C++ UserStringParameter类代码示例

partition_id
_user_find_partition(const char *_filename, size_t *neededSize)
{
	UserStringParameter<false> filename;
	status_t error = filename.Init(_filename, B_PATH_NAME_LENGTH);
	if (error != B_OK)
		return error;

	KDiskDeviceManager *manager = KDiskDeviceManager::Default();
	// find the partition
	KPartition *partition = manager->RegisterPartition(filename);
	if (partition == NULL)
		return B_ENTRY_NOT_FOUND;
	PartitionRegistrar _(partition, true);
	partition_id id = partition->ID();
	if (neededSize != NULL) {
		// get and lock the partition's device
		KDiskDevice *device = manager->RegisterDevice(partition->ID(), false);
		if (device == NULL)
			return B_ENTRY_NOT_FOUND;
		PartitionRegistrar _2(device, true);
		if (DeviceReadLocker locker = device) {
			// get the needed size
			UserDataWriter writer;
			device->WriteUserData(writer);
			error = copy_to_user_value(neededSize, writer.AllocatedSize());
			if (error != B_OK)
				return error;
		} else
			return B_ERROR;
	}
	return id;
}

partition_id
_user_find_file_disk_device(const char *_filename, size_t *neededSize)
{
	UserStringParameter<false> filename;
	status_t error = filename.Init(_filename, B_PATH_NAME_LENGTH);
	if (error != B_OK)
		return error;

	KPath path(filename, KPath::NORMALIZE);

	KDiskDeviceManager *manager = KDiskDeviceManager::Default();
	// find the device
	KFileDiskDevice* device = manager->RegisterFileDevice(path.Path());
	if (device == NULL)
		return B_ENTRY_NOT_FOUND;
	PartitionRegistrar _(device, true);
	partition_id id = device->ID();
	if (neededSize != NULL) {
		if (DeviceReadLocker locker = device) {
			// get the needed size
			UserDataWriter writer;
			device->WriteUserData(writer);
			error = copy_to_user_value(neededSize, writer.AllocatedSize());
			if (error != B_OK)
				return error;
		} else
			return B_ERROR;
	}
	return id;
}

status_t
_user_set_partition_content_name(partition_id partitionID,
	int32* _changeCounter, const char* _name)
{
	// copy parameters in
	UserStringParameter<true> name;
	int32 changeCounter;

	status_t error = name.Init(_name, B_DISK_DEVICE_NAME_LENGTH);
	if (error == B_OK)
		error = copy_from_user_value(changeCounter, _changeCounter);
	if (error != B_OK)
		return error;

	// get the partition
	KDiskDeviceManager* manager = KDiskDeviceManager::Default();
	KPartition* partition = manager->WriteLockPartition(partitionID);
	if (partition == NULL)
		return B_ENTRY_NOT_FOUND;

	PartitionRegistrar registrar1(partition, true);
	PartitionRegistrar registrar2(partition->Device(), true);
	DeviceWriteLocker locker(partition->Device(), true);

	// check change counter
	if (changeCounter != partition->ChangeCounter())
		return B_BAD_VALUE;

	// the partition must be initialized
	KDiskSystem* diskSystem = partition->DiskSystem();
	if (diskSystem == NULL)
		return B_BAD_VALUE;

	// mark the partition busy and unlock
	if (!partition->CheckAndMarkBusy(false))
		return B_BUSY;
	locker.Unlock();

	// set content parameters
	error = diskSystem->SetContentName(partition, name.value, DUMMY_JOB_ID);

	// re-lock and unmark busy
	locker.Lock();
	partition->UnmarkBusy(false);

	if (error != B_OK)
		return error;

	// return change counter
	return copy_to_user_value(_changeCounter, partition->ChangeCounter());
}

status_t
_user_unregister_file_device(partition_id deviceID, const char *_filename)
{
	if (deviceID < 0 && _filename == NULL)
		return B_BAD_VALUE;
	KDiskDeviceManager *manager = KDiskDeviceManager::Default();
	if (deviceID >= 0)
		return manager->DeleteFileDevice(deviceID);

