Merge pull request #2261 from abitmore/liquidity-pool

Implement liquidity pool

libraries/app/application.cpp

@@ -326,6 +326,9 @@ void application_impl::set_api_limit() {
    if(_options->count("api-limit-get-withdraw-permissions-by-recipient")) {
       _app_options.api_limit_get_withdraw_permissions_by_recipient = _options->at("api-limit-get-withdraw-permissions-by-recipient").as<uint64_t>();
    }
+   if(_options->count("api-limit-get-liquidity-pools")) {
+      _app_options.api_limit_get_liquidity_pools = _options->at("api-limit-get-liquidity-pools").as<uint64_t>();
+   }
 }
 
 void application_impl::startup()
@@ -1054,6 +1057,8 @@ void application::set_program_options(boost::program_options::options_descriptio
           "For database_api_impl::get_withdraw_permissions_by_giver to set max limit value")
          ("api-limit-get-withdraw-permissions-by-recipient",boost::program_options::value<uint64_t>()->default_value(101),
           "For database_api_impl::get_withdraw_permissions_by_recipient to set max limit value")
+         ("api-limit-get-liquidity-pools",boost::program_options::value<uint64_t>()->default_value(101),
+          "For database_api_impl::get_liquidity_pools_* to set max limit value")
          ;
    command_line_options.add(configuration_file_options);
    command_line_options.add_options()

libraries/app/database_api.cpp

@@ -1736,6 +1736,141 @@ vector<market_trade> database_api_impl::get_trade_history_by_sequence(
    return result;
 }
 
+//////////////////////////////////////////////////////////////////////
+//                                                                  //
+// Liquidity pools                                                  //
+//                                                                  //
+//////////////////////////////////////////////////////////////////////
+
+vector<liquidity_pool_object> database_api::get_liquidity_pools_by_asset_a(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit,
+            optional<liquidity_pool_id_type> start_id )const
+{
+   return my->get_liquidity_pools_by_asset_a(
+            asset_symbol_or_id,
+            limit,
+            start_id );
+}
+
+vector<liquidity_pool_object> database_api_impl::get_liquidity_pools_by_asset_a(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit,
+            optional<liquidity_pool_id_type> start_id )const
+{
+   return get_liquidity_pools_by_asset_x<by_asset_a>(
+            asset_symbol_or_id,
+            limit,
+            start_id );
+}
+
+vector<liquidity_pool_object> database_api::get_liquidity_pools_by_asset_b(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit,
+            optional<liquidity_pool_id_type> start_id )const
+{
+   return my->get_liquidity_pools_by_asset_b(
+            asset_symbol_or_id,
+            limit,
+            start_id );
+}
+
+vector<liquidity_pool_object> database_api_impl::get_liquidity_pools_by_asset_b(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit,
+            optional<liquidity_pool_id_type> start_id )const
+{
+   return get_liquidity_pools_by_asset_x<by_asset_b>(
+            asset_symbol_or_id,
+            limit,
+            start_id );
+}
+
+vector<liquidity_pool_object> database_api::get_liquidity_pools_by_both_assets(
+            std::string asset_symbol_or_id_a,
+            std::string asset_symbol_or_id_b,
+            optional<uint32_t> limit,
+            optional<liquidity_pool_id_type> start_id )const
+{
+   return my->get_liquidity_pools_by_both_assets(
+            asset_symbol_or_id_a,
+            asset_symbol_or_id_b,
+            limit,
+            start_id );
+}
+
+vector<liquidity_pool_object> database_api_impl::get_liquidity_pools_by_both_assets(
+            std::string asset_symbol_or_id_a,
+            std::string asset_symbol_or_id_b,
+            optional<uint32_t> olimit,
+            optional<liquidity_pool_id_type> ostart_id )const
+{
+   uint32_t limit = olimit.valid() ? *olimit : 101;
+
+   FC_ASSERT( _app_options, "Internal error" );
+   const auto configured_limit = _app_options->api_limit_get_liquidity_pools;
+   FC_ASSERT( limit <= configured_limit,
+              "limit can not be greater than ${configured_limit}",
+              ("configured_limit", configured_limit) );
+
+   vector<liquidity_pool_object> results;
+
+   asset_id_type asset_id_a = get_asset_from_string(asset_symbol_or_id_a)->id;
+   asset_id_type asset_id_b = get_asset_from_string(asset_symbol_or_id_b)->id;
+   if( asset_id_a > asset_id_b )
+      std::swap( asset_id_a, asset_id_b );
+
+   liquidity_pool_id_type start_id = ostart_id.valid() ? *ostart_id : liquidity_pool_id_type();
+
+   const auto& idx = _db.get_index_type<liquidity_pool_index>().indices().get<by_asset_ab>();
+   auto lower_itr = idx.lower_bound( std::make_tuple( asset_id_a, asset_id_b, start_id ) );
+   auto upper_itr = idx.upper_bound( std::make_tuple( asset_id_a, asset_id_b ) );
+
+   results.reserve( limit );
+   uint32_t count = 0;
+   for ( ; lower_itr != upper_itr && count < limit; ++lower_itr, ++count)
+   {
+      results.emplace_back( *lower_itr );
+   }
+
+   return results;
+}
+
+vector<optional<liquidity_pool_object>> database_api::get_liquidity_pools_by_share_asset(
+            const vector<std::string>& asset_symbols_or_ids,
+            optional<bool> subscribe )const
+{
+   return my->get_liquidity_pools_by_share_asset(
+            asset_symbols_or_ids,
+            subscribe );
+}
+
+vector<optional<liquidity_pool_object>> database_api_impl::get_liquidity_pools_by_share_asset(
+            const vector<std::string>& asset_symbols_or_ids,
+            optional<bool> subscribe )const
+{
+   FC_ASSERT( _app_options, "Internal error" );
+   const auto configured_limit = _app_options->api_limit_get_liquidity_pools;
+   FC_ASSERT( asset_symbols_or_ids.size() <= configured_limit,
+              "size of the querying list can not be greater than ${configured_limit}",
+              ("configured_limit", configured_limit) );
+
+   bool to_subscribe = get_whether_to_subscribe( subscribe );
+   vector<optional<liquidity_pool_object>> result; result.reserve(asset_symbols_or_ids.size());
+   std::transform(asset_symbols_or_ids.begin(), asset_symbols_or_ids.end(), std::back_inserter(result),
+                  [this,to_subscribe](std::string id_or_name) -> optional<liquidity_pool_object> {
+
+      const asset_object* asset_obj = get_asset_from_string( id_or_name, false );
+      if( asset_obj == nullptr || !asset_obj->is_liquidity_pool_share_asset() )
+         return {};
+      const liquidity_pool_object& lp_obj = (*asset_obj->for_liquidity_pool)(_db);
+      if( to_subscribe )
+         subscribe_to_item( lp_obj.id );
+      return lp_obj;
+   });
+   return result;
+}
+
 //////////////////////////////////////////////////////////////////////
 //                                                                  //
 // Witnesses                                                        //

