zdoom-macos-deps/deps/wxwidgets/include/wx-3.1/wx/msw/private/fswatcher.h
2021-06-28 10:54:57 +03:00

335 lines
10 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/msw/private/fswatcher.h
// Purpose: File system watcher impl classes
// Author: Bartosz Bekier
// Created: 2009-05-26
// Copyright: (c) 2009 Bartosz Bekier <bartosz.bekier@gmail.com>
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef WX_MSW_PRIVATE_FSWATCHER_H_
#define WX_MSW_PRIVATE_FSWATCHER_H_
#include "wx/filename.h"
#include "wx/vector.h"
#include "wx/msw/private.h"
// ============================================================================
// wxFSWatcherEntry implementation & helper declarations
// ============================================================================
class wxFSWatcherImplMSW;
class wxFSWatchEntryMSW : public wxFSWatchInfo
{
public:
enum
{
BUFFER_SIZE = 4096 // TODO parametrize
};
wxFSWatchEntryMSW(const wxFSWatchInfo& winfo) :
wxFSWatchInfo(winfo)
{
// get handle for this path
m_handle = OpenDir(m_path);
m_overlapped = (OVERLAPPED*)calloc(1, sizeof(OVERLAPPED));
wxZeroMemory(m_buffer);
}
virtual ~wxFSWatchEntryMSW()
{
wxLogTrace(wxTRACE_FSWATCHER, "Deleting entry '%s'", m_path);
if (m_handle != INVALID_HANDLE_VALUE)
{
if (!CloseHandle(m_handle))
{
wxLogSysError(_("Unable to close the handle for '%s'"),
m_path);
}
}
free(m_overlapped);
}
bool IsOk() const
{
return m_handle != INVALID_HANDLE_VALUE;
}
HANDLE GetHandle() const
{
return m_handle;
}
void* GetBuffer()
{
return m_buffer;
}
OVERLAPPED* GetOverlapped() const
{
return m_overlapped;
}
private:
// opens dir with all flags, attributes etc. necessary to be later
// asynchronous watched with ReadDirectoryChangesW
static HANDLE OpenDir(const wxString& path)
{
HANDLE handle = CreateFile(path.t_str(),
FILE_LIST_DIRECTORY,
FILE_SHARE_READ |
FILE_SHARE_WRITE |
FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS |
FILE_FLAG_OVERLAPPED,
NULL);
if (handle == INVALID_HANDLE_VALUE)
{
wxLogSysError(_("Failed to open directory \"%s\" for monitoring."),
path);
}
return handle;
}
HANDLE m_handle; // handle to opened directory
char m_buffer[BUFFER_SIZE]; // buffer for fs events
OVERLAPPED* m_overlapped;
wxDECLARE_NO_COPY_CLASS(wxFSWatchEntryMSW);
};
// ============================================================================
// wxFSWatcherImplMSW helper classes implementations
// ============================================================================
class wxIOCPService
{
public:
wxIOCPService() :
m_iocp(INVALID_HANDLE_VALUE)
{
Init();
}
~wxIOCPService()
{
if (m_iocp != INVALID_HANDLE_VALUE)
{
if (!CloseHandle(m_iocp))
{
wxLogSysError(_("Unable to close I/O completion port handle"));
}
}
m_watches.clear();
}
// associates a wxFSWatchEntryMSW with completion port
bool Add(wxSharedPtr<wxFSWatchEntryMSW> watch)
{
wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, false, "IOCP not init" );
wxCHECK_MSG( watch->IsOk(), false, "Invalid watch" );
// associate with IOCP
HANDLE ret = CreateIoCompletionPort(watch->GetHandle(), m_iocp,
(ULONG_PTR)watch.get(), 0);
if (ret == NULL)
{
wxLogSysError(_("Unable to associate handle with "
"I/O completion port"));
return false;
}
else if (ret != m_iocp)
{
wxFAIL_MSG(_("Unexpectedly new I/O completion port was created"));
return false;
}
// add to watch map
wxFSWatchEntries::value_type val(watch->GetPath(), watch);
return m_watches.insert(val).second;
}
// Removes a watch we're currently using. Notice that this doesn't happen
// immediately, CompleteRemoval() must be called later when it's really
// safe to delete the watch, i.e. after completion of the IO operation
// using it.
bool ScheduleForRemoval(const wxSharedPtr<wxFSWatchEntryMSW>& watch)
{
wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, false, "IOCP not init" );
wxCHECK_MSG( watch->IsOk(), false, "Invalid watch" );
const wxString path = watch->GetPath();
wxFSWatchEntries::iterator it = m_watches.find(path);
wxCHECK_MSG( it != m_watches.end(), false,
"Can't remove a watch we don't use" );
// We can't just delete the watch here as we can have pending events
// for it and if we destroyed it now, we could get a dangling (or,
// worse, reused to point to another object) pointer in ReadEvents() so
// just remember that this one should be removed when CompleteRemoval()
// is called later.
m_removedWatches.push_back(watch);
m_watches.erase(it);
return true;
}
// Really remove the watch previously passed to ScheduleForRemoval().
