include/wx/msw/private/fswatcher.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/msw/private/fswatcher.h
   3 // Purpose:     File system watcher impl classes
   4 // Author:      Bartosz Bekier
   5 // Created:     2009-05-26
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2009 Bartosz Bekier <bartosz.bekier@gmail.com>
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef WX_MSW_PRIVATE_FSWATCHER_H_
  12 #define WX_MSW_PRIVATE_FSWATCHER_H_
  13
  14 #include "wx/filename.h"
  15 #include "wx/vector.h"
  16 #include "wx/msw/private.h"
  17
  18 // ============================================================================
  19 // wxFSWatcherEntry implementation & helper declarations
  20 // ============================================================================
  21
  22 class wxFSWatcherImplMSW;
  23
  24 class wxFSWatchEntryMSW : public wxFSWatchInfo
  25 {
  26 public:
  27     enum
  28     {
  29         BUFFER_SIZE = 4096   // TODO parametrize
  30     };
  31
  32     wxFSWatchEntryMSW(const wxFSWatchInfo& winfo) :
  33         wxFSWatchInfo(winfo)
  34     {
  35         // get handle for this path
  36         m_handle = OpenDir(m_path);
  37         m_overlapped = (OVERLAPPED*)calloc(1, sizeof(OVERLAPPED));
  38         wxZeroMemory(m_buffer);
  39     }
  40
  41     virtual ~wxFSWatchEntryMSW()
  42     {
  43         wxLogTrace(wxTRACE_FSWATCHER, "Deleting entry '%s'", m_path);
  44
  45         if (m_handle != INVALID_HANDLE_VALUE)
  46         {
  47             if (!CloseHandle(m_handle))
  48             {
  49                 wxLogSysError(_("Unable to close the handle for '%s'"),
  50                                 m_path);
  51             }
  52         }
  53         delete m_overlapped;
  54     }
  55
  56     bool IsOk() const
  57     {
  58         return m_handle != INVALID_HANDLE_VALUE;
  59     }
  60
  61     HANDLE GetHandle() const
  62     {
  63         return m_handle;
  64     }
  65
  66     void* GetBuffer()
  67     {
  68         return m_buffer;
  69     }
  70
  71     OVERLAPPED* GetOverlapped() const
  72     {
  73         return m_overlapped;
  74     }
  75
  76 private:
  77     // opens dir with all flags, attributes etc. necessary to be later
  78     // asynchronous watched with ReadDirectoryChangesW
  79     static HANDLE OpenDir(const wxString& path)
  80     {
  81         HANDLE handle = CreateFile(path.t_str(),
  82                                    FILE_LIST_DIRECTORY,
  83                                    FILE_SHARE_READ |
  84                                    FILE_SHARE_WRITE |
  85                                    FILE_SHARE_DELETE,
  86                                    NULL,
  87                                    OPEN_EXISTING,
  88                                    FILE_FLAG_BACKUP_SEMANTICS |
  89                                    FILE_FLAG_OVERLAPPED,
  90                                    NULL);
  91         if (handle == INVALID_HANDLE_VALUE)
  92         {
  93             wxLogSysError(_("Failed to open directory \"%s\" for monitoring."),
  94                             path);
  95         }
  96
  97         return handle;
  98     }
  99
 100     HANDLE m_handle;             // handle to opened directory
 101     char m_buffer[BUFFER_SIZE];  // buffer for fs events
 102     OVERLAPPED* m_overlapped;
 103
 104     wxDECLARE_NO_COPY_CLASS(wxFSWatchEntryMSW);
 105 };
 106
 107
 108 // ============================================================================
 109 // wxFSWatcherImplMSW helper classes implementations
 110 // ============================================================================
 111
 112 class wxIOCPService
 113 {
 114 public:
 115     wxIOCPService() :
 116         m_iocp(INVALID_HANDLE_VALUE)
 117     {
 118         Init();
 119     }
 120
 121     ~wxIOCPService()
 122     {
 123         if (m_iocp != INVALID_HANDLE_VALUE)
 124         {
 125             if (!CloseHandle(m_iocp))
 126             {
 127                 wxLogSysError(_("Unable to close I/O completion port handle"));
 128             }
 129         }
 130         m_watches.clear();
 131     }
 132
 133     // associates a wxFSWatchEntryMSW with completion port
 134     bool Add(wxSharedPtr<wxFSWatchEntryMSW> watch)
 135     {
 136         wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, false, "IOCP not init" );
 137         wxCHECK_MSG( watch->IsOk(), false, "Invalid watch" );
 138
 139         // associate with IOCP
 140         HANDLE ret = CreateIoCompletionPort(watch->GetHandle(), m_iocp,
 141                                             (ULONG_PTR)watch.get(), 0);
 142         if (ret == NULL)
 143         {
 144             wxLogSysError(_("Unable to associate handle with "
 145                             "I/O completion port"));
 146             return false;
 147         }
 148         else if (ret != m_iocp)
 149         {
 150             wxFAIL_MSG(_("Unexpectedly new I/O completion port was created"));
 151             return false;
 152         }
 153
 154         // add to watch map
 155         wxFSWatchEntries::value_type val(watch->GetPath(), watch);
 156         return m_watches.insert(val).second;
 157     }
 158
 159     // post completion packet
 160     bool PostEmptyStatus()
 161     {
 162         wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, false, "IOCP not init" );
 163
 164         int ret = PostQueuedCompletionStatus(m_iocp, 0, 0, NULL);
 165         if (!ret)
 166         {
 167             wxLogSysError(_("Unable to post completion status"));
 168         }
 169
 170         return ret != 0;
 171     }
 172
 173     // Wait for completion status to arrive.
