fcoin/lib/bcoin/chain.js
Christopher Jeffrey 849f1d842e more refactoring.
2016-04-04 17:37:53 -07:00

2075 lines
52 KiB
JavaScript

/**
* chain.js - blockchain management for bcoin
* Copyright (c) 2014-2015, Fedor Indutny (MIT License)
* https://github.com/indutny/bcoin
*/
var EventEmitter = require('events').EventEmitter;
var bcoin = require('../bcoin');
var bn = require('bn.js');
var constants = bcoin.protocol.constants;
var network = bcoin.protocol.network;
var utils = require('./utils');
var assert = utils.assert;
var VerifyError = utils.VerifyError;
/**
* Chain
*/
function Chain(node, options) {
if (!(this instanceof Chain))
return new Chain(node, options);
EventEmitter.call(this);
if (!options)
options = {};
this.options = options;
this.node = node;
this.loaded = false;
this.mempool = node.mempool;
this.db = new bcoin.chaindb(this, options);
this.total = 0;
this.orphanLimit = options.orphanLimit || (20 << 20);
this.pendingLimit = options.pendingLimit || (20 << 20);
this.locker = new bcoin.locker(this, this.add, this.pendingLimit);
this.invalid = {};
this.bestHeight = -1;
this.lastUpdate = utils.now();
this.tip = null;
this.height = -1;
this.segwitActive = null;
this.spv = !!options.spv;
this.orphan = {
map: {},
bmap: {},
count: 0,
size: 0
};
Chain.global = this;
this._init();
}
utils.inherits(Chain, EventEmitter);
Chain.prototype._init = function _init() {
var self = this;
function getHost() {
var peer;
if (!self.node || !self.node.pool)
return;
peer = self.node.pool.peers.load;
if (!peer)
return 'unknown';
return peer.host;
}
// Hook into events for debugging
this.on('block', function(block, entry) {
if (self.height < 400000)
return;
utils.debug('Block %s (%d) added to chain (%s)',
utils.revHex(entry.hash), entry.height, getHost());
});
this.on('competitor', function(block, entry) {
utils.debug('Heads up: Competing chain at height %d:'
+ ' tip-height=%d competitor-height=%d'
+ ' tip-hash=%s competitor-hash=%s'
+ ' tip-chainwork=%s competitor-chainwork=%s'
+ ' chainwork-diff=%s (%s)',
entry.height,
self.tip.height,
entry.height,
utils.revHex(self.tip.hash),
utils.revHex(entry.hash),
self.tip.chainwork.toString(),
entry.chainwork.toString(),
self.tip.chainwork.sub(entry.chainwork).toString(),
getHost());
});
this.on('resolved', function(block, entry) {
utils.debug('Orphan %s (%d) was resolved (%s)',
utils.revHex(entry.hash), entry.height, getHost());
});
this.on('checkpoint', function(block, data) {
utils.debug('Hit checkpoint block %s (%d) (%s)',
utils.revHex(data.checkpoint), data.height, getHost());
});
this.on('fork', function(block, data) {
utils.debug(
'Fork at height %d: expected=%s received=%s checkpoint=%s',
data.height,
utils.revHex(data.expected),
utils.revHex(data.received),
data.checkpoint,
getHost()
);
if (data.checkpoint)
utils.debug('WARNING: Block failed a checkpoint.');
});
this.on('invalid', function(block, data) {
utils.debug(
'Invalid block at height %d: hash=%s (%s)',
data.height,
utils.revHex(data.hash),
getHost()
);
if (data.chain) {
utils.debug(
'Peer is sending an invalid continuation chain (%s)',
getHost());
} else if (data.seen) {
utils.debug('Peer is sending an invalid chain (%s)', getHost());
}
});
this.on('exists', function(block, data) {
utils.debug('Already have block %s (%s)',
data.height, getHost());
});
this.on('orphan', function(block, data) {
utils.debug('Handled orphan %s (%s)', utils.revHex(data.hash), getHost());
});
this.on('purge', function(count, size) {
utils.debug('Warning: %d (%dmb) orphans cleared!', count, utils.mb(size));
});
this.db.on('add entry', function(entry) {
self.emit('add entry', entry);
});
this.db.on('remove entry', function(entry) {
self.emit('remove entry', entry);
});
this.db.on('add block', function(block) {
self.emit('add block', block);
});
this.db.on('remove block', function(block) {
self.emit('remove block', block);
});
utils.debug('Chain is loading.');
self.db.open(function(err) {
if (err)
return self.emit('error', err);
self._preload(function(err) {
if (err)
return self.emit('error', err);
self.db.getTip(function(err, tip) {
if (err)
return self.emit('error', err);
assert(tip);
self.tip = tip;
self.height = tip.height;
if (self.bestHeight === -1)
network.height = tip.height;
self.isSegwitActive(function(err, result) {
if (err)
return self.emit('error', err);
if (result)
utils.debug('Segwit is active.');
self.loaded = true;
self.emit('open');
self.emit('tip', tip);
if (self.isFull())
self.emit('full');
});
});
});
});
};
Chain.prototype.open = function open(callback) {
if (this.loaded)
return utils.nextTick(callback);
this.once('open', callback);
};
Chain.prototype.close =
Chain.prototype.destroy = function destroy(callback) {
this.db.close(utils.ensure(callback));
};
Chain.prototype._lock = function _lock(func, args, force) {
return this.locker.lock(func, args, force);
};
// Stream headers from electrum.org for quickly
// preloading the chain. Electrum.org stores
// headers in the standard block header format,
// but they do not store chainwork, so we have
// to calculate it ourselves.
