Kernel interface abstraction for attribute access

* Introduce interface AttributeCookie and currently only implementation
  UnpackingAttributeCookie. This is an interface for reading/stat()ing
  an attribute.
* Add abstract virtual Node::OpenAttribute() method that returns an
  AttributeCookie and implemented it for derived classes.
* In the kernel interface attribute hooks use AttributeCookie now. The
  attribute directory hooks are unchanged.

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

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "AttributeCookie.h"
+
+
+AttributeCookie::~AttributeCookie()
+{
+}

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

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef ATTRIBUTE_COOKIE_H
+#define ATTRIBUTE_COOKIE_H
+
+
+#include <sys/stat.h>
+
+#include <SupportDefs.h>
+
+
+class AttributeCookie {
+public:
+	virtual						~AttributeCookie();
+
+	virtual	status_t			Close() = 0;
+	virtual	status_t			ReadAttribute(off_t offset, void* buffer,
+									size_t* bufferSize) = 0;
+	virtual	status_t			ReadAttributeStat(struct stat* st) = 0;
+};
+
+
+#endif	// ATTRIBUTE_COOKIE_H

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

@@ -7,6 +7,7 @@
 #include "Directory.h"
 
 #include "DebugSupport.h"
+#include "UnpackingAttributeCookie.h"
 #include "Utils.h"
 
 
@@ -171,6 +172,15 @@ Directory::ReadSymlink(void* buffer, size_t* bufferSize)
 }
 
 
+status_t
+Directory::OpenAttribute(const char* name, int openMode,
+	AttributeCookie*& _cookie)
+{
+	return UnpackingAttributeCookie::Open(fPackageDirectories.Head(), name,
+		openMode, _cookie);
+}
+
+
 void
 Directory::AddChild(Node* node)
 {

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

@@ -51,6 +51,9 @@ public:
 	virtual	status_t			ReadSymlink(void* buffer,
 									size_t* bufferSize);
 
+	virtual	status_t			OpenAttribute(const char* name, int openMode,
+									AttributeCookie*& _cookie);
+
 			void				AddChild(Node* node);
 			void				RemoveChild(Node* node);
 			Node*				FindChild(const char* name);

src/add-ons/kernel/file_systems/packagefs/Jamfile

@@ -7,6 +7,7 @@ UsePrivateHeaders shared ;
 
 
 HAIKU_PACKAGE_FS_SOURCES =
+	AttributeCookie.cpp
 	BlockBufferCacheKernel.cpp
 	DebugSupport.cpp
 	Dependency.cpp
@@ -26,6 +27,7 @@ HAIKU_PACKAGE_FS_SOURCES =
 	PackageNodeAttribute.cpp
 	PackageSymlink.cpp
 	Resolvable.cpp
+	UnpackingAttributeCookie.cpp
 	Version.cpp
 	Volume.cpp
 ;

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

@@ -10,6 +10,7 @@
 
 #include <algorithm>
 
+#include "UnpackingAttributeCookie.h"
 #include "Utils.h"
 
 
@@ -193,6 +194,15 @@ LeafNode::ReadSymlink(void* buffer, size_t* bufferSize)
 }
 
 
+status_t
+LeafNode::OpenAttribute(const char* name, int openMode,
+	AttributeCookie*& _cookie)
+{
+	return UnpackingAttributeCookie::Open(fPackageNodes.Head(), name, openMode,
+		_cookie);
+}
+
+
 const char*
 LeafNode::SymlinkPath() const
 {

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

@@ -38,6 +38,9 @@ public:
 	virtual	status_t			ReadSymlink(void* buffer,
 									size_t* bufferSize);
 
+	virtual	status_t			OpenAttribute(const char* name, int openMode,
+									AttributeCookie*& _cookie);
+
 			const char*			SymlinkPath() const;
 
 private:

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

@@ -17,6 +17,7 @@
 #include <util/OpenHashTable.h>
 
 
+class AttributeCookie;
 class Directory;
 class PackageNode;
 
