Add a class CWorkLimiter that isolates limiting work duration

CWorkLimiter limits the amount of work done on any idle cycle, exiting when a set amount of ticks has elapsed or when an input event is pending on the message queue.

7 files changed, 128 insertions, 12 deletions

diff --git a/windirstat/WorkLimiter.cpp b/windirstat/WorkLimiter.cpp
new file mode 100644
index 0000000..038e21e
--- /dev/null
+++ b/windirstat/WorkLimiter.cpp
@@ -0,0 +1,60 @@
+#include "stdafx.h"

+#include "WorkLimiter.h"

+

+CWorkLimiter::CWorkLimiter()

+	: m_done()

+	, m_tickLimit()

+	, m_prevTicks()

+{

+}

+

+CWorkLimiter::~CWorkLimiter()

+{

+}

+

+void CWorkLimiter::Start(DWORD ticks)

+{

+	DWORD start = Now();

+	m_done = false;

+	m_tickLimit = start + ticks;

+	m_prevTicks = start;

+}

+

+bool CWorkLimiter::IsDone() const

+{

+	if (m_done) return true;

+

+	// check remaining ticks

+	DWORD now = Now();

+	// signed subtraction to deal with overflow

+	long remaining = m_tickLimit - now;

+	if (remaining <= 0)

+	{

+		m_done = true;

+		return true;

+	}

+

+	// check if there are any pending window messages

+	long elapsed = now - m_prevTicks;

+	if (elapsed > 10)

+	{

+		m_prevTicks = now;

+		MSG msg;
+		if (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE | PM_QS_INPUT))
+		{
+			m_done = true;
+			return true;
+		}
+	}

+

+	return false;

+}

+

+void CWorkLimiter::DoFileWork()

+{

+}

+

+DWORD CWorkLimiter::Now() const

+{

+	return ::GetTickCount();

+}
\ No newline at end of file
diff --git a/windirstat/WorkLimiter.h b/windirstat/WorkLimiter.h
new file mode 100644
index 0000000..ffda715
--- /dev/null
+++ b/windirstat/WorkLimiter.h
@@ -0,0 +1,46 @@
+// WorkLimiter.h - Declaration of CWorkLimiter
+//
+// WinDirStat - Directory Statistics
+// Copyright (C) 2003-2005 Bernhard Seifert
+// Copyright (C) 2004-2016 WinDirStat team (windirstat.info)
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//

+#ifndef __WDS_WORKLIMITER_H__
+#define __WDS_WORKLIMITER_H__
+#pragma once

+

+#include <WinDef.h>

+

+class CWorkLimiter

+{

+public:

+	CWorkLimiter();

+	~CWorkLimiter();

+

+	void Start(DWORD ticks);

+	bool IsDone() const;

+	void DoFileWork();

+

+private:

+	DWORD Now() const;

+

+private:

+	mutable bool m_done;

+	DWORD m_tickLimit;

+	mutable DWORD m_prevTicks;

+};

+

+#endif
\ No newline at end of file
diff --git a/windirstat/dirstatdoc.cpp b/windirstat/dirstatdoc.cpp
index ee730e2..d116f82 100644
--- a/windirstat/dirstatdoc.cpp
+++ b/windirstat/dirstatdoc.cpp
@@ -358,7 +358,7 @@ void CDirstatDoc::ForgetItemTree()
 // This method does some work for ticks ms.
 // return: true if done or suspended.
 //
-bool CDirstatDoc::Work(DWORD ticks)
+bool CDirstatDoc::Work(CWorkLimiter* limiter)
 {
     if(NULL == m_rootItem)
     {
@@ -372,7 +372,7 @@ bool CDirstatDoc::Work(DWORD ticks)
 
     if(!m_rootItem->IsDone())
     {
-        m_rootItem->DoSomeWork(ticks);
+        m_rootItem->DoSomeWork(limiter);
         if(m_rootItem->IsDone())
         {
             m_extensionDataValid = false;
diff --git a/windirstat/dirstatdoc.h b/windirstat/dirstatdoc.h
index 8145b9e..6924996 100644
--- a/windirstat/dirstatdoc.h
+++ b/windirstat/dirstatdoc.h
@@ -28,6 +28,7 @@
 #include "options.h"
 
 class CItem;
+class CWorkLimiter;
 