	UserStringParameter<false> filename;
	status_t error = filename.Init(_filename, B_PATH_NAME_LENGTH);
	if (error != B_OK)
		return error;

	return manager->DeleteFileDevice(filename);
}

status_t
_user_set_partition_parameters(partition_id partitionID, int32* _changeCounter,
	partition_id childID, int32* _childChangeCounter, const char* _parameters)
{
	// copy parameters in
	UserStringParameter<true> parameters;
	int32 changeCounter;
	int32 childChangeCounter;

	status_t error
		= parameters.Init(_parameters, B_DISK_DEVICE_MAX_PARAMETER_SIZE);
	if (error == B_OK)
		error = copy_from_user_value(changeCounter, _changeCounter);
	if (error == B_OK)
		error = copy_from_user_value(childChangeCounter, _childChangeCounter);
	if (error != B_OK)
		return error;

	// get the partition
	KDiskDeviceManager* manager = KDiskDeviceManager::Default();
	KPartition* partition = manager->WriteLockPartition(partitionID);
	if (partition == NULL)
		return B_ENTRY_NOT_FOUND;

	PartitionRegistrar registrar1(partition, true);
	PartitionRegistrar registrar2(partition->Device(), true);
	DeviceWriteLocker locker(partition->Device(), true);

	// register child
	KPartition* child = manager->RegisterPartition(childID);
	if (child == NULL)
		return B_ENTRY_NOT_FOUND;

	PartitionRegistrar registrar3(child, true);

	// check change counters
	if (changeCounter != partition->ChangeCounter()
		|| childChangeCounter != child->ChangeCounter()) {
		return B_BAD_VALUE;
	}

	// the partition must be initialized
	KDiskSystem* diskSystem = partition->DiskSystem();
	if (diskSystem == NULL)
		return B_BAD_VALUE;

	// child must indeed be a child of partition
	if (child->Parent() != partition)
		return B_BAD_VALUE;

	// mark the partition busy and unlock
	if (partition->IsBusy() || child->IsBusy())
		return B_BUSY;
	partition->SetBusy(true);
	child->SetBusy(true);
	locker.Unlock();

	// set the child parameters
	error = diskSystem->SetParameters(child, parameters.value, DUMMY_JOB_ID);

	// re-lock and unmark busy
	locker.Lock();
	partition->SetBusy(false);
	child->SetBusy(false);

	if (error != B_OK)
		return error;

	// return change counters
	error = copy_to_user_value(_changeCounter, partition->ChangeCounter());
	if (error == B_OK)
		error = copy_to_user_value(_childChangeCounter, child->ChangeCounter());
	return error;
}

status_t
_user_create_child_partition(partition_id partitionID, int32* _changeCounter,
	off_t offset, off_t size, const char* _type, const char* _name,
	const char* _parameters, partition_id* childID, int32* childChangeCounter)
{
	// copy parameters in
	UserStringParameter<false> type;
	UserStringParameter<true> name;
	UserStringParameter<true> parameters;
	int32 changeCounter;

	status_t error = type.Init(_type, B_DISK_DEVICE_TYPE_LENGTH);
	if (error == B_OK)
		error = name.Init(_name, B_DISK_DEVICE_NAME_LENGTH);
	if (error == B_OK)
		error = parameters.Init(_parameters, B_DISK_DEVICE_MAX_PARAMETER_SIZE);
	if (error == B_OK)
		error = copy_from_user_value(changeCounter, _changeCounter);
	if (error != B_OK)
		return error;

	// get the partition
	KDiskDeviceManager* manager = KDiskDeviceManager::Default();
	KPartition* partition = manager->WriteLockPartition(partitionID);
	if (partition == NULL)
		return B_ENTRY_NOT_FOUND;

