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 : public MessageInstance<MMonSubscribe> {
  33 public:
  34   friend factory;
  35
  36   static constexpr int HEAD_VERSION = 3;
  37   static constexpr int COMPAT_VERSION = 1;
  38
  39   string hostname;
  40   map<string, ceph_mon_subscribe_item> what;
  41
  42   MMonSubscribe() : MessageInstance(CEPH_MSG_MON_SUBSCRIBE, HEAD_VERSION, COMPAT_VERSION) { }
  43 private:
  44   ~MMonSubscribe() override {}
  45
  46 public:
  47   void sub_want(const char *w, version_t start, unsigned flags) {
  48     what[w].start = start;
  49     what[w].flags = flags;
  50   }
  51
  52   std::string_view get_type_name() const override { return "mon_subscribe"; }
  53   void print(ostream& o) const override {
  54     o << "mon_subscribe(" << what << ")";
  55   }
  56
  57   void decode_payload() override {
  58     auto p = payload.cbegin();
  59     if (header.version < 2) {
  60       map<string, ceph_mon_subscribe_item_old> oldwhat;
  61       decode(oldwhat, p);
  62       what.clear();
  63       for (map<string, ceph_mon_subscribe_item_old>::iterator q = oldwhat.begin();
  64            q != oldwhat.end();
  65            q++) {
  66         if (q->second.have)
  67           what[q->first].start = q->second.have + 1;
  68         else
  69           what[q->first].start = 0;
  70         what[q->first].flags = 0;
  71         if (q->second.onetime)
  72           what[q->first].flags |= CEPH_SUBSCRIBE_ONETIME;
  73       }
  74       return;
  75     }
  76     decode(what, p);
  77     if (header.version >= 3) {
  78       decode(hostname, p);
  79     }
  80   }
  81   void encode_payload(uint64_t features) override {
  82     using ceph::encode;
  83     if ((features & CEPH_FEATURE_SUBSCRIBE2) == 0) {
  84       header.version = 0;
  85       map<string, ceph_mon_subscribe_item_old> oldwhat;
  86       for (map<string, ceph_mon_subscribe_item>::iterator q = what.begin();
  87            q != what.end();
  88            q++) {
  89         if (q->second.start)
  90           // warning: start=1 -> have=0, which was ambiguous
  91           oldwhat[q->first].have = q->second.start - 1;
  92         else
  93           oldwhat[q->first].have = 0;
  94         oldwhat[q->first].onetime = q->second.flags & CEPH_SUBSCRIBE_ONETIME;
  95       }
  96       encode(oldwhat, payload);
  97       return;
  98     }
  99     header.version = HEAD_VERSION;
 100     encode(what, payload);
 101     encode(hostname, payload);
 102   }
 103 };
 104
 105 #endif