liquidity_math.gno
12.43 Kb · 315 lines
1package gnsmath
2
3import (
4 ufmt "gno.land/p/nt/ufmt/v0"
5
6 "gno.land/p/gnoswap/consts/v1"
7 i256 "gno.land/p/gnoswap/int256/v1"
8 u256 "gno.land/p/gnoswap/uint256/v1"
9)
10
11// computeLiquidityForAmount0 calculates the liquidity for a given amount of token0.
12//
13// This function computes the maximum possible liquidity that can be provided for `token0`
14// based on the provided price boundaries (sqrtRatioAX96 and sqrtRatioBX96) in Q64.96 format.
15//
16// Parameters:
17// - sqrtRatioAX96: *u256.Uint - The square root price at the lower tick boundary (Q64.96).
18// - sqrtRatioBX96: *u256.Uint - The square root price at the upper tick boundary (Q64.96).
19// - amount0: *u256.Uint - The amount of token0 to be converted to liquidity.
20//
21// Returns:
22// - *u256.Uint: The calculated liquidity, represented as an unsigned 128-bit integer (uint128).
23//
24// Panics:
25// - If the resulting liquidity exceeds the uint128 range, `SafeConvertToUint128` will trigger a panic.
26func computeLiquidityForAmount0(sqrtRatioAX96, sqrtRatioBX96, amount0 *u256.Uint) *u256.Uint {
27 sqrtRatioAX96, sqrtRatioBX96 = toAscendingOrder(sqrtRatioAX96, sqrtRatioBX96)
28 intermediate := u256.MulDiv(sqrtRatioAX96, sqrtRatioBX96, consts.Q96())
29
30 diff := u256.Zero().Sub(sqrtRatioBX96, sqrtRatioAX96)
31 if diff.IsZero() {
32 panic(newErrorWithDetail(
33 errLiquidityIdenticalTicks,
34 ufmt.Sprintf("sqrtRatioAX96 (%s) and sqrtRatioBX96 (%s) are identical", sqrtRatioAX96.ToString(), sqrtRatioBX96.ToString()),
35 ))
36 }
37 res := u256.MulDiv(amount0, intermediate, diff)
38 return SafeConvertToUint128(res)
39}
40
41// computeLiquidityForAmount1 calculates liquidity based on the provided token1 amount and price range.
42//
43// This function computes the liquidity for a given amount of token1 by using the difference
44// between the upper and lower square root price ratios. The calculation uses Q96 fixed-point
45// arithmetic to maintain precision.
46//
47// Parameters:
48// - sqrtRatioAX96: *u256.Uint - The square root ratio of price at the lower tick, represented in Q96 format.
49// - sqrtRatioBX96: *u256.Uint - The square root ratio of price at the upper tick, represented in Q96 format.
50// - amount1: *u256.Uint - The amount of token1 to calculate liquidity for.
51//
52// Returns:
53// - *u256.Uint: The calculated liquidity based on the provided amount of token1 and price range.
54//
55// Notes:
56// - The result is not directly limited to uint128, as liquidity values can exceed uint128 bounds.
57// - If `sqrtRatioAX96 == sqrtRatioBX96`, the function will panic due to division by zero.
58// - Q96 is a constant representing `2^96`, ensuring that precision is maintained during division.
59//
60// Panics:
61// - If the resulting liquidity exceeds the uint128 range, `SafeConvertToUint128` will trigger a panic.
62func computeLiquidityForAmount1(sqrtRatioAX96, sqrtRatioBX96, amount1 *u256.Uint) *u256.Uint {
63 sqrtRatioAX96, sqrtRatioBX96 = toAscendingOrder(sqrtRatioAX96, sqrtRatioBX96)
64
65 diff := u256.Zero().Sub(sqrtRatioBX96, sqrtRatioAX96)
66 if diff.IsZero() {
67 panic(newErrorWithDetail(
68 errLiquidityIdenticalTicks,
69 ufmt.Sprintf("sqrtRatioAX96 (%s) and sqrtRatioBX96 (%s) are identical", sqrtRatioAX96.ToString(), sqrtRatioBX96.ToString()),
70 ))
71 }
72 res := u256.MulDiv(amount1, consts.Q96(), diff)
73 return SafeConvertToUint128(res)
74}
75
76// GetLiquidityForAmounts calculates the maximum liquidity supported by two token amounts.
