src/add-ons/kernel/file_systems/nfs4/MetadataCache.h

   1 /*
   2  * Copyright 2012 Haiku, Inc. All rights reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Paweł Dziepak, pdziepak@quarnos.org
   7  */
   8 #ifndef METADATACACHE_H
   9 #define METADATACACHE_H
  10
  11
  12 #include <fs_interface.h>
  13 #include <lock.h>
  14 #include <SupportDefs.h>
  15 #include <util/AutoLock.h>
  16 #include <util/AVLTreeMap.h>
  17
  18
  19 class Inode;
  20
  21 struct AccessEntry {
  22         time_t  fExpire;
  23         bool    fForceValid;
  24
  25         uint32  fAllowed;
  26 };
  27
  28 class MetadataCache {
  29 public:
  30                                                                 MetadataCache(Inode* inode);
  31                                                                 ~MetadataCache();
  32
  33                                         status_t        GetStat(struct stat* st);
  34                                         void            SetStat(const struct stat& st);
  35                                         void            GrowFile(size_t newSize);
  36
  37                                         status_t        GetAccess(uid_t uid, uint32* allowed);
  38                                         void            SetAccess(uid_t uid, uint32 allowed);
  39
  40                                         status_t        LockValid();
  41                                         void            UnlockValid();
  42
  43         inline                  void            InvalidateStat();
  44         inline                  void            InvalidateAccess();
  45
  46         inline                  void            Invalidate();
  47
  48         static const    time_t          kExpirationTime = 60;
  49
  50 protected:
  51                                         void            NotifyChanges(const struct stat* oldStat,
  52                                                                         const struct stat* newStat);
  53
  54 private:
  55                                         struct stat     fStatCache;
  56                                         time_t          fExpire;
  57                                         bool            fForceValid;
  58
  59                                         Inode*          fInode;
  60                                         bool            fInited;
  61
  62                                         AVLTreeMap<uid_t, AccessEntry>  fAccessCache;
  63
  64                                         mutex           fLock;
  65 };
  66
  67
  68 inline void
  69 MetadataCache::InvalidateStat()
  70 {
  71         MutexLocker _(fLock);
  72         if (!fForceValid)
  73                 fExpire = 0;
  74 }
  75
  76
  77 inline void
  78 MetadataCache::InvalidateAccess()
  79 {
  80         MutexLocker _(fLock);
  81         if (!fForceValid)
  82                 fAccessCache.MakeEmpty();
  83 }
  84
  85
  86 inline void
  87 MetadataCache::Invalidate()
  88 {
  89         InvalidateStat();
  90         InvalidateAccess();
  91 }
  92
  93
  94 #endif  // METADATACACHE_H
  95