Allow Closed pools to be opened

docs/changelog_for_devs.md

@@ -1,3 +1,10 @@
+# v0.3.5
+
+- Added `Initialized` status for pools. A pool now starts in `Initialized`
+  status and must be opened using `Swaps::open_pool`. While the pool is
+  `Initialized`, it is allowed to call `pool_join` and `pool_exit`, but trading
+  and single-asset operations are prohibited.
+
 # v0.3.4
 
 - Implemented swap fees for CPMM pools. This means that the following extrinsics

misc/types.json

@@ -288,7 +288,9 @@
     "_enum": [
       "Active",
       "CollectingSubsidy",
-      "Stale"
+      "Closed",
+      "Clean",
+      "Initialized"
     ]
   },
   "RegistrationInfo": {

primitives/src/pool_status.rs

@@ -23,4 +23,6 @@ pub enum PoolStatus {
     Closed,
     /// The pool has been cleaned up, usually after the corresponding market has been resolved.
     Clean,
+    /// The pool has just been created.
+    Initialized,
 }

primitives/src/traits/swaps.rs

@@ -58,6 +58,8 @@ pub trait Swaps<AccountId> {
     /// * `pool_id`: Unique pool identifier associated with the pool to be destroyed.
     fn destroy_pool_in_subsidy_phase(pool_id: PoolId) -> Result<Weight, DispatchError>;
 
+    fn open_pool(pool_id: PoolId) -> Result<Weight, DispatchError>;
+
     /// Pool - Exit with exact pool amount
     ///
     /// Takes an asset from `pool_id` and transfers to `origin`. Differently from `pool_exit`,

zrml/prediction-markets/src/lib.rs

@@ -646,6 +646,7 @@ mod pallet {
                 Some(amount),
                 Some(weights),
             )?;
+            T::Swaps::open_pool(pool_id)?;
 
             // This errors if a pool already exists!
             T::MarketCommons::insert_market_pool(market_id, pool_id)?;

zrml/swaps/src/benchmarks.rs

@@ -106,6 +106,10 @@ fn bench_create_pool<T: Config>(
     .unwrap();
     let pool_id = <NextPoolId<T>>::get() - 1;
 
+    if scoring_rule == ScoringRule::CPMM {
+        let _ = Pallet::<T>::open_pool(pool_id);
+    }
+
     if subsidize {
         let min_subsidy = T::MinSubsidy::get();
         T::Shares::deposit(base_asset, &caller, min_subsidy).unwrap();

zrml/swaps/src/lib.rs

@@ -370,9 +370,12 @@ mod pallet {
         ) -> DispatchResultWithPostInfo {
             let who = ensure_signed(origin)?;
             let pool = Self::pool_by_id(pool_id)?;
+            ensure!(
+                matches!(pool.pool_status, PoolStatus::Initialized | PoolStatus::Active),
+                Error::<T>::InvalidPoolStatus,
+            );
             let pool_account_id = Pallet::<T>::pool_account_id(pool_id);
 
-            Self::check_if_pool_is_active(&pool)?;
             let params = PoolParams {
                 asset_bounds: max_assets_in,
                 event: |evt| Self::deposit_event(Event::PoolJoin(evt)),
@@ -765,6 +768,8 @@ mod pallet {
         InvalidAmountArgument,
         /// Could not create CPMM pool since no fee was supplied.
         InvalidFeeArgument,
+        /// Dispatch called on pool with invalid status.
+        InvalidPoolStatus,
         /// A function that is only valid for pools with specific scoring rules was called for a
         /// pool with another scoring rule.
         InvalidScoringRule,
@@ -846,6 +851,8 @@ mod pallet {
         PoolClosed(PoolId),
         /// A pool was cleaned up. \[pool_id\]
         PoolCleanedUp(PoolId),
+        /// A pool was opened. \[pool_id\]
+        PoolActive(PoolId),
         /// Someone has exited a pool. \[PoolAssetsEvent\]
         PoolExit(
             PoolAssetsEvent<
@@ -1412,7 +1419,7 @@ mod pallet {
                         );
                         T::Shares::deposit(pool_shares_id, &who, amount_unwrapped)?;
 
-                        let pool_status = PoolStatus::Active;
+                        let pool_status = PoolStatus::Initialized;
                         let total_subsidy = None;
                         let total_weight = Some(total_weight);
                         let weights = Some(map);
@@ -1667,6 +1674,20 @@ mod pallet {
             })
         }
 
+        fn open_pool(pool_id: PoolId) -> Result<Weight, DispatchError> {
+            Self::mutate_pool(pool_id, |pool| {
+                ensure!(
+                    pool.pool_status == PoolStatus::Initialized,
+                    Error::<T>::InvalidStateTransition
+                );
+                pool.pool_status = PoolStatus::Active;
+                Ok(())
+            })?;
+            Self::deposit_event(Event::PoolActive(pool_id));
+            // TODO(#603): Fix weight calculation!
+            Ok(T::DbWeight::get().reads_writes(1, 1))
+        }
+
         /// Pool - Exit with exact pool amount
         ///
         /// Takes an asset from `pool_id` and transfers to `origin`. Differently from `pool_exit`,