Refactor Flow files

.flowconfig

@@ -2,8 +2,8 @@
 ./node_modules/
 
 [libs]
-./src/_interfaces/
-./test/_interfaces/
+./src/_flow/
+./test/_flow/
 
 [options]
 unsafe.enable_getters_and_setters=true

src/_interfaces/gauge.js → src/_flow/jaeger-thrift.js

@@ -19,8 +19,27 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-// Gauge returns instantaneous measurements of something as an int64 value
-declare interface Gauge {
-    // Update the gauge to the value passed in.
-    gauge(value: number): void;
-}
+declare type Tag = {
+    key: string,
+    value: any
+};
+
+declare type LogData = {
+    timestamp: number,
+    fields: Array<Tag>
+};
+
+declare type Process = {
+    serviceName: string,
+    tags: Array<Tag>
+};
+
+declare type Batch = {
+    process: Process,
+    spans: Array<any>
+};
+
+declare type Reference = {
+    type(): string;
+    referencedContext(): SpanContext;
+};

src/_interfaces/metric_factory.js → src/_flow/metrics.js

@@ -19,6 +19,26 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
+// Counter tracks the number of times an event has occurred
+declare interface Counter {
+    // Add adds the given value to the counter.
+    increment(delta: number): void;
+}
+
+// Timer tracks how long an operation took and also computes percentiles.
+declare interface Timer {
+    // Records the time passed in.
+    // TODO what are the units of measurement for the value?
+    // TODO consider replacing this with Histogram
+    record(value: number): void;
+}
+
+// Gauge returns instantaneous measurements of something as an int64 value
+declare interface Gauge {
+    // Update the gauge to the value passed in.
+    update(value: number): void;
+}
+
 declare interface MetricFactory {
     createCounter(name: string, tags: any): Counter;
     createTimer(name: string, tags: any): Timer;

src/_interfaces/types.js → src/_flow/samlper-thrift.js

@@ -19,60 +19,6 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-import SpanContext from '../span_context.js';
-
-declare type Tag = {
-    key: string,
-    value: any
-};
-
-declare type LogData = {
-    timestamp: number,
-    fields: Array<Tag>
-};
-
-declare type Process = {
-    serviceName: string,
-    tags: Array<Tag>
-};
-
-declare type Batch = {
-    process: Process,
-    spans: Array<any>
-};
-
-declare type Endpoint = {
-    ipv4: number,
-    port: number,
-    serviceName: string
-};
-
-declare type Annotation = {
-    timestamp: number,
-    value: string,
-    host: ?Endpoint
-};
-
-declare type BinaryAnnotation = {
-    key: string,
-    value: any,
-    annotationType: string,
-    host: ?Endpoint
-};
-
-declare type Reference = {
-    type(): string;
-    referencedContext(): SpanContext;
-};
-
-declare type startSpanArgs = {
-    operationName?: string,
-    childOf?: SpanContext,
-    references?: Array<Reference>,
-    tags?: any,
-    startTime?: number,
-};
-
 declare type ProbabilisticSamplingStrategy = {
     samplingRate: number
 };
@@ -81,15 +27,24 @@ declare type RateLimitingSamplingStrategy = {
     maxTracesPerSecond: number
 };
 
+// OperationSamplingStrategy defines a sampling strategy for a given operation
+// that randomly samples a fixed percentage of traces.
+declare type OperationSamplingStrategy = {
+    operation: string,
+    probabilisticSampling: ProbabilisticSamplingStrategy
+};
+
+// PerOperationSamplingStrategies defines a collection of sampling strategies
+// per operation name, and a pair of parameters for the default sampling strategy
+// applicable to unknown operation names.
+declare type PerOperationSamplingStrategies = {
+    defaultSamplingProbability: number,
+    defaultLowerBoundTracesPerSecond: number,
+    perOperationStrategies: Array<OperationSamplingStrategy>
+}
+
 declare type SamplingStrategyResponse = {
     strategyType: number,
     probabilisticSampling?: ProbabilisticSamplingStrategy,
     rateLimitingSampling?: RateLimitingSamplingStrategy
 };
-
-declare type TChannelSpan = {
-    id: Array<number>,
-    traceid: Array<number>,
-    parentid: Array<number>,
-    flags: number
-};

src/_interfaces/timer.js → src/_flow/tchannel.js

@@ -19,8 +19,9 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-// Timer tracks how long an envent has occurred.
-declare interface Timer {
-    // Records the time passed in.
-    record(value: number): void;
-}
+declare type TChannelSpan = {
+    id: Array<number>,
+    traceid: Array<number>,
+    parentid: Array<number>,
+    flags: number
+};

src/_interfaces/counter.js → src/_flow/tracer.js

@@ -19,8 +19,13 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-// Counter tracks the number of times an event has occurred
-declare interface Counter {
-    // Add adds the given value to the counter.
-    increment(delta: number): void;
-}
+import SpanContext from '../span_context.js';
+
+// startSpanOptions is used to type-check Trace.startSpan() options.
+declare type startSpanOptions = {
+    operationName?: string,
+    childOf?: SpanContext,
+    references?: Array<Reference>,
+    tags?: any,
+    startTime?: number,
+};

src/metrics/noop/gauge.js

@@ -20,5 +20,5 @@
 // THE SOFTWARE.
 
 export default class NoopGauge {
-    gauge(value: number): void {}
+    update(value: number): void {}
 }

src/tracer.js

@@ -172,7 +172,7 @@ export default class Tracer {
     *        to represent time values with sub-millisecond accuracy.
     * @return {Span} - a new Span object.
     **/
-    startSpan(operationName: string, options: ?startSpanArgs): Span {
+    startSpan(operationName: string, options: ?startSpanOptions): Span {
         // Convert options.childOf to options.references as needed.
         options = options || {};
         let references = options.references || [];

test/lib/metrics/local/gauge.js

@@ -30,7 +30,7 @@ export default class LocalGauge {
         this._backend = backend;
     }
 
-    gauge(value: number): void {
+    update(value: number): void {
         this._backend.gauge(this._name, value, this._tags);
     }
 }