Chain.prototype._preload = function _preload(callback) {
var self = this;
var url = 'https://headers.electrum.org/blockchain_headers';
var buf, height, stream;
var request = require('./http/request');
var locker = new bcoin.locker();
if (!this.options.preload)
return callback();
if (!this.spv)
return callback();
if (network.type !== 'main')
return callback(new Error('Electrum.org only offers `main` headers.'));
utils.debug('Loading %s', url);
function parseHeader(buf) {
var headers = bcoin.protocol.parser.parseBlockHeaders(buf);
headers.hash = utils.toHex(utils.dsha256(buf.slice(0, 80)));
return headers;
}
function save(entry) {
var unlock = locker.lock(save, [entry]);
if (!unlock)
return;
self.db.save(entry, null, true, function(err) {
if (err) {
stream.destroy();
locker.destroy();
return callback(err);
}
if (locker.jobs.length === 0 && save.ended)
return callback();
unlock();
});
}
this.db.getChainHeight(function(err, chainHeight) {
if (err)
return callback(err);
stream = request({ method: 'GET', uri: url });
height = 0;
buf = {
data: [],
size: 0
};
stream.on('response', function(res) {
if (res.statusCode >= 400) {
stream.destroy();
return callback(new Error('Bad response code: ' + res.statusCode));
}
});
stream.on('error', function(err) {
var start = Math.max(0, height - 2);
self.reset(start, function(e) {
if (e)
return callback(e);
return callback(err);
});
});
stream.on('data', function(data) {
var blocks = [];
var need = 80 - buf.size;
var lastEntry;
while (data.length >= need) {
buf.data.push(data.slice(0, need));
blocks.push(Buffer.concat(buf.data));
buf.data.length = 0;
buf.size = 0;
data = data.slice(need);
need = 80 - buf.size;
}
if (data.length > 0) {
assert(data.length < 80);
buf.data.push(data);
buf.size += data.length;
}
if (blocks.length === 0)
return;
blocks.forEach(function(data) {
var block, entry, start;
try {
data = parseHeader(data);
} catch (e) {
return callback(e);
}
data.height = height;
// Make sure the genesis block is correct.
if (data.height === 0 && data.hash !== network.genesis.hash) {
stream.destroy();
return callback(new Error('Bad genesis block.'));
}
// Do some paranoid checks.
if (lastEntry && data.prevBlock !== lastEntry.hash) {
start = Math.max(0, height - 2);
stream.destroy();
return self.reset(start, function(err) {
if (err)
return callback(err);
return callback(new Error('Corrupt headers.'));
});
}
// Create headers object for validation.
block = new bcoin.headers(data);
// Verify the block headers. We don't want to
// trust an external centralized source completely.
if (!block.verifyHeaders()) {
start = Math.max(0, height - 2);
stream.destroy();
return self.reset(start, function(err) {
if (err)
return callback(err);
return callback(new Error('Bad headers.'));
});
}
// Create a chain entry.
entry = new bcoin.chainblock(self, data, lastEntry);
if (entry.height <= chainHeight)
self.db.addCache(entry);
else
save(entry);
if ((height + 1) % 50000 === 0)
utils.debug('Received %d headers from electrum.org.', height + 1);
lastEntry = entry;
height++;
});
});
stream.on('end', function() {
save.ended = true;
if (!locker.busy && locker.jobs.length === 0)
return callback();
});
});
};
Chain.prototype._verifyContext = function _verifyContext(block, prev, callback) {
var self = this;
this._verify(block, prev, function(err, flags) {
if (err)
return callback(err);
self._checkDuplicates(block, prev, function(err, result) {
if (err)
return callback(err);
self._checkInputs(block, prev, flags, function(err) {
if (err)
return callback(err);
return callback();
});
});
});
};
Chain.prototype._verify = function _verify(block, prev, callback) {
var self = this;
var flags = constants.flags.MANDATORY_VERIFY_FLAGS;
var lockFlags = constants.flags.MANDATORY_LOCKTIME_FLAGS;
var height, ts, i, tx, coinbaseHeight;
var medianTime, segwit;
var ret = {};
function done(err, result) {
prev.free();
callback(err, result);
}
if (!block.verify(ret))
return done(new VerifyError(block, 'invalid', ret.reason, ret.score));
// Skip the genesis block
if (block.isGenesis())
return done(null, flags);
// Ensure it's not an orphan
if (!prev)
return done(new VerifyError(block, 'invalid', 'bad-prevblk', 0));
prev.ensureAncestors(function(err) {
if (err)
return done(err);
height = prev.height + 1;
medianTime = prev.getMedianTime();
// Ensure the timestamp is correct
if (block.ts <= medianTime)
return done(new VerifyError(block, 'invalid', 'time-too-old', 0));
if (block.bits !== self.getTarget(prev, block))
return done(new VerifyError(block, 'invalid', 'bad-diffbits', 100));
// For some reason bitcoind has p2sh in the
// mandatory flags by default, when in reality
// it wasn't activated until march 30th 2012.
// The first p2sh output and redeem script
// appeared on march 7th 2012, only it did
// not have a signature. See:
// 6a26d2ecb67f27d1fa5524763b49029d7106e91e3cc05743073461a719776192
// 9c08a4d78931342b37fd5f72900fb9983087e6f46c4a097d8a1f52c74e28eaf6
if (block.ts < constants.block.bip16time)
flags &= ~constants.flags.VERIFY_P2SH;
// Only allow version 2 blocks (coinbase height)
// once the majority of blocks are using it.
if (block.version < 2 && prev.isOutdated(2))
return done(new VerifyError(block, 'obsolete', 'bad-version', 0));
// Only allow version 3 blocks (sig validation)
// once the majority of blocks are using it.
if (block.version < 3 && prev.isOutdated(3))
return done(new VerifyError(block, 'obsolete', 'bad-version', 0));
// Only allow version 4 blocks (checklocktimeverify)
// once the majority of blocks are using it.
if (block.version < 4 && prev.isOutdated(4))
return done(new VerifyError(block, 'obsolete', 'bad-version', 0));
// Only allow version 5 blocks (segwit)
// once the majority of blocks are using it.
if (network.type === 'segnet3' && height >= network.segwitHeight) {
if (block.version < 5 && prev.isOutdated(5))
return done(new VerifyError(block, 'obsolete', 'bad-version', 0));
}
// Only allow version 8 blocks (locktime median past)
// once the majority of blocks are using it.
