1 files changed, 66 insertions, 0 deletions
diff --git a/src/rgw/rgw_realm_watcher.h b/src/rgw/rgw_realm_watcher.h
new file mode 100644
index 000000000..2a0c0d076
--- /dev/null
+++ b/src/rgw/rgw_realm_watcher.h
@@ -0,0 +1,66 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab ft=cpp
+
+#pragma once
+
+#include "include/rados/librados.hpp"
+#include "include/ceph_assert.h"
+#include "common/Timer.h"
+#include "common/Cond.h"
+
+class RGWRados;
+class RGWRealm;
+
+enum class RGWRealmNotify {
+  Reload,
+  ZonesNeedPeriod,
+};
+WRITE_RAW_ENCODER(RGWRealmNotify);
+
+/**
+ * RGWRealmWatcher establishes a watch on the current RGWRealm's control object,
+ * and forwards notifications to registered observers.
+ */
+class RGWRealmWatcher : public librados::WatchCtx2 {
+ public:
+  /**
+   * Watcher is an interface that allows the RGWRealmWatcher to pass
+   * notifications on to other interested objects.
+   */
+  class Watcher {
+   public:
+    virtual ~Watcher() = default;
+
+    virtual void handle_notify(RGWRealmNotify type,
+                               bufferlist::const_iterator& p) = 0;
+  };
+
+  RGWRealmWatcher(const DoutPrefixProvider *dpp, CephContext* cct, const RGWRealm& realm);
+  ~RGWRealmWatcher() override;
+
+  /// register a watcher for the given notification type
+  void add_watcher(RGWRealmNotify type, Watcher& watcher);
+
+  /// respond to realm notifications by calling the appropriate watcher
+  void handle_notify(uint64_t notify_id, uint64_t cookie,
+                     uint64_t notifier_id, bufferlist& bl) override;
+
+  /// reestablish the watch if it gets disconnected
+  void handle_error(uint64_t cookie, int err) override;
+
+ private:
+  CephContext *const cct;
+
+  /// keep a separate Rados client whose lifetime is independent of RGWRados
+  /// so that we don't miss notifications during realm reconfiguration
+  librados::Rados rados;
+  librados::IoCtx pool_ctx;
+  uint64_t watch_handle = 0;
+  std::string watch_oid;
+
+  int watch_start(const DoutPrefixProvider *dpp, const RGWRealm& realm);
+  int watch_restart();
+  void watch_stop();
+
+  std::map<RGWRealmNotify, Watcher&> watchers;
+};