fcoin/lib/script/program.js
2017-07-17 14:26:37 -07:00

109 lines
2.5 KiB
JavaScript

/*!
* program.js - program object for bcoin
* Copyright (c) 2014-2015, Fedor Indutny (MIT License)
* Copyright (c) 2014-2017, Christopher Jeffrey (MIT License).
* https://github.com/bcoin-org/bcoin
*/
'use strict';
const assert = require('assert');
const util = require('../utils/util');
const common = require('./common');
const scriptTypes = common.types;
/**
* Witness Program
* @constructor
* @alias module:script.Program
* @param {Number} version
* @param {Buffer} data
* @property {Number} version - Ranges from 0 to 16.
* @property {String|null} type - Null if malformed. `unknown` if unknown
* version (treated as anyone-can-spend). Otherwise one of `witnesspubkeyhash`
* or `witnessscripthash`.
* @property {Buffer} data - The hash (for now).
*/
function Program(version, data) {
if (!(this instanceof Program))
return new Program(version, data);
assert(util.isNumber(version));
assert(Buffer.isBuffer(data));
assert(version >= 0 && version <= 16);
assert(data.length >= 2 && data.length <= 40);
this.version = version;
this.data = data;
}
/**
* Get the witness program type.
* @returns {ScriptType}
*/
Program.prototype.getType = function getType() {
if (this.version === 0) {
if (this.data.length === 20)
return scriptTypes.WITNESSPUBKEYHASH;
if (this.data.length === 32)
return scriptTypes.WITNESSSCRIPTHASH;
// Fail on bad version=0
return scriptTypes.WITNESSMALFORMED;
}
if (this.version === 1) {
if (this.data.length === 32)
return scriptTypes.WITNESSMASTHASH;
// Fail on bad version=1
return scriptTypes.WITNESSMALFORMED;
}
// No interpretation of script (anyone can spend)
return scriptTypes.NONSTANDARD;
};
/**
* Test whether the program is either
* an unknown version or malformed.
* @returns {Boolean}
*/
Program.prototype.isUnknown = function isUnknown() {
let type = this.getType();
return type === scriptTypes.WITNESSMALFORMED
|| type === scriptTypes.NONSTANDARD;
};
/**
* Test whether the program is malformed.
* @returns {Boolean}
*/
Program.prototype.isMalformed = function isMalformed() {
return this.getType() === scriptTypes.WITNESSMALFORMED;
};
/**
* Inspect the program.
* @returns {String}
*/
Program.prototype.inspect = function inspect() {
return '<Program:'
+ ' version=' + this.version
+ ' data=' + this.data.toString('hex')
+ ' type=' + common.typesByVal[this.getType()].toLowerCase()
+ '>';
};
/*
* Expose
*/
module.exports = Program;