// if (block.version < 8 && prev.isOutdated(8))
// return done(new VerifyError(block, 'obsolete', 'bad-version', 0));
// Make sure the height contained in the coinbase is correct.
if (network.block.bip34height !== -1 && height >= network.block.bip34height) {
if (block.version >= 2 && prev.isUpgraded(2))
coinbaseHeight = true;
}
// Signature validation is now enforced (bip66)
if (block.version >= 3 && prev.isUpgraded(3))
flags |= constants.flags.VERIFY_DERSIG;
// CHECKLOCKTIMEVERIFY is now usable (bip65)
if (block.version >= 4 && prev.isUpgraded(4))
flags |= constants.flags.VERIFY_CHECKLOCKTIMEVERIFY;
// Segregrated witness is now usable
if (network.type === 'segnet3' && height >= network.segwitHeight) {
if (block.version >= 5 && prev.isUpgraded(5)) {
flags |= constants.flags.VERIFY_WITNESS;
segwit = true;
self.segwitActive = true;
} else if (block.version >= 5) {
self.segwitActive = false;
}
}
// Locktime median time past is now enforced.
// if (block.version >= 8 && prev.isUpgraded(8))
// lockFlags |= constants.flags.MEDIAN_TIME_PAST;
if (network.type === 'segnet4') {
self.getState(prev, 'witness', function(err, state) {
if (err)
return callback(err);
if (state === constants.thresholdStates.ACTIVE) {
flags |= constants.flags.VERIFY_WITNESS;
segwit = true;
self.segwitActive = true;
} else {
self.segwitActive = false;
}
return finish();
});
} else {
finish();
}
function finish() {
// Can't verify any further when merkleblock or headers.
if (block.type !== 'block')
return done(null, flags);
// Make sure the height contained in the coinbase is correct.
if (coinbaseHeight) {
if (block.getCoinbaseHeight() !== height)
return done(new VerifyError(block, 'invalid', 'bad-cb-height', 100));
}
if (segwit) {
if (block.commitmentHash !== block.getCommitmentHash('hex')) {
return done(new VerifyError(block,
'invalid',
'bad-blk-wit-length',
100));
}
} else {
if (block.hasWitness()) {
return done(new VerifyError(block,
'invalid',
'unexpected-witness',
100));
}
}
// Get timestamp for tx.isFinal().
ts = (lockFlags & constants.flags.MEDIAN_TIME_PAST) !== 0
? medianTime
: block.ts;
// Check all transactions
for (i = 0; i < block.txs.length; i++) {
tx = block.txs[i];
// Transactions must be finalized with
// regards to nSequence and nLockTime.
if (!tx.isFinal(height, ts)) {
return done(new VerifyError(block,
'invalid',
'bad-txns-nonfinal',
10));
}
}
return done(null, flags);
}
});
};
Chain.prototype._checkDuplicates = function _checkDuplicates(block, prev, callback) {
var self = this;
var height = prev.height + 1;
if (this.spv || block.type !== 'block')
return callback();
if (block.isGenesis())
return callback();
// Check all transactions
utils.forEachSerial(block.txs, function(tx, next) {
var hash = tx.hash('hex');
// BIP30 - Ensure there are no duplicate txids
self.db.isUnspentTX(hash, function(err, result) {
if (err)
return next(err);
if (result) {
// Blocks 91842 and 91880 created duplicate
// txids by using the same exact output script
// and extraNonce.
if (network.type === 'main') {
if (height === 91842 || height === 91880)
return next();
}
return next(new VerifyError(block, 'invalid', 'bad-txns-BIP30', 100));
}
next();
});
}, callback);
};
Chain.prototype._checkInputs = function _checkInputs(block, prev, flags, callback) {
var self = this;
var height = prev.height + 1;
var scriptCheck = true;
var historical = false;
if (this.spv || block.type !== 'block')
return callback();
if (block.isGenesis())
return callback();
// If we are an ancestor of a checkpoint, we can
// skip the input verification.
if (height <= network.checkpoints.lastHeight) {
if (this.options.useCheckpoints)
scriptCheck = false;
historical = true;
}
this.db.fillBlock(block, function(err) {
var ret = {};
var sigops = 0;
var i, j, input, tx, hash;
if (err)
return callback(err);
if (block.getClaimed().cmp(block.getReward()) > 0)
return callback(new VerifyError(block, 'invalid', 'bad-cb-amount', 100));
// Check all transactions
for (i = 0; i < block.txs.length; i++) {
tx = block.txs[i];
hash = tx.hash('hex');
// Check for block sigops limits
// Start counting P2SH sigops once block
// timestamps reach March 31st, 2012.
if (block.ts >= constants.block.bip16time)
sigops += tx.getSigops(true);
else
sigops += tx.getSigops();
if (sigops > constants.block.maxSigops) {
return callback(new VerifyError(block,
'invalid',
'bad-blk-sigops',
100));
}
// Coinbases do not have prevouts
if (tx.isCoinbase())
continue;
if (!tx.checkInputs(height, ret)) {
return callback(new VerifyError(block,
'invalid',
ret.reason,
ret.score));
}
for (j = 0; j < tx.inputs.length; j++) {
input = tx.inputs[j];
// Ensure tx is not double spending an output
if (!input.coin) {
assert(!historical, 'BUG: Spent inputs in historical data!');
return callback(new VerifyError(block,
'invalid',
'bad-txns-inputs-missingorspent',
100));
}
if (self.options.verifySync !== true)
continue;
if (!scriptCheck)
continue;
// Verify the scripts
if (!tx.verify(j, true, flags)) {
assert(!historical, 'BUG: Invalid inputs in historical data!');
return callback(new VerifyError(block,
'invalid',
'mandatory-script-verify-flag-failed',
100));
}
}
}
if (self.options.verifySync === true)
return callback();
if (!scriptCheck)
return callback();
// Verify all txs in parallel.