libraries/app/database_api_impl.hxx

@@ -138,6 +138,24 @@ class database_api_impl : public std::enable_shared_from_this<database_api_impl>
                                                                         int64_t start, fc::time_point_sec stop,
                                                                         unsigned limit = 100 )const;
 
+      // Liquidity pools
+      vector<liquidity_pool_object> get_liquidity_pools_by_asset_a(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit = 101,
+            optional<liquidity_pool_id_type> start_id = optional<liquidity_pool_id_type>() )const;
+      vector<liquidity_pool_object> get_liquidity_pools_by_asset_b(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit = 101,
+            optional<liquidity_pool_id_type> start_id = optional<liquidity_pool_id_type>() )const;
+      vector<liquidity_pool_object> get_liquidity_pools_by_both_assets(
+            std::string asset_symbol_or_id_a,
+            std::string asset_symbol_or_id_b,
+            optional<uint32_t> limit = 101,
+            optional<liquidity_pool_id_type> start_id = optional<liquidity_pool_id_type>() )const;
+      vector<optional<liquidity_pool_object>> get_liquidity_pools_by_share_asset(
+            const vector<std::string>& asset_symbols_or_ids,
+            optional<bool> subscribe = optional<bool>() )const;
+
       // Witnesses
       vector<optional<witness_object>> get_witnesses(const vector<witness_id_type>& witness_ids)const;
       fc::optional<witness_object> get_witness_by_account(const std::string account_id_or_name)const;
@@ -239,6 +257,45 @@ class database_api_impl : public std::enable_shared_from_this<database_api_impl>
       vector<limit_order_object> get_limit_orders( const asset_id_type a, const asset_id_type b,
                                                    const uint32_t limit )const;
 