77//
78// The current square-root price determines which token amounts are active. Below
79// the range only token0 is used, above it only token1 is used, and inside it the
80// smaller of the token0- and token1-derived liquidities is returned.
81//
82// Parameters:
83// - sqrtRatioX96: Current square-root price, encoded as a Q64.96 ratio.
84// - sqrtRatioAX96: First price-range endpoint, encoded as a Q64.96 ratio.
85// - sqrtRatioBX96: Second price-range endpoint, encoded as a Q64.96 ratio; the endpoints are sorted.
86// - amount0: Available token0 amount.
87// - amount1: Available token1 amount.
88//
89// Returns:
90// - liquidity: Maximum liquidity supported by the amounts, constrained to uint128.
91//
92// Panics if a selected amount/range calculation has identical bounds or exceeds uint128.
93func GetLiquidityForAmounts(sqrtRatioX96, sqrtRatioAX96, sqrtRatioBX96, amount0, amount1 *u256.Uint) (liquidity *u256.Uint) {
94 sqrtRatioAX96, sqrtRatioBX96 = toAscendingOrder(sqrtRatioAX96, sqrtRatioBX96)
95
96 if sqrtRatioX96.Lte(sqrtRatioAX96) {
97 liquidity = computeLiquidityForAmount0(sqrtRatioAX96, sqrtRatioBX96, amount0)
98 } else if sqrtRatioX96.Lt(sqrtRatioBX96) {
99 liquidity0 := computeLiquidityForAmount0(sqrtRatioX96, sqrtRatioBX96, amount0)
100 liquidity1 := computeLiquidityForAmount1(sqrtRatioAX96, sqrtRatioX96, amount1)
101
102 if liquidity0.Lt(liquidity1) {
103 liquidity = liquidity0
104 } else {
105 liquidity = liquidity1
106 }
107 } else {
108 liquidity = computeLiquidityForAmount1(sqrtRatioAX96, sqrtRatioBX96, amount1)
109 }
110 return liquidity
111}
112
113// computeAmount0ForLiquidity calculates the required amount of token0 for a given liquidity level
114// within a specified price range (represented by sqrt ratios).
115//
116// This function determines the amount of token0 needed to provide a specified amount of liquidity
117// within a price range defined by sqrtRatioAX96 (lower bound) and sqrtRatioBX96 (upper bound).
118//
119// Parameters:
120// - sqrtRatioAX96: The lower bound of the price range as a square root ratio in Q64.96 format (*u256.Uint).
121// - sqrtRatioBX96: The upper bound of the price range as a square root ratio in Q64.96 format (*u256.Uint).
122// - liquidity: The liquidity to be provided (*u256.Uint).
123//
124// Returns:
125// - *u256.Uint: The amount of token0 required to achieve the specified liquidity level.
126//
127// Notes:
128// - This function assumes the price bounds are expressed in Q64.96 fixed-point format.
129// - The function returns 0 if the liquidity is 0 or the price bounds are invalid.
130// - Handles edge cases where sqrtRatioAX96 equals sqrtRatioBX96 by returning 0 (to prevent division by zero).
