ceph/src/messages/MMDSMap.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15
  16 #ifndef CEPH_MMDSMAP_H
  17 #define CEPH_MMDSMAP_H
  18
  19 #include "msg/Message.h"
  20 #include "mds/MDSMap.h"
  21 #include "include/ceph_features.h"
  22
  23 class MMDSMap : public MessageInstance<MMDSMap> {
  24 public:
  25   friend factory;
  26 private:
  27   static constexpr int HEAD_VERSION = 1;
  28   static constexpr int COMPAT_VERSION = 1;
  29 public:
  30   uuid_d fsid;
  31   epoch_t epoch = 0;
  32   bufferlist encoded;
  33
  34   version_t get_epoch() const { return epoch; }
  35   const bufferlist& get_encoded() const { return encoded; }
  36
  37 protected:
  38   MMDSMap() :
  39     MessageInstance(CEPH_MSG_MDS_MAP, HEAD_VERSION, COMPAT_VERSION) {}
  40   MMDSMap(const uuid_d &f, const MDSMap &mm) :
  41     MessageInstance(CEPH_MSG_MDS_MAP, HEAD_VERSION, COMPAT_VERSION),
  42     fsid(f) {
  43     epoch = mm.get_epoch();
  44     mm.encode(encoded, -1);  // we will reencode with fewer features as necessary
  45   }
  46   ~MMDSMap() override {}
  47
  48 public:
  49   std::string_view get_type_name() const override { return "mdsmap"; }
  50   void print(ostream& out) const override {
  51     out << "mdsmap(e " << epoch << ")";
  52   }
  53
  54   // marshalling
  55   void decode_payload() override {
  56     auto p = payload.cbegin();
  57     decode(fsid, p);
  58     decode(epoch, p);
  59     decode(encoded, p);
  60   }
  61   void encode_payload(uint64_t features) override {
  62     using ceph::encode;
  63     encode(fsid, payload);
  64     encode(epoch, payload);
  65     if ((features & CEPH_FEATURE_PGID64) == 0 ||
  66         (features & CEPH_FEATURE_MDSENC) == 0 ||
  67         (features & CEPH_FEATURE_MSG_ADDR2) == 0 ||
  68         !HAVE_FEATURE(features, SERVER_NAUTILUS)) {
  69       // reencode for old clients.
  70       MDSMap m;
  71       m.decode(encoded);
  72       encoded.clear();
  73       m.encode(encoded, features);
  74     }
  75     encode(encoded, payload);
  76   }
  77 };
  78
  79 #endif