 174     // This function can block forever in it's wait for completion status.
 175     // Use PostEmptyStatus() to wake it up (and end the worker thread)
 176     bool GetStatus(unsigned long* count, wxFSWatchEntryMSW** watch,
 177                    OVERLAPPED** overlapped)
 178     {
 179         wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, false, "IOCP not init" );
 180         wxCHECK_MSG( count != NULL, false, "Null out parameter 'count'");
 181         wxCHECK_MSG( watch != NULL, false, "Null out parameter 'watch'");
 182         wxCHECK_MSG( overlapped != NULL, false,
 183                      "Null out parameter 'overlapped'");
 184
 185         int ret = GetQueuedCompletionStatus(m_iocp, count, (ULONG_PTR *)watch,
 186                                             overlapped, INFINITE);
 187         if (!ret)
 188         {
 189             wxLogSysError(_("Unable to dequeue completion packet"));
 190         }
 191         return ret != 0;
 192     }
 193
 194 protected:
 195     bool Init()
 196     {
 197         m_iocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
 198         if (m_iocp == NULL)
 199         {
 200             wxLogSysError(_("Unable to create I/O completion port"));
 201         }
 202         return m_iocp != NULL;
 203     }
 204
 205     HANDLE m_iocp;
 206     wxFSWatchEntries m_watches;
 207 };
 208
 209
 210 class wxIOCPThread : public wxThread
 211 {
 212 public:
 213     wxIOCPThread(wxFSWatcherImplMSW* service, wxIOCPService* iocp);
 214
 215     // finishes this thread
 216     bool Finish();
 217
 218 protected:
 219     // structure to hold information needed to process one native event
 220     // this is just a dummy holder, so it doesn't take ownership of it's data
 221     struct wxEventProcessingData
 222     {
 223         wxEventProcessingData(const FILE_NOTIFY_INFORMATION* ne,
 224                               const wxFSWatchEntryMSW* watch) :
 225             nativeEvent(ne), watch(watch)
 226         {}
 227
 228         const FILE_NOTIFY_INFORMATION* nativeEvent;
 229         const wxFSWatchEntryMSW* watch;
 230     };
 231
 232     virtual ExitCode Entry();
 233
 234     // wait for events to occur, read them and send to interested parties
 235     // returns false it empty status was read, which means we whould exit
 236     //         true otherwise
 237     bool ReadEvents();
 238
 239     void ProcessNativeEvents(wxVector<wxEventProcessingData>& events);
 240
 241     void SendEvent(wxFileSystemWatcherEvent& evt);
 242
 243     static int Native2WatcherFlags(int flags);
 244
 245     static wxString FileNotifyInformationToString(
 246                                             const FILE_NOTIFY_INFORMATION& e);
 247
 248     static wxFileName GetEventPath(const wxFSWatchEntryMSW& watch,
 249                                    const FILE_NOTIFY_INFORMATION& e);
 250
 251     wxFSWatcherImplMSW* m_service;
 252     wxIOCPService* m_iocp;
 253 };
 254
 255 #endif /* WX_MSW_PRIVATE_FSWATCHER_H_ */