web3.js/lib/formatters.js

/*
    This file is part of ethereum.js.

    ethereum.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.

    ethereum.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 ethereum.js.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file formatters.js
 * @authors:
 *   Marek Kotewicz <marek@ethdev.com>
 * @date 2015
 */

if (process.env.NODE_ENV !== 'build') {
    var BigNumber = require('bignumber.js'); // jshint ignore:line
}

var utils = require('./utils');
var c = require('./const');

/// @param string string to be padded
/// @param number of characters that result string should have
/// @param sign, by default 0
/// @returns right aligned string
var padLeft = function (string, chars, sign) {
    return new Array(chars - string.length + 1).join(sign ? sign : "0") + string;
};

/// Formats input value to byte representation of int
/// If value is negative, return it's two's complement
/// If the value is floating point, round it down
/// @returns right-aligned byte representation of int
var formatInputInt = function (value) {
    /*jshint maxcomplexity:7 */
    var padding = c.ETH_PADDING * 2;
    if (value instanceof BigNumber || typeof value === 'number') {
        if (typeof value === 'number')
            value = new BigNumber(value);
        BigNumber.config(c.ETH_BIGNUMBER_ROUNDING_MODE);
        value = value.round();

        if (value.lessThan(0)) 
            value = new BigNumber("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 16).plus(value).plus(1);
        value = value.toString(16);
    }
    else if (value.indexOf('0x') === 0)
        value = value.substr(2);
    else if (typeof value === 'string')
        value = formatInputInt(new BigNumber(value));
    else
        value = (+value).toString(16);
    return padLeft(value, padding);
};

/// Formats input value to byte representation of string
/// @returns left-algined byte representation of string
var formatInputString = function (value) {
    return utils.fromAscii(value, c.ETH_PADDING).substr(2);
};

/// Formats input value to byte representation of bool
/// @returns right-aligned byte representation bool
var formatInputBool = function (value) {
    return '000000000000000000000000000000000000000000000000000000000000000' + (value ?  '1' : '0');
};

/// Formats input value to byte representation of real
/// Values are multiplied by 2^m and encoded as integers
/// @returns byte representation of real
var formatInputReal = function (value) {
    return formatInputInt(new BigNumber(value).times(new BigNumber(2).pow(128))); 
};


/// Check if input value is negative
/// @param value is hex format
/// @returns true if it is negative, otherwise false
var signedIsNegative = function (value) {
    return (new BigNumber(value.substr(0, 1), 16).toString(2).substr(0, 1)) === '1';
};

/// Formats input right-aligned input bytes to int
/// @returns right-aligned input bytes formatted to int
var formatOutputInt = function (value) {

    value = value || "0";

    // check if it's negative number
    // it it is, return two's complement
    if (signedIsNegative(value)) {
        return new BigNumber(value, 16).minus(new BigNumber('ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff', 16)).minus(1);
    }
    return new BigNumber(value, 16);
};


/// Formats big right-aligned input bytes to uint
/// @returns right-aligned input bytes formatted to uint
var formatOutputUInt = function (value) {
    value = value || "0";
    return new BigNumber(value, 16);
};

/// @returns input bytes formatted to real
var formatOutputReal = function (value) {
    return formatOutputInt(value).dividedBy(new BigNumber(2).pow(128)); 
};

/// @returns input bytes formatted to ureal
var formatOutputUReal = function (value) {
    return formatOutputUInt(value).dividedBy(new BigNumber(2).pow(128)); 
};

/// @returns right-aligned input bytes formatted to hex
var formatOutputHash = function (value) {
    return "0x" + value;
};

/// @returns right-aligned input bytes formatted to bool
var formatOutputBool = function (value) {
    return value === '0000000000000000000000000000000000000000000000000000000000000001' ? true : false;
};

/// @returns left-aligned input bytes formatted to ascii string
var formatOutputString = function (value) {
    return utils.toAscii(value);
};

/// @returns right-aligned input bytes formatted to address
var formatOutputAddress = function (value) {
    return "0x" + value.slice(value.length - 40, value.length);
};


/// Formats the input to a big number
/// @returns a BigNumber object
var convertToBigNumber = function (value) {

