Fix package link updates/node monitoring

* PackageLinksListener: Rename methods from *Directory*() to *Node*()
  and change parameter to Node*. Also add a *Changed() method.
* PackageLinkDirectory: Update only when necessary and what is necessary
  (currently only the self link).

src/add-ons/kernel/file_systems/packagefs/PackageLinkDirectory.cpp

@@ -9,6 +9,8 @@
 #include <algorithm>
 #include <new>
 
+#include <NodeMonitor.h>
+
 #include <AutoDeleter.h>
 
 #include "EmptyAttributeDirectoryCookie.h"
@@ -49,18 +51,22 @@ class PackageLinkDirectory::SelfLink : public Node {
 public:
 	SelfLink(Package* package)
 		:
-		Node(0),
-		fPackage(package),
-		fLinkPath(link_path_for_mount_type(
-			package->Domain()->Volume()->MountType()))
+		Node(0)
 	{
-		get_real_time(fModifiedTime);
+		Update(package);
 	}
 
 	virtual ~SelfLink()
 	{
 	}
 
+	void Update(Package* package)
+	{
+		fLinkPath = link_path_for_mount_type(
+			package->Domain()->Volume()->MountType());
+		get_real_time(fModifiedTime);
+	}
+
 	virtual mode_t Mode() const
 	{
 		return S_IFLNK | S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH
@@ -124,7 +130,6 @@ public:
 	}
 
 private:
-	Package*	fPackage;
 	timespec	fModifiedTime;
 	const char*	fLinkPath;
 };
@@ -153,17 +158,6 @@ PackageLinkDirectory::~PackageLinkDirectory()
 status_t
 PackageLinkDirectory::Init(Directory* parent, Package* package)
 {
-	// create the self link
-	fSelfLink = new(std::nothrow) SelfLink(package);
-	if (fSelfLink == NULL)
-		return B_NO_MEMORY;
-
-	status_t error = fSelfLink->Init(this, kSelfLinkName, NODE_FLAG_CONST_NAME);
-	if (error != B_OK)
-		RETURN_ERROR(error);
-
-	AddChild(fSelfLink);
-
 	// compute the allocation size needed for the versioned name
 	size_t nameLength = strlen(package->Name());
 	size_t size = nameLength + 1;
@@ -186,7 +180,7 @@ PackageLinkDirectory::Init(Directory* parent, Package* package)
 	}
 
 	// init the directory/node
-	error = Init(parent, name, NODE_FLAG_KEEP_NAME);
+	status_t error = Init(parent, name, NODE_FLAG_KEEP_NAME);
 	if (error != B_OK)
 		RETURN_ERROR(error);
 
@@ -267,16 +261,21 @@ PackageLinkDirectory::AddPackage(Package* package,
 {
 	NodeWriteLocker writeLocker(this);
 
-	if (listener != NULL)
-		listener->PackageLinkDirectoryRemoved(this);
+	// Find the insertion point in the list. We sort by mount type -- the more
+	// specific the higher the priority.
+	MountType mountType = package->Domain()->Volume()->MountType();
+	Package* otherPackage = NULL;
+	for (PackageList::Iterator it = fPackages.GetIterator();
+			(otherPackage = it.Next()) != NULL;) {
+		if (otherPackage->Domain()->Volume()->MountType() <= mountType)
+			break;
+	}
 
-	// TODO: Add in priority order!
-	fPackages.Add(package);
+	fPackages.InsertBefore(otherPackage, package);
 	package->SetLinkDirectory(this);
 
-	if (listener != NULL)
-		listener->PackageLinkDirectoryAdded(this);
-	// TODO: The notifications should only happen as necessary!
+	if (package == fPackages.Head())
+		_Update(listener);
 }
 
 
@@ -288,14 +287,62 @@ PackageLinkDirectory::RemovePackage(Package* package,
 
 	NodeWriteLocker writeLocker(this);
 
-	if (listener != NULL)
-		listener->PackageLinkDirectoryRemoved(this);
+	bool firstPackage = package == fPackages.Head();
 
 	package->SetLinkDirectory(NULL);
 	fPackages.Remove(package);
-	// TODO: Check whether that was the top priority package!
 
