Generic watching support classes.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@1573 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/registrar/EventMaskWatcher.cpp

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+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		EventMaskWatcher.cpp
+//	Author:			Ingo Weinhold (bonefish@users.sf.net)
+//	Description:	EventMaskWatcher is a Watcher extended by an event mask.
+//					EventMaskWatcherFilter filters EventMaskWatchers with
+//					respect to their event mask and a specific event.
+//------------------------------------------------------------------------------
+
+#include "EventMaskWatcher.h"
+
+// EventMaskWatcher
+
+// constructor
+EventMaskWatcher::EventMaskWatcher(const BMessenger &target, uint32 eventMask)
+	: Watcher(target),
+	  fEventMask(eventMask)
+{
+}
+
+// EventMask
+uint32
+EventMaskWatcher::EventMask() const
+{
+	return fEventMask;
+}
+
+
+// EventMaskWatcherFilter
+
+// constructor
+EventMaskWatcherFilter::EventMaskWatcherFilter(uint32 event)
+	: WatcherFilter(),
+	  fEvent(event)
+{
+}
+
+// Filter
+bool
+EventMaskWatcherFilter::Filter(Watcher *watcher, BMessage *message)
+{
+	EventMaskWatcher *emWatcher = dynamic_cast<EventMaskWatcher *>(watcher);
+	return (emWatcher && (emWatcher->EventMask() & fEvent));
+}
+

src/servers/registrar/EventMaskWatcher.h

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+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		EventMaskWatcher.h
+//	Author:			Ingo Weinhold (bonefish@users.sf.net)
+//	Description:	EventMaskWatcher is a Watcher extended by an event mask.
+//					EventMaskWatcherFilter filters EventMaskWatchers with
+//					respect to their event mask and a specific event.
+//------------------------------------------------------------------------------
+
+#ifndef EVENT_MASK_WATCHER_H
+#define EVENT_MASK_WATCHER_H
+
+#include "Watcher.h"
+
+// EventMaskWatcher
+class EventMaskWatcher : public Watcher {
+public:
+	EventMaskWatcher(const BMessenger &target, uint32 eventMask);
+
+	uint32 EventMask() const;
+
+private:
+	uint32	fEventMask;
+};
+
+// EventMaskWatcherFilter
+class EventMaskWatcherFilter : public WatcherFilter {
+public:
+	EventMaskWatcherFilter(uint32 event);
+
+	virtual bool Filter(Watcher *watcher, BMessage *message);
+
+private:
+	uint32	fEvent;
+};
+
+#endif	// EVENT_MASK_WATCHER_H

src/servers/registrar/Watcher.cpp

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+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		Watcher.cpp
+//	Author:			Ingo Weinhold (bonefish@users.sf.net)
+//	Description:	A Watcher represents a target of a watching service.
+//					A WatcherFilter represents a predicate on a Watcher.
+//------------------------------------------------------------------------------
+
+#include <Message.h>
+
+#include "Watcher.h"
+
+// Watcher
+
+// constructor
+Watcher::Watcher(const BMessenger &target)
+	: fTarget(target)
+{
+}
+
+// destructor
+Watcher::~Watcher()
+{
+}
+
+// Target
+const BMessenger&
+Watcher::Target() const
+{
+	return fTarget;
+}
+
+// SendMessage
+status_t
+Watcher::SendMessage(BMessage *message)
+{
+	return fTarget.SendMessage(message, (BHandler*)NULL, 0);
+}
+
+
+// WatcherFilter
+
+// constructor
+WatcherFilter::WatcherFilter()
+{
+}
+
+// destructor
+WatcherFilter::~WatcherFilter()
+{
+}
+
+// Filter
+bool
+WatcherFilter::Filter(Watcher *watcher, BMessage *message)
+{
+	return true;
+}
+

src/servers/registrar/Watcher.h

@@ -0,0 +1,56 @@
+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		Watcher.h
+//	Author:			Ingo Weinhold (bonefish@users.sf.net)
+//	Description:	A Watcher represents a target of a watching service.
+//					A WatcherFilter represents a predicate on a Watcher.
+//------------------------------------------------------------------------------
+
+#ifndef WATCHER_H
+#define WATCHER_H
+
+#include <Messenger.h>
+
+// Watcher
+class Watcher {
+public:
+	Watcher(const BMessenger &target);
+	virtual ~Watcher();
+
+	const BMessenger &Target() const;
+
+	status_t SendMessage(BMessage *message);
+
+private:
+	BMessenger	fTarget;
+};
+
+// WatcherFilter
+class WatcherFilter {
+public:
+	WatcherFilter();
+	virtual ~WatcherFilter();
+
+	virtual bool Filter(Watcher *watcher, BMessage *message);
+};
+
+#endif	// WATCHER_H

