perf: fast timers

Author: ronag

lib/client.js

@@ -83,6 +83,46 @@ try {
   channels.connected = { hasSubscribers: false }
 }
 
+let fastNow = Date.now()
+const fastTimers = new Set()
+const fastNowInterval = setInterval(() => {
+  fastNow = Date.now()
+  for (const timer of fastTimers) {
+    if (fastNow >= timer.expires) {
+      timer.expires = 0
+      timer.callback(timer.opaque)
+    }
+  }
+}, 1e3)
+if (fastNowInterval.unref) {
+  fastNowInterval.unref()
+}
+
+function setFastTimeout (callback, delay, opaque) {
+  const timer = {
+    callback,
+    delay,
+    expires: fastNow + delay,
+    opaque
+  }
+
+  fastTimers.add(timer)
+
+  return timer
+}
+
+function refreshFastTimeout (timer) {
+  if (timer) {
+    timer.expires = fastNow + timer.delay
+  }
+}
+
+function clearFastTimeout (timer) {
+  if (timer) {
+    fastTimers.delete(timer)
+  }
+}
+
 class Client extends DispatcherBase {
   constructor (url, {
     interceptors,
@@ -447,9 +487,9 @@ class Parser {
   setTimeout (value, type) {
     this.timeoutType = type
     if (value !== this.timeoutValue) {
-      clearTimeout(this.timeout)
+      clearFastTimeout(this.timeout)
       if (value) {
-        this.timeout = setTimeout(onParserTimeout, value, this)
+        this.timeout = setFastTimeout(onParserTimeout, value, this)
         // istanbul ignore else: only for jest
         if (this.timeout.unref) {
           this.timeout.unref()
@@ -463,13 +503,12 @@ class Parser {
     }
   }
 
-  refreshTimeout() {
-    if (this.timeout) {
-      // istanbul ignore else: only for jest
-      if (this.timeout.refresh) {
-        this.timeout.refresh()
-      }
-    }
+  refreshTimeout () {
+    refreshFastTimeout(this.timeout)
+  }
+
+  clearTimeout () {
+    clearFastTimeout(this.timeout)
   }
 
   resume () {
@@ -566,7 +605,7 @@ class Parser {
     this.llhttp.llhttp_free(this.ptr)
     this.ptr = null
 
-    clearTimeout(this.timeout)
+    this.clearTimeout()
     this.timeout = null
     this.timeoutValue = null
     this.timeoutType = null