-	if (listener != NULL && !IsEmpty())
-		listener->PackageLinkDirectoryAdded(this);
-	// TODO: The notifications should only happen as necessary!
+	if (firstPackage)
+		_Update(listener);
+}
+
+
+status_t
+PackageLinkDirectory::_Update(PackageLinksListener* listener)
+{
+	// check, if empty
+	Package* package = fPackages.Head();
+	if (package == NULL) {
+		// remove self link, if any
+		if (fSelfLink != NULL) {
+			NodeWriteLocker selfLinkLocker(fSelfLink);
+			if (listener != NULL)
+				listener->PackageLinkNodeRemoved(fSelfLink);
+
+			RemoveChild(fSelfLink);
+			fSelfLink->ReleaseReference();
+			fSelfLink = NULL;
+		}
+
+		return B_OK;
+	}
+
+	// create/update self link
+	if (fSelfLink == NULL) {
+		fSelfLink = new(std::nothrow) SelfLink(package);
+		if (fSelfLink == NULL)
+			return B_NO_MEMORY;
+
+		status_t error = fSelfLink->Init(this, kSelfLinkName,
+			NODE_FLAG_CONST_NAME);
+		if (error != B_OK)
+			RETURN_ERROR(error);
+
+		AddChild(fSelfLink);
+
+		if (listener != NULL) {
+			NodeWriteLocker selfLinkLocker(fSelfLink);
+			listener->PackageLinkNodeAdded(fSelfLink);
+		}
+	} else {
+		NodeWriteLocker selfLinkLocker(fSelfLink);
+		fSelfLink->Update(package);
+
+		if (listener != NULL) {
+			listener->PackageLinkNodeChanged(fSelfLink,
+				B_STAT_SIZE | B_STAT_MODIFICATION_TIME);
+		}
+	}
+
+	return B_OK;
 }

src/add-ons/kernel/file_systems/packagefs/PackageLinkDirectory.h

@@ -44,6 +44,9 @@ public:
 private:
 			class SelfLink;
 
+private:
+			status_t			_Update(PackageLinksListener* listener);
+
 private:
 			timespec			fModifiedTime;
 			PackageList			fPackages;

src/add-ons/kernel/file_systems/packagefs/PackageLinksDirectory.cpp

@@ -123,7 +123,7 @@ PackageLinksDirectory::AddPackage(Package* package)
 
 		if (fListener != NULL) {
 			NodeWriteLocker linkDirectoryWriteLocker(linkDirectory);
-			fListener->PackageLinkDirectoryAdded(linkDirectory);
+			fListener->PackageLinkNodeAdded(linkDirectory);
 		}
 	}
 

src/add-ons/kernel/file_systems/packagefs/PackageLinksListener.h

@@ -6,17 +6,20 @@
 #define PACKAGE_LINKS_LISTENER_H
 
 
-class PackageLinkDirectory;
+#include <SupportDefs.h>
+
+
+class Node;
 
 
 class PackageLinksListener {
 public:
 	virtual						~PackageLinksListener();
 
-	virtual	void				PackageLinkDirectoryAdded(
-										PackageLinkDirectory* directory) = 0;
-	virtual	void				PackageLinkDirectoryRemoved(
-										PackageLinkDirectory* directory) = 0;
+	virtual	void				PackageLinkNodeAdded(Node* node) = 0;
+	virtual	void				PackageLinkNodeRemoved(Node* node) = 0;
+	virtual	void				PackageLinkNodeChanged(Node* node,
+									uint32 statFields) = 0;
 };
 
 

src/add-ons/kernel/file_systems/packagefs/Volume.cpp

@@ -639,22 +639,27 @@ Volume::AddPackageDomain(const char* path)
 
 
 void
-Volume::PackageLinkDirectoryAdded(PackageLinkDirectory* directory)
+Volume::PackageLinkNodeAdded(Node* node)
 {
-	_AddPackageLinksNode(directory);
+	_AddPackageLinksNode(node);
 
-	notify_entry_created(ID(), directory->Parent()->ID(), directory->Name(),
-		directory->ID());
+	notify_entry_created(ID(), node->Parent()->ID(), node->Name(), node->ID());
 }
 
 
 void
-Volume::PackageLinkDirectoryRemoved(PackageLinkDirectory* directory)
+Volume::PackageLinkNodeRemoved(Node* node)
 {
-	_RemovePackageLinksNode(directory);
+	_RemovePackageLinksNode(node);
 
-	notify_entry_removed(ID(), directory->Parent()->ID(), directory->Name(),
-		directory->ID());
+	notify_entry_removed(ID(), node->Parent()->ID(), node->Name(), node->ID());
+}
+
+
+void
+Volume::PackageLinkNodeChanged(Node* node, uint32 statFields)
+{
+	notify_stat_changed(ID(), node->ID(), statFields);
 }
 
 

src/add-ons/kernel/file_systems/packagefs/Volume.h

@@ -76,10 +76,10 @@ public:
 
 private:
 	// PackageLinksListener
-	virtual	void				PackageLinkDirectoryAdded(
-										PackageLinkDirectory* directory);
-	virtual	void				PackageLinkDirectoryRemoved(
-										PackageLinkDirectory* directory);
+	virtual	void				PackageLinkNodeAdded(Node* node);
+	virtual	void				PackageLinkNodeRemoved(Node* node);
+	virtual	void				PackageLinkNodeChanged(Node* node,
+									uint32 statFields);
 
 private:
 			struct Job;