graphene::db::index Class Reference

abstract base class for accessing objects indexed in various ways. More...

#include <index.hpp>

Inheritance diagram for graphene::db::index:

Public Member Functions
virtual	~index ()=default
virtual uint8_t	object_space_id () const =0
virtual uint8_t	object_type_id () const =0
virtual object_id_type	get_next_id () const =0
virtual void	use_next_id ()=0
virtual void	set_next_id (object_id_type id)=0
virtual const object &	load (const std::vector< char > &data)=0
virtual const object &	insert (object &&obj)=0
virtual const object &	create (const std::function< void(object &)> &constructor)=0
virtual void	open (const fc::path &db)=0
virtual void	save (const fc::path &db)=0
virtual const object *	find (object_id_type id) const =0
const object &	get (object_id_type id) const
virtual void	modify (const object &obj, const std::function< void(object &)> &)=0
virtual void	remove (const object &obj)=0
template<typename Object , typename Lambda >
void	modify (const Object &obj, const Lambda &l)
virtual void	inspect_all_objects (std::function< void(const object &)> inspector) const =0
virtual void	add_observer (const std::shared_ptr< index_observer > &)=0
virtual void	object_from_variant (const fc::variant &var, object &obj, uint32_t max_depth) const =0
virtual void	object_default (object &obj) const =0

Detailed Description

abstract base class for accessing objects indexed in various ways.

All indexes assume that there exists an object ID space that will grow forever in a seqential manner. These IDs are used to identify the index, type, and instance of the object.

Items in an index can only be modified via a call to modify and all references to objects outside of that callback are const references.

Most implementations will probably be some form of boost::multi_index_container which means that they can covnert a reference to an object to an iterator. When at all possible save a pointer/reference to your objects rather than constantly looking them up by ID.

Definition at line 70 of file index.hpp.

Constructor & Destructor Documentation

~index()

virtual graphene::db::index::~index ( )

virtualdefault

Member Function Documentation

add_observer()

virtual void graphene::db::index::add_observer ( const std::shared_ptr< index_observer > &  )

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

create()

virtual const object& graphene::db::index::create ( const std::function< void(object &)> &  constructor )

pure virtual

Builds a new object and assigns it the next available ID and then initializes it with constructor and lastly inserts it into the index.

Implemented in graphene::db::primary_index< graphene::db::generic_index >, graphene::db::generic_index< ObjectType, MultiIndexType >, graphene::db::generic_index< T, boost::multi_index_container< T, indexed_by< ordered_unique< tag< by_id >, member< object, object_id_type, &object::id > > > > >, and graphene::db::simple_index< T >.

find()

virtual const object* graphene::db::index::find ( object_id_type  id ) const

pure virtual

Returns

the object with id or nullptr if not found

Implemented in graphene::db::primary_index< graphene::db::generic_index >, graphene::db::generic_index< ObjectType, MultiIndexType >, graphene::db::generic_index< T, boost::multi_index_container< T, indexed_by< ordered_unique< tag< by_id >, member< object, object_id_type, &object::id > > > > >, and graphene::db::simple_index< T >.

get()

const object& graphene::db::index::get ( object_id_type  id ) const

inline

This version will automatically check for nullptr and throw an exception if the object ID could not be found.

Definition at line 110 of file index.hpp.

get_next_id()

virtual object_id_type graphene::db::index::get_next_id ( ) const

pure virtual

insert()

virtual const object& graphene::db::index::insert ( object &&  obj )

pure virtual

Polymorphically insert by moving an object into the index. this should throw if the object is already in the database.

Implemented in graphene::db::primary_index< graphene::db::generic_index >, graphene::db::simple_index< T >, graphene::db::generic_index< ObjectType, MultiIndexType >, and graphene::db::generic_index< T, boost::multi_index_container< T, indexed_by< ordered_unique< tag< by_id >, member< object, object_id_type, &object::id > > > > >.

inspect_all_objects()

virtual void graphene::db::index::inspect_all_objects ( std::function< void(const object &)>  inspector ) const

pure virtual

Implemented in graphene::db::generic_index< ObjectType, MultiIndexType >, graphene::db::generic_index< T, boost::multi_index_container< T, indexed_by< ordered_unique< tag< by_id >, member< object, object_id_type, &object::id > > > > >, and graphene::db::simple_index< T >.

load()

virtual const object& graphene::db::index::load ( const std::vector< char > &  data )

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

modify() [1/2]

template<typename Object , typename Lambda >

void graphene::db::index::modify ( const Object &  obj, const Lambda &  l  )

inline

When forming your lambda to modify obj, it is natural to have Object& be the signature, but that is not compatible with the type erasue required by the virtual method. This method provides a helper to wrap the lambda in a form compatible with the virtual modify call.

Note

Lambda should have the signature: void(Object&)

Definition at line 127 of file index.hpp.

modify() [2/2]

virtual void graphene::db::index::modify ( const object &  obj, const std::function< void(object &)> &    )

pure virtual

Implemented in graphene::db::simple_index< T >, graphene::db::primary_index< graphene::db::generic_index >, graphene::db::generic_index< ObjectType, MultiIndexType >, and graphene::db::generic_index< T, boost::multi_index_container< T, indexed_by< ordered_unique< tag< by_id >, member< object, object_id_type, &object::id > > > > >.

object_default()

virtual void graphene::db::index::object_default ( object &  obj ) const

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

object_from_variant()

virtual void graphene::db::index::object_from_variant ( const fc::variant &  var, object &  obj, uint32_t  max_depth  ) const

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

object_space_id()

virtual uint8_t graphene::db::index::object_space_id ( ) const

pure virtual

object_type_id()

virtual uint8_t graphene::db::index::object_type_id ( ) const

pure virtual

open()

virtual void graphene::db::index::open ( const fc::path &  db )

pure virtual

Opens the index loading objects from a file

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

remove()

virtual void graphene::db::index::remove ( const object &  obj )

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >, graphene::db::generic_index< ObjectType, MultiIndexType >, graphene::db::generic_index< T, boost::multi_index_container< T, indexed_by< ordered_unique< tag< by_id >, member< object, object_id_type, &object::id > > > > >, and graphene::db::simple_index< T >.

save()

virtual void graphene::db::index::save ( const fc::path &  db )

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

set_next_id()

virtual void graphene::db::index::set_next_id ( object_id_type  id )

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

use_next_id()

virtual void graphene::db::index::use_next_id ( )

pure virtual

Implemented in graphene::db::primary_index< graphene::db::generic_index >.

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

• libraries/db/include/graphene/db/index.hpp