libremidi update to v5.4.3 and added virtual midi out as default

include/libremidi/backends/linux/udev.hpp

@@ -1,12 +1,14 @@
 #pragma once
 #include <libremidi/backends/linux/dylib_loader.hpp>
 #include <libremidi/backends/linux/helpers.hpp>
+#include <libremidi/observer_configuration.hpp>
 
 #include <libudev.h>
 
 #include <cassert>
+#include <optional>
 
-namespace libremidi
+NAMESPACE_LIBREMIDI
 {
 
 struct libudev
@@ -25,12 +27,28 @@ struct libudev
 
     LIBREMIDI_SYMBOL_INIT(udev, device_get_action)
     LIBREMIDI_SYMBOL_INIT(udev, device_get_subsystem)
+    LIBREMIDI_SYMBOL_INIT(udev, device_get_property_value)
+    LIBREMIDI_SYMBOL_INIT(udev, device_new_from_syspath)
+    LIBREMIDI_SYMBOL_INIT(udev, device_get_parent_with_subsystem_devtype)
     LIBREMIDI_SYMBOL_INIT(udev, device_unref)
+
     LIBREMIDI_SYMBOL_INIT(udev, monitor_enable_receiving)
     LIBREMIDI_SYMBOL_INIT(udev, monitor_get_fd)
     LIBREMIDI_SYMBOL_INIT(udev, monitor_new_from_netlink)
     LIBREMIDI_SYMBOL_INIT(udev, monitor_receive_device)
     LIBREMIDI_SYMBOL_INIT(udev, monitor_unref)
+
+    LIBREMIDI_SYMBOL_INIT(udev, enumerate_new)
+    LIBREMIDI_SYMBOL_INIT(udev, enumerate_unref)
+    LIBREMIDI_SYMBOL_INIT(udev, enumerate_add_match_is_initialized)
+    LIBREMIDI_SYMBOL_INIT(udev, enumerate_add_match_subsystem)
+    LIBREMIDI_SYMBOL_INIT(udev, enumerate_add_match_sysname)
+    LIBREMIDI_SYMBOL_INIT(udev, enumerate_scan_devices)
+    LIBREMIDI_SYMBOL_INIT(udev, enumerate_get_list_entry)
+
+    LIBREMIDI_SYMBOL_INIT(udev, list_entry_get_name)
+    LIBREMIDI_SYMBOL_INIT(udev, list_entry_get_next)
+
     LIBREMIDI_SYMBOL_INIT2(udev, new, create)
     LIBREMIDI_SYMBOL_INIT(udev, unref)
   }
@@ -46,12 +64,28 @@ struct libudev
 
   LIBREMIDI_SYMBOL_DEF(udev, device_get_action)
   LIBREMIDI_SYMBOL_DEF(udev, device_get_subsystem)
+  LIBREMIDI_SYMBOL_DEF(udev, device_new_from_syspath)
+  LIBREMIDI_SYMBOL_DEF(udev, device_get_property_value)
+  LIBREMIDI_SYMBOL_DEF(udev, device_get_parent_with_subsystem_devtype)
   LIBREMIDI_SYMBOL_DEF(udev, device_unref)
+
   LIBREMIDI_SYMBOL_DEF(udev, monitor_enable_receiving)
   LIBREMIDI_SYMBOL_DEF(udev, monitor_get_fd)
   LIBREMIDI_SYMBOL_DEF(udev, monitor_new_from_netlink)
   LIBREMIDI_SYMBOL_DEF(udev, monitor_receive_device)
   LIBREMIDI_SYMBOL_DEF(udev, monitor_unref)
+
+  LIBREMIDI_SYMBOL_DEF(udev, enumerate_new)
+  LIBREMIDI_SYMBOL_DEF(udev, enumerate_unref)
+  LIBREMIDI_SYMBOL_DEF(udev, enumerate_add_match_is_initialized)
+  LIBREMIDI_SYMBOL_DEF(udev, enumerate_add_match_subsystem)
+  LIBREMIDI_SYMBOL_DEF(udev, enumerate_add_match_sysname)
+  LIBREMIDI_SYMBOL_DEF(udev, enumerate_scan_devices)
+  LIBREMIDI_SYMBOL_DEF(udev, enumerate_get_list_entry)
+
+  LIBREMIDI_SYMBOL_DEF(udev, list_entry_get_name)
+  LIBREMIDI_SYMBOL_DEF(udev, list_entry_get_next)
+
   LIBREMIDI_SYMBOL_DEF2(udev, new, create)
   LIBREMIDI_SYMBOL_DEF(udev, unref)
 };
@@ -89,4 +123,107 @@ struct udev_helper
   udev_monitor* monitor{};
 };
 
