ceph/src/messages/MMonSubscribe.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 #ifndef CEPH_MMONSUBSCRIBE_H
  16 #define CEPH_MMONSUBSCRIBE_H
  17
  18 #include "msg/Message.h"
  19 #include "include/ceph_features.h"
  20
  21 /*
  22  * compatibility with old crap
  23  */
  24 struct ceph_mon_subscribe_item_old {
  25         ceph_le64 unused;
  26         ceph_le64 have;
  27         __u8 onetime;
  28 } __attribute__ ((packed));
  29 WRITE_RAW_ENCODER(ceph_mon_subscribe_item_old)
  30
  31
  32 class MMonSubscribe final : public Message {
  33 public:
  34   static constexpr int HEAD_VERSION = 3;
  35   static constexpr int COMPAT_VERSION = 1;
  36
  37   std::string hostname;
  38   std::map<std::string, ceph_mon_subscribe_item> what;
  39
  40   MMonSubscribe() : Message{CEPH_MSG_MON_SUBSCRIBE, HEAD_VERSION, COMPAT_VERSION} { }
  41 private:
  42   ~MMonSubscribe() final {}
  43
  44 public:
  45   void sub_want(const char *w, version_t start, unsigned flags) {
  46     what[w].start = start;
  47     what[w].flags = flags;
  48   }
  49
  50   std::string_view get_type_name() const override { return "mon_subscribe"; }
  51   void print(std::ostream& o) const override {
  52     o << "mon_subscribe(" << what << ")";
  53   }
  54
  55   void decode_payload() override {
  56     using ceph::decode;
  57     auto p = payload.cbegin();
  58     if (header.version < 2) {
  59       std::map<std::string, ceph_mon_subscribe_item_old> oldwhat;
  60       decode(oldwhat, p);
  61       what.clear();
  62       for (auto q = oldwhat.begin(); q != oldwhat.end(); q++) {
  63         if (q->second.have)
  64           what[q->first].start = q->second.have + 1;
  65         else
  66           what[q->first].start = 0;
  67         what[q->first].flags = 0;
  68         if (q->second.onetime)
  69           what[q->first].flags |= CEPH_SUBSCRIBE_ONETIME;
  70       }
  71       return;
  72     }
  73     decode(what, p);
  74     if (header.version >= 3) {
  75       decode(hostname, p);
  76     }
  77   }
  78   void encode_payload(uint64_t features) override {
  79     using ceph::encode;
  80     if ((features & CEPH_FEATURE_SUBSCRIBE2) == 0) {
  81       header.version = 0;
  82       std::map<std::string, ceph_mon_subscribe_item_old> oldwhat;
  83       for (auto q = what.begin(); q != what.end(); q++) {
  84         if (q->second.start)
  85           // warning: start=1 -> have=0, which was ambiguous
  86           oldwhat[q->first].have = q->second.start - 1;
  87         else
  88           oldwhat[q->first].have = 0;
  89         oldwhat[q->first].onetime = q->second.flags & CEPH_SUBSCRIBE_ONETIME;
  90       }
  91       encode(oldwhat, payload);
  92       return;
  93     }
  94     header.version = HEAD_VERSION;
  95     encode(what, payload);
  96     encode(hostname, payload);
  97   }
  98 private:
  99   template<class T, typename... Args>
 100   friend boost::intrusive_ptr<T> ceph::make_message(Args&&... args);
 101 };
 102
 103 #endif