port information: refactor, add various possible implementations of lookup and a heuristics-based find_closest_port function

cmake/libremidi.examples.cmake

@@ -17,6 +17,7 @@ add_example(midiobserve)
 add_example(echo)
 add_example(cmidiin)
 add_example(cmidiin2)
+add_example(lookup)
 add_example(midi1_to_midi2)
 add_example(midiclock_in)
 add_example(midiclock_out)

cmake/libremidi.sources.cmake

@@ -142,6 +142,8 @@ target_sources(libremidi PRIVATE
     include/libremidi/input_configuration.hpp
     include/libremidi/libremidi.hpp
     include/libremidi/message.hpp
+    include/libremidi/port_comparison.hpp
+    include/libremidi/port_information.hpp
     include/libremidi/output_configuration.hpp
     include/libremidi/ump_events.hpp
 

examples/lookup.cpp

@@ -0,0 +1,61 @@
+// midiprobe.cpp
+//
+// Simple program to check MIDI inputs and outputs.
+//
+// by Gary Scavone, 2003-2012.
+
+#include "utils.hpp"
+
+#include <libremidi/libremidi.hpp>
+#include <libremidi/port_comparison.hpp>
+
+#if defined(_WIN32) && __has_include(<winrt/base.h>)
+  #include <winrt/base.h>
+#endif
+
+#include <chrono>
+#include <cstdlib>
+#include <iostream>
+#include <thread>
+
+void lookup_api(libremidi::API api, const libremidi::input_port& searched)
+{
+  std::string_view api_name = libremidi::get_api_display_name(api);
+  std::cout << "Displaying ports for: " << api_name << std::endl;
+
+  // On Windows 10, apparently the MIDI devices aren't exactly available as soon as the app open...
+  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+
+  libremidi::observer midi{
+      {.track_hardware = true, .track_virtual = true}, libremidi::observer_configuration_for(api)};
+
+  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+
+  {
+    // Check inputs.
+    auto ports = midi.get_input_ports();
+    auto res = libremidi::find_closest_port(searched, ports);
+    if (res.found) {
+      std::cout << "Found: " << *res.port << "\n";
+    }
+  }
+}
+
+int main()
+{
+#if defined(_WIN32) && __has_include(<winrt/base.h>)
+  // Necessary for using WinUWP and WinMIDI, must be done as early as possible in your main()
+  winrt::init_apartment();
+#endif
+
+  // This will find the port that is closest to this.
+  // For instance, given a Launchpad and a Launchpad Mini,
+  // the launchpad will be returned. Otherwise, the mini will be returned.
+  libremidi::input_port searched{{.port_name = "launchpad"}};
+
+  for (auto& api : libremidi::available_apis())
+    lookup_api(api, searched);
+  for (auto& api : libremidi::available_ump_apis())
+    lookup_api(api, searched);
+  return 0;
+}

examples/midiprobe.cpp

@@ -19,11 +19,6 @@
 
 void enumerate_api(libremidi::API api)
 {
-#if defined(_WIN32) && __has_include(<winrt/base.h>)
-  // Necessary for using WinUWP and WinMIDI, must be done as early as possible in your main()
-  winrt::init_apartment();
-#endif
-
   std::string_view api_name = libremidi::get_api_display_name(api);
   std::cout << "Displaying ports for: " << api_name << std::endl;
 
@@ -58,6 +53,10 @@ void enumerate_api(libremidi::API api)
 
 int main()
 {
+#if defined(_WIN32) && __has_include(<winrt/base.h>)
+  // Necessary for using WinUWP and WinMIDI, must be done as early as possible in your main()
+  winrt::init_apartment();
+#endif
   for (auto& api : libremidi::available_apis())
     enumerate_api(api);
   for (auto& api : libremidi::available_ump_apis())

include/libremidi/backends/jack/helpers.hpp

@@ -50,7 +50,7 @@ struct jack_client
         .client = reinterpret_cast<std::uintptr_t>(client),
         .port = 0,
         .manufacturer = "",
-        .device_name = "",
+        .device_name = jack_get_client_name(client),
         .port_name = jack_port_name(port),
         .display_name = get_port_display_name(port),
     }};

include/libremidi/observer_configuration.hpp

@@ -1,129 +1,8 @@
 #pragma once
-#include <libremidi/api.hpp>
-#include <libremidi/config.hpp>
-#include <libremidi/error.hpp>
-#include <libremidi/types.hpp>
-
-#include <array>
-#include <compare>
-#include <string>
-#include <variant>
+#include <libremidi/port_information.hpp>
 