utils.every(block.txs, function(tx, next) {
tx.verifyAsync(null, true, flags, next);
}, function(err, verified) {
if (err)
return callback(err);
if (!verified) {
assert(!historical, 'BUG: Invalid inputs in historical data!');
return callback(new VerifyError(block,
'invalid',
'mandatory-script-verify-flag-failed',
100));
}
return callback();
});
});
};
Chain.prototype._getCachedHeight = function _getCachedHeight(hash) {
if (Buffer.isBuffer(hash))
hash = utils.toHex(hash);
else if (hash.hash)
hash = hash.hash('hex');
if (this.db.hasCache(hash))
return this.db.getCache(hash).height;
return -1;
};
Chain.prototype._findFork = function _findFork(fork, longer, callback) {
(function find() {
if (fork.hash === longer.hash)
return callback(null, fork);
(function next() {
if (longer.height <= fork.height)
return done();
longer.getPrevious(function(err, entry) {
if (err)
return callback(err);
if (!entry)
return callback(new Error('No previous entry for new tip.'));
longer = entry;
next();
});
})();
function done() {
if (fork.hash === longer.hash)
return callback(null, fork);
fork.getPrevious(function(err, entry) {
if (err)
return callback(err);
if (!entry)
return callback(new Error('No previous entry for old tip.'));
fork = entry;
find();
});
}
})();
};
Chain.prototype._reorganize = function _reorganize(entry, block, callback) {
var self = this;
return this._findFork(this.tip, entry, function(err, fork) {
if (err)
return callback(err);
assert(fork);
// Disconnect blocks/txs.
function disconnect(callback) {
var entries = [];
(function collect(entry) {
entry.getPrevious(function(err, entry) {
if (err)
return callback(err);
assert(entry);
entries.push(entry);
if (entry.hash === fork.hash)
return finish();
collect(entry);
});
})(self.tip);
function finish() {
assert(entries.length > 0);
utils.forEachSerial(entries, function(entry, next) {
self.db.disconnect(entry, next);
}, callback);
}
}
// Connect blocks/txs.
function connect(callback) {
var entries = [];
(function collect(entry) {
entry.getPrevious(function(err, entry) {
if (err)
return callback(err);
assert(entry);
entries.push(entry);
if (entry.hash === fork.hash)
return finish();
collect(entry);
});
})(entry);
function finish() {
entries = entries.slice().reverse();
assert(entries.length > 0);
utils.forEachSerial(entries, function(entry, next) {
self.db.connect(entry, next);
}, callback);
}
}
return disconnect(function(err) {
if (err)
return callback(err);
return connect(function(err) {
if (err)
return callback(err);
self.emit('fork', block, {
height: fork.height,
expected: self.tip.hash,
received: entry.hash,
checkpoint: false
});
return callback();
});
});
});
};
Chain.prototype._setBestChain = function _setBestChain(entry, block, callback) {
var self = this;
function done(err) {
if (err)
return callback(err);
// Save block and connect inputs.
self.db.save(entry, block, true, function(err) {
if (err)
return callback(err);
self.tip = entry;
self.height = entry.height;
if (self.bestHeight === -1)
network.height = entry.height;
self.emit('tip', entry);
// Return true (added to the main chain)
return callback(null, true);
});
}
// Update the timestamp to
// maintain a time delta of blocks.
this.lastUpdate = utils.now();
// We don't have a genesis block yet.
if (!this.tip) {
if (entry.hash !== network.genesis.hash) {
return utils.asyncify(callback)(new VerifyError(block,
'invalid',
'bad-genblk',
100));
}
return done();
}
// The block is on a side chain if the
// chainwork is less than or equal to
// our tip's. Add the block but do _not_
// connect the inputs.
if (entry.chainwork.cmp(this.tip.chainwork) <= 0) {
return this.db.save(entry, block, false, function(err) {
if (err)
return callback(err);
// Return false (added to side chain)
return callback(null, false);
});
}
// Everything is in order.
if (entry.prevBlock === this.tip.hash)
return done();
// A higher fork has arrived.
// Time to reorganize the chain.
utils.debug('WARNING: Reorganizing chain.');
return this._reorganize(entry, block, done);
};
Chain.prototype.reset = function reset(height, callback, force) {
var self = this;
var unlock = this._lock(reset, [height, callback], force);
if (!unlock)
return;
callback = utils.wrap(callback, unlock);
this.db.reset(height, function(err, result) {
if (err)
return callback(err);
// Reset the orphan map completely. There may
// have been some orphans on a forked chain we
// no longer need.
self.purgeOrphans();
self.purgePending();
callback(null, result);
});
};
Chain.prototype.resetTime = function resetTime(ts, callback, force) {
var self = this;
var unlock = this._lock(resetTime, [ts, callback], force);
if (!unlock)
return;
callback = utils.wrap(callback, unlock);
this.byTime(ts, function(err, entry) {
if (err)
return callback(err);
if (!entry)
return callback();
self.reset(entry.height, callback, true);
}, true);
};
Chain.prototype.onFlush = function onFlush(callback) {
return this.locker.onFlush(callback);
};
Chain.prototype.add = function add(block, callback, force) {
var self = this;
var total = 0;
var ret = {};
assert(this.loaded);
var unlock = this._lock(add, [block, callback], force);
if (!unlock)
return;
callback = utils.wrap(callback, unlock);
(function next(block, initial) {
var hash = block.hash('hex');
var prevHash = block.prevBlock;
var height, checkpoint, orphan;
// Do not revalidate known invalid blocks.
if (self.invalid[hash] || self.invalid[prevHash]) {
self.emit('invalid', block, {
height: block.getCoinbaseHeight(),
hash: hash,
seen: !!self.invalid[hash],
chain: !!self.invalid[prevHash]
});
self.invalid[hash] = true;
return done(new VerifyError(block, 'duplicate', 'duplicate', 100));
}
// Do we already have this block?
if (self.hasPending(hash)) {
self.emit('exists', block, {
height: block.getCoinbaseHeight(),
hash: hash
});
return done(new VerifyError(block, 'duplicate', 'duplicate', 0));
}
// If the block is already known to be
// an orphan, ignore it.
orphan = self.orphan.map[prevHash];
if (orphan) {
// If the orphan chain forked, simply
// reset the orphans.
if (orphan.hash('hex') !== hash) {
self.purgeOrphans();
self.purgePending();
self.emit('fork', block, {
height: block.getCoinbaseHeight(),
expected: orphan.hash('hex'),
received: hash,
checkpoint: false
});
return done(new VerifyError(block, 'duplicate', 'duplicate', 0));
}
self.emit('orphan', block, {
height: block.getCoinbaseHeight(),
hash: hash,
seen: true
});
return done(new VerifyError(block, 'invalid', 'bad-prevblk', 0));
}
// Special case for genesis block.
if (block.isGenesis())
return done();
// Validate the block we want to add.
