Refactor[mqbi::Cluster]: remove unused StateObserver APIs (#826)

Signed-off-by: Evgeny Malygin <emalygin@bloomberg.net>

Author: 678098

src/groups/mqb/mqbblp/mqbblp_cluster.cpp

@@ -2714,28 +2714,6 @@ void Cluster::terminate(mqbu::ExitCode::Enum reason)
     mqbu::ExitUtil::shutdown(reason);  // EXIT
 }
 
-void Cluster::registerStateObserver(mqbc::ClusterStateObserver* observer)
-{
-    // executed by *ANY* thread
-
-    dispatcher()->execute(
-        bdlf::BindUtil::bind(&mqbc::ClusterState::registerObserver,
-                             &d_state,
-                             observer),
-        this);
-}
-
-void Cluster::unregisterStateObserver(mqbc::ClusterStateObserver* observer)
-{
-    // executed by *ANY* thread
-
-    dispatcher()->execute(
-        bdlf::BindUtil::bind(&mqbc::ClusterState::unregisterObserver,
-                             &d_state,
-                             observer),
-        this);
-}
-
 void Cluster::openQueue(
     const bmqt::Uri&                                          uri,
     mqbi::Domain*                                             domain,

src/groups/mqb/mqbblp/mqbblp_cluster.h

@@ -550,16 +550,6 @@ class Cluster : public mqbi::Cluster,
     /// Stop the `Cluster`.
     void stop() BSLS_KEYWORD_OVERRIDE;
 
-    /// Register the specified `observer` to be notified of cluster state
-    /// changes.
-    void registerStateObserver(mqbc::ClusterStateObserver* observer)
-        BSLS_KEYWORD_OVERRIDE;
-
-    /// Un-register the specified `observer` from being notified of cluster
-    /// state changes.
-    void unregisterStateObserver(mqbc::ClusterStateObserver* observer)
-        BSLS_KEYWORD_OVERRIDE;
-
     /// Open the queue with the specified `uri`, belonging to the specified
     /// `domain` with the specified `parameters` from a client identified
     /// with the specified `clientContext`.  Invoke the specified `callback`

src/groups/mqb/mqbblp/mqbblp_clusterproxy.cpp

@@ -1201,28 +1201,6 @@ void ClusterProxy::stop()
     dispatcher()->synchronize(this);
 }
 
-void ClusterProxy::registerStateObserver(
-    BSLA_UNUSED mqbc::ClusterStateObserver* observer)
-{
-    // executed by *ANY* thread
-
-    // NOTHING
-    //
-    // TODO_CSL Register the observer to 'dummy state' after it becomes the
-    //          true state.
-}
-
-void ClusterProxy::unregisterStateObserver(
-    BSLA_UNUSED mqbc::ClusterStateObserver* observer)
-{
-    // executed by *ANY* thread
-
-    // NOTHING
-    //
-    // TODO_CSL Register the observer to 'dummy state' after it becomes the
-    //          true state.
-}
-
 void ClusterProxy::openQueue(
     const bmqt::Uri&                                          uri,
     mqbi::Domain*                                             domain,

src/groups/mqb/mqbblp/mqbblp_clusterproxy.h

@@ -462,16 +462,6 @@ class ClusterProxy : public mqbc::ClusterStateObserver,
     /// used by this cluster.
     mqbnet::Cluster& netCluster() BSLS_KEYWORD_OVERRIDE;
 
-    /// Register the specified `observer` to be notified of cluster state
-    /// changes.
-    void registerStateObserver(mqbc::ClusterStateObserver* observer)
-        BSLS_KEYWORD_OVERRIDE;
-
-    /// Un-register the specified `observer` from being notified of cluster
-    /// state changes.
-    void unregisterStateObserver(mqbc::ClusterStateObserver* observer)
-        BSLS_KEYWORD_OVERRIDE;
-
     /// Open the queue with the specified `uri`, belonging to the specified
     /// `domain` with the specified `parameters` from a client identified
     /// with the specified `clientContext`.  Invoke the specified `callback`

src/groups/mqb/mqbi/mqbi_cluster.h

@@ -70,9 +70,6 @@ class FixedThreadPool;
 namespace bmqt {
 class Uri;
 }
-namespace mqbc {
-class ClusterStateObserver;
-}
 namespace mqbcmd {
 class ClusterCommand;
 }
@@ -290,16 +287,6 @@ class Cluster : public DispatcherClient {
     // manager used by this cluster.
     virtual MultiRequestManagerType& multiRequestManager() = 0;
 
-    /// Register the specified `observer` to be notified of cluster state
-    /// changes.
-    virtual void
-    registerStateObserver(mqbc::ClusterStateObserver* observer) = 0;
-
-    /// Un-register the specified `observer` from being notified of cluster
-    /// state changes.
-    virtual void
-    unregisterStateObserver(mqbc::ClusterStateObserver* observer) = 0;
-
     /// Send the specified `request` with the specified `timeout` to the
     /// specified `target` node.  If `target` is 0, it is the Cluster's
     /// implementation responsibility to decide which node to use (in

src/groups/mqb/mqbmock/mqbmock_cluster.cpp

@@ -369,22 +369,6 @@ void Cluster::stop()
     d_isStarted = false;
 }
 
-void Cluster::registerStateObserver(
-    BSLA_UNUSED mqbc::ClusterStateObserver* observer)
-{
-    // executed by *ANY* thread
-
-    // NOTHING
-}
-
-void Cluster::unregisterStateObserver(
-    BSLA_UNUSED mqbc::ClusterStateObserver* observer)
-{
-    // executed by *ANY* thread
-
-    // NOTHING
-}
-
 mqbnet::Cluster& Cluster::netCluster()
 {
     return *(d_clusterData_mp->membership().netCluster());

src/groups/mqb/mqbmock/mqbmock_cluster.h

@@ -315,16 +315,6 @@ class Cluster : public mqbi::Cluster {
     /// Stop the `Cluster`.
     void stop() BSLS_KEYWORD_OVERRIDE;
 
-    /// Register the specified `observer` to be notified of cluster state
-    /// changes.
-    void registerStateObserver(mqbc::ClusterStateObserver* observer)
-        BSLS_KEYWORD_OVERRIDE;
-
-    /// Un-register the specified `observer` from being notified of cluster
-    /// state changes.
-    void unregisterStateObserver(mqbc::ClusterStateObserver* observer)
-        BSLS_KEYWORD_OVERRIDE;
-
     /// Return a reference offering modifiable access to the net cluster
     /// used by this cluster.
     mqbnet::Cluster& netCluster() BSLS_KEYWORD_OVERRIDE;