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 final : public SafeMessage {
  24 private:
  25   static constexpr int HEAD_VERSION = 2;
  26   static constexpr int COMPAT_VERSION = 1;
  27 public:
  28   uuid_d fsid;
  29   epoch_t epoch = 0;
  30   ceph::buffer::list encoded;
  31   // don't really need map_fs_name. it was accidentally added in 51af2346fdf
  32   // set it to empty string.
  33   std::string map_fs_name = std::string();
  34
  35   version_t get_epoch() const { return epoch; }
  36   const ceph::buffer::list& get_encoded() const { return encoded; }
  37
  38 protected:
  39   MMDSMap() :
  40     SafeMessage{CEPH_MSG_MDS_MAP, HEAD_VERSION, COMPAT_VERSION} {}
  41
  42   MMDSMap(const uuid_d &f, const MDSMap &mm) :
  43     SafeMessage{CEPH_MSG_MDS_MAP, HEAD_VERSION, COMPAT_VERSION},
  44     fsid(f) {
  45     epoch = mm.get_epoch();
  46     mm.encode(encoded, -1);  // we will reencode with fewer features as necessary
  47   }
  48
  49   ~MMDSMap() final {}
  50
  51 public:
  52   std::string_view get_type_name() const override { return "mdsmap"; }
  53   void print(std::ostream& out) const override {
  54     out << "mdsmap(e " << epoch << ")";
  55   }
  56
  57   // marshalling
  58   void decode_payload() override {
  59     using ceph::decode;
  60     auto p = payload.cbegin();
  61     decode(fsid, p);
  62     decode(epoch, p);
  63     decode(encoded, p);
  64     if (header.version >= 2) {
  65       decode(map_fs_name, p);
  66     }
  67   }
  68   void encode_payload(uint64_t features) override {
  69     using ceph::encode;
  70     encode(fsid, payload);
  71     encode(epoch, payload);
  72     if ((features & CEPH_FEATURE_PGID64) == 0 ||
  73         (features & CEPH_FEATURE_MDSENC) == 0 ||
  74         (features & CEPH_FEATURE_MSG_ADDR2) == 0 ||
  75         !HAVE_FEATURE(features, SERVER_NAUTILUS)) {
  76       // reencode for old clients.
  77       MDSMap m;
  78       m.decode(encoded);
  79       encoded.clear();
  80       m.encode(encoded, features);
  81     }
  82     encode(encoded, payload);
  83     encode(map_fs_name, payload);
  84   }
  85 private:
  86   template<class T, typename... Args>
  87   friend boost::intrusive_ptr<T> ceph::make_message(Args&&... args);
  88   template<class T, typename... Args>
  89   friend MURef<T> crimson::make_message(Args&&... args);
  90 };
  91
  92 #endif