131func computeAmount0ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity *u256.Uint) *u256.Uint {
132 sqrtRatioAX96, sqrtRatioBX96 = toAscendingOrder(sqrtRatioAX96, sqrtRatioBX96)
133 if sqrtRatioAX96.IsZero() || sqrtRatioBX96.IsZero() || liquidity.IsZero() || sqrtRatioAX96.Eq(sqrtRatioBX96) {
134 return u256.Zero()
135 }
136
137 val1 := u256.Zero().Lsh(liquidity, Q96_RESOLUTION)
138 val2 := u256.Zero().Sub(sqrtRatioBX96, sqrtRatioAX96)
139
140 res := u256.MulDiv(val1, val2, sqrtRatioBX96)
141 res = res.Div(res, sqrtRatioAX96)
142
143 return res
144}
145
146// computeAmount1ForLiquidity calculates the required amount of token1 for a given liquidity level
147// within a specified price range (represented by sqrt ratios).
148//
149// This function determines the amount of token1 needed to provide liquidity between the
150// lower (sqrtRatioAX96) and upper (sqrtRatioBX96) price bounds. The calculation is performed
151// in Q64.96 fixed-point format, which is standard for many liquidity calculations.
152//
153// Parameters:
154// - sqrtRatioAX96: The lower bound of the price range as a square root ratio in Q64.96 format (*u256.Uint).
155// - sqrtRatioBX96: The upper bound of the price range as a square root ratio in Q64.96 format (*u256.Uint).
156// - liquidity: The liquidity amount to be used in the calculation (*u256.Uint).
157//
158// Returns:
159// - *u256.Uint: The amount of token1 required to achieve the specified liquidity level.
160//
161// Notes:
162// - This function handles edge cases where the liquidity is zero or when sqrtRatioAX96 equals sqrtRatioBX96
163// to prevent division by zero.
164// - The calculation assumes sqrtRatioAX96 is always less than or equal to sqrtRatioBX96 after the initial
165// ascending order sorting.
166func computeAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity *u256.Uint) *u256.Uint {
167 sqrtRatioAX96, sqrtRatioBX96 = toAscendingOrder(sqrtRatioAX96, sqrtRatioBX96)
168 if liquidity.IsZero() || sqrtRatioAX96.Eq(sqrtRatioBX96) {
169 return u256.Zero()
170 }
171
172 diff := u256.Zero().Sub(sqrtRatioBX96, sqrtRatioAX96)
173 res := u256.MulDiv(liquidity, diff, consts.Q96())
174
175 return res
176}
177
178// GetAmountsForLiquidity calculates the amounts of token0 and token1 represented
179// by a specified liquidity within a price range.
180//
181// If the current price is below the lower bound, only token0 is required. If the
182// current price is above the upper bound, only token1 is required. When the
183// price is within the range, both token0 and token1 are calculated.
184//
185// Parameters:
186// - sqrtRatioX96: Current square-root price in Q64.96 format.
187// - sqrtRatioAX96: First price-range endpoint in Q64.96 format.
188// - sqrtRatioBX96: Second price-range endpoint in Q64.96 format; the endpoints are ordered internally.
189// - liquidity: Non-negative liquidity amount to value.
190//
191// Returns:
192// - amount0: Token0 amount represented by liquidity; zero when the current price is at or above the upper endpoint.
193// - amount1: Token1 amount represented by liquidity; zero when the current price is at or below the lower endpoint.
194// Call ToString() on either value for decimal display.
195//
196// Notes:
197// - If liquidity is zero, the function returns zero values for both tokens.
198// - At a boundary, the corresponding out-of-range token amount is zero.
