From 075b9beed4b1fb613ccd4331f89147558ace6948 Mon Sep 17 00:00:00 2001
From: Xiliang Chen <xlchen1291@gmail.com>
Date: Tue, 29 Jun 2021 00:45:09 +1200
Subject: [PATCH] add RelaychainBlockNumberProvider (#515)
* add RelaychainBlockNumberProvider
* add docs
---
cumulus/pallets/parachain-system/src/lib.rs | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/cumulus/pallets/parachain-system/src/lib.rs b/cumulus/pallets/parachain-system/src/lib.rs
index 9e658b90da2..3deb45d42f5 100644
--- a/cumulus/pallets/parachain-system/src/lib.rs
+++ b/cumulus/pallets/parachain-system/src/lib.rs
@@ -51,6 +51,7 @@ use sp_runtime::{
InvalidTransaction, TransactionLongevity, TransactionSource, TransactionValidity,
ValidTransaction,
},
+ offchain::storage_lock::BlockNumberProvider,
};
use sp_std::{cmp, collections::btree_map::BTreeMap, prelude::*};
@@ -1038,3 +1039,18 @@ pub trait CheckInherents<Block: BlockT> {
validation_data: &RelayChainStateProof,
) -> frame_support::inherent::CheckInherentsResult;
}
+
+/// Implements [`BlockNumberProvider`] that returns relaychain block number fetched from
+/// validation data.
+/// NTOE: When validation data is not available (e.g. within on_initialize), 0 will be returned.
+pub struct RelaychainBlockNumberProvider<T>(sp_std::marker::PhantomData<T>);
+
+impl<T: Config> BlockNumberProvider for RelaychainBlockNumberProvider<T> {
+ type BlockNumber = relay_chain::BlockNumber;
+
+ fn current_block_number() -> relay_chain::BlockNumber {
+ Pallet::<T>::validation_data()
+ .map(|d| d.relay_parent_number)
+ .unwrap_or_default()
+ }
+}
--
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