@@ -63,6 +64,9 @@ public:
 	virtual	status_t			ReadSymlink(void* buffer,
 									size_t* bufferSize) = 0;
 
+	virtual	status_t			OpenAttribute(const char* name, int openMode,
+									AttributeCookie*& _cookie) = 0;
+
 protected:
 			rw_lock				fLock;
 			ino_t				fID;

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

@@ -0,0 +1,142 @@
+/*
+ * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "UnpackingAttributeCookie.h"
+
+#include <algorithm>
+#include <new>
+
+#include <package/hpkg/DataReader.h>
+#include <package/hpkg/PackageData.h>
+#include <package/hpkg/PackageDataReader.h>
+
+#include <AutoDeleter.h>
+
+#include "DebugSupport.h"
+#include "GlobalFactory.h"
+#include "Package.h"
+#include "PackageNode.h"
+
+
+using BPackageKit::BHPKG::BBufferDataReader;
+//using BPackageKit::BHPKG::BDataReader;
+using BPackageKit::BHPKG::BFDDataReader;
+//using BPackageKit::BHPKG::BPackageData;
+//using BPackageKit::BHPKG::BPackageDataReader;
+
+
+static status_t
+read_package_data(const BPackageData& data, BDataReader* dataReader,
+	off_t offset, void* buffer, size_t* bufferSize)
+{
+	// create a BPackageDataReader
+	BPackageDataReader* reader;
+	status_t error = GlobalFactory::Default()->CreatePackageDataReader(
+		dataReader, data, reader);
+	if (error != B_OK)
+		RETURN_ERROR(error);
+	ObjectDeleter<BPackageDataReader> readerDeleter(reader);
+
+	// check the offset
+	if (offset < 0 || (uint64)offset > data.UncompressedSize())
+		return B_BAD_VALUE;
+
+	// clamp the size
+	size_t toRead = std::min((uint64)*bufferSize,
+		data.UncompressedSize() - offset);
+
+	// read
+	if (toRead > 0) {
+		status_t error = reader->ReadData(offset, buffer, toRead);
+		if (error != B_OK)
+			RETURN_ERROR(error);
+	}
+
+	*bufferSize = toRead;
+	return B_OK;
+}
+
+
+UnpackingAttributeCookie::UnpackingAttributeCookie(PackageNode* packageNode,
+	PackageNodeAttribute* attribute, int openMode)
+	:
+	fPackageNode(packageNode),
+	fPackage(packageNode->GetPackage()),
+	fAttribute(attribute),
+	fOpenMode(openMode)
+{
+	fPackageNode->AcquireReference();
+	fPackage->AcquireReference();
+}
+
+
+UnpackingAttributeCookie::~UnpackingAttributeCookie()
+{
+	fPackageNode->ReleaseReference();
+	fPackage->ReleaseReference();
+}
+
+
+/*static*/ status_t
+UnpackingAttributeCookie::Open(PackageNode* packageNode, const char* name,
+	int openMode, AttributeCookie*& _cookie)
+{
+	if (packageNode == NULL)
+		return B_ENTRY_NOT_FOUND;
+
+	// get the attribute
+	PackageNodeAttribute* attribute = packageNode->FindAttribute(name);
+	if (attribute == NULL)
+		return B_ENTRY_NOT_FOUND;
+
+	// allocate the cookie
+	UnpackingAttributeCookie* cookie = new(std::nothrow)
+		UnpackingAttributeCookie(packageNode, attribute, openMode);
+	if (cookie == NULL)
+		RETURN_ERROR(B_NO_MEMORY);
+
+	_cookie = cookie;
+	return B_OK;
+}
+
+
+status_t
+UnpackingAttributeCookie::Close()
+{
+	return B_OK;
+}
+
+
+status_t
+UnpackingAttributeCookie::ReadAttribute(off_t offset, void* buffer,
+	size_t* bufferSize)
+{
+	const BPackageData& data = fAttribute->Data();
+	if (data.IsEncodedInline()) {
+		// inline data
+		BBufferDataReader dataReader(data.InlineData(), data.CompressedSize());
+		return read_package_data(data, &dataReader, offset, buffer, bufferSize);
+	}
+
+	// data not inline -- open the package
+	int fd = fPackage->Open();
+	if (fd < 0)
+		RETURN_ERROR(fd);
+	PackageCloser packageCloser(fPackage);
+
+	BFDDataReader dataReader(fd);
+	return read_package_data(data, &dataReader, offset, buffer, bufferSize);
+}
+
+
+status_t
+UnpackingAttributeCookie::ReadAttributeStat(struct stat* st)
+{
+	st->st_size = fAttribute->Data().UncompressedSize();
+	st->st_type = fAttribute->Type();
+
+	return B_OK;
+}

