src/TGitCache/FolderCrawler.h

   1 // TortoiseGit - a Windows shell extension for easy version control
   2
   3 // External Cache Copyright (C) 2005-2007, 2009-2011, 2014 TortoiseSVN
   4 // Copyright (C) 2008-2012, 2023 - TortoiseGit
   5
   6 // This program is free software; you can redistribute it and/or
   7 // modify it under the terms of the GNU General Public License
   8 // as published by the Free Software Foundation; either version 2
   9 // of the License, or (at your option) any later version.
  10
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software Foundation,
  18 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 //
  20 #pragma once
  21
  22 #include "TGitPath.h"
  23 #include "CacheInterface.h"
  24 #include "SmartHandle.h"
  25 #include "UniqueQueue.h"
  26 #include <set>
  27 //////////////////////////////////////////////////////////////////////////
  28
  29
  30
  31 #pragma pack(push, r1, 16)
  32
  33 /**
  34  * \ingroup TGitCache
  35  * Helper class to crawl folders in the background (in a separate thread)
  36  * so that the main cache isn't blocked until all the status are fetched.
  37  */
  38 class CFolderCrawler
  39 {
  40 public:
  41         CFolderCrawler();
  42         ~CFolderCrawler();
  43
  44 public:
  45         void Initialise();
  46         void AddDirectoryForUpdate(const CTGitPath& path);
  47         void AddPathForUpdate(const CTGitPath& path);
  48         void ReleasePathForUpdate(const CTGitPath& path);
  49         void Stop();
  50         bool SetHoldoff(DWORD milliseconds = 100);
  51         void BlockPath(const CTGitPath& path, DWORD ticks = 0);
  52 private:
  53         static unsigned int __stdcall ThreadEntry(void* pContext);
  54         void WorkerThread();
  55
  56 private:
  57         CComAutoCriticalSection m_critSec;
  58         CAutoGeneralHandle m_hThread;
  59         UniqueQueue<CTGitPath> m_foldersToUpdate;
  60         UniqueQueue<CTGitPath> m_pathsToUpdate;
  61         UniqueQueue<CTGitPath> m_pathsToRelease;
  62
  63         CAutoGeneralHandle m_hTerminationEvent;
  64         CAutoGeneralHandle m_hWakeEvent;
  65
  66         // This will be *asynchronously* modified by CCrawlInhibitor.
  67         // So, we have to mark it volatile, preparing compiler and
  68         // optimizer for the "worst".
  69         volatile LONG m_lCrawlInhibitSet = 0;
  70
  71         // While the shell is still asking for items, we don't
  72         // want to start crawling.  This timer is pushed-out for
  73         // every shell request, and stops us crawling until
  74         // a bit of quiet time has elapsed
  75         LONGLONG m_crawlHoldoffReleasesAt;
  76         bool m_bItemsAddedSinceLastCrawl = false;
  77         bool m_bPathsAddedSinceLastCrawl = false;
  78
  79         CTGitPath m_blockedPath;
  80         ULONGLONG m_blockReleasesAt = 0;
  81         bool m_bRun = false;
  82
  83
  84         friend class CCrawlInhibitor;
  85 };
  86
  87
  88 //////////////////////////////////////////////////////////////////////////
  89
  90
  91 class CCrawlInhibitor
  92 {
  93 private:
  94         CCrawlInhibitor(); // Not defined
  95 public:
  96         explicit CCrawlInhibitor(CFolderCrawler* pCrawler)
  97         {
  98                 m_pCrawler = pCrawler;
  99
 100                 // Count locks instead of a mere flag toggle (exchange)
 101                 // to allow for multiple, concurrent locks.
 102                 ::InterlockedIncrement(&m_pCrawler->m_lCrawlInhibitSet);
 103         }
 104         ~CCrawlInhibitor()
 105         {
 106                 ::InterlockedDecrement(&m_pCrawler->m_lCrawlInhibitSet);
 107                 m_pCrawler->SetHoldoff();
 108         }
 109 private:
 110         CFolderCrawler* m_pCrawler;
 111 };
 112
 113 #pragma pack(pop, r1)