ccf::kv::ReadableValueHandle< V, VSerialiser, Unit > Class Template Reference

#include <value_handle.h>

Inherited by ccf::kv::ValueHandle< V, VSerialiser, Unit >.

Public Types
using	ValueType = V

Public Member Functions
	ReadableValueHandle (ccf::kv::untyped::MapHandle &uh)
std::optional< V >	get ()
std::optional< V >	get_globally_committed ()
bool	has ()
std::optional< Version >	get_version_of_previous_write ()

Protected Attributes
ccf::kv::untyped::MapHandle &	read_handle

Detailed Description

template<typename V, typename VSerialiser, typename Unit>
class ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >

Grants read access to a ccf::kv::Value, as part of a ccf::kv::Tx.

Member Typedef Documentation

ValueType

template<typename V , typename VSerialiser , typename Unit >

using ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >::ValueType = V

Constructor & Destructor Documentation

ReadableValueHandle()

template<typename V , typename VSerialiser , typename Unit >

ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >::ReadableValueHandle ( ccf::kv::untyped::MapHandle &  uh )

inline

Member Function Documentation

get()

template<typename V , typename VSerialiser , typename Unit >

std::optional< V > ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >::get ( )

inline

Get the stored value.

This will return nullopt of the value has never been set, or has been removed.

Returns

Optional containing associated value, or empty if the value doesn't exist

get_globally_committed()

template<typename V , typename VSerialiser , typename Unit >

std::optional< V > ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >::get_globally_committed ( )

inline

Get globally committed value, which has been replicated and acknowledged by consensus protocol.

Returns

Optional containing associated value, or empty if the value doesn't exist in globally committed state

get_version_of_previous_write()

template<typename V , typename VSerialiser , typename Unit >

std::optional< Version > ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >::get_version_of_previous_write ( )

inline

Get version when this value was last written to, by a previous transaction.

See also

ccf::kv::ReadableMapHandle::get_version_of_previous_write

Returns

Optional containing version of applied transaction which last wrote to this value, or nullopt if such a version does not exist

has()

template<typename V , typename VSerialiser , typename Unit >

bool ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >::has ( )

inline

Test if value is defined.

This is equivalent to get().has_value(), but is more efficient as it doesn't need to deserialise the value.

Returns

Boolean true iff value is defined

Member Data Documentation

read_handle

template<typename V , typename VSerialiser , typename Unit >

ccf::kv::untyped::MapHandle& ccf::kv::ReadableValueHandle< V, VSerialiser, Unit >::read_handle

protected

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

• include/ccf/kv/value_handle.h