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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#ifndef CEPHFS_MIRROR_WATCHER_H
#define CEPHFS_MIRROR_WATCHER_H
#include <string_view>
#include "common/ceph_mutex.h"
#include "include/Context.h"
#include "include/rados/librados.hpp"
class ContextWQ;
namespace cephfs {
namespace mirror {
// generic watcher class -- establish watch on a given rados object
// and invoke handle_notify() when notified. On notify error, try
// to re-establish the watch. Errors during rewatch are notified via
// handle_rewatch_complete().
class Watcher {
public:
Watcher(librados::IoCtx &ioctx, std::string_view oid, ContextWQ *work_queue);
virtual ~Watcher();
void register_watch(Context *on_finish);
void unregister_watch(Context *on_finish);
protected:
std::string m_oid;
void acknowledge_notify(uint64_t notify_if, uint64_t handle, bufferlist &bl);
bool is_registered() const {
return m_state == STATE_IDLE && m_watch_handle != 0;
}
bool is_unregistered() const {
return m_state == STATE_IDLE && m_watch_handle == 0;
}
virtual void handle_rewatch_complete(int r) { }
private:
enum State {
STATE_IDLE,
STATE_REGISTERING,
STATE_REWATCHING
};
struct WatchCtx : public librados::WatchCtx2 {
Watcher &watcher;
WatchCtx(Watcher &parent) : watcher(parent) {}
void handle_notify(uint64_t notify_id,
uint64_t handle,
uint64_t notifier_id,
bufferlist& bl) override;
void handle_error(uint64_t handle, int err) override;
};
struct C_RegisterWatch : public Context {
Watcher *watcher;
Context *on_finish;
C_RegisterWatch(Watcher *watcher, Context *on_finish)
: watcher(watcher),
on_finish(on_finish) {
}
void finish(int r) override {
watcher->handle_register_watch(r, on_finish);
}
};
librados::IoCtx &m_ioctx;
ContextWQ *m_work_queue;
mutable ceph::shared_mutex m_lock;
State m_state;
bool m_watch_error = false;
bool m_watch_blocklisted = false;
uint64_t m_watch_handle;
WatchCtx m_watch_ctx;
Context *m_unregister_watch_ctx = nullptr;
virtual void handle_notify(uint64_t notify_id, uint64_t handle,
uint64_t notifier_id, bufferlist& bl) = 0;
void handle_error(uint64_t handle, int err);
void rewatch();
void handle_rewatch(int r);
void handle_rewatch_callback(int r);
void handle_register_watch(int r, Context *on_finish);
};
} // namespace mirror
} // namespace cephfs
#endif // CEPHFS_MIRROR_WATCHER_H
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