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.
• dispatch_context
  Provides functions to interact with the dispatch context.
• 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.
• metadata_ir
  Intermediate representation of the runtime metadata.
• migrations
• pallet_macros
  Contains macro stubs for all of the pallet:: macros
• 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
  Re-exports sp-weights public API, and contains benchmarked weight constants specific to FRAME.

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.
• defensive_assert
  Trigger a defensive failure if a condition is not met.
• 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.
• std_enabled
  Enable/disable the given code depending on feature = "std" being enabled for the crate or not.

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.
• OpaqueMetadata
  Stores the encoded RuntimeMetadata for the native side as opaque type.
• 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
  The pallet attribute macro defines a pallet that can be used with construct_runtime!. It must be attached to a module named pallet as follows:
• 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.