ceph/src/client/Delegation.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 #ifndef _CEPH_CLIENT_DELEGATION_H
   4 #define _CEPH_CLIENT_DELEGATION_H
   5
   6 #include "common/Clock.h"
   7 #include "common/Timer.h"
   8
   9 class Fh;
  10
  11 /* Commands for manipulating delegation state */
  12 #ifndef CEPH_DELEGATION_NONE
  13 # define CEPH_DELEGATION_NONE   0
  14 # define CEPH_DELEGATION_RD     1
  15 # define CEPH_DELEGATION_WR     2
  16 #endif
  17
  18 /* Callback for delegation recalls */
  19 typedef void (*ceph_deleg_cb_t)(Fh *fh, void *priv);
  20
  21 /* Converts CEPH_DELEGATION_* to cap mask */
  22 int ceph_deleg_caps_for_type(unsigned type);
  23
  24 /*
  25  * A delegation is a container for holding caps on behalf of a client that
  26  * wants to be able to rely on them until recalled.
  27  */
  28 class Delegation {
  29 public:
  30   Delegation(Fh *_fh, unsigned _type, ceph_deleg_cb_t _cb, void *_priv);
  31   ~Delegation();
  32   Fh *get_fh() { return fh; }
  33   unsigned get_type() { return type; }
  34   bool is_recalled() { return !recall_time.is_zero(); }
  35
  36   void reinit(unsigned _type, ceph_deleg_cb_t _recall_cb, void *_priv);
  37   void recall(bool skip_read);
  38 private:
  39   // Filehandle against which it was acquired
  40   Fh                            *fh;
  41
  42   // opaque token that will be passed to the callback
  43   void                          *priv;
  44
  45   // CEPH_DELEGATION_* type
  46   unsigned                      type;
  47
  48   // callback into application to recall delegation
  49   ceph_deleg_cb_t               recall_cb;
  50
  51   // time of first recall
  52   utime_t                       recall_time;
  53
  54   // timer for unreturned delegations
  55   Context                       *timeout_event;
  56
  57   void arm_timeout();
  58   void disarm_timeout();
  59 };
  60
  61 #endif /* _CEPH_CLIENT_DELEGATION_H */