// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
// vim: ts=8 sw=2 smarttab
/*
 * Ceph - scalable distributed file system
 *
 * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
 *
 * This is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software 
 * Foundation.  See file COPYING.
 * 
 */

#ifndef CEPH_MDSTABLECLIENT_H
#define CEPH_MDSTABLECLIENT_H

#include "include/types.h"
#include "MDSContext.h"
#include "mds_table_types.h"

#include "messages/MMDSTableRequest.h"

class MDSRank;
class LogSegment;

class MDSTableClient {
public:
  MDSTableClient(MDSRank *m, int tab) :
    mds(m), table(tab) {}
  virtual ~MDSTableClient() {}

  void handle_request(const cref_t<MMDSTableRequest> &m);

  void _prepare(bufferlist& mutation, version_t *ptid, bufferlist *pbl, MDSContext *onfinish);
  void commit(version_t tid, LogSegment *ls);

  void resend_commits();
  void resend_prepares();

  // for recovery (by me)
  void got_journaled_agree(version_t tid, LogSegment *ls);
  void got_journaled_ack(version_t tid);

  bool has_committed(version_t tid) const {
    return pending_commit.count(tid) == 0;
  }
  void wait_for_ack(version_t tid, MDSContext *c) {
    ack_waiters[tid].push_back(c);
  }

  set<version_t> get_journaled_tids() const {
    set<version_t> tids;
    for (auto p : pending_commit)
      tids.insert(p.first);
    return tids;
  }

  void handle_mds_failure(mds_rank_t mds);

  // child must implement
  virtual void resend_queries() = 0;
  virtual void handle_query_result(const cref_t<MMDSTableRequest> &m) = 0;
  virtual void handle_notify_prep(const cref_t<MMDSTableRequest> &m) = 0;
  virtual void notify_commit(version_t tid) = 0;
protected:
  // prepares
  struct _pending_prepare {
    _pending_prepare() {}
    _pending_prepare(MDSContext *c, version_t *pt, bufferlist *pb, bufferlist& m) :
      onfinish(c), ptid(pt), pbl(pb), mutation(m) {}

    MDSContext *onfinish = nullptr;
    version_t *ptid = nullptr;
    bufferlist *pbl = nullptr;
    bufferlist mutation;
  };

  friend class C_LoggedAck;

  void handle_reply(class MMDSTableQuery *m);
  void _logged_ack(version_t tid);

  MDSRank *mds;
  int table;

  uint64_t last_reqid = ~0ULL;

  bool server_ready = false;

  map<uint64_t, _pending_prepare> pending_prepare;
  map<version_t, uint64_t> prepared_update;
  list<_pending_prepare> waiting_for_reqid;

  // pending commits
  map<version_t, LogSegment*> pending_commit;
  map<version_t, MDSContext::vec > ack_waiters;
};
#endif