| SC Arguments: [Name:SC_ACTION Type:uint64 Value:'1' Name:SC_CODE Type:string Value:'' Ghost exchange interface
' Use at your own risk
' For more info visit: Ghost.trading
Function Initialize() Uint64
10 STORE("owner", SIGNER())
20 STORE("feeTo", SIGNER())
30 RETURN 0
End Function
' AFAIK you can't send both assets and dero in the same call, so the first step of the flow
' of adding liquidity is to deposit the DERO.
' DERO deposited by an address will be stored in a variable identified by the address of the
' signer.
Function Deposit_dero() Uint64
10 DIM dero_reserve as Uint64
30 IF EXISTS(ADDRESS_STRING(SIGNER())) THEN GOTO 50
40 STORE(ADDRESS_STRING(SIGNER()),0)
50 LET dero_reserve = LOAD(ADDRESS_STRING(SIGNER()))
60 STORE(ADDRESS_STRING(SIGNER()), dero_reserve + DEROVALUE())
70 RETURN 0
End Function
' Provided liquidity will be tracked using BOO tokens.
' BOO TOKENS ARE NOT ASSETS. Each account's BOO balance per token pair is stored
' inside the Smart Contract as a variable with the following schema:
' <provider_address>:BOO:<asset_address>
' The total liquidity provided by all LPs of a pair at a given moment is denominated supply.
' supply is tracked inside the Smart Contract as a variable with the following schema:
' <asset_address>:BOO
' Deposit assets & use previously deposited DERO (Deposit_dero()) at current ratio to get BOO tokens.
' {asset_address} The deposited asset's SCID
' {min_liquidity} Minimum number of BOO sender will get if total BOO supply is greater than 0.
' min_liquidity does nothing when total BOO supply is 0.
Function AddLiquidity(asset_address String, min_liquidity Uint64) Uint64
01 DIM total_liquidity, dero_reserve, asset_reserve, asset_amount, liquidity_minted, dero_deposited, asset_deposited as Uint64
02 LET dero_deposited = get_dero_deposited()
03 LET asset_deposited = ASSETVALUE(asset_address)
10 IF (asset_deposited > 0 & dero_deposited > 0 ) THEN GOTO 30
20 GOTO 666
30 LET total_liquidity = get_supply_per_asset(asset_address)
' Pair already exists
40 IF total_liquidity > 0 THEN GOTO 41 ELSE GOTO 60
41 IF min_liquidity > 0 THEN GOTO 43
42 GOTO 666
43 LET dero_reserve = get_dero_reserve_per_asset(asset_address)
44 LET asset_reserve = get_asset_reserve(asset_address)
45 mintFee(dero_reserve, asset_reserve, asset_address)
46 LET total_liquidity = get_supply_per_asset(asset_address) ' Must be defined again since totalSupply can update in mintFee
47 LET asset_amount = dero_deposited * asset_reserve / dero_reserve + 1
48 LET liquidity_minted = dero_deposited * total_liquidity / dero_reserve
49 IF asset_deposited >= asset_amount & liquidity_minted >= min_liquidity THEN GOTO 51
50 GOTO 666
51 increase_liquidity_by(SIGNER(), liquidity_minted, asset_address)
52 set_supply_per_asset(total_liquidity + liquidity_minted, asset_address)
53 IF asset_deposited == asset_amount THEN GOTO 55
' Return any reminding assets
54 SEND_ASSET_TO_ADDRESS(SIGNER(), asset_deposited - asset_amount, asset_address)
' Increase the dero reserve record for this asset
55 set_dero_reserve_per_asset(dero_reserve + dero_deposited, asset_address)
' Increase the asset reserve record
56 set_asset_reserve(asset_reserve + asset_amount, asset_address)
57 STORE(HEX(asset_address)+":kLast", (dero_reserve + dero_deposited) * (asset_reserve + asset_amount))
' The user's dero deposit count has been used, set it to 0
58 reset_dero_deposited()
' Return gracefully
59 GOTO 70
' else
' Creating pair
60 IF dero_deposited >= 1000 THEN GOTO 62
61 GOTO 666
' Initialize the asset reserve record for this asset
62 set_asset_reserve(asset_deposited, asset_address)
63 DIM initial_liquidity as Uint64
64 LET initial_liquidity = dero_deposited
65 set_supply_per_asset(initial_liquidity, asset_address)
' Initialize the dero reserve record for this asset
66 set_dero_reserve_per_asset(dero_deposited, asset_address)
67 STORE(HEX(asset_address)+":kLast", (asset_deposited) * (dero_deposited))
68 increase_liquidity_by(SIGNER(), initial_liquidity, asset_address)
' The user's dero deposit count has been used, set it to 0
69 reset_dero_deposited()
70 RETURN 0
666 RETURN 1
End Function
' Burn BOO tokens to withdraw Dero & assets at current ratio.
