
 import BinaryPropagator from './propagators/binary_propagator';
 import { TracerConfig } from './tracer-config';
+import { Generator, UUIDGenerator } from './generators';
 
 export default class Tracer extends opentracing.Tracer {
     _serviceName: string;
     _dispatcher: Dispatcher;
+    _idGenerator: Generator;
     _commonTags: { [key: string]: any };
     _logger: any;
     _registry: PropagationRegistry;
 
     constructor(serviceName: string,
                 dispatcher: Dispatcher = new NoopDispatcher(),
                 commonTags: { [key: string]: any } = {},
-                logger: Logger = new NullLogger()) {
+                logger: Logger = new NullLogger(),
+                idGenerator: Generator = new UUIDGenerator()) {
         super();
         this._commonTags = commonTags || {};
         this._serviceName = serviceName;
@@ -50,6 +53,7 @@ export default class Tracer extends opentracing.Tracer {
         this._registry.register(opentracing.FORMAT_TEXT_MAP, new TextMapPropagator());
         this._registry.register(opentracing.FORMAT_BINARY, new BinaryPropagator());
         this._registry.register(opentracing.FORMAT_HTTP_HEADERS, new TextMapPropagator(new URLCodex()));
+        this._idGenerator = idGenerator;
     }
 
     startSpan(operationName: string, fields?: StartSpanFields): Span {
@@ -83,7 +87,7 @@ export default class Tracer extends opentracing.Tracer {
             }
         }
 
-        const ctx = Tracer._createSpanContext(parent, fields.callerSpanContext);
+        const ctx = this._createSpanContext(parent, fields.callerSpanContext);
         return this._spanStart(operationName, ctx, startTime, references, spanTags);
     }
 
@@ -98,16 +102,16 @@ export default class Tracer extends opentracing.Tracer {
         return span;
     }
 
-    static _createSpanContext(parent: SpanContext, callerContext: SpanContext): SpanContext {
+    _createSpanContext(parent: SpanContext, callerContext: SpanContext): SpanContext {
         if (!parent || !parent.isValid) {
             if (callerContext) {
                 return new SpanContext(callerContext.traceId, callerContext.spanId, callerContext.parentSpanId, callerContext.baggage);
             } else {
                 const parentBaggage = parent && parent.baggage;
-                return new SpanContext(Utils.randomUUID(), Utils.randomUUID(), parentBaggage);
+                return new SpanContext(this._idGenerator.generate(), this._idGenerator.generate(), parentBaggage);
             }
         } else {
-            return new SpanContext(parent.traceId, Utils.randomUUID(), parent.spanId, parent.baggage);
+            return new SpanContext(parent.traceId, this._idGenerator.generate(), parent.spanId, parent.baggage);
         }
     }
 
@@ -178,7 +182,6 @@ export default class Tracer extends opentracing.Tracer {
         if (config.logger) {
             config.logger.info(`Initializing Haystack Tracer with ${dispatcher.name()}`);
         }
-
-        return new Tracer(config.serviceName, dispatcher, config.commonTags, config.logger);
+        return new Tracer(config.serviceName, dispatcher, config.commonTags, config.logger, config.idGenerator);
     }
 }

tests/integration/agent-integration.spec.ts

@@ -19,8 +19,9 @@ import * as opentracing from 'opentracing';
 import SpanContext from '../../src/span_context';
 import * as kafka from 'kafka-node';
 import { expect } from 'chai';
+import { Logger } from '../../src/logger'
 
-class ConsoleLogger {
+class ConsoleLogger implements Logger {
     log(msg) { console.log(msg); }
     debug(msg: string): void { this.log(msg); }
     info(msg: string): void { this.log(msg); }
@@ -42,7 +43,7 @@ describe('Haystack Integration Tests', () => {
                         type: 'haystack_agent',
                         agentHost: 'haystack_agent'
                     },
-                    logger: new ConsoleLogger()
+                    logger: new ConsoleLogger(),
                 });
 
                 const serverSpan = tracer.startSpan('my-operation', {