    // remove the leading 0x
    if(typeof value === 'string')
        value = value.replace('0x', '');

    value = value || "0";

    return new BigNumber(value, 16);
};


/**
Formats the input of a transaction and converts all values to HEX

@returns object
*/
var inputTransactionFormatter = function(options){

    // make code -> data
    if(options.code) {
        options.data = options.code;
        delete options.code;
    }

    // make endowment -> value
    if(options.endowment) {
        options.value = options.endowment;
        delete options.endowment;
    }


    // format the following options
    /*jshint maxcomplexity:5 */
    ['gasPrice', 'value'].forEach(function(key){

        // if hex or string integer
        if(typeof options[key] === 'string') {

            // if not hex assume its a number string
            if(options[key].indexOf('0x') === -1)
                options[key] = utils.fromDecimal(options[key]);

        // if number
        } else if(typeof options[key] === 'number') {
            options[key] = utils.fromDecimal(options[key]);

        // if bignumber
        } else if(options[key] instanceof BigNumber) {
            options[key] = '0x'+ options[key].toString(16);
        }
    });

    // format gas to number
    options.gas = Number(options.gas);


    return options;
};

/**
Formats the output of a transaction to its proper values

@returns object
*/
var outputTransactionFormatter = function(tx){
    // transform to number
    tx.gas = Number(tx.gas);

    // gasPrice to bignumber
    if(typeof tx.gasPrice === 'string' && tx.gasPrice.indexOf('0x') === 0)
        tx.gasPrice = new BigNumber(tx.gasPrice, 16);
    else
        tx.gasPrice = new BigNumber(tx.gasPrice.toString(10), 10);

    // value to bignumber
    if(typeof tx.value === 'string' && tx.value.indexOf('0x') === 0)
        tx.value = new BigNumber(tx.value, 16);
    else
        tx.value = new BigNumber(tx.value.toString(10), 10);

    return tx;
};


/**
Formats the output of a block to its proper values

@returns object
*/
var outputBlockFormatter = function(block){
    /*jshint maxcomplexity:7 */

    // transform to number
    block.gasLimit = Number(block.gasLimit);
    block.gasUsed = Number(block.gasUsed);
    block.size = Number(block.size);
    block.timestamp = Number(block.timestamp);
    block.number = Number(block.number);

    // minGasPrice to bignumber
    if(block.minGasPrice) {
        if(typeof block.minGasPrice === 'string' && block.minGasPrice.indexOf('0x') === 0)
            block.minGasPrice = new BigNumber(block.minGasPrice, 16);
        else
            block.minGasPrice = new BigNumber(block.minGasPrice.toString(10), 10);
    }


    // difficulty to bignumber
    if(block.difficulty) {
        if(typeof block.difficulty === 'string' && block.difficulty.indexOf('0x') === 0)
            block.difficulty = new BigNumber(block.difficulty, 16);
        else
            block.difficulty = new BigNumber(block.difficulty.toString(10), 10);
    }


    // difficulty to bignumber
    if(block.totalDifficulty) {
        if(typeof block.totalDifficulty === 'string' && block.totalDifficulty.indexOf('0x') === 0)
            block.totalDifficulty = new BigNumber(block.totalDifficulty, 16);
        else
            block.totalDifficulty = new BigNumber(block.totalDifficulty.toString(10), 10);
    }

    return block;
};


module.exports = {
    formatInputInt: formatInputInt,
    formatInputString: formatInputString,
    formatInputBool: formatInputBool,
    formatInputReal: formatInputReal,
    formatOutputInt: formatOutputInt,
    formatOutputUInt: formatOutputUInt,
    formatOutputReal: formatOutputReal,
    formatOutputUReal: formatOutputUReal,
    formatOutputHash: formatOutputHash,
    formatOutputBool: formatOutputBool,
    formatOutputString: formatOutputString,
    formatOutputAddress: formatOutputAddress,
    convertToBigNumber: convertToBigNumber,
    inputTransactionFormatter: inputTransactionFormatter,
    outputTransactionFormatter: outputTransactionFormatter,
    outputBlockFormatter: outputBlockFormatter
};