 namespace libremidi
 {
-struct LIBREMIDI_EXPORT port_information
-{
-  // Compat
-  using port_type = libremidi::transport_type;
-
-  /// Which API is this port for. port_information objects are in general
-  /// not useable for different APIs than the API of the observer that created them.
-  libremidi::API api{};
-
-  /// Handle to the API client object if the API provides one
-  // ALSA Raw: unused
-  // ALSA Seq: snd_seq_t*
-  // CoreMIDI: MidiClientRef
-  // JACK: jack_client_t*
-  // PipeWire: unused // FIXME: pw_context? pw_main_loop?
-  // WebMIDI: unused
-  // WinMIDI: TODO
-  // WinMM: unused
-  // WinUWP: unused
-  client_handle client = static_cast<client_handle>(-1);
-
-  /// Container identifier if the API provides one
-  // ALSA: device id (std::string), e.g. ID_PATH as returned by udev: "pci-0000:00:14.0-usb-0:12:1.0"
-  // CoreMIDI: USBLocationID (int32_t)
-  // WinMIDI: ContainerID GUID (bit_cast to a winapi or winrt::GUID ;
-  //        this is not the string but the binary representation).
-  container_identifier container = std::monostate{};
-
-  /// Device identifier if the API provides one
-  // ALSA: sysfs path (std::string), e.g. "/sys/devices/pci0000:00/0000:00:02.2/0000:02:00.0/sound/card0/controlC0"
-  // CoreMIDI: USBVendorProduct (int32_t)
-  // WinMIDI: EndpointDeviceId (std::string), e.g. "\\?\swd#midisrv#midiu_ksa..."
-  // WinMM: MIDI{IN,OUT}CAPS mId / pId { uint16_t manufacturer_id, uint16_t product_id; }
-  device_identifier device = std::monostate{};
-
-  /// Handle to the port identifier if the API provides one
-  // ALSA Raw: bit_cast to struct { uint16_t card, device, sub, padding; }.
-  // ALSA Seq: bit_cast to struct { uint32_t client, port; }
-  // CoreMIDI: MidiObjectRef's kMIDIPropertyUniqueID (uint32_t)
-  // JACK: jack_port_id_t
-  // PipeWire: port.id
-  // WebMIDI: index of the MIDI device in the list provided by the browser.
-  // WinMIDI: uint64_t terminal_block_number; (MidiGroupTerminalBlock::Number(), index is 1-based)
-  // WinMM: port index between 0 and midi{In,Out}GetNumDevs()
-  // WinUWP: index of the MIDI device in the list provided by the OS.
-  port_handle port = static_cast<port_handle>(-1);
-
-  /// User-readable information
-  // ALSA Raw: ID_VENDOR_FROM_DATABASE if provided by udev
-  // ALSA Seq: ID_VENDOR_FROM_DATABASE if provided by udev
-  // CoreMIDI: kMIDIPropertyManufacturer
-  // WinMIDI: MidiEndpointDeviceInformation::GetTransportSuppliedInfo().ManufacturerName
-  // WinMM: unavailable
-  std::string manufacturer{};
-
-  // ALSA Raw: ID_MODEL_FROM_DATABASE if provided by udev
-  // ALSA Seq: ID_MODEL_FROM_DATABASE if provided by udev
-  // WinMIDI: MidiEndpointDeviceInformation::GetTransportSuppliedInfo().Name
-  std::string product{};
-
-  /// "Unique" serial number. Note that this is super unreliable - pretty
-  /// much no MIDI device manufacturer bothers with unique per-device serial number
-  /// unlike most USB devices.
-  // ALSA Raw: ID_USB_SERIAL if provided by udev.
-  // ALSA Seq: ID_USB_SERIAL if provided by udev.
-  // WinMIDI: MidiEndpointDeviceInformation::GetTransportSuppliedInfo().SerialNumber
-  std::string serial{};
-
-  // ALSA Raw: Name returned by snd_rawmidi_info_get_name
-  // ALSA Seq: Name returned by snd_seq_client_info_get_name
-  // CoreMIDI: kMIDIPropertyModel
-  // WinMIDI: MidiEndpointDeviceInformation::Name
-  // WinMM: unavailable
-  std::string device_name{};
-
-  // ALSA Raw: Name returned by snd_rawmidi_info_get_subdevice_name
-  // ALSA Seq: Name returned by snd_seq_port_info_get_name
-  // CoreMIDI: kMIDIPropertyName
-  // WinMIDI: MidiGroupTerminalBlock::Name
-  // WinMM: szPname
-  std::string port_name{};
-
-  // CoreMIDI: kMIDIPropertyDisplayName
-  // Otherwise: the closest to a unique name we can get
-  std::string display_name{};
-
-  /// Port type
-  // CoreMIDI: available
-  // WinMIDI: available
-  // WinMM: unavailable
-  port_type type = port_type::unknown;
-
-  // Equality and comparison operators are deleted as there is not one
-  // single correct way to compare two port_information:
-  // in some cases it may be useful to only compare the names, while in other cases
-  // it is necessary to check whether this is the exact same low-level identifier.
-  // Thus, the end-user must define their own custom equality operators
-  // if using std:: containers or algorithms
-  bool operator==(const port_information& other) const noexcept = delete;
-  std::strong_ordering operator<=>(const port_information& other) const noexcept = delete;
-};
-
-struct input_port : port_information
-{
-  bool operator==(const input_port& other) const noexcept = delete;
-  std::strong_ordering operator<=>(const input_port& other) const noexcept = delete;
-};
-struct output_port : port_information
-{
-  bool operator==(const output_port& other) const noexcept = delete;
-  std::strong_ordering operator<=>(const output_port& other) const noexcept = delete;
-};
-
 using input_port_callback = std::function<void(const input_port&)>;
 using output_port_callback = std::function<void(const output_port&)>;
 struct observer_configuration