web3-utils
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Collection of utility functions used in web3.js.
147 lines (144 loc) • 6.09 kB
JavaScript
;
/*
This file is part of web3.js.
web3.js is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
web3.js is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with web3.js. If not, see <http://www.gnu.org/licenses/>.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.fromTwosComplement = exports.toTwosComplement = exports.leftPad = exports.rightPad = exports.padRight = exports.padLeft = void 0;
const web3_errors_1 = require("web3-errors");
const web3_validator_1 = require("web3-validator");
const converters_js_1 = require("./converters.js");
/**
* Adds a padding on the left of a string, if value is a integer or bigInt will be converted to a hex string.
* @param value - The value to be padded.
* @param characterAmount - The amount of characters the string should have.
* @param sign - The sign to be added (default is 0).
* @returns The padded string.
*
* @example
* ```ts
*
* console.log(web3.utils.padLeft('0x123', 10));
* >0x0000000123
* ```
*/
const padLeft = (value, characterAmount, sign = '0') => {
// To avoid duplicate code and circular dependency we will
// use `padLeft` implementation from `web3-validator`
if (typeof value === 'string') {
if (!(0, web3_validator_1.isHexStrict)(value)) {
return value.padStart(characterAmount, sign);
}
return web3_validator_1.utils.padLeft(value, characterAmount, sign);
}
web3_validator_1.validator.validate(['int'], [value]);
return web3_validator_1.utils.padLeft(value, characterAmount, sign);
};
exports.padLeft = padLeft;
/**
* Adds a padding on the right of a string, if value is a integer or bigInt will be converted to a hex string.
* @param value - The value to be padded.
* @param characterAmount - The amount of characters the string should have.
* @param sign - The sign to be added (default is 0).
* @returns The padded string.
*
* @example
* ```ts
* console.log(web3.utils.padRight('0x123', 10));
* > 0x1230000000
*
* console.log(web3.utils.padRight('0x123', 10, '1'));
* > 0x1231111111
* ```
*/
const padRight = (value, characterAmount, sign = '0') => {
if (typeof value === 'string' && !(0, web3_validator_1.isHexStrict)(value)) {
return value.padEnd(characterAmount, sign);
}
const hexString = typeof value === 'string' && (0, web3_validator_1.isHexStrict)(value) ? value : (0, converters_js_1.numberToHex)(value);
const prefixLength = hexString.startsWith('-') ? 3 : 2;
web3_validator_1.validator.validate([hexString.startsWith('-') ? 'int' : 'uint'], [value]);
return hexString.padEnd(characterAmount + prefixLength, sign);
};
exports.padRight = padRight;
/**
* Adds a padding on the right of a string, if value is a integer or bigInt will be converted to a hex string. @alias `padRight`
*/
exports.rightPad = exports.padRight;
/**
* Adds a padding on the left of a string, if value is a integer or bigInt will be converted to a hex string. @alias `padLeft`
*/
exports.leftPad = exports.padLeft;
/**
* Converts a negative number into the two’s complement and return a hexstring of 64 nibbles.
* @param value - The value to be converted.
* @param nibbleWidth - The nibble width of the hex string (default is 64).
*
* @returns The hex string of the two’s complement.
*
* @example
* ```ts
* console.log(web3.utils.toTwosComplement(13, 32));
* > 0x0000000000000000000000000000000d
*
* console.log(web3.utils.toTwosComplement('-0x1', 32));
* > 0xffffffffffffffffffffffffffffffff
*
* console.log(web3.utils.toTwosComplement(BigInt('9007199254740992'), 32));
* > 0x00000000000000000020000000000000
* ```
*/
const toTwosComplement = (value, nibbleWidth = 64) => {
web3_validator_1.validator.validate(['int'], [value]);
const val = (0, converters_js_1.toNumber)(value);
if (val >= 0)
return (0, exports.padLeft)((0, converters_js_1.toHex)(val), nibbleWidth);
const largestBit = (0, web3_validator_1.bigintPower)(BigInt(2), BigInt(nibbleWidth * 4));
if (-val >= largestBit) {
throw new web3_errors_1.NibbleWidthError(`value: ${value}, nibbleWidth: ${nibbleWidth}`);
}
const updatedVal = BigInt(val);
const complement = updatedVal + largestBit;
return (0, exports.padLeft)((0, converters_js_1.numberToHex)(complement), nibbleWidth);
};
exports.toTwosComplement = toTwosComplement;
/**
* Converts the twos complement into a decimal number or big int.
* @param value - The value to be converted.
* @param nibbleWidth - The nibble width of the hex string (default is 64).
* @returns The decimal number or big int.
*
* @example
* ```ts
* console.log(web3.utils.fromTwosComplement('0x0000000000000000000000000000000d', 32'));
* > 13
*
* console.log(web3.utils.fromTwosComplement('0x00000000000000000020000000000000', 32));
* > 9007199254740992n
* ```
*/
const fromTwosComplement = (value, nibbleWidth = 64) => {
web3_validator_1.validator.validate(['int'], [value]);
const val = (0, converters_js_1.toNumber)(value);
if (val < 0)
return val;
const largestBit = Math.ceil(Math.log(Number(val)) / Math.log(2));
if (largestBit > nibbleWidth * 4)
throw new web3_errors_1.NibbleWidthError(`value: "${value}", nibbleWidth: "${nibbleWidth}"`);
// check the largest bit to see if negative
if (nibbleWidth * 4 !== largestBit)
return val;
const complement = (0, web3_validator_1.bigintPower)(BigInt(2), BigInt(nibbleWidth) * BigInt(4));
return (0, converters_js_1.toNumber)(BigInt(val) - complement);
};
exports.fromTwosComplement = fromTwosComplement;
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