@drift-labs/sdk/lib/browser/tx/priorityFeeCalculator.js

SDK for Drift Protocol

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.PriorityFeeCalculator = void 0;
const web3_js_1 = require("@solana/web3.js");
/**
 * This class determines whether a priority fee needs to be included in a transaction based on
 * a recent history of timed out transactions.
 */
class PriorityFeeCalculator {
    /**
     * Constructor for the PriorityFeeCalculator class.
     * @param currentTimeMs - The current time in milliseconds.
     * @param priorityFeeLatchDurationMs - The duration for how long to stay in triggered state before resetting. Default value is 10 seconds.
     */
    constructor(currentTimeMs, priorityFeeLatchDurationMs = 10 * 1000) {
        this.lastTxTimeoutCount = 0;
        this.priorityFeeTriggered = false;
        this.lastTxTimeoutCountTriggered = currentTimeMs;
        this.priorityFeeLatchDurationMs = priorityFeeLatchDurationMs;
    }
    /**
     * Update the priority fee state based on the current time and the current timeout count.
     * @param currentTimeMs current time in milliseconds
     * @returns true if priority fee should be included in the next transaction
     */
    updatePriorityFee(currentTimeMs, txTimeoutCount) {
        let triggerPriorityFee = false;
        if (txTimeoutCount > this.lastTxTimeoutCount) {
            this.lastTxTimeoutCount = txTimeoutCount;
            this.lastTxTimeoutCountTriggered = currentTimeMs;
            triggerPriorityFee = true;
        }
        else {
            if (!this.priorityFeeTriggered) {
                triggerPriorityFee = false;
            }
            else if (currentTimeMs - this.lastTxTimeoutCountTriggered <
                this.priorityFeeLatchDurationMs) {
                triggerPriorityFee = true;
            }
        }
        this.priorityFeeTriggered = triggerPriorityFee;
        return triggerPriorityFee;
    }
    /**
     * This method returns a transaction instruction list that sets the compute limit on the ComputeBudget program.
     * @param computeUnitLimit - The maximum number of compute units that can be used by the transaction.
     * @returns An array of transaction instructions.
     */
    generateComputeBudgetIxs(computeUnitLimit) {
        const ixs = [
            web3_js_1.ComputeBudgetProgram.setComputeUnitLimit({
                units: computeUnitLimit,
            }),
        ];
        return ixs;
    }
    /**
     * Calculates the compute unit price to use based on the desired additional fee to pay and the compute unit limit.
     * @param computeUnitLimit desired CU to use
     * @param additionalFeeMicroLamports desired additional fee to pay, in micro lamports
     * @returns the compute unit price to use, in micro lamports
     */
    calculateComputeUnitPrice(computeUnitLimit, additionalFeeMicroLamports) {
        return additionalFeeMicroLamports / computeUnitLimit;
    }
    /**
     * This method generates a list of transaction instructions for the ComputeBudget program, and includes a priority fee if it's required
     * @param computeUnitLimit - The maximum number of compute units that can be used by the transaction.
     * @param usePriorityFee - A boolean indicating whether to include a priority fee in the transaction, this should be from `this.updatePriorityFee()` or `this.priorityFeeTriggered`.
     * @param additionalFeeMicroLamports - The additional fee to be paid, in micro lamports, the actual price will be calculated.
     * @returns An array of transaction instructions.
     */
    generateComputeBudgetWithPriorityFeeIx(computeUnitLimit, usePriorityFee, additionalFeeMicroLamports) {
        const ixs = this.generateComputeBudgetIxs(computeUnitLimit);
        if (usePriorityFee) {
            const computeUnitPrice = this.calculateComputeUnitPrice(computeUnitLimit, additionalFeeMicroLamports);
            ixs.push(web3_js_1.ComputeBudgetProgram.setComputeUnitPrice({
                microLamports: computeUnitPrice,
            }));
        }
        return ixs;
    }
}
exports.PriorityFeeCalculator = PriorityFeeCalculator;