// This is only necessary for new
// blocks coming in, not the resolving
// orphans.
if (initial && !block.verify(ret)) {
self.invalid[hash] = true;
self.emit('invalid', block, {
height: block.getCoinbaseHeight(),
hash: hash,
seen: false,
chain: false
});
return done(new VerifyError(block, 'invalid', ret.reason, ret.score));
}
self.db.has(hash, function(err, existing) {
if (err)
return done(err);
// Do we already have this block?
if (existing) {
self.emit('exists', block, {
height: block.getCoinbaseHeight(),
hash: hash
});
return done(new VerifyError(block, 'duplicate', 'duplicate', 0));
}
// Find the previous block height/index.
self.db.get(prevHash, function(err, prev) {
if (err)
return done(err);
height = !prev ? -1 : prev.height + 1;
// Update the best height based on the coinbase.
// We do this even for orphans (peers will send
// us their highest block during the initial
// getblocks sync, making it an orphan).
if (block.getCoinbaseHeight() > self.bestHeight) {
self.bestHeight = block.getCoinbaseHeight();
network.height = self.bestHeight;
}
// If previous block wasn't ever seen,
// add it current to orphans and break.
if (!prev) {
self.orphan.count++;
self.orphan.size += block.getSize();
self.orphan.map[prevHash] = block;
self.orphan.bmap[hash] = block;
self.emit('orphan', block, {
height: block.getCoinbaseHeight(),
hash: hash,
seen: false
});
return done(new VerifyError(block, 'invalid', 'bad-prevblk', 0));
}
// Verify the checkpoint.
checkpoint = network.checkpoints[height];
if (checkpoint) {
self.emit('checkpoint', block, {
height: height,
hash: hash,
checkpoint: checkpoint
});
// Block did not match the checkpoint. The
// chain could be reset to the last sane
// checkpoint, but it really isn't necessary,
// so we don't do it. The misbehaving peer has
// been killed and hopefully we find a peer
// who isn't trying to fool us.
if (hash !== checkpoint) {
self.purgeOrphans();
self.purgePending();
self.emit('fork', block, {
height: height,
expected: checkpoint,
received: hash,
checkpoint: true
});
return done(new VerifyError(block,
'checkpoint',
'checkpoint mismatch',
100));
}
}
assert(prev);
// Explanation: we try to keep as much data
// off the javascript heap as possible. Blocks
// in the future may be 8mb or 20mb, who knows.
// In fullnode-mode we store the blocks in
// "compact" form (the headers plus the raw
// Buffer object) until they're ready to be
// fully validated here. They are deserialized,
// validated, and emitted. Hopefully the deserialized
// blocks get cleaned up by the GC quickly.
if (block.type === 'compactblock') {
try {
block = block.toBlock();
} catch (e) {
return done(new VerifyError(block,
'malformed',
'error parsing message',
100));
}
}
// Update the block height early
// Some things in verifyContext may
// need access to height on txs.
block.setHeight(height);
// Do "contextual" verification on our block
// now that we're certain its previous
// block is in the chain.
self._verifyContext(block, prev, function(err) {
var entry;
if (err) {
// Couldn't verify block.
// Revert the height.
block.setHeight(-1);
if (err.type === 'VerifyError') {
self.invalid[hash] = true;
self.emit('invalid', block, {
height: height,
hash: hash,
seen: false,
chain: false
});
}
return done(err);
}
// Create a new chain entry.
entry = new bcoin.chainblock(self, {
hash: hash,
version: block.version,
prevBlock: block.prevBlock,
merkleRoot: block.merkleRoot,
ts: block.ts,
bits: block.bits,
nonce: block.nonce,
height: height
}, prev);
// Attempt to add block to the chain index.
self._setBestChain(entry, block, function(err, mainChain) {
if (err)
return done(err);
// Keep track of the number of blocks we
// added and the number of orphans resolved.
total++;
// Emit our block (and potentially resolved
// orphan) only if it is on the main chain.
if (mainChain) {
self.emit('block', block, entry);
if (!initial)
self.emit('resolved', block, entry);
} else {
self.emit('competitor', block, entry);
if (!initial)
self.emit('competitor resolved', block, entry);
}
// No orphan chain.
if (!self.orphan.map[hash])
return done();
// An orphan chain was found, start resolving.
block = self.orphan.map[hash];
delete self.orphan.bmap[block.hash('hex')];
delete self.orphan.map[hash];
self.orphan.count--;
self.orphan.size -= block.getSize();
next(block);
});
});
});
});
})(block, true);
function done(err) {
// Failsafe for large orphan chains. Do not
// allow more than 20mb stored in memory.
if (self.orphan.size > self.orphanLimit)
self.pruneOrphans();
// Keep track of total blocks handled.
self.total += total;
// Take heap snapshot for debugging.