' {amount} Amount of BOO burned.
' {min_dero} Minimum DERO withdrawn.
' {min_assets} Minimum assets withdrawn.
' {asset_address} The deposited asset's SCID
Function RemoveLiquidity(amount Uint64, min_dero Uint64, min_assets Uint64, asset_address String) Uint64
01 DIM total_liquidity, asset_reserve, dero_amount, asset_amount as Uint64
10 IF amount > 0 & (min_dero > 0 & min_assets > 0) & Get_liquidity(SIGNER(), asset_address) >= amount THEN GOTO 30
20 GOTO 666
30 LET total_liquidity = get_supply_per_asset(asset_address)
40 IF total_liquidity > 0 THEN GOTO 60
50 GOTO 666
60 LET asset_reserve = get_asset_reserve(asset_address)
70 LET dero_reserve = get_dero_reserve_per_asset(asset_address)
80 mintFee(dero_reserve, asset_reserve, asset_address)
90 LET total_liquidity = get_supply_per_asset(asset_address) ' Must be defined again since totalSupply can update in mintFee
100 LET dero_amount: = amount * dero_reserve / total_liquidity
110 LET asset_amount = amount * asset_reserve / total_liquidity
120 IF dero_amount >= min_dero & asset_amount >= min_assets THEN GOTO 140
130 GOTO 666
140 decrease_liquidity_by(SIGNER(), amount, asset_address)
150 set_supply_per_asset(total_liquidity - amount, asset_address)
160 set_dero_reserve_per_asset(dero_reserve - dero_amount, asset_address)
170 set_asset_reserve(asset_reserve - asset_amount, asset_address)
180 STORE(HEX(asset_address)+":kLast", (dero_reserve - dero_amount) * (asset_reserve - asset_amount) )
190 SEND_DERO_TO_ADDRESS(SIGNER(), dero_amount)
200 SEND_ASSET_TO_ADDRESS(SIGNER(),asset_amount, asset_address)
210 RETURN 0
666 RETURN 1
End Function
' Pricing function for converting between DERO & Assets.
' {input_amount} Amount of DERO or Assets being sold.
' {input_reserve} Amount of DERO or Assets (input type) in exchange reserves.
' {output_reserve} Amount of DERO or Assets (output type) in exchange reserves.
Function getInputPrice(input_amount Uint64, input_reserve Uint64, output_reserve Uint64) Uint64
10 IF input_reserve > 0 & output_reserve > 0 THEN GOTO 30
20 PANIC
30 DIM input_amount_with_fee, numerator, denominator as Uint64
40 LET input_amount_with_fee = input_amount * 997
50 LET numerator = input_amount_with_fee * output_reserve
60 LET denominator = (input_reserve * 1000) + input_amount_with_fee
70 RETURN numerator / denominator
End Function
' Pricing function for converting between DERO & Assets.
' output_amount Amount of DERO or Assets being bought.
' input_reserve Amount of DERO or Assets (input type) in exchange reserves.
' output_reserve Amount of DERO or Assets (output type) in exchange reserves.
