ceph/src/rgw/rgw_realm_watcher.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab ft=cpp
   3
   4 #ifndef RGW_REALM_WATCHER_H
   5 #define RGW_REALM_WATCHER_H
   6
   7 #include "include/rados/librados.hpp"
   8 #include "include/ceph_assert.h"
   9 #include "common/Timer.h"
  10 #include "common/Cond.h"
  11
  12 class RGWRados;
  13 class RGWRealm;
  14
  15 enum class RGWRealmNotify {
  16   Reload,
  17   ZonesNeedPeriod,
  18 };
  19 WRITE_RAW_ENCODER(RGWRealmNotify);
  20
  21 /**
  22  * RGWRealmWatcher establishes a watch on the current RGWRealm's control object,
  23  * and forwards notifications to registered observers.
  24  */
  25 class RGWRealmWatcher : public librados::WatchCtx2 {
  26  public:
  27   /**
  28    * Watcher is an interface that allows the RGWRealmWatcher to pass
  29    * notifications on to other interested objects.
  30    */
  31   class Watcher {
  32    public:
  33     virtual ~Watcher() = default;
  34
  35     virtual void handle_notify(RGWRealmNotify type,
  36                                bufferlist::const_iterator& p) = 0;
  37   };
  38
  39   RGWRealmWatcher(CephContext* cct, const RGWRealm& realm);
  40   ~RGWRealmWatcher() override;
  41
  42   /// register a watcher for the given notification type
  43   void add_watcher(RGWRealmNotify type, Watcher& watcher);
  44
  45   /// respond to realm notifications by calling the appropriate watcher
  46   void handle_notify(uint64_t notify_id, uint64_t cookie,
  47                      uint64_t notifier_id, bufferlist& bl) override;
  48
  49   /// reestablish the watch if it gets disconnected
  50   void handle_error(uint64_t cookie, int err) override;
  51
  52  private:
  53   CephContext *const cct;
  54
  55   /// keep a separate Rados client whose lifetime is independent of RGWRados
  56   /// so that we don't miss notifications during realm reconfiguration
  57   librados::Rados rados;
  58   librados::IoCtx pool_ctx;
  59   uint64_t watch_handle = 0;
  60   std::string watch_oid;
  61
  62   int watch_start(const RGWRealm& realm);
  63   int watch_restart();
  64   void watch_stop();
  65
  66   std::map<RGWRealmNotify, Watcher&> watchers;
  67 };
  68
  69 #endif // RGW_REALM_WATCHER_H