class eosio::kv::table::index

Class List > eosio :: kv :: table :: index

Defines an index on an EOSIO Key Value Table. More...

Public Types

Type	Name
typedef table::iterator	iterator

Public Functions

Type	Name
	index (eosio::name name, KF && kf)
iterator	find (const K & key) const
bool	exists (const K & key) const
T	operator[] (const K & key) const
std::optional< T >	get (const K & key) const
iterator	begin () const
iterator	end () const
reverse_iterator	rbegin () const
reverse_iterator	rend () const
iterator	lower_bound (const K & key) const
iterator	upper_bound (const K & key) const
std::vector< T >	range (const K & b, const K & e) const
void	setup () override

Public Attributes

Type	Name
table_base *	tbl
eosio::name	table_name
eosio::name	contract_name
eosio::name	index_name
key_type	prefix

Detailed Description

A Key Value Index allows a user of the table to search based on a given field. The only restrictions on that field are that it is serializable to a binary representation sortable by the KV intrinsics. Convenience functions exist to handle most of the primitive types as well as some more complex types, and are used automatically where possible.

Template parameters:

K - The type of the key used in the index.

Public Types Documentation

typedef iterator

using eosio::kv::table< T, TableName >::index< K >::iterator =  table::iterator;

Public Functions Documentation

function index

template<typename KF>
eosio::kv::table< T, TableName >::index< K >::index(
    eosio::name name,
    KF && kf
)

function find

iterator eosio::kv::table< T, TableName >::index< K >::find(
    const K & key
) const

Search for an existing object in a table by the index, using the given key.

Parameters:

key - The key to search for.

Returns:

An iterator to the found object OR the end iterator if the given key was not found.

function exists

bool eosio::kv::table< T, TableName >::index< K >::exists(
    const K & key
) const

Check if a given key exists in the index.

Parameters:

key - The key to check for.

Returns:

If the key exists or not.

function operator[]

T eosio::kv::table< T, TableName >::index< K >::operator[](
    const K & key
) const

Get the value for an existing object in a table by the index, using the given key.

Parameters:

key - The key to search for.

Returns:

The value corresponding to the key.

function get

std::optional<T> eosio::kv::table< T, TableName >::index< K >::get(
    const K & key
) const

Get the value for an existing object in a table by the index, using the given key.

Parameters:

key - The key to search for.

Returns:

A std::optional of the value corresponding to the key.

function begin

iterator eosio::kv::table< T, TableName >::index< K >::begin() const

Returns an iterator to the object with the lowest key (by this index) in the table.

Returns:

An iterator to the object with the lowest key (by this index) in the table.

function end

iterator eosio::kv::table< T, TableName >::index< K >::end() const

Returns an iterator pointing past the end. It does not point to any element, therefore value should not be called on it.

Returns:

An iterator pointing past the end.

function rbegin

reverse_iterator eosio::kv::table< T, TableName >::index< K >::rbegin() const

Returns a reverse iterator to the object with the highest key (by this index) in the table.

Returns:

A reverse iterator to the object with the highest key (by this index) in the table.

function rend

reverse_iterator eosio::kv::table< T, TableName >::index< K >::rend() const

Returns a reverse iterator pointing past the beginning. It does not point to any element, therefore value should not be called on it.

Returns:

A reverse iterator pointing past the beginning.

function lower_bound

iterator eosio::kv::table< T, TableName >::index< K >::lower_bound(
    const K & key
) const

Returns an iterator pointing to the element with the lowest key greater than or equal to the given key.

Returns:

An iterator pointing to the element with the lowest key greater than or equal to the given key.

function upper_bound

iterator eosio::kv::table< T, TableName >::index< K >::upper_bound(
    const K & key
) const

Returns an iterator pointing to the first element greater than the given key.

Returns:

An iterator pointing to the first element greater than the given key.

function range

std::vector<T> eosio::kv::table< T, TableName >::index< K >::range(
    const K & b,
    const K & e
) const

Returns a vector of objects that fall between the specifed range. The range is inclusive, exclusive.

Parameters:

begin - The beginning of the range (inclusive).
end - The end of the range (exclusive).

Returns:

A vector containing all the objects that fall between the range.

function setup

void eosio::kv::table< T, TableName >::index< K >::setup()

Public Attributes Documentation

variable tbl

table_base* eosio::kv::internal::index_base::tbl;

variable table_name

eosio::name eosio::kv::internal::index_base::table_name;

variable contract_name

eosio::name eosio::kv::internal::index_base::contract_name;

variable index_name

eosio::name eosio::kv::internal::index_base::index_name;

variable prefix

key_type eosio::kv::internal::index_base::prefix;

The documentation for this class was generated from the following file: libraries/eosiolib/contracts/eosio/table.hpp