Function getOutputPrice(output_amount Uint64, input_reserve Uint64, output_reserve Uint64) Uint64
10 IF input_reserve > 0 & output_reserve > 0 THEN GOTO 30
20 PANIC
30 DIM numerator, denominator as Uint64
40 LET numerator = input_reserve * output_amount * 1000
50 LET denominator = (output_reserve - output_amount) * 997
60 RETURN numerator / denominator + 1
End Function
Function deroToAssetInput(dero_sold Uint64, min_assets Uint64, asset_address String) Uint64
10 IF (dero_sold > 0 & min_assets > 0) THEN GOTO 30
20 PANIC
30 DIM assets_bought, asset_reserve, dero_reserve as Uint64
40 LET asset_reserve = get_asset_reserve(asset_address)
50 LET dero_reserve = get_dero_reserve_per_asset(asset_address)
60 LET assets_bought = getInputPrice(dero_sold, dero_reserve, asset_reserve)
70 IF assets_bought >= min_assets THEN GOTO 90
80 PANIC
90 SEND_ASSET_TO_ADDRESS(SIGNER(), assets_bought, asset_address)
100 set_asset_reserve(asset_reserve - assets_bought, asset_address)
110 set_dero_reserve_per_asset(dero_reserve + dero_sold, asset_address)
120 RETURN 0
End Function
' Convert DERO to Assets.
' User specifies exact input (DEROVALUE()).
' User cannot specify minimum output.
Function DeroToAssetSwapInput(asset_address String) Uint64
10 RETURN deroToAssetInput(DEROVALUE(), 1, asset_address)
End Function
' Convert DERO to Assets.
' User specifies exact input (DEROVALUE()) & minimum output.
' min_assets Minimum Assets bought.
Function DeroToAssetSwapInputMin(min_assets Uint64, asset_address String) Uint64
10 RETURN deroToAssetInput(DEROVALUE(), min_assets, asset_address)
End Function
Function deroToAssetOutput(assets_bought Uint64, max_dero Uint64, asset_address String) Uint64
10 IF (assets_bought > 0 & max_dero > 0) THEN GOTO 30
20 PANIC
30 DIM asset_reserve, dero_sold, dero_refund as Uint64
40 LET asset_reserve = get_asset_reserve(asset_address)
50 LET dero_sold = getOutputPrice(assets_bought, get_dero_reserve_per_asset(asset_address), asset_reserve)
60 IF dero_sold > max_dero THEN PANIC
70 LET dero_refund = max_dero - dero_sold
80 IF dero_refund == 0 THEN GOTO 100
90 SEND_DERO_TO_ADDRESS(SIGNER(), dero_refund)
100 SEND_ASSET_TO_ADDRESS(SIGNER(), assets_bought, asset_address)
110 set_asset_reserve(asset_reserve - assets_bought, asset_address)
120 set_dero_reserve_per_asset(dero_reserve + dero_sold, asset_address)
130 RETURN 0
End Function
' Convert DERO to Assets.
' User specifies maximum input (DEROVALUE()) & exact output.
' assets_bought Amount of Assets bought.
Function DeroToAssetSwapOutput(assets_bought Uint64, asset_address String) Uint64
10 RETURN deroToAssetOutput(assets_bought, DEROVALUE(), asset_address)
End Function
Function assetToDeroInput(assets_sold Uint64, min_dero Uint64, asset_address String) Uint64
10 IF (assets_sold > 0 & min_dero > 0) THEN GOTO 30
20 PANIC
30 DIM asset_reserve, dero_bought
40 LET asset_reserve = get_asset_reserve(asset_address)
50 LET dero_bought = getInputPrice(assets_sold, asset_reserve, get_dero_reserve_per_asset(asset_address))
60 IF dero_bought >= min_dero THEN GOTO 80
70 PANIC
80 SEND_DERO_TO_ADDRESS(SIGNER(),dero_bought)
90 set_dero_reserve_per_asset(get_dero_reserve_per_asset(asset_address) - dero_bought, asset_address)
100 set_asset_reserve(asset_reserve + assets_sold, asset_address)
110 RETURN 0
End Function
' Convert Assets to DERO.
' User specifies exact input (ASSETVALUE(asset_address)) & minimum output.
' {assets_sold} Amount of Assets sold.
' {min_dero} Minimum DERO purchased.
