/*!
* compactblock.js - compact block object for bcoin
* Copyright (c) 2014-2015, Fedor Indutny (MIT License)
* Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
* https://github.com/indutny/bcoin
*/
module.exports = function(bcoin) {
var bn = require('bn.js');
var utils = require('./utils');
var assert = utils.assert;
/**
* A block object which is essentially a "placeholder"
* for a full {@link Block} object. The v8 garbage
* collector's head will explode if there is too much
* data on the javascript heap. Blocks can currently
* be up to 1mb in size. In the future, they may be
* 2mb, 8mb, or maybe 20mb, who knows? A CompactBlock
* is an optimization in BCoin which defers parsing of
* the serialized transactions (the block Buffer) until
* the block has passed through the chain queue and
* is about to enter the chain. This keeps a lot data
* off of the javascript heap for most of the time a
* block even exists in memory, and manages to keep a
* lot of strain off of the garbage collector. Having
* 500mb of blocks on the js heap would not be a good
* thing.
* @exports CompactBlock
* @constructor
* @param {Object} data
* @property {Number} version - Block version. Note
* that BCoin reads versions as unsigned despite
* them being signed on the protocol level. This
* number will never be negative.
* @property {Hash} prevBlock - Previous block hash.
* @property {Hash} merkleRoot - Merkle root hash.
* @property {Number} ts - Timestamp.
* @property {Number} bits
* @property {Number} nonce
* @property {Number} totalTX - Transaction count.
* @property {Number} height - Block height (-1 if not present).
* @property {Number} coinbaseHeight - The coinbase height which
* was extracted by the parser (the coinbase is the only
* transaction we parse ahead of time).
* @property {Buffer} _raw - The raw block data.
* @property {ReversedHash} rhash - Reversed block hash (uint256le).
*/
function CompactBlock(data) {
if (!(this instanceof CompactBlock))
return new CompactBlock(data);
bcoin.abstractblock.call(this, data);
this.type = 'compactblock';
this.coinbaseHeight = -1;
if (this.version >= 2) {
if (Buffer.isBuffer(data.coinbaseHeight) && data.coinbaseHeight.length <= 6)
this.coinbaseHeight = new bn(data.coinbaseHeight, 'le').toNumber();
}
}
utils.inherits(CompactBlock, bcoin.abstractblock);
/**
* Verify the block headers.
* @alias verify
* @param {Object?} ret - Return object, may be
* set with properties `reason` and `score`.
* @returns {Boolean}
*/
CompactBlock.prototype._verify = function _verify(ret) {
return this.verifyHeaders(ret);
};
/**
* Retrieve the coinbase height from the coinbase input script (already
* extracted in actuality).
* @returns {Number} height (-1 if not present).
*/
CompactBlock.prototype.getCoinbaseHeight = function getCoinbaseHeight() {
return this.coinbaseHeight;
};
/**
* Parse the serialized block data and create an actual {@link Block}.
* @returns {Block}
* @throws Parse error
*/
CompactBlock.prototype.toBlock = function toBlock() {
var block = bcoin.protocol.parser.parseBlock(this._raw);
delete this._raw;
assert(!block._raw);
block = new bcoin.block(block);
if (this.valid != null)
block.valid = this.valid;
return block;
};
/**
* Test an object to see if it is a CompactBlock.
* @param {Object} obj
* @returns {Boolean}
*/
CompactBlock.isCompactBlock = function isCompactBlock(block) {
return block
&& block.type === 'compactblock'
&& typeof block.toBlock === 'function';
};
return CompactBlock;
};