Use BoundedBTreeMap in neo-swaps Pool struct

zrml/neo-swaps/src/lib.rs

@@ -38,11 +38,11 @@ pub use pallet::*;
 #[frame_support::pallet]
 mod pallet {
     use crate::{
-        consts::{LN_NUMERICAL_LIMIT, MAX_ASSETS},
+        consts::LN_NUMERICAL_LIMIT,
         liquidity_tree::types::{BenchmarkInfo, LiquidityTree, LiquidityTreeError},
         math::{Math, MathOps},
         traits::{pool_operations::PoolOperations, LiquiditySharesManager},
-        types::{FeeDistribution, Pool},
+        types::{FeeDistribution, MaxAssets, Pool},
         weights::*,
     };
     use alloc::{collections::BTreeMap, vec, vec::Vec};
@@ -99,7 +99,7 @@ mod pallet {
     pub(crate) type MarketIdOf<T> =
         <<T as Config>::MarketCommons as MarketCommonsPalletApi>::MarketId;
     pub(crate) type LiquidityTreeOf<T> = LiquidityTree<T, <T as Config>::MaxLiquidityTreeDepth>;
-    pub(crate) type PoolOf<T> = Pool<T, LiquidityTreeOf<T>>;
+    pub(crate) type PoolOf<T> = Pool<T, LiquidityTreeOf<T>, MaxAssets>;
 
     #[pallet::config]
     pub trait Config: frame_system::Config {
@@ -833,7 +833,7 @@ mod pallet {
             ensure!(market.scoring_rule == ScoringRule::Lmsr, Error::<T>::InvalidTradingMechanism);
             let asset_count = spot_prices.len();
             ensure!(asset_count as u16 == market.outcomes(), Error::<T>::IncorrectVecLen);
-            ensure!(market.outcomes() <= MAX_ASSETS, Error::<T>::AssetCountAboveMax);
+            ensure!(market.outcomes() as u32 <= MaxAssets::get(), Error::<T>::AssetCountAboveMax);
             ensure!(swap_fee >= MIN_SWAP_FEE.saturated_into(), Error::<T>::SwapFeeBelowMin);
             ensure!(swap_fee <= T::MaxSwapFee::get(), Error::<T>::SwapFeeAboveMax);
             ensure!(
@@ -869,7 +869,7 @@ mod pallet {
             let collateral = market.base_asset;
             let pool = Pool {
                 account_id: pool_account_id.clone(),
-                reserves: reserves.clone(),
+                reserves: reserves.clone().try_into().map_err(|_| Error::<T>::Unexpected)?,
                 collateral,
                 liquidity_parameter,
                 liquidity_shares_manager: LiquidityTree::new(who.clone(), amount)?,

zrml/neo-swaps/src/tests/sell.rs

@@ -267,7 +267,7 @@ fn sell_fails_if_price_is_too_low() {
         // speaking this leaves the pool in an inconsistent state (reserve recorded in the `Pool`
         // struct is smaller than actual reserve), but this doesn't matter in this test.
         NeoSwaps::try_mutate_pool(&market_id, |pool| {
-            pool.reserves.insert(asset_in, 11 * pool.liquidity_parameter);
+            pool.reserves.try_insert(asset_in, 11 * pool.liquidity_parameter).unwrap();
             Ok(())
         })
         .unwrap();
@@ -306,7 +306,7 @@ fn sell_fails_if_price_is_pushed_below_threshold() {
         NeoSwaps::try_mutate_pool(&market_id, |pool| {
             // The price is right at the brink here. Any further shift and sells won't be accepted
             // anymore.
-            pool.reserves.insert(asset_in, 10 * pool.liquidity_parameter);
+            pool.reserves.try_insert(asset_in, 10 * pool.liquidity_parameter).unwrap();
             Ok(())
         })
         .unwrap();

zrml/neo-swaps/src/types/max_assets.rs

@@ -0,0 +1,26 @@
+// Copyright 2023-2024 Forecasting Technologies LTD.
+//
+// This file is part of Zeitgeist.
+//
+// Zeitgeist is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at
+// your option) any later version.
+//
+// Zeitgeist is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Zeitgeist. If not, see <https://www.gnu.org/licenses/>.
+
+use sp_runtime::traits::Get;
+
+pub(crate) struct MaxAssets;
+
+impl Get<u32> for MaxAssets {
+    fn get() -> u32 {
+        128
+    }
+}

zrml/neo-swaps/src/types/mod.rs

@@ -16,7 +16,9 @@
 // along with Zeitgeist. If not, see <https://www.gnu.org/licenses/>.
 
