ceph/src/librbd/operation/RenameRequest.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #ifndef CEPH_LIBRBD_RENAME_REQUEST_H
   5 #define CEPH_LIBRBD_RENAME_REQUEST_H
   6
   7 #include "librbd/operation/Request.h"
   8 #include <string>
   9
  10 class Context;
  11
  12 namespace librbd {
  13
  14 class ImageCtx;
  15
  16 namespace operation {
  17
  18 template <typename ImageCtxT = ImageCtx>
  19 class RenameRequest : public Request<ImageCtxT>
  20 {
  21 public:
  22   /**
  23    * Rename goes through the following state machine:
  24    *
  25    * @verbatim
  26    *
  27    * <start>
  28    *    |
  29    *    v
  30    * STATE_READ_DIRECTORY
  31    *    |
  32    *    v
  33    * STATE_READ_SOURCE_HEADER
  34    *    |
  35    *    v
  36    * STATE_WRITE_DEST_HEADER
  37    *    |
  38    *    v
  39    * STATE_UPDATE_DIRECTORY
  40    *    |
  41    *    v
  42    * STATE_REMOVE_SOURCE_HEADER
  43    *    |
  44    *    v
  45    * <finish>
  46    *
  47    * @endverbatim
  48    *
  49    */
  50   enum State {
  51     STATE_READ_DIRECTORY,
  52     STATE_READ_SOURCE_HEADER,
  53     STATE_WRITE_DEST_HEADER,
  54     STATE_UPDATE_DIRECTORY,
  55     STATE_REMOVE_SOURCE_HEADER
  56   };
  57
  58   RenameRequest(ImageCtxT &image_ctx, Context *on_finish,
  59                 const std::string &dest_name);
  60
  61 protected:
  62   void send_op() override;
  63   bool should_complete(int r) override;
  64   int filter_return_code(int r) const override;
  65
  66   journal::Event create_event(uint64_t op_tid) const override {
  67     return journal::RenameEvent(op_tid, m_dest_name);
  68   }
  69
  70 private:
  71   std::string m_dest_name;
  72
  73   std::string m_source_oid;
  74   std::string m_dest_oid;
  75
  76   State m_state = STATE_READ_DIRECTORY;
  77
  78   bufferlist m_source_name_bl;
  79   bufferlist m_header_bl;
  80
  81   void send_read_directory();
  82   void send_read_source_header();
  83   void send_write_destination_header();
  84   void send_update_directory();
  85   void send_remove_source_header();
  86
  87   void apply();
  88 };
  89
  90 } // namespace operation
  91 } // namespace librbd
  92
  93 extern template class librbd::operation::RenameRequest<librbd::ImageCtx>;
  94
  95 #endif // CEPH_LIBRBD_RENAME_REQUEST_H