From 7faac2aef4084d70479521acd85dce9c03affa96 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Tue, 29 Aug 2023 20:31:30 +0200
Subject: [PATCH] remote-desktop/session: Add API to acquire new mapping ID

They are guaranteed to be unique per session, and never reused.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3228>
---
 src/backends/meta-remote-desktop-session.c | 25 ++++++++++++++++++++++
 src/backends/meta-remote-desktop-session.h |  2 ++
 2 files changed, 27 insertions(+)

diff --git a/src/backends/meta-remote-desktop-session.c b/src/backends/meta-remote-desktop-session.c
index 7cd374fea..60b34fade 100644
--- a/src/backends/meta-remote-desktop-session.c
+++ b/src/backends/meta-remote-desktop-session.c
@@ -102,6 +102,8 @@ struct _MetaRemoteDesktopSession
   MetaSelectionSourceRemote *current_source;
   GHashTable *transfer_requests;
   guint transfer_request_timeout_id;
+
+  GHashTable *mapping_ids;
 };
 
 static void initable_init_iface (GInitableIface *iface);
@@ -296,6 +298,25 @@ meta_remote_desktop_session_register_screen_cast (MetaRemoteDesktopSession  *ses
   return TRUE;
 }
 
+const char *
+meta_remote_desktop_session_acquire_mapping_id (MetaRemoteDesktopSession *session)
+{
+  while (TRUE)
+    {
+      char *mapping_id;
+
+      mapping_id = g_uuid_string_random ();
+      if (g_hash_table_contains (session->mapping_ids, mapping_id))
+        {
+          g_free (mapping_id);
+          continue;
+        }
+
+      g_hash_table_add (session->mapping_ids, mapping_id);
+      return mapping_id;
+    }
+}
+
 static gboolean
 check_permission (MetaRemoteDesktopSession *session,
                   GDBusMethodInvocation    *invocation)
@@ -1731,6 +1752,8 @@ meta_remote_desktop_session_initable_init (GInitable     *initable,
                           session, "num-lock-state",
                           G_BINDING_DEFAULT | G_BINDING_SYNC_CREATE);
 
+  session->mapping_ids = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
+
   return TRUE;
 }
 
@@ -1784,6 +1807,8 @@ meta_remote_desktop_session_finalize (GObject *object)
   cancel_selection_read (session);
   g_hash_table_unref (session->transfer_requests);
 
+  g_clear_pointer (&session->mapping_ids, g_hash_table_unref);
+
   g_clear_object (&session->handle);
   g_free (session->peer_name);
   g_free (session->session_id);
diff --git a/src/backends/meta-remote-desktop-session.h b/src/backends/meta-remote-desktop-session.h
index efbe12730..6555fc310 100644
--- a/src/backends/meta-remote-desktop-session.h
+++ b/src/backends/meta-remote-desktop-session.h
@@ -42,6 +42,8 @@ gboolean meta_remote_desktop_session_register_screen_cast (MetaRemoteDesktopSess
                                                            MetaScreenCastSession     *screen_cast_session,
                                                            GError                   **error);
 
+const char * meta_remote_desktop_session_acquire_mapping_id (MetaRemoteDesktopSession *session);
+
 void meta_remote_desktop_session_request_transfer (MetaRemoteDesktopSession  *session,
                                                    const char                *mime_type,
                                                    GTask                     *task);