src/servers/registrar/WatchingService.cpp

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+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		WatchingService.cpp
+//	Author:			Ingo Weinhold (bonefish@users.sf.net)
+//	Description:	Features everything needed to provide a watching service.
+//------------------------------------------------------------------------------
+
+#include <List.h>
+
+#include "Watcher.h"
+#include "WatchingService.h"
+
+// constructor
+WatchingService::WatchingService()
+	: fWatchers()
+{
+}
+
+// destructor
+WatchingService::~WatchingService()
+{
+	// delete the watchers
+	for (watcher_map::iterator it = fWatchers.begin();
+		 it != fWatchers.end();
+		 ++it) {
+		delete it->second;
+	}
+}
+
+// AddWatcher
+bool
+WatchingService::AddWatcher(Watcher *watcher)
+{
+	bool result = (watcher);
+	if (result) {
+		RemoveWatcher(watcher->Target(), true);
+		fWatchers[watcher->Target()] = watcher;
+	}
+	return result;
+}
+
+// AddWatcher
+bool
+WatchingService::AddWatcher(const BMessenger &target)
+{
+	return AddWatcher(new(nothrow) Watcher(target));
+}
+
+// RemoveWatcher
+bool
+WatchingService::RemoveWatcher(Watcher *watcher, bool deleteWatcher)
+{
+	return (watcher && RemoveWatcher(watcher->Target(), deleteWatcher));
+}
+
+// RemoveWatcher
+bool
+WatchingService::RemoveWatcher(const BMessenger &target, bool deleteWatcher)
+{
+	watcher_map::iterator it = fWatchers.find(target);
+	bool result = (it != fWatchers.end());
+	if (result) {
+		if (deleteWatcher)
+			delete it->second;
+		fWatchers.erase(it);
+	}
+	return result;
+}
+
+// NotifyWatchers
+void
+WatchingService::NotifyWatchers(BMessage *message, WatcherFilter *filter)
+{
+	BList staleWatchers;
+	// deliver the message
+	for (watcher_map::iterator it = fWatchers.begin();
+		 it != fWatchers.end();
+		 ++it) {
+		Watcher *watcher = it->second;
+// TODO: If a watcher is invalid, but the filter never selects it, it will
+// not be removed.
+		if (!filter || filter->Filter(watcher, message)) {
+			status_t error = watcher->SendMessage(message);
+			if (error != B_OK && error != B_WOULD_BLOCK)
+				staleWatchers.AddItem(watcher);
+		}
+	}
+	// remove the stale watchers
+	for (int32 i = 0;
+		 Watcher *watcher = (Watcher*)staleWatchers.ItemAt(i);
+		 i++) {
+		RemoveWatcher(watcher, true);
+	}
+}
+

src/servers/registrar/WatchingService.h

@@ -0,0 +1,56 @@
+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		WatchingService.h
+//	Author:			Ingo Weinhold (bonefish@users.sf.net)
+//	Description:	Features everything needed to provide a watching service.
+//------------------------------------------------------------------------------
+
+#ifndef WATCHING_SERVICE_H
+#define WATCHING_SERVICE_H
+
+#include <map>
+
+#include <Messenger.h>
+
+class Watcher;
+class WatcherFilter;
+
+class WatchingService {
+public:
+	WatchingService();
+	virtual ~WatchingService();
+
+	bool AddWatcher(Watcher *watcher);
+	bool AddWatcher(const BMessenger &target);
+	bool RemoveWatcher(Watcher *watcher, bool deleteWatcher = true);
+	bool RemoveWatcher(const BMessenger &target, bool deleteWatcher = true);
+
+	void NotifyWatchers(BMessage *message, WatcherFilter *filter = NULL);
+
+private:
+	typedef map<BMessenger,Watcher*> watcher_map;
+
+private:
+	watcher_map	fWatchers;
+};
+
+#endif	// WATCHING_SERVICE_H