if (self.total % 20 === 0) {
bcoin.profiler.snapshot();
utils.gc();
}
utils.nextTick(function() {
if (self.isFull())
self.emit('full');
if (err)
callback(err);
else
callback(null, total);
});
}
};
Chain.prototype.purgeOrphans = function purgeOrphans() {
this.emit('purge', this.orphan.count, this.orphan.size);
this.orphan.map = {};
this.orphan.bmap = {};
this.orphan.count = 0;
this.orphan.size = 0;
};
Chain.prototype.pruneOrphans = function pruneOrphans() {
var self = this;
var best, last;
best = Object.keys(this.orphan.map).reduce(function(best, prevBlock) {
var orphan = self.orphan.map[prevBlock];
var height = orphan.getCoinbaseHeight();
last = orphan;
if (!best || height > best.getCoinbaseHeight())
return orphan;
return best;
}, null);
// Save the best for last... or the
// last for the best in this case.
if (!best || best.getCoinbaseHeight() <= 0)
best = last;
this.emit('purge',
this.orphan.count - (best ? 1 : 0),
this.orphan.size - (best ? best.getSize() : 0));
Object.keys(this.orphan.bmap).forEach(function(hash) {
var orphan = self.orphan.bmap[hash];
if (orphan !== best)
self.emit('unresolved', orphan);
});
this.orphan.map = {};
this.orphan.bmap = {};
this.orphan.count = 0;
this.orphan.size = 0;
if (!best)
return;
this.orphan.map[best.prevBlock] = best;
this.orphan.bmap[best.hash('hex')] = best;
this.orphan.count++;
this.orphan.size += best.getSize();
};
Chain.prototype.purgePending = function purgePending() {
return this.locker.purgePending();
};
Chain.prototype.has = function has(hash, callback) {
if (this.hasOrphan(hash))
return callback(null, true);
if (this.hasPending(hash))
return callback(null, true);
return this.hasBlock(hash, callback);
};
Chain.prototype.byTime = function byTime(ts, callback, force) {
var self = this;
var start = 0;
var end = this.height;
var pos, delta;
// var unlock = this._lock(byTime, [ts, callback], force);
// if (!unlock)
// return;
// callback = utils.wrap(callback, unlock);
function done(err, result) {
if (err)
return callback(err);
if (result)
return callback(null, result);
self.db.get(start, callback);
}
if (ts >= this.tip.ts)
return utils.asyncify(done)(null, this.tip);
// Do a binary search for a block
// mined within an hour of the
// timestamp.
(function next() {
if (start >= end)
return done();
pos = (start + end) >>> 1;
self.db.get(pos, function(err, entry) {
if (err)
return done(err);
delta = Math.abs(ts - entry.ts);
if (delta <= 60 * 60)
return done(null, entry);
if (ts < entry.ts)
end = pos - 1;
else
start = pos + 1;
next();
});
})();
};
Chain.prototype.hasBlock = function hasBlock(hash, callback) {
if (typeof hash === 'number')
return this.db.has(hash, callback);
if (Buffer.isBuffer(hash))
hash = utils.toHex(hash);
else if (hash.hash)
hash = hash.hash('hex');
return this.db.has(hash, callback);
};
Chain.prototype.hasOrphan = function hasOrphan(hash) {
return !!this.getOrphan(hash);
};
Chain.prototype.hasPending = function hasPending(hash) {
if (Buffer.isBuffer(hash))
hash = utils.toHex(hash);
else if (hash.hash)
hash = hash.hash('hex');
return this.locker.hasPending(hash);
};
Chain.prototype.getEntry = function getEntry(hash, callback) {
if (typeof hash === 'number')
return this.db.get(hash, callback);
if (Buffer.isBuffer(hash))
hash = utils.toHex(hash);
else if (hash.hash)
hash = hash.hash('hex');
return this.db.get(hash, callback);
};
Chain.prototype.getOrphan = function getOrphan(hash) {
if (Buffer.isBuffer(hash))
hash = utils.toHex(hash);
else if (hash.hash)
hash = hash.hash('hex');
return this.orphan.bmap[hash] || null;
};
Chain.prototype.isFull = function isFull() {
var delta;
if (!this.tip)
return false;
delta = utils.now() - this.tip.ts;
return delta < 4 * 60 * 60;
};
Chain.prototype.isInitial = function isInitial() {
var now, delta;
if (!this.tip)
return true;
now = utils.now();
delta = now - this.lastUpdate;
// Should mimic the original IsInitialBlockDownload() function
return delta < 10 && this.tip.ts < now - 24 * 60 * 60;
};
Chain.prototype.getProgress = function getProgress() {
if (!this.tip)
return 0;
return Math.min(1, this.tip.ts / (utils.now() - 40 * 60));
};
Chain.prototype.getHashRange = function getHashRange(start, end, callback, force) {
var self = this;
// var unlock = this._lock(getHashRange, [start, end, callback], force);
// if (!unlock)
// return;
// callback = utils.wrap(callback, unlock);
this.byTime(start, function(err, start) {
if (err)
return callback(err);
self.byTime(end, function(err, end) {
var hashes;
if (err)
return callback(err);
hashes = [];
if (!start || !end)
return callback(null, hashes);
utils.forRange(start.height, end.height + 1, function(i, next) {
self.db.get(i, function(err, entry) {
if (err)
return next(err);
if (!entry)
return next(new Error('No entry for hash range.'));
hashes[i - start.height] = entry.hash;
next();
});
}, function(err) {
if (err)
return callback(err);
return callback(null, hashes);
});
}, true);
}, true);
};
Chain.prototype.getLocator = function getLocator(start, callback, force) {
var self = this;
var hashes = [];
var top = this.height;
var step = 1;
var i;
var unlock = this._lock(getLocator, [start, callback], force);
if (!unlock)
return;
callback = utils.wrap(callback, unlock);
if (start) {
if (Buffer.isBuffer(start))
start = utils.toHex(start);
else if (start.hash)
start = start.hash('hex');
}
function build(err, top) {
if (err)
return callback(err);
i = top;
for (;;) {
hashes.push(i);
i = i - step;
if (i <= 0) {
if (i + step !== 0)
hashes.push(network.genesis.hash);
break;
}
if (hashes.length >= 10)
step *= 2;
}
utils.forEach(hashes, function(height, next, i) {
if (typeof height === 'string')
return next();
self.db.getHash(height, function(err, hash) {
if (err)
return next(err);
assert(hash);
hashes[i] = hash;
next();
});
}, function(err) {
if (err)
return callback(err);
return callback(null, hashes);
});
}
if (typeof start === 'string') {
return self.db.getHeight(start, function(err, top) {
if (err)
return build(err);
if (top === -1) {
// We could simply `return [start]` here,
// but there is no standardized "spacing"
// for locator hashes. Pretend this hash
// is our tip. This is useful for getheaders
// when not using headers-first.
