From 3c987e12b3f231035989d1b4a3ca35af71faa38b Mon Sep 17 00:00:00 2001
From: Jeroen Vermeulen <jtvjtv@gmail.com>
Date: Wed, 18 Dec 2024 04:53:07 +0100
Subject: [PATCH] Wire up notification mechanism to new handlers.

---
 NEWS                          |  1 +
 include/pqxx/connection.hxx   |  1 +
 include/pqxx/notification.hxx |  3 +++
 src/connection.cxx            | 16 ++++++++++++++--
 4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index 6d9a646d5..9d11cd0ff 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,6 @@
 7.10.0
  - Deprecate `errorhandler`; replace with lambda-friendly "notice handlers."
+ - Deprecate `notification_receiver`; replace with "notification handlers"
  - Bump minimum CMake version to 3.28. (#874)
  - Fixed error message on clashing transaction focuses. (#879)
  - Don't call`/bin/true`; macOS doesn't have it.  Just call `true`. (#885)
diff --git a/include/pqxx/connection.hxx b/include/pqxx/connection.hxx
index 54245e6f1..1fcc36a89 100644
--- a/include/pqxx/connection.hxx
+++ b/include/pqxx/connection.hxx
@@ -1283,6 +1283,7 @@ private:
   /// 9.0: Replace with just notice handler.
   std::shared_ptr<pqxx::internal::notice_waiters> m_notice_waiters;
 
+  // TODO: Remove these when we retire notification_receiver.
   // TODO: Can we make these movable?
   using receiver_list =
     std::multimap<std::string, pqxx::notification_receiver *>;
diff --git a/include/pqxx/notification.hxx b/include/pqxx/notification.hxx
index 7dd3befe1..4ea3a5afc 100644
--- a/include/pqxx/notification.hxx
+++ b/include/pqxx/notification.hxx
@@ -61,10 +61,13 @@ public:
    * @param cx Connnection to operate on.
    * @param channel Name of the notification to listen for.
    */
+  [[deprecated("Use pqxx::connection::listen() instead.")]]
   notification_receiver(connection &cx, std::string_view channel);
   /// Register the receiver with a connection.
+  [[deprecated("Use pqxx::connection::listen() instead.")]]
   notification_receiver(notification_receiver const &) = delete;
   /// Register the receiver with a connection.
+  [[deprecated("Use pqxx::connection::listen() instead.")]]
   notification_receiver &operator=(notification_receiver const &) = delete;
   /// Deregister the receiver.
   virtual ~notification_receiver();
diff --git a/src/connection.cxx b/src/connection.cxx
index d39cc6034..329a00488 100644
--- a/src/connection.cxx
+++ b/src/connection.cxx
@@ -608,16 +608,20 @@ int pqxx::connection::get_notifs()
 
   // Even if somehow we receive notifications during our transaction, don't
   // deliver them.
-  if (m_trans)
+  if (m_trans != nullptr)
     PQXX_UNLIKELY
   return 0;
 
   int notifs = 0;
+
+  // Old mechanism.  This is going away.
   for (auto N{get_notif(m_conn)}; N.get(); N = get_notif(m_conn))
   {
     notifs++;
 
-    auto const Hit{m_receivers.equal_range(std::string{N->relname})};
+    std::string const name{N->relname};
+
+    auto const Hit{m_receivers.equal_range(name)};
     if (Hit.second != Hit.first)
     {
       std::string const payload{N->extra};
@@ -649,8 +653,16 @@ int pqxx::connection::get_notifs()
         }
     }
 
+    auto const handler{m_notification_handlers.find(N->relname)};
+    if (handler != std::end(m_notification_handlers))
+    {
+      ++notifs;
+      (handler->second)(name, N->be_pid, N->extra);
+    }
+
     N.reset();
   }
+
   return notifs;
 }