inputs.js
function pickMultipleCoinsAndContinue(){
		conn.query(
			"SELECT unit, message_index, output_index, amount, address, blinding \n\
			FROM outputs \n\
			CROSS JOIN units USING(unit) \n\
			WHERE address IN(?) AND asset"+(asset ? "="+conn.escape(asset) : " IS NULL")+" AND is_spent=0 \n\
				AND sequence='good' "+confirmation_condition+"  \n\
			ORDER BY amount DESC LIMIT ?",
			[arrSpendableAddresses, constants.MAX_INPUTS_PER_PAYMENT_MESSAGE-2],
			function(rows){
				async.eachSeries(
					rows,
					function(row, cb){
						var input = row;
						objectHash.cleanNulls(input);
						required_amount += is_base*TRANSFER_INPUT_SIZE;
						addInput(input);
						// if we allow equality, we might get 0 amount for change which is invalid
						var bFound = is_base ? (total_amount > required_amount) : (total_amount >= required_amount);
						bFound ? cb('found') : cb();
					},
					function(err){
						if (err === 'found')
							onDone(arrInputsWithProofs, total_amount);
						else if (asset)
							issueAsset();
						else
							addHeadersCommissionInputs();
					}
				);
			}
		);
	}
function pickMultipleCoinsAndContinue(){
		conn.query(
			"SELECT unit, message_index, output_index, amount, address, blinding \n\
			FROM outputs \n\
			CROSS JOIN units USING(unit) \n\
			WHERE address IN(?) AND asset"+(asset ? "="+conn.escape(asset) : " IS NULL")+" AND is_spent=0 \n\
				AND sequence='good' "+confirmation_condition+"  \n\
			ORDER BY amount DESC LIMIT ?",
			[arrSpendableAddresses, constants.MAX_INPUTS_PER_PAYMENT_MESSAGE-2],
			function(rows){
				async.eachSeries(
					rows,
					function(row, cb){
						var input = row;
						objectHash.cleanNulls(input);
						required_amount += is_base*TRANSFER_INPUT_SIZE;
						addInput(input);
						// if we allow equality, we might get 0 amount for change which is invalid
						var bFound = is_base ? (total_amount > required_amount) : (total_amount >= required_amount);
						bFound ? cb('found') : cb();
					},
					function(err){
						if (err === 'found')
							onDone(arrInputsWithProofs, total_amount);
						else if (asset)
							issueAsset();
						else
							addHeadersCommissionInputs();
					}
				);
			}
		);
	}
function pickMultipleCoinsAndContinue ( ) { conn . query ( "SELECT unit, message_index, output_index, amount, address, blinding \n\
			FROM outputs \n\
			CROSS JOIN units USING(unit) \n\
			WHERE address IN(?) AND asset" + ( asset ? "=" + conn . escape ( asset ) : " IS NULL" ) + " AND is_spent=0 \n\
				AND sequence='good' " + confirmation_condition + "  \n\
			ORDER BY amount DESC LIMIT ?" , [ arrSpendableAddresses , constants . MAX_INPUTS_PER_PAYMENT_MESSAGE - 2 ] , function ( rows ) { async . eachSeries ( rows , function ( row , cb ) { var input = row ; objectHash . cleanNulls ( input ) ; required_amount += is_base * TRANSFER_INPUT_SIZE ; addInput ( input ) ; // if we allow equality, we might get 0 amount for change which is invalid var bFound = is_base ? ( total_amount > required_amount ) : ( total_amount >= required_amount ) ; bFound ? cb ( 'found' ) : cb ( ) ; } , function ( err ) { if ( err === 'found' ) onDone ( arrInputsWithProofs , total_amount ) ; else if ( asset ) issueAsset ( ) ; else addHeadersCommissionInputs ( ) ; } ) ; } ) ; }
then, try to add smaller coins until we accumulate the target amount
then try to add smaller coins until we accumulate the target amount