Function AssetToDeroSwapInput(assets_sold Uint64, min_dero Uint64, asset_address String) Uint64
10 RETURN assetToDeroInput(ASSETVALUE(asset_address), min_dero, asset_address)
End Function
//TODO: Optimize get_dero_reserve_per_asset access
Function assetToDeroOutput(dero_bought Uint64, max_assets Uint64 , deadline Uint64, asset_address String) Uint64
10 IF dero_bought > 0 THEN GOTO 30
20 PANIC
30 DIM asset_reserve, assets_sold, asset_refund as Uint64
40 LET asset_reserve = get_asset_reserve(asset_address)
50 LET assets_sold = getOutputPrice(dero_bought, asset_reserve, get_dero_reserve_per_asset(asset_address))
//' # assets_sold is always > 0
60 IF max_assets >= assets_sold THEN GOTO 80
70 PANIC
80 SEND_DERO_TO_ADDRESS(SIGNER(), dero_bought)
90 LET asset_refund = max_assets - assets_sold
100 IF asset_refund == 0 THEN GOTO 120
110 SEND_ASSET_TO_ADDRESS(SIGNER(), asset_refund, asset_address)
120 set_dero_reserve_per_asset(get_dero_reserve_per_asset(asset_address) - dero_bought, asset_address)
130 set_asset_reserve(asset_reserve + assets_sold, asset_address)
140 RETURN 0
End Function
' Convert Assets to DERO.
' User specifies maximum input (ASSETVALUE(asset_address)) & exact output.
' dero_bought Amount of DERO purchased.
Function AssetToDeroSwapOutput(dero_bought Uint64, asset_address String) Uint64
10 RETURN assetToDeroOutput(dero_bought, ASSETVALUE(asset_address), asset_address)
End Function
' Public price function for DERO to Asset trades with an exact input.
' dero_sold Amount of DERO sold.
' Amount of Assets that can be bought with input DERO.
Function GetDeroToAssetInputPrice(dero_sold Uint64, asset_address String) Uint64
10 IF dero_sold > 0 THEN GOTO 30
20 RETURN 0
30 RETURN getInputPrice(dero_sold, get_dero_reserve_per_asset(asset_address), get_asset_reserve(asset_address))
End Function
' Public price function for DERO to Asset trades with an exact output.
' assets_bought Amount of Assets bought.
' Amount of DERO needed to buy output Assets.
Function GetDeroToAssetOutputPrice(assets_bought Uint64, asset_address String) Uint64
10 IF assets_bought > 0 THEN GOTO 30
20 RETURN 0
30 RETURN getOutputPrice(assets_bought, get_dero_reserve_per_asset(asset_address), get_asset_reserve(asset_address))
End Function
' Public price function for Asset to DERO trades with an exact input.
' assets_sold Amount of Assets sold.
' Amount of DERO that can be bought with input Assets.
Function GetAssetToDeroInputPrice(assets_sold Uint64, asset_address String) Uint64
10 IF assets_sold > 0 THEN GOTO 30
20 RETURN 0
30 RETURN getInputPrice(assets_sold, get_asset_reserve(asset_address), get_dero_reserve_per_asset(asset_address))
End Function
' Public price function for Asset to DERO trades with an exact output.
' eth_bought Amount of output DERO.
' Amount of Assets needed to buy output DERO.
Function GetAssetToDeroOutputPrice(dero_bought Uint64, asset_address String) Uint64
10 IF dero_bought > 0 THEN GOTO 30
20 RETURN 0
30 RETURN getOutputPrice(dero_bought, get_asset_reserve(asset_address), get_dero_reserve_per_asset(asset_address))
End Function
// Helper functions
' Encapsulated to better understand what's happening and absctract BOO storage schema
' from main code.
' Stores the existing liquidity for a specific asset.
Function set_supply_per_asset(amount Uint64, asset_address String)
10 STORE(HEX(asset_address)+":BOO", amount)
20 RETURN
End Function
' Returns all existing liquidity for a specific asset.
Function get_supply_per_asset(asset_address String) Uint64
10 IF EXISTS(HEX(asset_address)+":BOO") THEN GOTO 30
20 RETURN 0
30 RETURN LOAD(HEX(asset_address)+":BOO")
End Function
' Stores the amount of DERO owned by a specific asset trading pair.