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

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef UNPACKING_ATTRIBUTE_COOKIE_H
+#define UNPACKING_ATTRIBUTE_COOKIE_H
+
+
+#include "AttributeCookie.h"
+
+
+class Package;
+class PackageNode;
+class PackageNodeAttribute;
+
+
+class UnpackingAttributeCookie : public AttributeCookie {
+public:
+								UnpackingAttributeCookie(
+									PackageNode* packageNode,
+									PackageNodeAttribute* attribute,
+									int openMode);
+	virtual						~UnpackingAttributeCookie();
+
+	static	status_t			Open(PackageNode* packageNode, const char* name,
+									int openMode, AttributeCookie*& _cookie);
+
+	virtual	status_t			Close();
+	virtual	status_t			ReadAttribute(off_t offset, void* buffer,
+									size_t* bufferSize);
+	virtual	status_t			ReadAttributeStat(struct stat* st);
+
+private:
+			PackageNode*		fPackageNode;
+			Package*			fPackage;
+			PackageNodeAttribute* fAttribute;
+			int					fOpenMode;
+};
+
+
+#endif	// UNPACKING_ATTRIBUTE_COOKIE_H

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

@@ -8,7 +8,6 @@
 
 #include <dirent.h>
 
-#include <algorithm>
 #include <new>
 
 #include <fs_info.h>
@@ -18,6 +17,7 @@
 
 #include <AutoDeleter.h>
 
+#include "AttributeCookie.h"
 #include "DebugSupport.h"
 #include "Directory.h"
 #include "GlobalFactory.h"
@@ -25,10 +25,6 @@
 #include "Volume.h"
 
 
-using BPackageKit::BHPKG::BBufferDataReader;
-using BPackageKit::BHPKG::BFDDataReader;
-
-
 static const uint32 kOptimalIOSize = 64 * 1024;
 
 
@@ -860,32 +856,6 @@ packagefs_rewind_attr_dir(fs_volume* fsVolume, fs_vnode* fsNode, void* _cookie)
 // #pragma mark - Attribute Operations
 
 
-struct AttributeCookie {
-	PackageNode*			packageNode;
-	Package*				package;
-	PackageNodeAttribute*	attribute;
-	int						openMode;
-
-	AttributeCookie(PackageNode* packageNode, PackageNodeAttribute* attribute,
-		int openMode)
-		:
-		packageNode(packageNode),
-		package(packageNode->GetPackage()),
-		attribute(attribute),
-		openMode(openMode)
-	{
-		packageNode->AcquireReference();
-		package->AcquireReference();
-	}
-
-	~AttributeCookie()
-	{
-		packageNode->ReleaseReference();
-		package->ReleaseReference();
-	}
-};
-
-
 status_t
 packagefs_open_attr(fs_volume* fsVolume, fs_vnode* fsNode, const char* name,
 	int openMode, void** _cookie)
@@ -907,21 +877,12 @@ packagefs_open_attr(fs_volume* fsVolume, fs_vnode* fsNode, const char* name,
 	if (error != B_OK)
 		return error;
 
