@pythnetwork/price-service-sdk/dist/esm/AccumulatorUpdateData.mjs

Pyth price service SDK

import BN from "bn.js";
const ACCUMULATOR_MAGIC = "504e4155";
const MAJOR_VERSION = 1;
const MINOR_VERSION = 0;
const KECCAK160_HASH_SIZE = 20;
const PRICE_FEED_MESSAGE_VARIANT = 0;
const TWAP_MESSAGE_VARIANT = 1;
export function isAccumulatorUpdateData(updateBytes) {
    return updateBytes.toString("hex").startsWith(ACCUMULATOR_MAGIC) && updateBytes[4] === MAJOR_VERSION && updateBytes[5] === MINOR_VERSION;
}
export function parsePriceFeedMessage(message) {
    let cursor = 0;
    const variant = message.readUInt8(cursor);
    if (variant !== PRICE_FEED_MESSAGE_VARIANT) {
        throw new Error("Not a price feed message");
    }
    cursor += 1;
    const feedId = message.subarray(cursor, cursor + 32);
    cursor += 32;
    const price = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const confidence = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const exponent = message.readInt32BE(cursor);
    cursor += 4;
    const publishTime = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const prevPublishTime = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const emaPrice = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const emaConf = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    return {
        feedId,
        price,
        confidence,
        exponent,
        publishTime,
        prevPublishTime,
        emaPrice,
        emaConf
    };
}
export function parseTwapMessage(message) {
    let cursor = 0;
    const variant = message.readUInt8(cursor);
    if (variant !== TWAP_MESSAGE_VARIANT) {
        throw new Error("Not a twap message");
    }
    cursor += 1;
    const feedId = message.subarray(cursor, cursor + 32);
    cursor += 32;
    const cumulativePrice = new BN(message.subarray(cursor, cursor + 16), "be");
    cursor += 16;
    const cumulativeConf = new BN(message.subarray(cursor, cursor + 16), "be");
    cursor += 16;
    const numDownSlots = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const exponent = message.readInt32BE(cursor);
    cursor += 4;
    const publishTime = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const prevPublishTime = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    const publishSlot = new BN(message.subarray(cursor, cursor + 8), "be");
    cursor += 8;
    return {
        feedId,
        cumulativePrice,
        cumulativeConf,
        numDownSlots,
        exponent,
        publishTime,
        prevPublishTime,
        publishSlot
    };
}
/**
 * An AccumulatorUpdateData contains a VAA and a list of updates. This function returns a new serialized AccumulatorUpdateData with only the updates in the range [start, end).
 */ export function sliceAccumulatorUpdateData(data, start, end) {
    if (!isAccumulatorUpdateData(data)) {
        throw new Error("Invalid accumulator message");
    }
    let cursor = 6;
    const trailingPayloadSize = data.readUint8(cursor);
    cursor += 1 + trailingPayloadSize;
    // const proofType = data.readUint8(cursor);
    cursor += 1;
    const vaaSize = data.readUint16BE(cursor);
    cursor += 2;
    cursor += vaaSize;
    const endOfVaa = cursor;
    const updates = [];
    const numUpdates = data.readUInt8(cursor);
    cursor += 1;
    for(let i = 0; i < numUpdates; i++){
        const updateStart = cursor;
        const messageSize = data.readUint16BE(cursor);
        cursor += 2;
        cursor += messageSize;
        const numProofs = data.readUInt8(cursor);
        cursor += 1;
        cursor += KECCAK160_HASH_SIZE * numProofs;
        updates.push(data.subarray(updateStart, cursor));
    }
    if (cursor !== data.length) {
        throw new Error("Didn't reach the end of the message");
    }
    const sliceUpdates = updates.slice(start, end);
    return Buffer.concat([
        data.subarray(0, endOfVaa),
        Buffer.from([
            sliceUpdates.length
        ]),
        ...updates.slice(start, end)
    ]);
}
export function parseAccumulatorUpdateData(data) {
    if (!isAccumulatorUpdateData(data)) {
        throw new Error("Invalid accumulator message");
    }
    let cursor = 6;
    const trailingPayloadSize = data.readUint8(cursor);
    cursor += 1 + trailingPayloadSize;
    // const proofType = data.readUint8(cursor);
    cursor += 1;
    const vaaSize = data.readUint16BE(cursor);
    cursor += 2;
    const vaa = data.subarray(cursor, cursor + vaaSize);
    cursor += vaaSize;
    const numUpdates = data.readUInt8(cursor);
    const updates = [];
    cursor += 1;
    for(let i = 0; i < numUpdates; i++){
        const messageSize = data.readUint16BE(cursor);
        cursor += 2;
        const message = data.subarray(cursor, cursor + messageSize);
        cursor += messageSize;
        const numProofs = data.readUInt8(cursor);
        cursor += 1;
        const proof = [];
        for(let j = 0; j < numProofs; j++){
            proof.push([
                ...data.subarray(cursor, cursor + KECCAK160_HASH_SIZE)
            ]);
            cursor += KECCAK160_HASH_SIZE;
        }
        updates.push({
            message,
            proof
        });
    }
    if (cursor !== data.length) {
        throw new Error("Didn't reach the end of the message");
    }
    return {
        vaa,
        updates
    };
}