ceph/src/mds/LogEvent.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_LOGEVENT_H
  16 #define CEPH_LOGEVENT_H
  17
  18 #define EVENT_NEW_ENCODING 0 // indicates that the encoding is versioned
  19 #define EVENT_UNUSED       1 // was previously EVENT_STRING
  20
  21 #define EVENT_SUBTREEMAP   2
  22 #define EVENT_EXPORT       3
  23 #define EVENT_IMPORTSTART  4
  24 #define EVENT_IMPORTFINISH 5
  25 #define EVENT_FRAGMENT     6
  26
  27 #define EVENT_RESETJOURNAL 9
  28
  29 #define EVENT_SESSION      10
  30 #define EVENT_SESSIONS_OLD 11
  31 #define EVENT_SESSIONS     12
  32
  33 #define EVENT_UPDATE       20
  34 #define EVENT_SLAVEUPDATE  21
  35 #define EVENT_OPEN         22
  36 #define EVENT_COMMITTED    23
  37 #define EVENT_PURGED       24
  38
  39 #define EVENT_TABLECLIENT  42
  40 #define EVENT_TABLESERVER  43
  41
  42 #define EVENT_SUBTREEMAP_TEST   50
  43 #define EVENT_NOOP        51
  44
  45
  46 #include "include/buffer_fwd.h"
  47 #include "include/Context.h"
  48 #include "include/utime.h"
  49
  50 class MDSRank;
  51 class LogSegment;
  52 class EMetaBlob;
  53
  54 // generic log event
  55 class LogEvent {
  56 public:
  57   typedef __u32 EventType;
  58   friend class MDLog;
  59
  60   LogEvent() = delete;
  61   explicit LogEvent(int t) : _type(t) {}
  62   LogEvent(const LogEvent&) = delete;
  63   LogEvent& operator=(const LogEvent&) = delete;
  64   virtual ~LogEvent() {}
  65
  66   std::string_view get_type_str() const;
  67   static EventType str_to_type(std::string_view str);
  68   EventType get_type() const { return _type; }
  69   void set_type(EventType t) { _type = t; }
  70
  71   uint64_t get_start_off() const { return _start_off; }
  72   void set_start_off(uint64_t o) { _start_off = o; }
  73
  74   utime_t get_stamp() const { return stamp; }
  75   void set_stamp(utime_t t) { stamp = t; }
  76
  77   // encoding
  78   virtual void encode(bufferlist& bl, uint64_t features) const = 0;
  79   virtual void decode(bufferlist::const_iterator &) = 0;
  80   static std::unique_ptr<LogEvent> decode_event(bufferlist::const_iterator);
  81   virtual void dump(Formatter *f) const = 0;
  82
  83   void encode_with_header(bufferlist& bl, uint64_t features) {
  84     using ceph::encode;
  85     encode(EVENT_NEW_ENCODING, bl);
  86     ENCODE_START(1, 1, bl)
  87     encode(_type, bl);
  88     this->encode(bl, features);
  89     ENCODE_FINISH(bl);
  90   }
  91
  92   virtual void print(ostream& out) const {
  93     out << "event(" << _type << ")";
  94   }
  95
  96   /*** live journal ***/
  97   /* update_segment() - adjust any state we need to in the LogSegment
  98    */
  99   virtual void update_segment() { }
 100
 101   /*** recovery ***/
 102   /* replay() - replay given event.  this is idempotent.
 103    */
 104   virtual void replay(MDSRank *m) { ceph_abort(); }
 105
 106   /**
 107    * If the subclass embeds a MetaBlob, return it here so that
 108    * tools can examine metablobs while traversing lists of LogEvent.
 109    */
 110   virtual EMetaBlob *get_metablob() { return NULL; }
 111
 112 protected:
 113   LogSegment* get_segment() { return _segment; }
 114   LogSegment const* get_segment() const { return _segment; }
 115
 116   utime_t stamp;
 117
 118 private:
 119   static const std::map<std::string, LogEvent::EventType> types;
 120
 121   static std::unique_ptr<LogEvent> decode_event(bufferlist::const_iterator&, EventType);
 122
 123   EventType _type = 0;
 124   uint64_t _start_off = 0;
 125   LogSegment *_segment = nullptr;
 126 };
 127
 128 inline ostream& operator<<(ostream& out, const LogEvent &le) {
 129   le.print(out);
 130   return out;
 131 }
 132
 133 #endif