Cache getLocalAddress() to avoid per-request network address lookup (#…

…454)
openzipkin · Oct 25, 2019 · b3b5a0c · b3b5a0c
1 parent e656521
commit b3b5a0c
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Showing 2 changed files with 11 additions and 2 deletions.
diff --git a/packages/zipkin/src/InetAddress.js b/packages/zipkin/src/InetAddress.js
@@ -31,7 +31,7 @@ class InetAddress {
 }
 
 // In non-node environments we fallback to 127.0.0.1
-InetAddress.getLocalAddress = function getLocalAddress() {
+function getLocalAddress() {
   const isNode = typeof process === 'object' && typeof process.on === 'function';
   if (!isNode) {
     return new InetAddress('127.0.0.1');
@@ -40,6 +40,11 @@ InetAddress.getLocalAddress = function getLocalAddress() {
   // eslint-disable-next-line global-require
   const networkAddress = require('./network');
   return new InetAddress(networkAddress.ipv4());
-};
+}
+
+// Cache this value at import time so as to avoid network interface
+// lookup on every call
+const cachedLocalAddress = getLocalAddress();
+InetAddress.getLocalAddress = () => cachedLocalAddress;
 
 module.exports = InetAddress;
diff --git a/packages/zipkin/test/InetAddress.test.js b/packages/zipkin/test/InetAddress.test.js
@@ -5,6 +5,10 @@ describe('InetAddress', () => {
     InetAddress.getLocalAddress();
   });
 
+  it('should return the same object reference for multiple calls (cached)', () => {
+    expect(InetAddress.getLocalAddress()).to.equal(InetAddress.getLocalAddress());
+  });
+
   it('should convert an IP address to integer representation', () => {
     const addr = new InetAddress('80.91.37.133');
     expect(addr.toInt()).to.equal(1348150661);