@kamino-finance/klend-sdk
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Typescript SDK for interacting with the Kamino Lending (klend) protocol
261 lines • 10.1 kB
JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.positiveOrZero = exports.isEmptyObject = exports.valueOrZero = exports.isSolMint = exports.parseTokenSymbol = exports.getBorrowRate = exports.interpolate = exports.estimateCurrentScore = exports.calculateNewScore = void 0;
exports.parseZeroPaddedUtf8 = parseZeroPaddedUtf8;
exports.renderZeroPaddedUtf8 = renderZeroPaddedUtf8;
exports.sleep = sleep;
exports.numberToLamportsDecimal = numberToLamportsDecimal;
exports.lamportsToNumberDecimal = lamportsToNumberDecimal;
exports.lamportsToDecimal = lamportsToDecimal;
exports.calculateAPYFromAPR = calculateAPYFromAPR;
exports.calculateAPRFromAPY = calculateAPRFromAPY;
exports.sameLengthArrayEquals = sameLengthArrayEquals;
exports.getTokenBalanceFromAccountInfoLamports = getTokenBalanceFromAccountInfoLamports;
exports.bpsToPct = bpsToPct;
exports.truncateDecimals = truncateDecimals;
exports.decodeVaultName = decodeVaultName;
exports.pubkeyHashMapToJson = pubkeyHashMapToJson;
exports.toJson = toJson;
exports.assertNever = assertNever;
exports.orThrow = orThrow;
exports.blobEquals = blobEquals;
exports.roundNearest = roundNearest;
exports.getMedianSlotDurationInMsFromLastEpochs = getMedianSlotDurationInMsFromLastEpochs;
const utils_1 = require("../utils");
const decimal_js_1 = __importDefault(require("decimal.js"));
const spl_token_1 = require("@solana/spl-token");
const axios_1 = __importDefault(require("axios"));
function getLatestRewardRate(rewardRates, slot) {
return rewardRates
.filter((rr) => slot >= rr.beginningSlot)
.reduce((v1, v2) => (v1.beginningSlot > v2.beginningSlot ? v1 : v2), {
beginningSlot: 0,
rewardRate: '0',
});
}
const calculateNewScore = (rewardStat, pool, rewardRate, endSlot, startSlot) => {
const { balance, debt, score } = pool;
const { rewardsPerShare, totalBalance } = rewardStat;
const oldDebt = new decimal_js_1.default(debt);
const oldScore = new decimal_js_1.default(score);
const oldRewardsPerShare = new decimal_js_1.default(rewardsPerShare);
const oldBalance = new decimal_js_1.default(balance);
const totalBalanceVal = new decimal_js_1.default(totalBalance);
const newRewardsPerShare = !totalBalanceVal.isZero()
? oldRewardsPerShare.plus(new decimal_js_1.default(endSlot)
.minus(new decimal_js_1.default(startSlot.toString()))
.times(new decimal_js_1.default(rewardRate))
.div(totalBalanceVal)
.div(new decimal_js_1.default(utils_1.SLOTS_PER_YEAR)))
: new decimal_js_1.default(0);
return oldScore.plus(newRewardsPerShare.times(oldBalance).minus(oldDebt));
};
exports.calculateNewScore = calculateNewScore;
const estimateCurrentScore = (rewardStat, rewardScore, mostRecentSlot, mostRecentSlotTime) => {
const { lastSlot, rewardRates } = rewardStat;
const estimatedCurrentSlot = mostRecentSlot + utils_1.SLOTS_PER_SECOND * (Date.now() / 1000 - mostRecentSlotTime);
const { rewardRate } = getLatestRewardRate(rewardRates, estimatedCurrentSlot);
const currentScore = (0, exports.calculateNewScore)(rewardStat, rewardScore, rewardRate, estimatedCurrentSlot, lastSlot);
return currentScore;
};
exports.estimateCurrentScore = estimateCurrentScore;
const interpolate = (x, x0, x1, y0, y1) => {
if (x > x1) {
throw 'Cannot do extrapolation';
}
return y0 + ((x - x0) * (y1 - y0)) / (x1 - x0);
};
exports.interpolate = interpolate;
const getBorrowRate = (currentUtilization, curve) => {
let [x0, y0, x1, y1] = [0, 0, 0, 0];
if (curve.length < 2) {
throw 'Invalid borrow rate curve, only one point';
}
if (currentUtilization > 1) {
currentUtilization = 1;
}
for (let i = 1; i < curve.length; i++) {
const [pointUtilization, pointRate] = curve[i];
if (pointUtilization === currentUtilization) {
return pointRate;
}
if (currentUtilization <= pointUtilization) {
x0 = curve[i - 1][0];
y0 = curve[i - 1][1];
x1 = curve[i][0];
y1 = curve[i][1];
break;
}
}
if (x0 === 0 && y0 === 0 && x1 === 0 && y1 === 0) {
console.log('All are 0');
throw 'Invalid borrow rate curve, could not identify the interpolation points.';
}
if (x0 >= x1 || y0 > y1) {
console.log('(x0, y0), (x1, y1)', x0, y0, x1, y1);
throw 'Invalid borrow rate curve, curve is not uniformly increasing';
}
return (0, exports.interpolate)(currentUtilization, x0, x1, y0, y1);
};
exports.getBorrowRate = getBorrowRate;
const parseTokenSymbol = (tokenSymbol) => {
return String.fromCharCode(...tokenSymbol.filter((x) => x > 0));
};
exports.parseTokenSymbol = parseTokenSymbol;
function parseZeroPaddedUtf8(utf8Array) {
for (let last = utf8Array.length - 1; last >= 0; last--) {
