src/TGitCache/FolderCrawler.h

   1 // TortoiseSVN - a Windows shell extension for easy version control
   2
   3 // External Cache Copyright (C) 2005 - 2006 - Will Dean, Stefan Kueng
   4
   5 // This program is free software; you can redistribute it and/or
   6 // modify it under the terms of the GNU General Public License
   7 // as published by the Free Software Foundation; either version 2
   8 // of the License, or (at your option) any later version.
   9
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14
  15 // You should have received a copy of the GNU General Public License
  16 // along with this program; if not, write to the Free Software Foundation,
  17 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 //
  19 #pragma once
  20
  21 #include "TGitPath.h"
  22 #include "CacheInterface.h"
  23 #include <set>
  24 //////////////////////////////////////////////////////////////////////////
  25
  26
  27
  28 #pragma pack(push, r1, 16)
  29
  30 /**
  31  * \ingroup TSVNCache
  32  * Helper class to crawl folders in the background (in a separate thread)
  33  * so that the main cache isn't blocked until all the status are fetched.
  34  */
  35 class CFolderCrawler
  36 {
  37 public:
  38         CFolderCrawler(void);
  39         ~CFolderCrawler(void);
  40
  41 public:
  42         void Initialise();
  43         void AddDirectoryForUpdate(const CTGitPath& path);
  44         void AddPathForUpdate(const CTGitPath& path);
  45         void Stop();
  46         bool SetHoldoff(DWORD milliseconds = 100);
  47         void BlockPath(const CTGitPath& path, DWORD ticks = 0);
  48 private:
  49         static unsigned int __stdcall ThreadEntry(void* pContext);
  50         void WorkerThread();
  51
  52 private:
  53         CComAutoCriticalSection m_critSec;
  54         HANDLE m_hThread;
  55         std::deque<CTGitPath> m_foldersToUpdate;
  56         std::deque<CTGitPath> m_pathsToUpdate;
  57         HANDLE m_hTerminationEvent;
  58         HANDLE m_hWakeEvent;
  59
  60         // This will be *asynchronously* modified by CCrawlInhibitor.
  61         // So, we have to mark it volatile, preparing compiler and
  62         // optimizer for the "worst".
  63         volatile LONG m_lCrawlInhibitSet;
  64
  65         // While the shell is still asking for items, we don't
  66         // want to start crawling.  This timer is pushed-out for
  67         // every shell request, and stops us crawling until
  68         // a bit of quiet time has elapsed
  69         long m_crawlHoldoffReleasesAt;
  70         bool m_bItemsAddedSinceLastCrawl;
  71         bool m_bPathsAddedSinceLastCrawl;
  72
  73         CTGitPath m_blockedPath;
  74         DWORD m_blockReleasesAt;
  75         bool m_bRun;
  76
  77
  78         friend class CCrawlInhibitor;
  79 };
  80
  81
  82 //////////////////////////////////////////////////////////////////////////
  83
  84
  85 class CCrawlInhibitor
  86 {
  87 private:
  88         CCrawlInhibitor(); // Not defined
  89 public:
  90         explicit CCrawlInhibitor(CFolderCrawler* pCrawler)
  91         {
  92                 m_pCrawler = pCrawler;
  93
  94                 // Count locks instead of a mere flag toggle (exchange)
  95                 // to allow for multiple, concurrent locks.
  96                 ::InterlockedIncrement(&m_pCrawler->m_lCrawlInhibitSet);
  97         }
  98         ~CCrawlInhibitor()
  99         {
 100                 ::InterlockedDecrement(&m_pCrawler->m_lCrawlInhibitSet);
 101                 m_pCrawler->SetHoldoff();
 102         }
 103 private:
 104         CFolderCrawler* m_pCrawler;
 105 };
 106
 107 #pragma pack(pop, r1)