//
// It's ok to call this for a watch that hadn't been removed before, in
// this case we'll just return false and do nothing.
bool CompleteRemoval(wxFSWatchEntryMSW* watch)
{
for ( Watches::iterator it = m_removedWatches.begin();
it != m_removedWatches.end();
++it )
{
if ( (*it).get() == watch )
{
// Removing the object from here will result in deleting the
// watch itself as it's not referenced from anywhere else now.
m_removedWatches.erase(it);
return true;
}
}
return false;
}
// post completion packet
bool PostEmptyStatus()
{
wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, false, "IOCP not init" );
// The special values of 0 will make GetStatus() return Status_Exit.
const int ret = PostQueuedCompletionStatus(m_iocp, 0, 0, NULL);
if (!ret)
{
wxLogSysError(_("Unable to post completion status"));
}
return ret != 0;
}
// Possible return values of GetStatus()
enum Status
{
// Status successfully retrieved into the provided arguments.
Status_OK,
// Special status indicating that we should exit retrieved.
Status_Exit,
// An error occurred because the watched directory was deleted.
Status_Deleted,
// Some other error occurred.
Status_Error
};
// Wait for completion status to arrive.
// This function can block forever in it's wait for completion status.
// Use PostEmptyStatus() to wake it up (and end the worker thread)
Status
GetStatus(DWORD* count, wxFSWatchEntryMSW** watch,
OVERLAPPED** overlapped)
{
wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, Status_Error,
"Invalid IOCP object" );
wxCHECK_MSG( count && watch && overlapped, Status_Error,
"Output parameters can't be NULL" );
const int ret = GetQueuedCompletionStatus(m_iocp, count, (ULONG_PTR *)watch,
overlapped, INFINITE);
if ( ret != 0 )
{
return *count || *watch || *overlapped ? Status_OK : Status_Exit;
}
// An error is returned if the underlying directory has been deleted,
// but this is not really an unexpected failure, so handle it
// specially.
if ( wxSysErrorCode() == ERROR_ACCESS_DENIED &&
*watch && !wxFileName::DirExists((*watch)->GetPath()) )
return Status_Deleted;
// Some other error, at least log it.
wxLogSysError(_("Unable to dequeue completion packet"));
return Status_Error;
}
protected:
bool Init()
{
m_iocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
if (m_iocp == NULL)
{
wxLogSysError(_("Unable to create I/O completion port"));
}
return m_iocp != NULL;
}
HANDLE m_iocp;
// The hash containing all the wxFSWatchEntryMSW objects currently being
// watched keyed by their paths.
wxFSWatchEntries m_watches;
// Contains the watches which had been removed but are still pending.
typedef wxVector< wxSharedPtr<wxFSWatchEntryMSW> > Watches;
Watches m_removedWatches;
};
class wxIOCPThread : public wxThread
{
public:
wxIOCPThread(wxFSWatcherImplMSW* service, wxIOCPService* iocp);
// finishes this thread
bool Finish();
protected:
// structure to hold information needed to process one native event
// this is just a dummy holder, so it doesn't take ownership of it's data
struct wxEventProcessingData
{
wxEventProcessingData(const FILE_NOTIFY_INFORMATION* ne,
const wxFSWatchEntryMSW* watch_) :
nativeEvent(ne), watch(watch_)
{}
const FILE_NOTIFY_INFORMATION* nativeEvent;
const wxFSWatchEntryMSW* watch;
};
virtual ExitCode Entry() wxOVERRIDE;
// wait for events to occur, read them and send to interested parties
// returns false it empty status was read, which means we would exit
// true otherwise
bool ReadEvents();
void ProcessNativeEvents(wxVector<wxEventProcessingData>& events);
void SendEvent(wxFileSystemWatcherEvent& evt);
static int Native2WatcherFlags(int flags);
static wxString FileNotifyInformationToString(
const FILE_NOTIFY_INFORMATION& e);
static wxFileName GetEventPath(const wxFSWatchEntryMSW& watch,
const FILE_NOTIFY_INFORMATION& e);
wxFSWatcherImplMSW* m_service;
wxIOCPService* m_iocp;
};
#endif /* WX_MSW_PRIVATE_FSWATCHER_H_ */