+struct udev_enumerator
+{
+  explicit udev_enumerator(const udev_helper& h)
+      : helper{h}
+  {
+    auto& udev = helper.udev;
+    auto& instance = helper.instance;
+    enumerator = udev.enumerate_new(instance);
+    assert(enumerator);
+  }
+
+  ~udev_enumerator()
+  {
+    auto& udev = helper.udev;
+    udev.enumerate_unref(enumerator);
+  }
+
+  const udev_helper& helper;
+  udev_enumerate* enumerator{};
+  operator udev_enumerate*() const noexcept { return enumerator; }
+};
+
+struct udev_soundcard_info
+{
+  container_identifier container;
+  device_identifier path;
+  transport_type type{};
+  std::string vendor;
+  std::string product;
+  std::string serial;
+};
+
+inline udev_soundcard_info get_udev_soundcard_info(const udev_helper& helper, int card)
+{
+  auto& udev = helper.udev;
+  udev_enumerator e{helper};
+  udev.enumerate_add_match_subsystem(e, "sound");
+  udev.enumerate_add_match_sysname(e, ("controlC" + std::to_string(card)).c_str());
+  if (udev.enumerate_scan_devices(e) != 0)
+    return {};
+
+  for (auto entry = udev.enumerate_get_list_entry(e); entry;
+       entry = udev.list_entry_get_next(entry))
+  {
+    auto path = udev.list_entry_get_name(entry);
+    if (!path)
+      continue;
+
+    auto dev = udev.device_new_from_syspath(helper.instance, path);
+    if (!dev)
+      continue;
+
+    const auto usb_device
+        = udev.device_get_parent_with_subsystem_devtype(dev, "usb", "usb_device");
+    const auto pci_device = udev.device_get_parent_with_subsystem_devtype(dev, "pci", nullptr);
+
+    transport_type type = transport_type::hardware;
+    if (usb_device)
+      type = (transport_type)(type | transport_type::usb);
+    else if (pci_device)
+      type = (transport_type)(type | transport_type::pci);
+
+    auto id_path = udev.device_get_property_value(dev, "ID_PATH");
+    if (!id_path)
+      id_path = "";
+
+    auto read_property = [&](const char* property) {
+      auto res = udev.device_get_property_value(dev, property);
+      if (!res)
+        res = "";
+      if (strlen(res) == 0)
+      {
+        if (usb_device)
+        {
+          res = udev.device_get_property_value(usb_device, property);
+          if (!res)
+            res = "";
+        }
+        else if (pci_device)
+        {
+          res = udev.device_get_property_value(pci_device, property);
+          if (!res)
+            res = "";
+        }
+      }
+      return res;
+    };
+
+    auto id_vendor = read_property("ID_VENDOR_FROM_DATABASE");
+    auto id_product = read_property("ID_MODEL_FROM_DATABASE");
+    auto id_serial = read_property("ID_SERIAL");
+    auto ret = udev_soundcard_info{
+        .container = id_path,
+        .path = path,
+        .type = type,
+        .vendor = id_vendor,
+        .product = id_product,
+        .serial = id_serial};
+    udev.device_unref(dev);
+    return ret;
+  }
+  return {};
+}
 }