	PartitionRegistrar registrar1(partition, true);
	PartitionRegistrar registrar2(partition->Device(), true);
	DeviceWriteLocker locker(partition->Device(), true);

	// check change counter
	if (changeCounter != partition->ChangeCounter())
		return B_BAD_VALUE;

	// the partition must be initialized
	KDiskSystem* diskSystem = partition->DiskSystem();
	if (diskSystem == NULL)
		return B_BAD_VALUE;

	// mark the partition busy and unlock
	if (!partition->CheckAndMarkBusy(false))
		return B_BUSY;
	locker.Unlock();

	// create the child
	KPartition *child = NULL;
	error = diskSystem->CreateChild(partition, offset, size, type.value,
		name.value, parameters.value, DUMMY_JOB_ID, &child, -1);

	// re-lock and unmark busy
	locker.Lock();
	partition->UnmarkBusy(false);

	if (error != B_OK)
		return error;

	if (child == NULL)
		return B_ERROR;

	child->UnmarkBusy(true);

	// return change counter and child ID
	error = copy_to_user_value(_changeCounter, partition->ChangeCounter());
	if (error == B_OK)
		error = copy_to_user_value(childID, child->ID());
	return error;
}

status_t
_user_initialize_partition(partition_id partitionID, int32* _changeCounter,
	const char* _diskSystemName, const char* _name, const char* _parameters)
{
	// copy parameters in
	UserStringParameter<false> diskSystemName;
	UserStringParameter<true> name;
	UserStringParameter<true> parameters;
	int32 changeCounter;

	status_t error
		= diskSystemName.Init(_diskSystemName, B_DISK_SYSTEM_NAME_LENGTH);
	if (error == B_OK)
		error = name.Init(_name, B_DISK_DEVICE_NAME_LENGTH);
	if (error == B_OK)
		error = parameters.Init(_parameters, B_DISK_DEVICE_MAX_PARAMETER_SIZE);
	if (error == B_OK)
		error = copy_from_user_value(changeCounter, _changeCounter);
	if (error != B_OK)
		return error;

	// get the partition
	KDiskDeviceManager* manager = KDiskDeviceManager::Default();
	KPartition* partition = manager->WriteLockPartition(partitionID);
	if (partition == NULL)
		return B_ENTRY_NOT_FOUND;

	PartitionRegistrar registrar1(partition, true);
	PartitionRegistrar registrar2(partition->Device(), true);
	DeviceWriteLocker locker(partition->Device(), true);

	// check change counter
	if (changeCounter != partition->ChangeCounter())
		return B_BAD_VALUE;

	// the partition must be uninitialized
	if (partition->DiskSystem() != NULL)
		return B_BAD_VALUE;

	// load the new disk system
	KDiskSystem *diskSystem = manager->LoadDiskSystem(diskSystemName.value,
		true);
	if (diskSystem == NULL)
		return B_ENTRY_NOT_FOUND;
	DiskSystemLoader loader(diskSystem, true);

	// mark the partition busy and unlock
	if (!partition->CheckAndMarkBusy(true))
		return B_BUSY;
	locker.Unlock();

	// let the disk system initialize the partition
	error = diskSystem->Initialize(partition, name.value, parameters.value,
		DUMMY_JOB_ID);

	// re-lock and unmark busy
	locker.Lock();
	partition->UnmarkBusy(true);

	if (error != B_OK)
		return error;

	// Set the disk system. Re-check whether a disk system is already set on the
	// partition. Some disk systems just write the on-disk structures and let
	// the DDM rescan the partition, in which case the disk system will already
	// be set. In very unfortunate cases the on-disk structure of the previous
	// disk system has not been destroyed and the previous disk system has a
	// higher priority than the new one. The old disk system will thus prevail.
	// Not setting the new disk system will at least prevent that the partition
	// object gets into an inconsistent state.
	if (partition->DiskSystem() == NULL)
		partition->SetDiskSystem(diskSystem);

	// return change counter
	return copy_to_user_value(_changeCounter, partition->ChangeCounter());
}