const trailing_zero = utf8Array[last];
if (trailing_zero != 0) {
const encoding = new Uint8Array(last + 1);
for (let i = 0; i <= last; i++) {
encoding[i] = utf8Array[i];
}
return new TextDecoder().decode(encoding);
}
}
return '';
}
function renderZeroPaddedUtf8(str, utf8ArrayLength) {
const encoding = new TextEncoder().encode(str);
const result = new Array(utf8ArrayLength);
for (let i = 0; i < result.length; i++) {
result[i] = i < encoding.length ? encoding[i] : 0;
}
return result;
}
function sleep(ms) {
return new Promise((resolve) => setTimeout(resolve, ms));
}
function numberToLamportsDecimal(amount, decimals) {
const factor = 10 ** decimals;
return new decimal_js_1.default(amount).mul(factor);
}
function lamportsToNumberDecimal(amount, decimals) {
const factor = 10 ** decimals;
return new decimal_js_1.default(amount).div(factor);
}
function lamportsToDecimal(amount, decimals) {
const factor = new decimal_js_1.default(10).pow(decimals);
return new decimal_js_1.default(amount).div(factor);
}
const isSolMint = (mint) => {
return spl_token_1.NATIVE_MINT.equals(mint);
};
exports.isSolMint = isSolMint;
const valueOrZero = (value) => {
const zero = new decimal_js_1.default(0);
if (value.isNaN() || !value.isFinite()) {
return zero;
}
else {
return value;
}
};
exports.valueOrZero = valueOrZero;
const isEmptyObject = (obj) => {
return Object.keys(obj).length === 0 && obj.constructor === Object;
};
exports.isEmptyObject = isEmptyObject;
const positiveOrZero = (value) => {
const zero = new decimal_js_1.default(0);
return decimal_js_1.default.max(value, zero);
};
exports.positiveOrZero = positiveOrZero;
function calculateAPYFromAPR(apr) {
const apy = new decimal_js_1.default(1).plus(new decimal_js_1.default(apr).dividedBy(utils_1.SLOTS_PER_YEAR)).toNumber() ** utils_1.SLOTS_PER_YEAR - 1;
return apy;
}
function calculateAPRFromAPY(apy) {
return new decimal_js_1.default(apy)
.plus(1)
.pow(1 / utils_1.SLOTS_PER_YEAR)
.minus(1)
.times(utils_1.SLOTS_PER_YEAR);
}
function sameLengthArrayEquals(left, right) {
if (left.length != right.length) {
throw new Error(`Not same length: ${left.length} != ${right.length}`);
}
return left.every((value, index) => {
const other = right[index];
if (value != null && typeof value.eq === 'function') {
return value.eq(other);
}
return value === other;
});
}
function getTokenBalanceFromAccountInfoLamports(accountInfo) {
// Decode the buffer using the AccountLayout from @solana/spl-token
const tokenAccountData = spl_token_1.AccountLayout.decode(accountInfo.data);
// Extract the balance from the `amount` field, which is a 64-bit unsigned integer
const balance = tokenAccountData.amount;
return new decimal_js_1.default(balance.toString());
}
function bpsToPct(bps) {
return bps.div(100);
}
/**
* Truncate ( not round ) number to keep up to max amount of decimals
* @param num
* @param maxDecimals
*/
function truncateDecimals(num, maxDecimals) {
const factor = new decimal_js_1.default(10).pow(maxDecimals);
return new decimal_js_1.default(num).times(factor).floor().dividedBy(factor);
}
/**Convert an u8 array to a string */
function decodeVaultName(token) {
const maxArray = new Uint8Array(token);
let s = new TextDecoder().decode(maxArray);
// Remove trailing zeros and spaces
s = s.replace(/[\0 ]+$/, '');
return s;
}
function pubkeyHashMapToJson(map) {
const obj = {};
map.forEach((value, key) => {
obj[key.toBase58()] = value.toString();
});
return obj;
}
function toJson(object, inline = false) {
const replacer = (key, value) => (typeof value === 'bigint' ? value.toString() : value);
return inline ? JSON.stringify(object, replacer) : JSON.stringify(object, replacer, 2);
}
function assertNever(x) {
throw new Error('Unexpected object: ' + x);
}
function orThrow(message) {
throw new Error(message);
}
function blobEquals(left, right) {
if (left.length !== right.length) {
return false;
}
for (let i = 0; i < left.length; ++i) {
if (left[i] !== right[i]) {
return false;
}
}
return true;
}
/**
* Returns an integer {@link Decimal} nearest to the given one.
*
* NOTE: the `Decimal.round()` should actually be called `.trunc()` (by default, it uses floor rounding). In most cases,
* we prefer the traditional behavior (as `Math.round()`).
*/
function roundNearest(decimal) {
return decimal.toDecimalPlaces(0, decimal_js_1.default.ROUND_HALF_CEIL);
}
/**
* Fetch median slot duration in milliseconds from the last 10 epochs
*/
async function getMedianSlotDurationInMsFromLastEpochs() {
const response = await axios_1.default.get('https://api.kamino.finance/slots/duration');
return response.data.recentSlotDurationInMs;
}
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