199//
200// Example:
201// ```
202// amount0, amount1 := GetAmountsForLiquidity(
203//
204// u256.MustFromDecimal("79228162514264337593543950336"), // sqrtRatioX96 (1.0 in Q64.96)
205// u256.MustFromDecimal("39614081257132168796771975168"), // sqrtRatioAX96 (0.5 in Q64.96)
206// u256.MustFromDecimal("158456325028528675187087900672"), // sqrtRatioBX96 (2.0 in Q64.96)
207// u256.MustFromDecimal("1000000"), // Liquidity
208//
209// )
210//
211// println("Token0:", amount0.ToString(), "Token1:", amount1.ToString())
212//
213// // Output:
214// Token0: 500000, Token1: 500000
215// ```
216func GetAmountsForLiquidity(sqrtRatioX96, sqrtRatioAX96, sqrtRatioBX96, liquidity *u256.Uint) (*u256.Uint, *u256.Uint) {
217 if liquidity.IsZero() {
218 return u256.Zero(), u256.Zero()
219 }
220
221 sqrtRatioAX96, sqrtRatioBX96 = toAscendingOrder(sqrtRatioAX96, sqrtRatioBX96)
222
223 amount0 := u256.Zero()
224 amount1 := u256.Zero()
225
226 if sqrtRatioX96.Lte(sqrtRatioAX96) {
227 amount0 = computeAmount0ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity)
228 } else if sqrtRatioX96.Lt(sqrtRatioBX96) {
229 amount0 = computeAmount0ForLiquidity(sqrtRatioX96, sqrtRatioBX96, liquidity)
230 amount1 = computeAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioX96, liquidity)
231 } else {
232 amount1 = computeAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity)
233 }
234
235 return amount0, amount1
236}
237
238// LiquidityMathAddDelta calculates the new liquidity after applying a signed delta.
239// A negative delta subtracts its magnitude; a non-negative delta adds its magnitude.
240//
241// Parameters:
242// - x: Current non-negative liquidity value.
243// - y: Signed liquidity delta; positive values add and negative values subtract.
244//
245// Returns:
246// - liquidity: Updated liquidity, constrained to the uint128 range.
247//
248// Panics if x or y is nil, subtraction underflows, addition overflows uint256,
249// or the resulting liquidity exceeds MaxUint128.
250func LiquidityMathAddDelta(x *u256.Uint, y *i256.Int) *u256.Uint {
251 if x == nil || y == nil {
252 panic("liquidity_math: x or y is nil")
253 }
254
255 yAbs := y.Abs()
256
257 // Subtract or add based on the sign of y
258 if y.Lt(i256.Zero()) {
259 z := u256.Zero().Sub(x, yAbs)
260 if z.Gte(x) {
261 panic(ufmt.Sprintf(
262 "liquidity_math: underflow (x: %s, y: %s, z:%s)",
263 x.ToString(), y.ToString(), z.ToString()))
264 }
265 if z.Gt(consts.MaxUint128()) {
266 panic(ufmt.Sprintf(
267 "liquidity_math: result exceeds uint128 range (z: %s)",
268 z.ToString()))
269 }
270 return z
271 }
272
273 z := u256.Zero().Add(x, yAbs)
274 if z.Lt(x) {
275 panic(ufmt.Sprintf(
276 "liquidity_math: overflow (x: %s, y: %s, z:%s)",
277 x.ToString(), y.ToString(), z.ToString()))
278 }
279 if z.Gt(consts.MaxUint128()) {
280 panic(ufmt.Sprintf(
281 "liquidity_math: result exceeds uint128 range (z: %s)",
282 z.ToString()))
283 }
284 return z
285}
286
287// toAscendingOrder returns the two values in ascending order.
288func toAscendingOrder(a, b *u256.Uint) (*u256.Uint, *u256.Uint) {
289 if a.Gt(b) {
290 return b, a
291 }
292
293 return a, b
294}
295
296// SafeConvertToUint128 verifies that value fits in the uint128 range.
297//
298// No representation conversion is performed: the original pointer is returned
299// when its value is at most 2^128 - 1.
300//
301// Parameters:
302// - value: Non-nil unsigned 256-bit value to validate.
303//
304// Returns:
305// - converted: The same *u256.Uint pointer when value fits in uint128.
306//
307// Panics if value is nil or exceeds the maximum uint128 value.
308func SafeConvertToUint128(value *u256.Uint) *u256.Uint {
309 if value.Gt(consts.MaxUint128()) {
310 panic(ufmt.Sprintf(
311 "%v: amount(%s) overflows uint128 range",
312 errLiquidityOverflow, value.ToString()))
313 }
314 return value
315}