Detailed Description

The CYIPersistentStore class manages storing and retrieving application state data.

This class supports the use of custom types if they overide the << and >> operators.

Custom Type Example:

class CustomClass
{
public:
    CYIString contents;
    CustomClass(const CYIString &contents)
    : contents(contents)
    {
    }
};
std::ostream &operator<<(::std::ostream &os, const CustomClass &data)
{
    return os << data.contents;
}
std::istream &operator>>(::std::istream &is, CustomClass &data)
{
    return is >> data.contents;
}
CustomClass storedValue = CustomClass("value");
PersistentStore.Add("key", storedValue);
CustomClass retrievedValue;
if (PersistentStore.Find("key", &retrievedValue))
{
    // retrievedValue will be set to the key's corresponding value
}

Note

Platform Notes:

tvOS: The maximum data which can be stored per application is 500KB.
WebOS: The maximum data which can be stored is 10MB shared between all applications on the device. There are 3 reserved keys for the WebOS platform which are _id, _kind and _rev.
All Other Platforms: Persistent store data is written directly onto the device file system. The only limitation is the total available storage on the device.

#include <utility/YiPersistentStore.h>

Public Types
enum	StoreError { StoreError::OK = 0, StoreError::Corrupted, StoreError::NotEnoughSpace, StoreError::BadParameters, StoreError::Unknown }

Public Member Functions
	CYIPersistentStore (uint64_t maxSizeInBytes=0)

	CYIPersistentStore (const CYIPersistentStore &rRHS)

virtual	~CYIPersistentStore ()

CYIPersistentStore &	operator= (const CYIPersistentStore &rRHS)

template<typename T >
void	Add (const CYIString &Key, const T &value)

template<typename T >
bool	Find (const CYIString &Key, T *value) const

void	Remove (const CYIString &key)

std::vector< CYIString >	GetKeys () const

void	Clear ()

bool	Save (const CYIString &file)

bool	Load (const CYIString &file)

void	RequestSave (const CYIString &file)

void	RequestLoad (const CYIString &file)

bool	Clear (const CYIString &file)

StoreError	GetLastErrorCode () const

Public Attributes
CYISignal< bool >	SaveCompleted

CYISignal< bool >	LoadCompleted

Friends
class	IYIPersistentStorePriv

Member Enumeration Documentation

◆ StoreError

enum CYIPersistentStore::StoreError

strong

Enumerator
OK
Corrupted
NotEnoughSpace
BadParameters
Unknown

Constructor & Destructor Documentation

◆ CYIPersistentStore() [1/2]

CYIPersistentStore::CYIPersistentStore ( uint64_t maxSizeInBytes = 0 )

◆ CYIPersistentStore() [2/2]

CYIPersistentStore::CYIPersistentStore ( const CYIPersistentStore & rRHS )

◆ ~CYIPersistentStore()

virtual CYIPersistentStore::~CYIPersistentStore ( )

virtual

Member Function Documentation

◆ Add()

template<typename T >

void CYIPersistentStore::Add	(	const CYIString &	Key,
		const T &	value
	)

inline

Add a key-value pair to be saved as application state data. If the provided key already exists in the state data, it is updated with the provided value.

Example: int32_t num = 19; PersistentStore.Add("key", num);

◆ Clear() [1/2]

void CYIPersistentStore::Clear ( )

Clear the in-memory state.

◆ Clear() [2/2]

bool CYIPersistentStore::Clear ( const CYIString & file )

Synchronous - Clear the file contents.

◆ Find()

template<typename T >

bool CYIPersistentStore::Find	(	const CYIString &	Key,
		T *	value
	)		const

inline

Retrieve the value for the specified key from the loaded application state. If the key is found, returns true and value is set to the key's corresponding value. Returns false if the key is not found.

 Example:
 int32_t num = 19;
 if(PersistentStore.Find("key", &num))
 {

num will now be set to the key's corresponding value }

◆ GetKeys()

std::vector<CYIString> CYIPersistentStore::GetKeys ( ) const

Returns the all of the keys that exist in the state data.

◆ GetLastErrorCode()

StoreError CYIPersistentStore::GetLastErrorCode ( ) const

◆ Load()

bool CYIPersistentStore::Load ( const CYIString & file )

Synchronous - Load the state data from the specified file.

Note: This method will replace any existing state data with the state data from the file, including any keys in the state data that do not exist in the file.

◆ operator=()

CYIPersistentStore& CYIPersistentStore::operator= ( const CYIPersistentStore & rRHS )

◆ Remove()

void CYIPersistentStore::Remove ( const CYIString & key )

Removes the key-value pair entry associated with the key key.

Example: PersistentStore.Remove("key");

◆ RequestLoad()

void CYIPersistentStore::RequestLoad ( const CYIString & file )

Asynchronous - Load the state data from the specified file.

Note: This method will replace any existing state data with the state data from the file, including any keys in the state data that do not exist in the file.

See also: LoadCompleted Signal

◆ RequestSave()

void CYIPersistentStore::RequestSave ( const CYIString & file )

Asynchronous - Save the current state data to the specified file.

See also: SaveCompleted Signal

◆ Save()

bool CYIPersistentStore::Save ( const CYIString & file )

Synchronous - Save the current state data to the specified file.

Friends And Related Function Documentation

◆ IYIPersistentStorePriv

friend class IYIPersistentStorePriv

friend

Member Data Documentation

◆ LoadCompleted

CYISignal<bool> CYIPersistentStore::LoadCompleted

Callback for when the Asynchronous RequestLoad completes.

◆ SaveCompleted

CYISignal<bool> CYIPersistentStore::SaveCompleted

Callback for when the Asynchronous RequestSave completes.

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

utility/YiPersistentStore.h