Liquidity pool withdraw operation

[sschiessl-bcp]

In the operation

bitshares-core/libraries/protocol/include/graphene/protocol/liquidity_pool.hpp

Lines 94 to 107 in a06a712

	struct liquidity_pool_withdraw_operation : public base_operation
	{
	struct fee_parameters_type { uint64_t fee = 5 * GRAPHENE_BLOCKCHAIN_PRECISION; };
	asset fee; ///< Operation fee
	account_id_type account; ///< The account who withdraws from the liquidity pool
	liquidity_pool_id_type pool; ///< ID of the liquidity pool
	asset share_amount; ///< The amount of the share asset to use
	extensions_type extensions; ///< Unused. Reserved for future use.
	account_id_type fee_payer()const { return account; }
	void validate()const;
	};

How do I know how much of asset_a and asset_b does the account get?

[litepresence]

1.2.xxx
withdrew i TWENTIX
and withdrew j HONEST.USD
from liquidity pool contract 1.19.xxx
by burning an equivalent value of k TWENTIX.HUSDMM

share_amount in your transaction sent TO core is the k

you get the i and j amounts back in response FROM core as the receipt

[abitmore]

@sschiessl-bcp please check

bitshares-core/libraries/chain/liquidity_pool_evaluator.cpp

Lines 240 to 261 in a06a712

	if( _share_asset_dyn_data->current_supply == op.share_amount.amount )
	{
	_pool_pays_a = asset( _pool->balance_a, _pool->asset_a );
	_pool_pays_b = asset( _pool->balance_b, _pool->asset_b );
	}
	else
	{
	fc::uint128_t share128( op.share_amount.amount.value );
	fc::uint128_t a128 = share128 * _pool->balance_a.value / _share_asset_dyn_data->current_supply.value;
	FC_ASSERT( a128 < fc::uint128_t( _pool->balance_a.value ), "Internal error" );
	fc::uint128_t fee_a = a128 * _pool->withdrawal_fee_percent / GRAPHENE_100_PERCENT;
	FC_ASSERT( fee_a <= a128, "Withdrawal fee percent of the pool is too high" );
	a128 -= fee_a;
	fc::uint128_t b128 = share128 * _pool->balance_b.value / _share_asset_dyn_data->current_supply.value;
	FC_ASSERT( b128 < fc::uint128_t( _pool->balance_b.value ), "Internal error" );
	fc::uint128_t fee_b = b128 * _pool->withdrawal_fee_percent / GRAPHENE_100_PERCENT;
	FC_ASSERT( fee_b <= b128, "Withdrawal fee percent of the pool is too high" );
	b128 -= fee_b;
	FC_ASSERT( a128 > 0 || b128 > 0, "Aborting due to zero outcome" );
	_pool_pays_a = asset( static_cast<int64_t>( a128 ), _pool->asset_a );
	_pool_pays_b = asset( static_cast<int64_t>( b128 ), _pool->asset_b );
	}

[sschiessl-bcp]

I can only redo that calculation if I have the pool state at the time of execution of this operation, can't I?

When doing historical analysis or simple presentation in the explorer I find that unrealistic.

Would it be possible to add more data to the op in account history?

[abitmore]

@sschiessl-bcp they ARE in the account history. Please check operation_results. E.G.

locked >>> get_account_history bitcrab 20
...
56586482 2021-03-12T09:03:51 liquidity_pool_exchange_operation bitcrab fee: 1 BTS result: {"paid":[{"amount":1800000000,"asset_id":"1.3.5286"}],"received":[{"amount":500837540,"asset_id":"1.3.5925"}],"fees":[{"amount":1800000,"asset_id":"1.3.5286"},{"amount":1003682,"asset_id":"1.3.5925"},{"amount":1005693,"asset_id":"1.3.5925"}]}
56586457 2021-03-12T09:02:36 liquidity_pool_withdraw_operation bitcrab fee: 5 BTS result: {"paid":[{"amount":"80000000000","asset_id":"1.3.5921"}],"received":[{"amount":"2180064252","asset_id":"1.3.2635"},{"amount":"85479088347","asset_id":"1.3.5286"}],"fees":[{"amount":6559872,"asset_id":"1.3.2635"},{"amount":257208891,"asset_id":"1.3.5286"}]}

BTW I think what you want is #2380.

[sschiessl-bcp]

@sschiessl-bcp they ARE in the account history. Please check operation_results. E.G.

locked >>> get_account_history bitcrab 20
...
56586482 2021-03-12T09:03:51 liquidity_pool_exchange_operation bitcrab fee: 1 BTS result: {"paid":[{"amount":1800000000,"asset_id":"1.3.5286"}],"received":[{"amount":500837540,"asset_id":"1.3.5925"}],"fees":[{"amount":1800000,"asset_id":"1.3.5286"},{"amount":1003682,"asset_id":"1.3.5925"},{"amount":1005693,"asset_id":"1.3.5925"}]}
56586457 2021-03-12T09:02:36 liquidity_pool_withdraw_operation bitcrab fee: 5 BTS result: {"paid":[{"amount":"80000000000","asset_id":"1.3.5921"}],"received":[{"amount":"2180064252","asset_id":"1.3.2635"},{"amount":"85479088347","asset_id":"1.3.5286"}],"fees":[{"amount":6559872,"asset_id":"1.3.2635"},{"amount":257208891,"asset_id":"1.3.5286"}]}

BTW I think what you want is #2380.

I did not look there thx a lot!