snarky-smt/build/module/lib/utils.js

Sparse Merkle Tree for SnarkyJS

import { Field } from 'snarkyjs';
export { createEmptyValue, fieldToHexString, hexStringToField, strToFieldArry, countCommonPrefix, countSetBits, printBits, };
/**
 * Create a empty value for a Struct Type
 *
 * @template T
 * @param {Provable<T>} valueType
 * @return {*}  {T}
 */
function createEmptyValue(valueType) {
    const dummy = (() => {
        const n = valueType.sizeInFields();
        const xs = [];
        for (var i = 0; i < n; ++i) {
            xs.push(Field.zero);
        }
        return valueType.fromFields(xs, valueType.toAuxiliary());
    })();
    return dummy;
}
/**
 * Convert field to hex string.
 *
 * @param {Field} f
 * @return {*}  {string}
 */
function fieldToHexString(f) {
    return '0x' + f.toBigInt().toString(16);
}
/**
 * Convert hex strong to field.
 *
 * @param {string} hexStr
 * @return {*}  {Field}
 */
function hexStringToField(hexStr) {
    return Field(BigInt(hexStr));
}
/**
 * Convert a string to Field array.
 *
 * @param {string} str
 * @return {*}  {Field[]}
 */
function strToFieldArry(str) {
    const sarr = str.split(',');
    let fs = [];
    for (let i = 0, len = sarr.length; i < len; i++) {
        let v = sarr[i];
        fs.push(new Field(v));
    }
    return fs;
}
function countCommonPrefix(data1bits, data2bits) {
    let count = 0;
    const len = data1bits.length;
    for (let i = 0; i < len; i++) {
        if (data1bits[i].equals(data2bits[i]).toBoolean()) {
            count++;
        }
        else {
            break;
        }
    }
    return count;
}
function countSetBits(data) {
    let count = 0;
    for (let i = 0, len = data.length; i < len; i++) {
        if (data[i].toBoolean()) {
            count++;
        }
    }
    return count;
}
/**
 * Print bits string.
 *
 * @param {Bool[]} data
 */
function printBits(data, varName) {
    let str = '';
    let i = 0;
    data.forEach((v) => {
        if (v.toBoolean()) {
            str = str + '1';
        }
        else {
            str = str + '0';
        }
        i++;
    });
    if (varName) {
        console.log(`[${varName}]: ${str}, bit size: ${i}`);
    }
    else {
        console.log(`bit data: ${str}, bit size: ${i}`);
    }
}