From 0504edbddebf8d4b6935b00af2a9650d50c55749 Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Fri, 11 Nov 2022 14:09:56 +0100
Subject: [PATCH] add instrumentation

---
 resources/entry-point-trampoline.js | 9 +++++++--
 resources/main-template.cc          | 8 +++++++-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/resources/entry-point-trampoline.js b/resources/entry-point-trampoline.js
index 2d11ebf..d10f73a 100644
--- a/resources/entry-point-trampoline.js
+++ b/resources/entry-point-trampoline.js
@@ -7,7 +7,9 @@ const {
   requireMappings,
   enableBindingsPatch
 } = REPLACE_WITH_BOXEDNODE_CONFIG;
+mongoshStartupTiming.startReadingMainSource = process.hrtime.bigint();
 const src = require(srcMod);
+mongoshStartupTiming.finishReadingMainSource = process.hrtime.bigint();
 const hydatedRequireMappings =
   requireMappings.map(([re, reFlags, linked]) => [new RegExp(re, reFlags), linked]);
 
@@ -79,10 +81,13 @@ module.exports = (() => {
     path: __dirname,
     require
   };
-  vm.compileFunction(src, [
+  mongoshStartupTiming.startCompilingMainSource = process.hrtime.bigint();
+  const fn = vm.compileFunction(src, [
     '__filename', '__dirname', 'require', 'exports', 'module'
   ], {
     filename: __filename
-  })(__filename, __dirname, require, exports, module);
+  });
+  mongoshStartupTiming.finishCompilingMainSource = process.hrtime.bigint();
+  fn(__filename, __dirname, require, exports, module);
   return module.exports;
 })();
diff --git a/resources/main-template.cc b/resources/main-template.cc
index 8c19c30..4e0a244 100644
--- a/resources/main-template.cc
+++ b/resources/main-template.cc
@@ -16,6 +16,8 @@
 #include <openssl/rand.h>
 #endif
 
+static uint64_t process_start_time = uv_hrtime();
+
 using namespace node;
 using namespace v8;
 
@@ -125,9 +127,13 @@ static int RunNodeInstance(MultiIsolatePlatform* platform,
     // instead of the internal-only `require` function.
     MaybeLocal<Value> loadenv_ret = node::LoadEnvironment(
         env.get(),
+        ("globalThis.mongoshStartupTiming = {"
+        " processStartTime: " + std::to_string(process_start_time) + "n,\n"
+        " nodeStartup: process.hrtime.bigint()\n"
+        "};\n"
         "const path = require('path');\n"
         "if (process.argv[2] === '--') process.argv.splice(2, 1);\n"
-        "require(" REPLACE_WITH_ENTRY_POINT ")");
+        "require(" REPLACE_WITH_ENTRY_POINT ")").c_str());
 
     if (loadenv_ret.IsEmpty())  // There has been a JS exception.
       return 1;