Function set_dero_reserve_per_asset(amount Uint64, asset_address String)
10 STORE(HEX(asset_address)+":DERO", amount)
20 RETURN
End Function
' Loads the amount of DERO owned by a specific asset trading pair.
Function get_dero_reserve_per_asset(asset_address String) Uint64
20 RETURN LOAD(HEX(asset_address)+":DERO")
End Function
' Stores the amount of assets owned by a specific asset trading pair.
Function set_asset_reserve(amount Uint64, asset_address String)
10 STORE(HEX(asset_address), amount)
20 RETURN
End Function
' Loads the amount of assets owned by a specific asset trading pair.
Function get_asset_reserve(asset_address String) Uint64
20 RETURN LOAD(HEX(asset_address))
End Function
' Increases the amount of BOO of a specific traiding pair owned by a given provider_address.
Function increase_liquidity_by(provider_address String, amount Uint64, asset_address String)
10 IF EXISTS(HEX(provider_address)+":BOO:"+HEX(asset_address)) THEN GOTO 40
20 STORE(HEX(provider_address)+":BOO:"+HEX(asset_address), amount)
30 RETURN
40 STORE(HEX(provider_address)+":BOO:"+HEX(asset_address), Get_liquidity(provider_address, asset_address) + amount)
50 RETURN
End Function
' Decreases the amount of BOO of a specific traiding pair owned by a given provider_address.
Function decrease_liquidity_by(provider_address String, amount Uint64, asset_address String)
40 STORE(HEX(provider_address)+":BOO:"+HEX(asset_address), Get_liquidity(provider_address, asset_address) - amount)
50 RETURN
End Function
' Returns the amount of BOO of a specific traiding pair owned by a given provider_address.
Function Get_liquidity(provider_address String, asset_address String) Uint64
10 RETURN LOAD(HEX(provider_address)+":BOO:"+HEX(asset_address))
End Function
' Sets to 0 the amount of dero owned by the signer.
Function reset_dero_deposited()
10 STORE(ADDRESS_STRING(SIGNER()),0)
20 RETURN
End Function
' Returns the amount of dero deposited by the signer of the tx.
Function get_dero_deposited() Uint64
10 IF EXISTS(ADDRESS_STRING(SIGNER())) THEN GOTO 30
20 RETURN 0
30 RETURN LOAD(ADDRESS_STRING(SIGNER()))
End Function
' Mint liquidity to the feeTo address equivalent to 1/6th of the growth in sqrt(k) (0.05%)
Function mintFee(reserve0 Uint64, reserve1 Uint64, asset_address String) Uint64
10 DIM feeTo as String
11 DIM kLast as Uint64
20 LET feeTo = LOAD("feeTo")
//' Get the last k for the asset
30 LET kLast = LOAD(HEX(asset_address)+":kLast")
40 IF kLast != 0 THEN GOTO 50
41 RETURN 0
50 DIM rootK, rootKLast as Uint64
60 LET rootK = sqrt(reserve0 * reserve1)
70 LET rootKLast = sqrt(kLast)
80 IF rootK > rootKLast GOTO 90
81 RETURN 0
90 DIM numerator, denominator, supply, liquidity_minted as Uint64
100 LET supply = get_supply_per_asset(asset_address)
110 LET numerator = supply*(rootK-rootKLast)
120 LET denominator = rootK * 5 + rootKLast
130 LET liquidity_minted = numerator / denominator
140 IF liquidity_minted > 0 THEN GOTO 141 ELSE GOTO 150
141 increase_liquidity_by(feeTo, liquidity_minted, asset_address)
142 set_supply_per_asset(supply + liquidity_minted, asset_address)
150 RETURN 0
End Function
' Babylonian method for Square root
Function sqrt(y Uint64) Uint64
10 IF y > 3 GOTO 20 ELSE GOTO 90
20 DIM x,z as Uint64
30 LET z = y
40 LET x = y / 2 + 1
50 IF x < z THEN GOTO 60 ELSE GOTO 100
60 LET z = x
70 LET x = (y / x + x) / 2
80 GOTO 50
90 IF y != 0 THEN RETURN 1 ELSE RETURN 0
100 RETURN 0
End Function'] |
