mirror of
https://github.com/pezkuwichain/pezkuwi-subxt.git
synced 2026-04-29 18:27:56 +00:00
Shinsaku Ashizawa
52 lines
1.7 KiB
Markdown
52 lines
1.7 KiB
Markdown
# I'm online Module
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If the local node is a validator (i.e. contains an authority key), this module
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gossips a heartbeat transaction with each new session. The heartbeat functions
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as a simple mechanism to signal that the node is online in the current era.
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Received heartbeats are tracked for one era and reset with each new era. The
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module exposes two public functions to query if a heartbeat has been received
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in the current era or session.
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The heartbeat is a signed transaction, which was signed using the session key
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and includes the recent best block number of the local validators chain as well
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as the `NetworkState`.
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It is submitted as an Unsigned Transaction via off-chain workers.
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- [`im_online::Config`](https://docs.rs/pallet-im-online/latest/pallet_im_online/trait.Config.html)
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- [`Call`](https://docs.rs/pallet-im-online/latest/pallet_im_online/enum.Call.html)
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- [`Module`](https://docs.rs/pallet-im-online/latest/pallet_im_online/struct.Module.html)
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## Interface
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### Public Functions
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- `is_online` - True if the validator sent a heartbeat in the current session.
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## Usage
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```rust
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use frame_support::{decl_module, dispatch};
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use frame_system::ensure_signed;
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use pallet_im_online::{self as im_online};
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pub trait Config: im_online::Config {}
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decl_module! {
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pub struct Module<T: Config> for enum Call where origin: T::Origin {
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#[weight = 0]
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pub fn is_online(origin, authority_index: u32) -> dispatch::DispatchResult {
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let _sender = ensure_signed(origin)?;
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let _is_online = <im_online::Module<T>>::is_online(authority_index);
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Ok(())
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}
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}
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}
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```
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## Dependencies
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This module depends on the [Session module](https://docs.rs/pallet-session/latest/pallet_session/).
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License: Apache-2.0
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