 mod fee_distribution;
+mod max_assets;
 mod pool;
 
 pub(crate) use fee_distribution::*;
+pub(crate) use max_assets::*;
 pub(crate) use pool::*;

zrml/neo-swaps/src/types/pool.rs

@@ -16,37 +16,43 @@
 // along with Zeitgeist. If not, see <https://www.gnu.org/licenses/>.
 
 use crate::{
-    consts::{EXP_NUMERICAL_LIMIT, MAX_ASSETS},
+    consts::EXP_NUMERICAL_LIMIT,
     math::{Math, MathOps},
     pallet::{AssetOf, BalanceOf, Config},
     traits::{LiquiditySharesManager, PoolOperations},
     Error,
 };
-use alloc::{collections::BTreeMap, vec::Vec};
+use alloc::vec::Vec;
+use frame_support::{storage::bounded_btree_map::BoundedBTreeMap, CloneNoBound};
 use parity_scale_codec::{Decode, Encode, MaxEncodedLen};
 use scale_info::TypeInfo;
 use sp_runtime::{
-    traits::{CheckedAdd, CheckedSub},
+    traits::{CheckedAdd, CheckedSub, Get},
     DispatchError, DispatchResult, RuntimeDebug, SaturatedConversion, Saturating,
 };
 
-#[derive(Clone, Decode, Encode, Eq, PartialEq, RuntimeDebug, TypeInfo)]
-#[scale_info(skip_type_params(T))]
-pub struct Pool<T: Config, LSM>
+#[derive(CloneNoBound, Decode, Encode, Eq, MaxEncodedLen, PartialEq, RuntimeDebug, TypeInfo)]
+#[scale_info(skip_type_params(S, T))]
+pub struct Pool<T, LSM, S>
 where
-    LSM: LiquiditySharesManager<T>,
+    T: Config,
+    LSM: Clone + LiquiditySharesManager<T>,
+    S: Get<u32>,
 {
     pub account_id: T::AccountId,
-    pub reserves: BTreeMap<AssetOf<T>, BalanceOf<T>>,
+    pub reserves: BoundedBTreeMap<AssetOf<T>, BalanceOf<T>, S>,
     pub collateral: AssetOf<T>,
     pub liquidity_parameter: BalanceOf<T>,
     pub liquidity_shares_manager: LSM,
     pub swap_fee: BalanceOf<T>,
 }
 
-impl<T: Config, LSM: LiquiditySharesManager<T> + TypeInfo> PoolOperations<T> for Pool<T, LSM>
+impl<T, LSM, S> PoolOperations<T> for Pool<T, LSM, S>
 where
+    T: Config,
     BalanceOf<T>: SaturatedConversion,
+    LSM: Clone + LiquiditySharesManager<T> + TypeInfo,
+    S: Get<u32>,
 {
     fn assets(&self) -> Vec<AssetOf<T>> {
         self.reserves.keys().cloned().collect()
@@ -117,30 +123,3 @@ where
         Math::<T>::calculate_buy_ln_argument(reserve, amount_in, self.liquidity_parameter)
     }
 }
-
-// TODO(#1214): Replace BTreeMap with BoundedBTreeMap and remove the unnecessary `MaxEncodedLen`
-// implementation.
-impl<T: Config, LSM: LiquiditySharesManager<T>> MaxEncodedLen for Pool<T, LSM>
-where
-    T::AccountId: MaxEncodedLen,
-    AssetOf<T>: MaxEncodedLen,
-    BalanceOf<T>: MaxEncodedLen,
-    LSM: MaxEncodedLen,
-{
-    fn max_encoded_len() -> usize {
-        let len_account_id = T::AccountId::max_encoded_len();
-        let len_reserves = 1usize.saturating_add((MAX_ASSETS as usize).saturating_mul(
-            <AssetOf<T>>::max_encoded_len().saturating_add(BalanceOf::<T>::max_encoded_len()),
-        ));
-        let len_collateral = AssetOf::<T>::max_encoded_len();
-        let len_liquidity_parameter = BalanceOf::<T>::max_encoded_len();
-        let len_liquidity_shares_manager = LSM::max_encoded_len();
-        let len_swap_fee = BalanceOf::<T>::max_encoded_len();
-        len_account_id
-            .saturating_add(len_reserves)
-            .saturating_add(len_collateral)
-            .saturating_add(len_liquidity_parameter)
-            .saturating_add(len_liquidity_shares_manager)
-            .saturating_add(len_swap_fee)
-    }
-}