hashes.push(start);
top = self.height;
}
return build(null, top);
});
}
if (typeof start === 'number')
top = start;
return build(null, top);
};
Chain.prototype.getOrphanRoot = function getOrphanRoot(hash) {
var root;
if (Buffer.isBuffer(hash))
hash = utils.toHex(hash);
else if (hash.hash)
hash = hash.hash('hex');
assert(hash);
while (this.orphan.bmap[hash]) {
root = hash;
hash = this.orphan.bmap[hash].prevBlock;
}
if (!root)
return;
return {
root: root,
soil: this.orphan.bmap[root].prevBlock
};
};
Chain.prototype.getCurrentTarget = function getCurrentTarget(callback) {
if (!this.tip)
return callback(null, utils.toCompact(network.powLimit));
return this.getTargetAsync(this.tip, null, callback);
};
Chain.prototype.getTargetAsync = function getTargetAsync(last, block, callback) {
var self = this;
if ((last.height + 1) % network.powDiffInterval !== 0) {
if (!network.powAllowMinDifficultyBlocks)
return utils.asyncify(callback)(null, this.getTarget(last, block));
}
return last.getAncestors(network.powDiffInterval, function(err, ancestors) {
if (err)
return callback(err);
return callback(null, self.getTarget(last, block, ancestors));
});
};
Chain.prototype.getTarget = function getTarget(last, block, ancestors) {
var powLimit = utils.toCompact(network.powLimit);
var ts, first, i;
// Genesis
if (!last)
return powLimit;
if (!ancestors)
ancestors = last.ancestors;
// Do not retarget
if ((last.height + 1) % network.powDiffInterval !== 0) {
if (network.powAllowMinDifficultyBlocks) {
// Special behavior for testnet:
ts = block ? (block.ts || block) : utils.now();
if (ts > last.ts + network.powTargetSpacing * 2)
return powLimit;
i = 1;
while (ancestors[i]
&& last.height % network.powDiffInterval !== 0
&& last.bits === powLimit) {
last = ancestors[i++];
}
}
return last.bits;
}
// Back 2 weeks
first = ancestors[network.powDiffInterval - 1];
assert(first);
return this.retarget(last, first);
};
Chain.prototype.retarget = function retarget(last, first) {
var powTargetTimespan = new bn(network.powTargetTimespan);
var actualTimespan, target;
if (network.powNoRetargeting)
return last.bits;
actualTimespan = new bn(last.ts - first.ts);
target = utils.fromCompact(last.bits);
if (actualTimespan.cmp(powTargetTimespan.divn(4)) < 0)
actualTimespan = powTargetTimespan.divn(4);
if (actualTimespan.cmp(powTargetTimespan.muln(4)) > 0)
actualTimespan = powTargetTimespan.muln(4);
target.imul(actualTimespan);
target = target.div(powTargetTimespan);
if (target.cmp(network.powLimit) > 0)
target = network.powLimit.clone();
return utils.toCompact(target);
};
Chain.prototype.findLocator = function findLocator(locator, callback) {
var self = this;
if (!locator)
return utils.nextTick(callback);
utils.forEachSerial(locator, function(hash, next) {
self.db.has(hash, function(err, result) {
if (err)
return next(err);
if (result)
return callback(null, hash);
next();
});
}, callback);
};
Chain.prototype.getState = function getState(prev, id, callback) {
var self = this;
var period = network.minerConfirmationWindow;
var threshold = network.ruleChangeActivationThreshold;
var deployment = network.deployments[id];
var timeStart, timeTimeout, compute, height;
if (!deployment)
return callback(null, constants.thresholdStates.FAILED);
timeStart = deployment.startTime;
timeTimeout = deployment.timeout;
compute = [];
if (!prev)
return callback(null, constants.thresholdStates.DEFINED);
if (((prev.height + 1) % period) !== 0) {
height = prev.height - ((prev.height + 1) % period);
return prev.getAncestorByHeight(height, function(err, ancestor) {
if (err)
return callback(err);
if (ancestor) {
assert(ancestor.height === height);
assert(((ancestor.height + 1) % period) === 0);
}
return self.getState(ancestor, id, callback);
});
}
function condition(entry) {
var bits = entry.version & constants.versionbits.TOP_MASK;
var topBits = constants.versionbits.TOP_BITS;
var mask = 1 << deployment.bit;
return bits === topBits && (entry.version & mask) !== 0;
}
(function walk(err, entry) {
if (err)
return callback(err);
if (!entry)
return walkForward(constants.thresholdStates.DEFINED);
return entry.getMedianTimeAsync(function(err, medianTime) {
if (err)
return walk(err);
if (medianTime < timeStart)
return walkForward(constants.thresholdStates.DEFINED);
compute.push(entry);
height = entry.height - period;
return entry.getAncestorByHeight(height, walk);
});
})(null, prev);
function walkForward(state) {
var entry;
if (compute.length === 0)
return callback(null, state);
entry = compute.pop();
switch (state) {
case constants.thresholdStates.DEFINED:
return entry.getMedianTimeAsync(function(err, medianTime) {
if (err)
return callback(err);
if (medianTime >= timeTimeout)
return walkForward(constants.thresholdStates.FAILED);
if (medianTime >= timeStart)
return walkForward(constants.thresholdStates.STARTED);
return walkForward(state);
});
case constants.thresholdStates.STARTED:
return entry.getMedianTimeAsync(function(err, medianTime) {
if (err)
return callback(err);
if (medianTime >= timeTimeout)
return walkForward(constants.thresholdStates.FAILED);
var count = 0;
var i = 0;
(function next(err, entry) {
if (err)
return callback(err);
if (!entry)
return doneCounting();
if (i++ >= period)