 //
 // The treemap colors as calculated in CDirstatDoc::SetExtensionColors()
@@ -107,7 +108,7 @@ public:
     ULONGLONG GetRootSize();
 
     void ForgetItemTree();
-    bool Work(DWORD ticks); // return: true if done.
+    bool Work(CWorkLimiter* limiter); // return: true if done.
     bool IsDrive(CString spec);
     void RefreshMountPointItems();
     void RefreshJunctionItems();
diff --git a/windirstat/item.cpp b/windirstat/item.cpp
index b271359..2ee2abb 100644
--- a/windirstat/item.cpp
+++ b/windirstat/item.cpp
@@ -24,6 +24,7 @@
 #include "dirstatdoc.h" // GetItemColor()
 #include "mainframe.h"
 #include "item.h"
+#include "WorkLimiter.h"
 
 #ifdef _DEBUG
 #define new DEBUG_NEW
@@ -1043,18 +1044,22 @@ void CItem::AddTicksWorked(DWORD more)
     m_ticksWorked += more;
 }
 
-void CItem::DoSomeWork(DWORD ticks)
+void CItem::DoSomeWork(CWorkLimiter* limiter)
 {
     if(IsDone())
     {
         return;
     }
+	if (limiter->IsDone())
+	{
+		return;
+	}
 
     StartPacman(true);
 
     DriveVisualUpdateDuringWork();
 
-    DWORD start = ::GetTickCount();
+    const DWORD start = ::GetTickCount();
 
     if(GetType() == IT_DRIVE || GetType() == IT_DIRECTORY)
     {
@@ -1131,7 +1136,7 @@ void CItem::DoSomeWork(DWORD ticks)
             UpdateFreeSpaceItem();
         }
 
-        if(::GetTickCount() - start > ticks)
+        if(limiter->IsDone())
         {
             StartPacman(false);
             return;
@@ -1154,7 +1159,7 @@ void CItem::DoSomeWork(DWORD ticks)
         }
 
         DWORD startChildren = ::GetTickCount();
-        while(::GetTickCount() - start < ticks)
+        while(!limiter->IsDone())
         {
             DWORD minticks = UINT_MAX;
             CItem *minchild = NULL;
@@ -1176,10 +1181,9 @@ void CItem::DoSomeWork(DWORD ticks)
                 SetDone();
                 break;
             }
-            DWORD tickssofar = ::GetTickCount() - start;
-            if(ticks > tickssofar)
+			if (!limiter->IsDone())
             {
-                minchild->DoSomeWork(ticks - tickssofar);
+                minchild->DoSomeWork(limiter);
             }
         }
         AddTicksWorked(::GetTickCount() - startChildren);
diff --git a/windirstat/item.h b/windirstat/item.h
index 31951bd..9e5d0d5 100644
--- a/windirstat/item.h
+++ b/windirstat/item.h
@@ -29,6 +29,8 @@
 #include "FileFindWDS.h" // CFileFindWDS
 #include <common/wds_constants.h>
 
+class CWorkLimiter;
+
 // Columns
 enum
 {
@@ -184,7 +186,7 @@ public:
     void SetDone();
     DWORD GetTicksWorked() const;
     void AddTicksWorked(DWORD more);
-    void DoSomeWork(DWORD ticks);
+    void DoSomeWork(CWorkLimiter* limiter);
     bool StartRefresh();
     void UpwardSetUndone();
     void RefreshRecycler();
diff --git a/windirstat/windirstat.cpp b/windirstat/windirstat.cpp
index edc9df6..b62289c 100644
--- a/windirstat/windirstat.cpp
+++ b/windirstat/windirstat.cpp
@@ -29,6 +29,7 @@
 #include "dirstatdoc.h"

 #include "graphview.h"

 #include "osspecific.h"

+#include "WorkLimiter.h"

 #include <Dbghelp.h> // for mini dumps

 

 #ifdef _DEBUG

@@ -737,7 +738,9 @@ BOOL CDirstatApp::OnIdle(LONG lCount)
     bool more = false;

 

     CDirstatDoc *doc = GetDocument();

-    if((doc) && (!doc->Work(600)))

+	CWorkLimiter limiter;

+	limiter.Start(600);

+    if((doc) && (!doc->Work(&limiter)))

     {

         more = true;

     }