ethers.js/utils/solidity.js

'use strict';

var bigNumberify = require('./bignumber').bigNumberify;
var convert = require('./convert');
var getAddress = require('./address').getAddress;
var utf8 = require('./utf8');

var hashKeccak256 = require('./keccak256');
var hashSha256 = require('./sha2').sha256;

var regexBytes = new RegExp("^bytes([0-9]+)$");
var regexNumber = new RegExp("^(u?int)([0-9]*)$");
var regexArray = new RegExp("^(.*)\\[([0-9]*)\\]$");

var Zeros = '0000000000000000000000000000000000000000000000000000000000000000';

function _pack(type, value, isArray) {
    switch(type) {
        case 'address':
            if (isArray) { return convert.padZeros(value, 32); }
            return convert.arrayify(value);
        case 'string':
            return utf8.toUtf8Bytes(value);
        case 'bytes':
            return convert.arrayify(value);
        case 'bool':
            value = (value ? '0x01': '0x00');
            if (isArray) { return convert.padZeros(value, 32); }
            return convert.arrayify(value);
    }

    var match =  type.match(regexNumber);
    if (match) {
        var signed = (match[1] === 'int')
        var size = parseInt(match[2] || "256")
        if ((size % 8 != 0) || size === 0 || size > 256) {
            throw new Error('invalid number type - ' + type);
        }

        if (isArray) { size = 256; }

        value = bigNumberify(value).toTwos(size);

        return convert.padZeros(value, size / 8);
    }

    match = type.match(regexBytes);
    if (match) {
        var size = match[1];
        if (size != parseInt(size) || size === 0 || size > 32) {
            throw new Error('invalid number type - ' + type);
        }
        size = parseInt(size);
        if (convert.arrayify(value).byteLength !== size) { throw new Error('invalid value for ' + type); }
        if (isArray) { return (value + Zeros).substring(0, 66); }
        return value;
    }

    match = type.match(regexArray);
    if (match) {
        var baseType = match[1];
        var count = parseInt(match[2] || value.length);
        if (count != value.length) { throw new Error('invalid value for ' + type); }
        var result = [];
        value.forEach(function(value) {
            value = _pack(baseType, value, true);
            result.push(value);
        });
        return convert.concat(result);
    }

    throw new Error('unknown type - ' + type);
}

function pack(types, values) {
    if (types.length != values.length) { throw new Error('type/value count mismatch'); }
    var tight = [];
    types.forEach(function(type, index) {
        tight.push(_pack(type, values[index]));
    });
    return convert.hexlify(convert.concat(tight));
}

function keccak256(types, values) {
    return hashKeccak256(pack(types, values));
}

function sha256(types, values) {
    return hashSha256(pack(types, values));
}

module.exports = {
    pack: pack,

    keccak256: keccak256,
    sha256: sha256,
}