+      ////////////////////////////////////////////////
+      // Liquidity pools
+      ////////////////////////////////////////////////
+
+      // template function to reduce duplicate code
+      template <typename X>
+      vector<liquidity_pool_object> get_liquidity_pools_by_asset_x(
+                  std::string asset_symbol_or_id,
+                  optional<uint32_t> olimit,
+                  optional<liquidity_pool_id_type> ostart_id )const
+      {
+         uint32_t limit = olimit.valid() ? *olimit : 101;
+
+         FC_ASSERT( _app_options, "Internal error" );
+         const auto configured_limit = _app_options->api_limit_get_liquidity_pools;
+         FC_ASSERT( limit <= configured_limit,
+                    "limit can not be greater than ${configured_limit}",
+                    ("configured_limit", configured_limit) );
+
+         vector<liquidity_pool_object> results;
+
+         const asset_id_type asset_id = get_asset_from_string(asset_symbol_or_id)->id;
+
+         liquidity_pool_id_type start_id = ostart_id.valid() ? *ostart_id : liquidity_pool_id_type();
+
+         const auto& idx = _db.get_index_type<liquidity_pool_index>().indices().get<X>();
+         auto lower_itr = idx.lower_bound( std::make_tuple( asset_id, start_id ) );
+         auto upper_itr = idx.upper_bound( asset_id );
+
+         results.reserve( limit );
+         uint32_t count = 0;
+         for ( ; lower_itr != upper_itr && count < limit; ++lower_itr, ++count)
+         {
+            results.emplace_back( *lower_itr );
+         }
+
+         return results;
+      }
+
       ////////////////////////////////////////////////
       // Subscription
       ////////////////////////////////////////////////

libraries/app/include/graphene/app/application.hpp

@@ -72,6 +72,7 @@ namespace graphene { namespace app {
          uint64_t api_limit_get_trade_history_by_sequence = 100;
          uint64_t api_limit_get_withdraw_permissions_by_giver = 101;
          uint64_t api_limit_get_withdraw_permissions_by_recipient = 101;
+         uint64_t api_limit_get_liquidity_pools = 101;
    };
 
    class application

libraries/app/include/graphene/app/database_api.hpp

@@ -33,6 +33,7 @@
 #include <graphene/chain/chain_property_object.hpp>
 #include <graphene/chain/committee_member_object.hpp>
 #include <graphene/chain/confidential_object.hpp>
+#include <graphene/chain/liquidity_pool_object.hpp>
 #include <graphene/chain/operation_history_object.hpp>
 #include <graphene/chain/worker_object.hpp>
 #include <graphene/chain/witness_object.hpp>
@@ -118,6 +119,7 @@ class database_api
        * - lookup_accounts
        * - get_full_accounts
        * - get_htlc
+       * - get_liquidity_pools_by_share_asset
        *
        * Note: auto-subscription is enabled by default
        *
@@ -625,6 +627,81 @@ class database_api
                                                           unsigned limit = 100 )const;
 
