[vcpkg metrics] Allow someone to opt out after build (#11542)

* [vcpkg metrics] start using json library

Additionally, add floats to the JSON library since they're required.

* [vcpkg metrics] allow users to disable metrics after the build

Additionally, as a drive by, fix UUID generation

* fix metrics data

* code review

1 files changed, 17 insertions, 0 deletions

diff --git a/toolsrc/src/vcpkg.cpp b/toolsrc/src/vcpkg.cpp
index e1a0a2a0b..95cd39778 100644
--- a/toolsrc/src/vcpkg.cpp
+++ b/toolsrc/src/vcpkg.cpp
@@ -333,6 +333,11 @@ int main(const int argc, const char* const* const argv)
         auto flags = Strings::split(*v, ',');
         if (std::find(flags.begin(), flags.end(), "binarycaching") != flags.end()) GlobalState::g_binary_caching = true;
     }
+    const auto vcpkg_disable_metrics_env = System::get_environment_variable("VCPKG_DISABLE_METRICS");
+    if (vcpkg_disable_metrics_env.has_value())
+    {
+        Metrics::g_metrics.lock()->set_disabled(true);
+    }
 
     const VcpkgCmdArguments args = VcpkgCmdArguments::create_from_command_line(argc, argv);
 
@@ -340,8 +345,20 @@ int main(const int argc, const char* const* const argv)
 
     if (const auto p = args.printmetrics.get()) Metrics::g_metrics.lock()->set_print_metrics(*p);
     if (const auto p = args.sendmetrics.get()) Metrics::g_metrics.lock()->set_send_metrics(*p);
+    if (const auto p = args.disable_metrics.get()) Metrics::g_metrics.lock()->set_disabled(*p);
     if (const auto p = args.debug.get()) Debug::g_debugging = *p;
 
+    if (args.sendmetrics.has_value() && !Metrics::g_metrics.lock()->metrics_enabled())
+    {
+        System::print2(System::Color::warning,
+                       "Warning: passed either --sendmetrics or --no-sendmetrics, but metrics are disabled.\n");
+    }
+    if (args.printmetrics.has_value() && !Metrics::g_metrics.lock()->metrics_enabled())
+    {
+        System::print2(System::Color::warning,
+                       "Warning: passed either --printmetrics or --no-printmetrics, but metrics are disabled.\n");
+    }
+
     if (Debug::g_debugging)
     {
         inner(args);