return doneCounting();
if (condition(entry))
count++;
return entry.getPrevious(next);
})(null, entry);
function doneCounting(err) {
if (err)
return callback(err);
if (count >= threshold)
return walkForward(constants.thresholdStates.LOCKED_IN);
return walkForward(state);
}
});
case constants.thresholdStates.LOCKED_IN:
return walkForward(constants.thresholdStates.ACTIVE);
case constants.thresholdStates.FAILED:
case constants.thresholdStates.ACTIVE:
return walkForward(state);
}
assert(false, 'Bad state.');
}
};
Chain.prototype.computeBlockVersion = function computeBlockVersion(prev, callback) {
var self = this;
var version = 0;
utils.forEachSerial(Object.keys(network.deployments), function(id, next) {
var deployment = network.deployments[id];
self.getState(prev, id, function(err, state) {
if (err)
return next(err);
if (state === constants.thresholdStates.LOCKED_IN
|| state === constants.thresholdStates.STARTED) {
version |= (1 << deployment.bit);
}
next();
});
}, function(err) {
if (err)
return callback(err);
if (version === 0)
return callback(null, constants.versionbits.LAST_OLD_BLOCK_VERSION);
version |= constants.versionbits.TOP_BITS;
version >>>= 0;
return callback(null, version);
});
};
Chain.prototype.isSegwitActive = function isSegwitActive(callback, force) {
var self = this;
var unlock;
if (this.segwitActive != null)
return utils.asyncify(callback)(null, this.segwitActive);
if (!network.witness) {
this.segwitActive = false;
return utils.asyncify(callback)(null, false);
}
if (!this.tip)
return utils.asyncify(callback)(null, false);
// unlock = this._lock(isSegwitActive, [callback], force);
// if (!unlock)
// return;
// callback = utils.wrap(callback, unlock);
if (network.type === 'segnet4') {
return this.tip.getPrevious(function(err, prev) {
if (err)
return callback(err);
return self.getState(prev, 'witness', function(err, state) {
if (err)
return callback(err);
self.segwitActive = state === constants.thresholdStates.ACTIVE;
return callback(null, self.segwitActive);
});
});
}
assert(network.type === 'segnet3');
if (!(network.segwitHeight !== -1 && this.tip.height >= network.segwitHeight))
return utils.asyncify(callback)(null, false);
return this.tip.getPrevious(function(err, prev) {
if (err)
return callback(err);
if (!prev) {
self.segwitActive = false;
return callback(null, false);
}
prev.ensureAncestors(function(err) {
if (err)
return callback(err);
if (self.tip.version >= 5 && prev.isUpgraded(5)) {
prev.free();
self.segwitActive = true;
return callback(null, true);
}
prev.free();
self.segwitActive = false;
return callback(null, false);
});
});
};
Chain.prototype.checkFinal = function checkFinal(prev, tx, flags, callback, force) {
var height = prev.height + 1;
// var unlock = this._lock(checkFinal, [prev, tx, flags, callback], force);
// if (!unlock)
// return;
// callback = utils.wrap(callback, unlock);
function check(err, ts) {
if (err)
return callback(err);
return callback(null, tx.isFinal(ts, height));
}
if (flags & constants.flags.MEDIAN_TIME_PAST)
return prev.getMedianTimeAsync(check);
utils.asyncify(check)(null, utils.now());
};
Chain.prototype.getLocks = function getLocks(tx, flags, entry, callback) {
var self = this;
var mask = constants.sequenceLocktimeMask;
var granularity = constants.sequenceLocktimeGranularity;
var disableFlag = constants.sequenceLocktimeDisableFlag;
var typeFlag = constants.sequenceLocktimeTypeFlag;
var hasFlag = flags & constants.flags.VERIFY_SEQUENCE;
var minHeight = -1;
var minTime = -1;
var coinHeight;
if (tx.version < 2 || !hasFlag)
return utils.asyncify(callback)(null, minHeight, minTime);
utils.forEachSerial(tx.inputs, function(input, next) {
if (input.sequence & disableFlag)
return next();
coinHeight = input.coin.height === -1
? self.height + 1
: input.coin.height;
if ((input.sequence & typeFlag) === 0) {
coinHeight += (input.sequence & mask) - 1;
minHeight = Math.max(minHeight, coinHeight);
return next();
}
entry.getAncestorByHeight(Math.max(coinHeight - 1, 0), function(err, entry) {
if (err)
return next(err);
assert(entry, 'Database is corrupt.');
entry.getMedianTimeAsync(function(err, coinTime) {
if (err)
return next(err);
coinTime += ((input.sequence & mask) << granularity) - 1;
minTime = Math.max(minTime, coinTime);
next();
});
});
}, function(err) {
if (err)
return callback(err);
return callback(null, minHeight, minTime);
});
};
Chain.prototype.evalLocks = function evalLocks(entry, minHeight, minTime, callback) {
if (minHeight >= entry.height)
return utils.asyncify(callback)(null, false);
if (minTime === -1)
return utils.asyncify(callback)(null, true);
entry.getMedianTimeAsync(function(err, medianTime) {
if (err)
return callback(err);
if (minTime >= medianTime)
return callback(null, false);
return callback(null, true);
});
};
Chain.prototype.checkLocks = function checkLocks(tx, flags, entry, callback, force) {
var self = this;
// var unlock = this._lock(checkLocks, [tx, flags, entry, callback], force);
// if (!unlock)
// return;
// callback = utils.wrap(callback, unlock);
this.getLocks(tx, flags, entry, function(err, minHeight, minTime) {
if (err)
return callback(err);
self.evalLocks(entry, minHeight, minTime, callback);
});
};
/**
* Expose
*/
module.exports = Chain;