Removes Snowbridge parachain directory (#3186)

Removes the `bridges/snowbridge/parachain` directory and moves
everything up to under `snowbridge` directly. We are cleaning up our
local dev env after merging our crates into the polkadot-sdk.

---------

Co-authored-by: claravanstaden <Cats 4 life!>

bridges/snowbridge/primitives/core/src/ringbuffer.rs

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+use codec::FullCodec;
+use core::{cmp::Ord, marker::PhantomData, ops::Add};
+use frame_support::storage::{types::QueryKindTrait, StorageMap, StorageValue};
+use sp_core::{Get, GetDefault};
+use sp_runtime::traits::{One, Zero};
+
+/// Trait object presenting the ringbuffer interface.
+pub trait RingBufferMap<Key, Value, QueryKind>
+where
+	Key: FullCodec,
+	Value: FullCodec,
+	QueryKind: QueryKindTrait<Value, GetDefault>,
+{
+	/// Insert a map entry.
+	fn insert(k: Key, v: Value);
+
+	/// Check if map contains a key
+	fn contains_key(k: Key) -> bool;
+
+	/// Get the value of the key
+	fn get(k: Key) -> QueryKind::Query;
+}
+
+pub struct RingBufferMapImpl<Index, B, CurrentIndex, Intermediate, M, QueryKind>(
+	PhantomData<(Index, B, CurrentIndex, Intermediate, M, QueryKind)>,
+);
+
+/// Ringbuffer implementation based on `RingBufferTransient`
+impl<Key, Value, Index, B, CurrentIndex, Intermediate, M, QueryKind>
+	RingBufferMap<Key, Value, QueryKind>
+	for RingBufferMapImpl<Index, B, CurrentIndex, Intermediate, M, QueryKind>
+where
+	Key: FullCodec + Clone,
+	Value: FullCodec,
+	Index: Ord + One + Zero + Add<Output = Index> + Copy + FullCodec + Eq,
+	B: Get<Index>,
+	CurrentIndex: StorageValue<Index, Query = Index>,
+	Intermediate: StorageMap<Index, Key, Query = Key>,
+	M: StorageMap<Key, Value, Query = QueryKind::Query>,
+	QueryKind: QueryKindTrait<Value, GetDefault>,
+{
+	/// Insert a map entry.
+	fn insert(k: Key, v: Value) {
+		let bound = B::get();
+		let mut current_index = CurrentIndex::get();
+
+		// Adding one here as bound denotes number of items but our index starts with zero.
+		if (current_index + Index::one()) >= bound {
+			current_index = Index::zero();
+		} else {
+			current_index = current_index + Index::one();
+		}
+
+		// Deleting earlier entry if it exists
+		if Intermediate::contains_key(current_index) {
+			let older_key = Intermediate::get(current_index);
+			M::remove(older_key);
+		}
+
+		Intermediate::insert(current_index, k.clone());
+		CurrentIndex::set(current_index);
+		M::insert(k, v);
+	}
+
+	/// Check if map contains a key
+	fn contains_key(k: Key) -> bool {
+		M::contains_key(k)
+	}
+
+	/// Get the value associated with key
+	fn get(k: Key) -> M::Query {
+		M::get(k)
+	}
+}