Crate frame_system
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§System Pallet
The System pallet provides low-level access to core types and cross-cutting utilities. It acts as the base layer for other pallets to interact with the Substrate framework components.
§Overview
The System pallet defines the core data types used in a Substrate runtime. It also provides
several utility functions (see Pallet
) for other FRAME pallets.
In addition, it manages the storage items for extrinsic data, indices, event records, and digest items, among other things that support the execution of the current block.
It also handles low-level tasks like depositing logs, basic set up and take down of temporary storage entries, and access to previous block hashes.
§Interface
§Dispatchable Functions
The System pallet provides dispatchable functions that, with the exception of remark
, manage
low-level or privileged functionality of a Substrate-based runtime.
remark
: Make some on-chain remark.set_heap_pages
: Set the number of pages in the WebAssembly environment’s heap.set_code
: Set the new runtime code.set_code_without_checks
: Set the new runtime code without any checks.set_storage
: Set some items of storage.kill_storage
: Kill some items from storage.kill_prefix
: Kill all storage items with a key that starts with the given prefix.remark_with_event
: Make some on-chain remark and emit an event.do_task
: Do some specified task.authorize_upgrade
: Authorize new runtime code.authorize_upgrade_without_checks
: Authorize new runtime code and an upgrade sans verification.apply_authorized_upgrade
: Provide new, already-authorized runtime code.
§A Note on Upgrades
The pallet provides two primary means of upgrading the runtime, a single-phase means using
set_code
and a two-phase means using authorize_upgrade
followed by
apply_authorized_upgrade
. The first will directly attempt to apply the provided code
(application may have to be scheduled, depending on the context and implementation of the
OnSetCode
trait).
The authorize_upgrade
route allows the authorization of a runtime’s code hash. Once
authorized, anyone may upload the correct runtime to apply the code. This pattern is useful when
providing the runtime ahead of time may be unwieldy, for example when a large preimage (the
code) would need to be stored on-chain or sent over a message transport protocol such as a
bridge.
The *_without_checks
variants do not perform any version checks, so using them runs the risk
of applying a downgrade or entirely other chain specification. They will still validate that the
code
meets the authorized hash.
§Public Functions
See the Pallet
struct for details of publicly available functions.
§Signed Extensions
The System pallet defines the following extensions:
CheckWeight
: Checks the weight and length of the block and ensure that it does not exceed the limits.CheckNonce
: Checks the nonce of the transaction. Contains a single payload of typeT::Nonce
.CheckEra
: Checks the era of the transaction. Contains a single payload of typeEra
.CheckGenesis
: Checks the provided genesis hash of the transaction. Must be a part of the signed payload of the transaction.CheckSpecVersion
: Checks that the runtime version is the same as the one used to sign the transaction.CheckTxVersion
: Checks that the transaction version is the same as the one used to sign the transaction.
Look up the runtime aggregator file (e.g. node/runtime
) to see the full list of signed
extensions included in a chain.
Re-exports§
pub use weights::WeightInfo;
pub use pallet::*;
Modules§
- Block resource limits configuration structures.
- Migrate the reference counting state.
- Provide types to help defining a mock environment when testing pallets.
- Module helpers for off-chain calls.
- The
pallet
module in each FRAME pallet hosts the most important items needed to construct this pallet. - Prelude to be used alongside pallet macro, for ease of use.
- Autogenerated weights for
frame_system
Structs§
- Information of an account.
- Check for transaction mortality.
- Genesis hash check to provide replay protection between different networks.
- Check for transaction mortality.
- Check to ensure that the sender is not the zero address.
- Nonce check and increment to give replay protection for transactions.
- Ensure the runtime version registered in the transaction is the same as at present.
- Ensure the transaction version registered in the transaction is the same as at present.
- Block resource (weight) limit check.
- Information needed when a new runtime binary is submitted and needs to be authorized before replacing the current runtime.
- Event handler which registers a consumer when created.
- Always fail.
- Ensure the origin is
None
. i.e. unsigned transaction. - Ensure the origin is Root.
- Ensure the origin is Root and return the provided
Success
value. - Ensure the origin is any
Signed
origin. - Ensure the origin is
Signed
origin from the givenAccountId
. - Ensure the origin is provided
Ensure
origin and return the providedSuccess
value. - Record of an event happening.
- Stores the
spec_version
andspec_name
of when the last runtime upgrade happened. - Event handler which registers a provider when created.
- Event handler which registers a self-sufficient when created.
Enums§
- Some resultant status relevant to decrementing a provider/self-sufficient reference.
- Some resultant status relevant to incrementing a provider/self-sufficient reference.
- A phase of a block’s execution.
- Origin for the System pallet.
- Reference status; can be either referenced or unreferenced.
Traits§
- Numeric limits over the ability to add a consumer ref using
inc_consumers
. - Do something when we should be setting the code.
Functions§
- Ensure that the origin
o
represents an unsigned extrinsic. ReturnsOk
or anErr
otherwise. - Ensure that the origin
o
represents the root. ReturnsOk
or anErr
otherwise. - Ensure that the origin
o
represents a signed extrinsic (i.e. transaction). ReturnsOk
with the account that signed the extrinsic or anErr
otherwise. - Ensure that the origin
o
represents either a signed extrinsic (i.e. transaction) or the root. ReturnsOk
with the account that signed the extrinsic,None
if it was root, or anErr
otherwise. - Compute the trie root of a list of extrinsics.
- Compute the trie root of a list of extrinsics.
- Split an
option
into two constituent options, as defined by asplitter
function. - Returns a 32 byte datum which is guaranteed to be universally unique.
entropy
is provided as a facility to reduce the potential for precalculating results.
Type Aliases§
- An object to track the currently used extrinsic weight in a block.
- Type used to encode the number of references an account has.