 
+      /////////////////////
+      // Liquidity pools //
+      /////////////////////
+
+      /**
+       * @brief Get a list of liquidity pools by the symbol or ID of the first asset in the pool
+       * @param asset_symbol_or_id symbol name or ID of the asset
+       * @param limit  The limitation of items each query can fetch, not greater than a configured value
+       * @param start_id  Start liquidity pool id, fetch pools whose IDs are greater than or equal to this ID
+       * @return The liquidity pools
+       *
+       * @note
+       * 1. if @p asset_symbol_or_id cannot be tied to an asset, an error will be returned
+       * 2. @p limit can be omitted or be null, if so the default value 101 will be used
+       * 3. @p start_id can be omitted or be null, if so the api will return the "first page" of pools
+       * 4. can only omit one or more arguments in the end of the list, but not one or more in the middle
+       */
+      vector<liquidity_pool_object> get_liquidity_pools_by_asset_a(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit = 101,
+            optional<liquidity_pool_id_type> start_id = optional<liquidity_pool_id_type>() )const;
+
+      /**
+       * @brief Get a list of liquidity pools by the symbol or ID of the second asset in the pool
+       * @param asset_symbol_or_id symbol name or ID of the asset
+       * @param limit  The limitation of items each query can fetch, not greater than a configured value
+       * @param start_id  Start liquidity pool id, fetch pools whose IDs are greater than or equal to this ID
+       * @return The liquidity pools
+       *
+       * @note
+       * 1. if @p asset_symbol_or_id cannot be tied to an asset, an error will be returned
+       * 2. @p limit can be omitted or be null, if so the default value 101 will be used
+       * 3. @p start_id can be omitted or be null, if so the api will return the "first page" of pools
+       * 4. can only omit one or more arguments in the end of the list, but not one or more in the middle
+       */
+      vector<liquidity_pool_object> get_liquidity_pools_by_asset_b(
+            std::string asset_symbol_or_id,
+            optional<uint32_t> limit = 101,
+            optional<liquidity_pool_id_type> start_id = optional<liquidity_pool_id_type>() )const;
+
+      /**
+       * @brief Get a list of liquidity pools by the symbols or IDs of the two assets in the pool
+       * @param asset_symbol_or_id_a symbol name or ID of one asset
+       * @param asset_symbol_or_id_b symbol name or ID of the other asset
+       * @param limit  The limitation of items each query can fetch, not greater than a configured value
+       * @param start_id  Start liquidity pool id, fetch pools whose IDs are greater than or equal to this ID
+       * @return The liquidity pools
+       *
+       * @note
+       * 1. if @p asset_symbol_or_id_a or @p asset_symbol_or_id_b cannot be tied to an asset,
+       *    an error will be returned
+       * 2. @p limit can be omitted or be null, if so the default value 101 will be used
+       * 3. @p start_id can be omitted or be null, if so the api will return the "first page" of pools
+       * 4. can only omit one or more arguments in the end of the list, but not one or more in the middle
+       */
+      vector<liquidity_pool_object> get_liquidity_pools_by_both_assets(
+            std::string asset_symbol_or_id_a,
+            std::string asset_symbol_or_id_b,
+            optional<uint32_t> limit = 101,
+            optional<liquidity_pool_id_type> start_id = optional<liquidity_pool_id_type>() )const;
+
+      /**
+       * @brief Get a list of liquidity pools by their share asset symbols or IDs
+       * @param asset_symbols_or_ids symbol names or IDs of the share assets
+       * @param subscribe @a true to subscribe to the queried objects; @a false to not subscribe;
+       *                  @a null to subscribe or not subscribe according to current auto-subscription setting
+       *                  (see @ref set_auto_subscription)
+       * @return The liquidity pools that the assets are for
+       *
+       * @note if an asset in the list can not be found or is not a share asset of any liquidity pool,
+       *       the corresponding data in the returned list is null.
+       */
+      vector<optional<liquidity_pool_object>> get_liquidity_pools_by_share_asset(
+            const vector<std::string>& asset_symbols_or_ids,
+            optional<bool> subscribe = optional<bool>() )const;
 
       ///////////////
       // Witnesses //
@@ -996,6 +1073,12 @@ FC_API(graphene::app::database_api,
    (get_trade_history)
    (get_trade_history_by_sequence)
 
+   // Liquidity pools
+   (get_liquidity_pools_by_asset_a)
+   (get_liquidity_pools_by_asset_b)
+   (get_liquidity_pools_by_both_assets)
+   (get_liquidity_pools_by_share_asset)
+
    // Witnesses
    (get_witnesses)
    (get_witness_by_account)

libraries/chain/CMakeLists.txt

@@ -36,6 +36,7 @@ add_library( graphene_chain
              exceptions.cpp
 
              evaluator.cpp
+             liquidity_pool_evaluator.cpp
              balance_evaluator.cpp
              account_evaluator.cpp
              assert_evaluator.cpp

libraries/chain/asset_evaluator.cpp

@@ -290,6 +290,8 @@ void_result asset_issue_evaluator::do_evaluate( const asset_issue_operation& o )
    FC_ASSERT( o.issuer == a.issuer );
    FC_ASSERT( !a.is_market_issued(), "Cannot manually issue a market-issued asset." );
 
+   FC_ASSERT( !a.is_liquidity_pool_share_asset(), "Cannot manually issue a liquidity pool share asset." );
+
    FC_ASSERT( a.can_create_new_supply(), "Can not create new supply" );
 
    to_account = &o.issue_to_account(d);
@@ -324,11 +326,21 @@ void_result asset_reserve_evaluator::do_evaluate( const asset_reserve_operation&
       ("sym", a.symbol)
    );
 
-   from_account = &o.payer(d);
+   from_account = fee_paying_account;
    FC_ASSERT( is_authorized_asset( d, *from_account, a ) );
 
    asset_dyn_data = &a.dynamic_asset_data_id(d);
-   FC_ASSERT( (asset_dyn_data->current_supply - o.amount_to_reserve.amount) >= 0 );
+   if( !a.is_liquidity_pool_share_asset() )
+   {
+      FC_ASSERT( asset_dyn_data->current_supply >= o.amount_to_reserve.amount,
+                 "Can not reserve an amount that is more than the current supply" );
+   }
+   else
+   {
+      FC_ASSERT( asset_dyn_data->current_supply > o.amount_to_reserve.amount,
+                 "The asset is a liquidity pool share asset thus can only reserve an amount "
+                 "that is less than the current supply" );
+   }
 
    return void_result();
 } FC_CAPTURE_AND_RETHROW( (o) ) }