perf(cli): skip the forced info reads when the invocation performs an action

cli/main.cpp

@@ -37,8 +37,8 @@
 #include <algorithm>
 #include <cassert>
 #include <chrono>
-#include <cstdio>
 #include <csignal>
+#include <cstdio>
 #include <cstdlib>
 #include <format>
 #include <iostream>
@@ -420,7 +420,7 @@ class HIDEnumeration {
         if (devices_)
             hid_free_enumeration(devices_);
     }
-    HIDEnumeration(const HIDEnumeration&) = delete;
+    HIDEnumeration(const HIDEnumeration&)            = delete;
     HIDEnumeration& operator=(const HIDEnumeration&) = delete;
 
     hid_device_info* get() const { return devices_; }
@@ -1003,7 +1003,7 @@ void setupSignalHandler()
 #ifdef _WIN32
     signal(SIGINT, signalHandler);
 #else
-    struct sigaction act {};
+    struct sigaction act { };
     act.sa_handler = signalHandler;
     sigaction(SIGINT, &act, nullptr);
 #endif
@@ -1031,13 +1031,32 @@ std::vector<DeviceList> toLegacyDeviceList(std::vector<DiscoveredDevice>& device
     return legacy;
 }
 
+// Whether this device was asked to set something. Only counts requests that are
+// still live, so it has to run after handleMultiDeviceActions has had its say.
+bool hasRequestedAction(const DiscoveredDevice& device)
+{
+    for (const auto& req : device.feature_requests) {
+        if (req.type == CAPABILITYTYPE_ACTION && req.should_process) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 // Enable info requests for extended output formats (JSON, YAML, ENV)
+// Only for a pure query: the extra reads can cost far more than the action
+// itself (Maxwell 2: -s 20 is 0.07 s, -s 20 -o json is 2.90 s). Per device, so
+// an action on one headset does not silence the info reads of another.
 void enableExtendedInfoRequests(std::vector<DiscoveredDevice>& devices, bool extended)
 {
     if (!extended)
         return;
 
     for (auto& dev : devices) {
+        if (hasRequestedAction(dev))
+            continue;
+
         for (auto& req : dev.feature_requests) {
             if (req.type == CAPABILITYTYPE_INFO && !req.should_process && dev.hasCapability(req.cap)) {
                 req.should_process = true;
@@ -1201,8 +1220,11 @@ int main(int argc, char* argv[])
     // Initialize and configure feature requests
     initializeFeatureRequests(devices, opts);
     bool extended = opts.output_format == OUTPUT_YAML || opts.output_format == OUTPUT_JSON || opts.output_format == OUTPUT_ENV;
-    enableExtendedInfoRequests(devices, extended);
+    // Order matters: handleMultiDeviceActions neutralizes action requests, and
+    // enableExtendedInfoRequests has to see the result of that, not the requests
+    // as they were parsed.
     handleMultiDeviceActions(devices, opts);
+    enableExtendedInfoRequests(devices, extended);
 
     // Main loop
     do {

cli/output/output.cpp

@@ -23,7 +23,9 @@ using namespace headsetcontrol::serializers;
 // Constants
 // ============================================================================
 
-constexpr std::string_view API_VERSION = "1.4";
+// 1.5: an invocation that performs an action no longer reports info it was not
+// explicitly asked for.
+constexpr std::string_view API_VERSION = "1.5";
 constexpr std::string_view APP_NAME    = "HeadsetControl";
 
 // ============================================================================
@@ -179,8 +181,7 @@ void processFeatureRequest(const FeatureRequest& req, DeviceData& dev, std::stri
                 for (const auto& preset : presets->presets) {
                     preset_data.push_back(EqualizerPresetData {
                         .name   = preset.name,
-                        .values = preset.values
-                    });
+                        .values = preset.values });
                 }
                 dev.equalizer_presets = std::move(preset_data);
             }

docs/LIBRARY_USAGE.md

@@ -28,7 +28,7 @@ headsetcontrol -o env
 {
   "name": "HeadsetControl",
   "version": "3.0.0",
-  "api_version": "1.4",
+  "api_version": "1.5",
   "device_count": 1,
   "devices": [
     {