alexaClientSDK::acsdkAssets::manager::StorageManager Class Reference

#include <StorageManager.h>

Inheritance diagram for alexaClientSDK::acsdkAssets::manager::StorageManager:

Collaboration diagram for alexaClientSDK::acsdkAssets::manager::StorageManager:

Classes
struct	ReservationToken

Public Member Functions
	~StorageManager ()=default
void	purgeUnreferenced ()
std::shared_ptr< Resource >	registerAndAcquireResource (std::unique_ptr< StorageManager::ReservationToken > reservationToken, const std::string &id, const std::string &sourcePath)
std::shared_ptr< Resource >	acquireResource (const std::string &id)
size_t	releaseResource (const std::shared_ptr< Resource > &resource)
std::unique_ptr< ReservationToken >	reserveSpace (size_t requestedAmount)
size_t	availableBudget ()
size_t	getBudget ()
void	setBudget (size_t valueMB)

Static Public Member Functions
static std::shared_ptr< StorageManager >	create (const std::string &workingDirectory, const std::shared_ptr< AssetManager > &assetManager)

Static Public Attributes
static constexpr auto	MAX_BUDGET_MB = 500

Protected Member Functions
	StorageManager (const std::string &workingDirectory, const std::shared_ptr< AssetManager > &assetManager, size_t budget)
bool	init ()
void	requestGarbageCollection (size_t requestedAmount)
bool	requestSpace (size_t requestedAmount)
void	freeReservedSpace (size_t size)

Detailed Description

This class manages a certain budget that Asset Manager should not go over. If at any point the amount of space used by Asset Manager goes over the budget, this class will trigger a call to the Asset Manager to free up space by deleting unused artifacts.

Constructor & Destructor Documentation

~StorageManager()

alexaClientSDK::acsdkAssets::manager::StorageManager::~StorageManager ( )

default

StorageManager()

alexaClientSDK::acsdkAssets::manager::StorageManager::StorageManager ( const std::string &  workingDirectory, const std::shared_ptr< AssetManager > &  assetManager, size_t  budget  )

explicitprotected

Member Function Documentation

acquireResource()

shared_ptr< Resource > alexaClientSDK::acsdkAssets::manager::StorageManager::acquireResource

(

const std::string &

id

)

Given an id, attempt to acquire a resource which will increment its reference count and returns the resource accordingly. If no resource is found with this id, then return a nullptr.

Parameters

id	REQUIRED, a unique identifier for the requested resource.

Returns

NULLABLE, a smart pointer to an existing resource, null if not found.

availableBudget()

size_t alexaClientSDK::acsdkAssets::manager::StorageManager::availableBudget

(

)

Returns

the amount of bytes remaining that can be used for a new artifact. This is calculated as the lowest of:

1. Asset Manager Budget - reserved space - downloaded resource space
2. Amount of space left on the device - 5MB buffer

create()

shared_ptr< StorageManager > alexaClientSDK::acsdkAssets::manager::StorageManager::create ( const std::string &  workingDirectory, const std::shared_ptr< AssetManager > &  assetManager  )

static

Create a Storage Manager that is responsible for maintaining a budget for the artifacts to remain under.

Parameters

workingDirectory	REQUIRED, place to store budget configuration.
assetManager	REQUIRED, used to request low priority artifacts cleanup to meet the budget.

Returns

NULLABLE, a smart pointer to Storage Manager if successful, null otherwise.

freeReservedSpace()

void alexaClientSDK::acsdkAssets::manager::StorageManager::freeReservedSpace ( size_t  size )

protected

Free up reserved space, to be used by reservation tokens

getBudget()

size_t alexaClientSDK::acsdkAssets::manager::StorageManager::getBudget

(

)

Returns

Get the current budget in MB

init()

bool alexaClientSDK::acsdkAssets::manager::StorageManager::init ( )

protected

Goes through the working directory and initializes all the available resources.

Returns

true if the initialization succeeded, false otherwise.

purgeUnreferenced()

void alexaClientSDK::acsdkAssets::manager::StorageManager::purgeUnreferenced

(

)

Post initialization step that goes through the map of resources and erases any that are unreferenced.

registerAndAcquireResource()

shared_ptr< Resource > alexaClientSDK::acsdkAssets::manager::StorageManager::registerAndAcquireResource	(	std::unique_ptr< StorageManager::ReservationToken >	reservationToken,
		const std::string &	id,
		const std::string &	sourcePath
	)

Registers a resource given a path to its content. If the operation succeeds, then it will be acquired as well. If another resource is found with the same id, then this will delete the provided path and use the existing resource. If there is no other resource with this id, then this will move the source path to the resources directory.

Parameters

reservationToken	REQUIRED, a unique token that was used to reserve space ahead of download
id	REQUIRED, a unique identifier for this resource, preferably the sha2 checksum.
sourcePath	REQUIRED, the path on disk where this resource is found.

Returns

NULLABLE, a smart pointer to the newly created and acquired resource, null if the operation failed.

releaseResource()

size_t alexaClientSDK::acsdkAssets::manager::StorageManager::releaseResource

(

const std::shared_ptr< Resource > &

resource

)

Given a resource, attempt to find it in the list and decrement its reference count. If the reference count is 0, then erase the resource from the system and return the size of how much memory was freed. If there are others referencing this resource, then return 0 and keep the resource on disk.

Parameters

resource

REQUIRED, a valid resource that is registered by storage manager.

Returns

the size of the space that was cleared with this release, 0 if the resource was not deleted.

requestGarbageCollection()

void alexaClientSDK::acsdkAssets::manager::StorageManager::requestGarbageCollection ( size_t  requestedAmount )

protected

Asks the Asset Manager to free up a certain amount of space in a background task.

Parameters

requestedAmount

amount in bytes to be cleared.

requestSpace()

bool alexaClientSDK::acsdkAssets::manager::StorageManager::requestSpace ( size_t  requestedAmount )

protected

Forwards request to Asset Manager to free up space according to the given amount.

Parameters

requestedAmount

amount in bytes to clear.

Returns

true if the requested space was cleared, false otherwise.

reserveSpace()

unique_ptr< StorageManager::ReservationToken > alexaClientSDK::acsdkAssets::manager::StorageManager::reserveSpace

(

size_t

requestedAmount

)

Reserve the requested amount of space and return a token that will be used to track the reserved space and is needed for registering a new resource. If the token is destroyed, the space is automatically freed.

Parameters

requestedAmount

space to reserve

Returns

a new unique token if space is successfully reserved, nullptr otherwise

setBudget()

void alexaClientSDK::acsdkAssets::manager::StorageManager::setBudget

(

size_t

valueMB

)

Set a new budget value.

Parameters

value

the new budget in MB.

Member Data Documentation

MAX_BUDGET_MB

constexpr auto alexaClientSDK::acsdkAssets::manager::StorageManager::MAX_BUDGET_MB = 500

staticconstexpr

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The documentation for this class was generated from the following files:

• /workplace/avs-device-sdk/capabilities/AssetManager/acsdkAssetManager/src/StorageManager.h
• /workplace/avs-device-sdk/capabilities/AssetManager/acsdkAssetManager/src/StorageManager.cpp