Enable WASM for HdrHistogramJS (#283)

lib/run.js

@@ -36,7 +36,10 @@ function _run (opts, cb, tracker) {
     return tracker
   }
 
+  hdr.initWebAssemblySync()
+
   const latencies = hdr.build({
+    useWebAssembly: true,
     bitBucketSize: 64,
     autoResize: true,
     lowestDiscernibleValue: 1,
@@ -45,6 +48,7 @@ function _run (opts, cb, tracker) {
   })
 
   const requests = hdr.build({
+    useWebAssembly: true,
     bitBucketSize: 64,
     autoResize: true,
     lowestDiscernibleValue: 1,
@@ -53,6 +57,7 @@ function _run (opts, cb, tracker) {
   })
 
   const throughput = hdr.build({
+    useWebAssembly: true,
     bitBucketSize: 64,
     autoResize: true,
     lowestDiscernibleValue: 1,
@@ -190,12 +195,17 @@ function _run (opts, cb, tracker) {
       result.latency.totalCount = latencies.totalCount
       result.requests.sent = totalRequests
       statusCodes.forEach((code, index) => { result[(index + 1) + 'xx'] = code })
-      if (result.requests.min === Number.MAX_SAFE_INTEGER) result.requests.min = 0
-      if (result.throughput.min === Number.MAX_SAFE_INTEGER) result.throughput.min = 0
-      if (result.latency.min === Number.MAX_SAFE_INTEGER) result.latency.min = 0
+      if (result.requests.min >= Number.MAX_SAFE_INTEGER) result.requests.min = 0
+      if (result.throughput.min >= Number.MAX_SAFE_INTEGER) result.throughput.min = 0
+      if (result.latency.min >= Number.MAX_SAFE_INTEGER) result.latency.min = 0
 
       tracker.emit('done', result)
-      if (!opts.forever) cb(null, result)
+      if (!opts.forever) {
+        latencies.destroy()
+        requests.destroy()
+        throughput.destroy()
+        cb(null, result)
+      }
 
       // the restart function
       setImmediate(() => {

test/serial/wasm.test.js

@@ -0,0 +1,34 @@
+'use strict'
+
+const test = require('tap').test
+const run = require('../../lib/run')
+const helper = require('../helper')
+
+test('should clean up HdrHistogram WASM memory at each run', async (t) => {
+  const server = helper.startServer()
+  const runTwentyTimes = (resolve, reject, numberOfRuns = 0) => {
+    run({
+      url: 'http://localhost:' + server.address().port,
+      connections: 1,
+      amount: 1
+    }, (result) => {
+      // should get error " url or socketPath option required"
+      // we can ignore this error, we just want run() to execute
+      // and to instantiate new WASM histograms
+      if (numberOfRuns < 20) {
+        runTwentyTimes(resolve, reject, ++numberOfRuns)
+      } else {
+        resolve()
+      }
+    })
+  }
+  const lotsOfRuns = []
+  for (let index = 0; index < 50; index++) {
+    lotsOfRuns.push(new Promise(runTwentyTimes))
+  }
+
+  await Promise.all(lotsOfRuns)
+
+  // if the process has not crashed, we are good \o/
+  t.end()
+})