文件监控

w1146869587

2021-11-05 cbf39419a8299e7d119618e5e8e1b1eb35f72f45

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#include <efsw/WatcherWin32.hpp>
#include <efsw/String.hpp>
 
#if EFSW_PLATFORM == EFSW_PLATFORM_WIN32
 
namespace efsw
{
 
/// Unpacks events and passes them to a user defined callback.
void CALLBACK WatchCallback(DWORD dwNumberOfBytesTransfered, LPOVERLAPPED lpOverlapped)
{
    if (dwNumberOfBytesTransfered == 0 || NULL == lpOverlapped)
    {
        return;
    }
 
    char szFile[MAX_PATH];
    PFILE_NOTIFY_INFORMATION pNotify;
    WatcherStructWin32 * tWatch = (WatcherStructWin32*) lpOverlapped;
    WatcherWin32 * pWatch = tWatch->Watch;
    size_t offset = 0;
 
    do
    {
        bool skip = false;
 
        pNotify = (PFILE_NOTIFY_INFORMATION) &pWatch->Buffer[offset];
        offset += pNotify->NextEntryOffset;
 
        int count = WideCharToMultiByte(CP_UTF8, 0, pNotify->FileName,
            pNotify->FileNameLength / sizeof(WCHAR),
            szFile, MAX_PATH - 1, NULL, NULL);
        szFile[count] = TEXT('\0');
 
        std::string nfile( szFile );
 
        if ( FILE_ACTION_MODIFIED == pNotify->Action )
        {
            FileInfo fifile( std::string( pWatch->DirName ) + nfile );
 
            if ( pWatch->LastModifiedEvent.file.ModificationTime == fifile.ModificationTime && pWatch->LastModifiedEvent.file.Size == fifile.Size && pWatch->LastModifiedEvent.fileName == nfile )
            {
                skip = true;
            }
 
            pWatch->LastModifiedEvent.fileName    = nfile;
            pWatch->LastModifiedEvent.file        = fifile;
        }
 
        if ( !skip )
        {
            pWatch->Watch->handleAction(pWatch, nfile, pNotify->Action);
        }
    } while (pNotify->NextEntryOffset != 0);
 
    if (!pWatch->StopNow)
    {
        RefreshWatch(tWatch);
    }
}
 
/// Refreshes the directory monitoring.
bool RefreshWatch(WatcherStructWin32* pWatch)
{
    return ReadDirectoryChangesW(
                pWatch->Watch->DirHandle,
                pWatch->Watch->Buffer,
                sizeof(pWatch->Watch->Buffer),
                pWatch->Watch->Recursive,
                pWatch->Watch->NotifyFilter,
                NULL,
                &pWatch->Overlapped,
                NULL
    ) != 0;
}
 
/// Stops monitoring a directory.
void DestroyWatch(WatcherStructWin32* pWatch)
{
    if (pWatch)
    {
        WatcherWin32 * tWatch = pWatch->Watch;
        tWatch->StopNow = true;
        CancelIoEx(pWatch->Watch->DirHandle, &pWatch->Overlapped);
        CloseHandle(pWatch->Watch->DirHandle);
        efSAFE_DELETE_ARRAY( pWatch->Watch->DirName );
        efSAFE_DELETE( pWatch->Watch );
    }
}
 
/// Starts monitoring a directory.
WatcherStructWin32* CreateWatch(LPCWSTR szDirectory, bool recursive, DWORD NotifyFilter, HANDLE iocp)
{
    WatcherStructWin32 * tWatch;
    size_t ptrsize = sizeof(*tWatch);
    tWatch = static_cast<WatcherStructWin32*>(HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, ptrsize));
 
    WatcherWin32 * pWatch = new WatcherWin32();
    tWatch->Watch = pWatch;
 
    pWatch->DirHandle = CreateFileW(
                            szDirectory,
                            GENERIC_READ,
                            FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
                            NULL,
                            OPEN_EXISTING,
                            FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
                            NULL
                        );
 
    if (pWatch->DirHandle != INVALID_HANDLE_VALUE &&
        CreateIoCompletionPort(pWatch->DirHandle, iocp, 0, 1))
    {
        pWatch->NotifyFilter = NotifyFilter;
        pWatch->Recursive = recursive;
 
        if (RefreshWatch(tWatch))
        {
            return tWatch;
        }
    }
 
    CloseHandle(pWatch->DirHandle);
    efSAFE_DELETE( pWatch->Watch );
    HeapFree(GetProcessHeap(), 0, tWatch);
    return NULL;
}
 
}
 
 #endif