-	// get the package node and the respectively named attribute
-	PackageNode* packageNode = node->GetPackageNode();
-	PackageNodeAttribute* attribute = packageNode != NULL
-		? packageNode->FindAttribute(name) : NULL;
-	if (attribute == NULL)
-		return B_ENTRY_NOT_FOUND;
-
-	// allocate the cookie
-	AttributeCookie* cookie = new(std::nothrow) AttributeCookie(packageNode,
-		attribute, openMode);
-	if (cookie == NULL)
-		RETURN_ERROR(B_NO_MEMORY);
+	AttributeCookie* cookie;
+	error = node->OpenAttribute(name, openMode, cookie);
+	if (error != B_OK)
+		return error;
 
 	*_cookie = cookie;
-
 	return B_OK;
 }
 
@@ -929,7 +890,8 @@ packagefs_open_attr(fs_volume* fsVolume, fs_vnode* fsNode, const char* name,
 status_t
 packagefs_close_attr(fs_volume* fsVolume, fs_vnode* fsNode, void* _cookie)
 {
-	return B_OK;
+	AttributeCookie* cookie = (AttributeCookie*)_cookie;
+	RETURN_ERROR(cookie->Close());
 }
 
 
@@ -951,38 +913,6 @@ packagefs_free_attr_cookie(fs_volume* fsVolume, fs_vnode* fsNode, void* _cookie)
 }
 
 
-static status_t
-read_package_data(const BPackageData& data, BDataReader* dataReader, off_t offset,
-	void* buffer, size_t* bufferSize)
-{
-	// create a BPackageDataReader
-	BPackageDataReader* reader;
-	status_t error = GlobalFactory::Default()->CreatePackageDataReader(
-		dataReader, data, reader);
-	if (error != B_OK)
-		RETURN_ERROR(error);
-	ObjectDeleter<BPackageDataReader> readerDeleter(reader);
-
-	// check the offset
-	if (offset < 0 || (uint64)offset > data.UncompressedSize())
-		return B_BAD_VALUE;
-
-	// clamp the size
-	size_t toRead = std::min((uint64)*bufferSize,
-		data.UncompressedSize() - offset);
-
-	// read
-	if (toRead > 0) {
-		status_t error = reader->ReadData(offset, buffer, toRead);
-		if (error != B_OK)
-			RETURN_ERROR(error);
-	}
-
-	*bufferSize = toRead;
-	return B_OK;
-}
-
-
 status_t
 packagefs_read_attr(fs_volume* fsVolume, fs_vnode* fsNode, void* _cookie,
 	off_t offset, void* buffer, size_t* bufferSize)
@@ -996,21 +926,7 @@ packagefs_read_attr(fs_volume* fsVolume, fs_vnode* fsNode, void* _cookie,
 	TOUCH(volume);
 	TOUCH(node);
 
-	const BPackageData& data = cookie->attribute->Data();
-	if (data.IsEncodedInline()) {
-		// inline data
-		BBufferDataReader dataReader(data.InlineData(), data.CompressedSize());
-		return read_package_data(data, &dataReader, offset, buffer, bufferSize);
-	}
-
-	// data not inline -- open the package
-	int fd = cookie->package->Open();
-	if (fd < 0)
-		RETURN_ERROR(fd);
-	PackageCloser packageCloser(cookie->package);
-
-	BFDDataReader dataReader(fd);
-	return read_package_data(data, &dataReader, offset, buffer, bufferSize);
+	return cookie->ReadAttribute(offset, buffer, bufferSize);
 }
 
 
@@ -1027,10 +943,7 @@ packagefs_read_attr_stat(fs_volume* fsVolume, fs_vnode* fsNode,
 	TOUCH(volume);
 	TOUCH(node);
 
-	st->st_size = cookie->attribute->Data().UncompressedSize();
-	st->st_type = cookie->attribute->Type();
-
-	return B_OK;
+	return cookie->ReadAttributeStat(st);
 }