-
Notifications
You must be signed in to change notification settings - Fork 30
/
sqrt-price.js
45 lines (34 loc) · 1.29 KB
/
sqrt-price.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
/**
* @fileoverview Calculates the price (ratio) from sqrt ratio.
*/
const JSBI = require('jsbi');
const chainContext = require('./chain-context');
const { Q192 } = require('./constants');
const { expDecs } = require('./utils');
const entity = (module.exports = {});
/**
* Calculates the price (ratio) from sqrt price.
*
* @param {Array<number|string>} tokenDecimals Array tuple of token decimals.
* @param {string} sqrtRatioX96 The tick value.
* @return {Object} The chain context.
*/
entity.sqrtPrice = (tokenDecimals, sqrtRatioX96) => {
const [token0Decimals, token1Decimals] = tokenDecimals;
const scalarNumerator = expDecs(token0Decimals);
const scalarDenominator = expDecs(token1Decimals);
const sqrtRatioX96BI = JSBI.BigInt(sqrtRatioX96);
const inputNumerator = JSBI.multiply(sqrtRatioX96BI, sqrtRatioX96BI);
const inputDenominator = Q192;
const adjustedForDecimalsNumerator = JSBI.BigInt(
JSBI.multiply(scalarDenominator, inputDenominator),
);
const adjustedForDecimalsDenominator = JSBI.BigInt(
JSBI.multiply(scalarNumerator, inputNumerator),
);
const numerator = adjustedForDecimalsNumerator;
const denominator = adjustedForDecimalsDenominator;
const fraction = [numerator, denominator];
const chainCtx = chainContext(fraction);
return chainCtx;
};