Crate frame_support

Support code for the runtime.

Note on Tuple Traits

Many of the traits defined in traits have auto-implementations on tuples as well. Usually, the tuple is a function of number of pallets in the runtime. By default, the traits are implemented for tuples of up to 64 items.

Re-exports

pub use serde;

pub use self::storage::storage_noop_guard::StorageNoopGuard;

pub use self::dispatch::Callable;

pub use self::dispatch::Parameter;

pub use self::storage::migration;

pub use self::storage::IterableStorageDoubleMap;

pub use self::storage::IterableStorageMap;

pub use self::storage::IterableStorageNMap;

pub use self::storage::StorageDoubleMap;

pub use self::storage::StorageMap;

pub use self::storage::StorageNMap;

pub use self::storage::StoragePrefixedMap;

pub use self::storage::StorageValue;

pub use sp_runtime;

Modules

crypto

Utilities for dealing with crypto primitives. Sometimes we need to use these from inside WASM contracts, where crypto calculations have weak performance.

dispatch

Dispatch system. Contains a macro for defining runtime modules and generating values representing lazy module function calls.

error

Macro for declaring a module error.

event

Macros that define an Event types. Events can be used to easily report changes or conditions in your runtime to external entities like users, chain explorers, or dApps.

inherent

instances

Some instance placeholder to be used in frame_support::pallet attribute macro.

migrations

pallet_prelude

Prelude to be used alongside pallet macro, for ease of use.

storage

Stuff to do with the runtime’s storage.

traits

Traits and associated utilities for use in the FRAME environment.

weights

Primitives for transaction weighting.

Macros

assert_err

Assert an expression returns an error specified.

assert_err_ignore_postinfo

Assert an expression returns an error specified.

assert_err_with_weight

Assert an expression returns error with the given weight.

assert_error_encoded_size

Assert that the maximum encoding size does not exceed the value defined in MAX_MODULE_ERROR_ENCODED_SIZE during compilation.

assert_noop

Evaluate an expression, assert it returns an expected Err value and that runtime storage has not been mutated (i.e. expression is a no-operation).

assert_ok

Panic if an expression doesn’t evaluate to Ok.

assert_storage_noop

Evaluate any expression and assert that runtime storage has not been mutated (i.e. expression is a storage no-operation).

construct_runtime

Construct a runtime, with the given name and the given pallets.

crate_to_crate_version

Convert the current crate version into a CrateVersion.

decl_error

Declare an error type for a runtime module.

decl_event

Implement the Event for a module.

decl_module

Declares a Module struct and a Call enum, which implements the dispatch logic.

decl_storage

Declares strongly-typed wrappers around codec-compatible types in storage.

defensive

Generic function to mark an execution path as ONLY defensive.

ensure

Evaluate $x:expr and if not true return Err($y:expr).

fail

Return Err of the expression: return Err($expression);.

impl_filter_stack

match_and_insert

Macro that inserts some tokens after the first match of some pattern.

match_typeDeprecated

Create a type which implements the Contains trait for a particular type with syntax similar to matches!.

match_types

Create a type which implements the Contains trait for a particular type with syntax similar to matches!.

ord_parameter_types

Macro for easily creating a new implementation of both the Get and Contains traits. Use exactly as with parameter_types, only the type must be Ord.

parameter_types

Create new implementations of the Get trait.

parameter_types_impl_thread_local

runtime_print

Print out a formatted message.

Structs

Blake2_128

Hash storage keys with blake2 128

Blake2_128Concat

Hash storage keys with concat(blake2_128(key), key)

Blake2_256

Hash storage keys with blake2 256

BoundedBTreeMap

A bounded map based on a B-Tree.

BoundedBTreeSet

A bounded set based on a B-Tree.

BoundedSlice

A bounded slice.

BoundedVec

A bounded vector.

Identity

Store the key directly.

PalletId

A pallet identifier. These are per pallet and should be stored in a registry somewhere.

Twox64Concat

Hash storage keys with concat(twox64(key), key)

Twox128

Hash storage keys with twox 128

Twox256

Hash storage keys with twox 256

WeakBoundedVec

A weakly bounded vector.

Enums

Never

A type that cannot be instantiated.

Void

The void type - it cannot exist.

Constants

LOG_TARGET

A unified log target for support operations.

MAX_MODULE_ERROR_ENCODED_SIZE

The number of bytes of the module-specific error field defined in ModuleError. In FRAME, this is the maximum encoded size of a pallet error type.

Traits

Hashable

Printable

Trait for things which can be printed from the runtime.

ReversibleStorageHasher

Hasher to use to hash keys to insert to storage.

StorageHasher

Hasher to use to hash keys to insert to storage.

Functions

debug

Print out the debuggable type.

print

Print something that implements Printable from the runtime.

Type Definitions

ConsensusEngineId

Consensus engine unique ID.

Attribute Macros

pallet

pallet attribute macro allows to define a pallet to be used in construct_runtime!.

require_transactional

Assert the annotated function is executed within a storage transaction.

storage_alias

Generate a new type alias for storage::types::StorageValue, storage::types::StorageMap, storage::types::StorageDoubleMap and storage::types::StorageNMap.

transactional

Execute the annotated function in a new storage transaction.

Derive Macros

CloneNoBound

Derive Clone but do not bound any generic.

DebugNoBound

Derive Debug but do not bound any generic.

DefaultNoBound

Derive Default but do not bound any generic.

EqNoBound

Derive Eq but do not bound any generic.

PalletError

PartialEqNoBound

Derive PartialEq but do not bound any generic.

RuntimeDebugNoBound

Derive Debug, if std is enabled it uses frame_support::DebugNoBound, if std is not enabled it just returns "<stripped>". This behaviour is useful to prevent bloating the runtime WASM blob from unneeded code.