/*!
* chain.js - blockchain management for hsd
* Copyright (c) 2017-2018, Christopher Jeffrey (MIT License).
* https://github.com/handshake-org/hsd
*/
'use strict';
const assert = require('bsert');
const path = require('path');
const AsyncEmitter = require('bevent');
const Logger = require('blgr');
const {Lock} = require('bmutex');
const LRU = require('blru');
const {BufferMap, BufferSet} = require('buffer-map');
const Network = require('../protocol/network');
const ChainDB = require('./chaindb');
const common = require('./common');
const consensus = require('../protocol/consensus');
const rules = require('../covenants/rules');
const NameState = require('../covenants/namestate');
const util = require('../utils/util');
const ChainEntry = require('./chainentry');
const CoinView = require('../coins/coinview');
const Script = require('../script/script');
const {VerifyError} = require('../protocol/errors');
const {OwnershipProof} = require('../covenants/ownership');
const AirdropProof = require('../primitives/airdropproof');
const {CriticalError} = require('../errors');
const thresholdStates = common.thresholdStates;
const scanActions = common.scanActions;
const {states} = NameState;
const {
VERIFY_COVENANTS_HARDENED,
VERIFY_COVENANTS_LOCKUP
} = rules.nameFlags;
/** @typedef {import('../types').Hash} Hash */
/** @typedef {import('../types').LockFlags} LockFlags */
/** @typedef {import('@handshake-org/bfilter').BloomFilter} BloomFilter */
/** @typedef {import('../primitives/block')} Block */
/** @typedef {import('../primitives/tx')} TX */
/** @typedef {import('../primitives/txmeta')} TXMeta */
/** @typedef {import('../primitives/outpoint')} Outpoint */
/** @typedef {import('../primitives/coin')} Coin */
/** @typedef {import('../primitives/address')} Address */
/** @typedef {import('../coins/coinentry')} CoinEntry */
/**
* Blockchain
* @alias module:blockchain.Chain
* @property {ChainDB} db
* @property {ChainEntry?} tip
* @property {Number} height
* @property {DeploymentState} state
*/
class Chain extends AsyncEmitter {
/**
* Create a blockchain.
* @constructor
* @param {Object} options
*/
constructor(options) {
super();
this.opened = false;
this.options = new ChainOptions(options);
this.network = this.options.network;
this.logger = this.options.logger.context('chain');
this.workers = this.options.workers;
this.db = new ChainDB(this.options);
this.locker = new Lock(true, BufferMap);
this.invalid = new LRU(5000, null, BufferMap);
this.state = new DeploymentState(this.network.genesis.hash);
this.tip = new ChainEntry();
this.height = -1;
this.synced = false;
this.orphanMap = new BufferMap();
this.orphanPrev = new BufferMap();
}
/**
* Open the chain, wait for the database to load.
* @returns {Promise<void>}
*/
async open() {
assert(!this.opened, 'Chain is already open.');
this.opened = true;
this.logger.info('Chain is loading.');
if (this.options.checkpoints)
this.logger.info('Checkpoints are enabled.');
await this.db.open();
const tip = await this.db.getTip();
assert(tip);
this.tip = tip;
this.height = tip.height;
this.logger.info('Chain Height: %d', tip.height);
this.logger.memory();
const state = await this.getDeploymentState();
this.setDeploymentState(state);
if (!this.options.spv) {
const sync = await this.tryCompact();
if (sync)
await this.syncTree();
}
this.logger.memory();
this.emit('tip', tip);
this.maybeSync();
}
/**
* Close the chain, wait for the database to close.
* @returns {Promise<void>}
*/
async close() {
assert(this.opened, 'Chain is not open.');
this.opened = false;
return this.db.close();
}
/**
* Get compaction heights.
* @returns {Promise<Object>}
*/
async getCompactionHeights() {
if (this.options.spv)
return null;
const {keepBlocks} = this.network.block;
const {compactionHeight} = await this.db.getTreeState();
const {compactTreeInitInterval} = this.options;
const compactFrom = compactionHeight + keepBlocks + compactTreeInitInterval;
return {
compactionHeight,
compactFrom
};
}
/**
* Check if we need to compact tree data.
* @returns {Promise<Boolean>} - Should we sync
*/
async tryCompact() {
if (this.options.spv)
return false;
if (!this.options.compactTreeOnInit)
return true;
const {txStart} = this.network;
const {keepBlocks} = this.network.block;
const startFrom = txStart + keepBlocks;
if (this.height <= startFrom)
return true;
const {compactFrom} = await this.getCompactionHeights();
if (compactFrom > this.height) {
this.logger.debug(
`Tree will compact when restarted after height ${compactFrom}.`);
return true;
}
// Compact tree calls syncTree so we don't want to rerun it.
await this.compactTree();
return false;
}
/**
* Sync tree state.
*/
async syncTree() {
this.logger.info('Synchronizing Tree with block history...');
// Current state of the tree, loaded from chain database and
// injected in chainDB.open(). It should be in the most
// recently-committed state, which should have been at the last
// tree interval. We might also need to recover from a
// failed compactTree() operation. Either way, there might have been
// new blocks added to the chain since then.
const currentRoot = this.db.treeRoot();
// We store commit height for the tree in the tree state.
// commitHeight is the height of the block that committed tree root.
// Note that the block at commitHeight has different tree root.
const treeState = await this.db.getTreeState();
const {commitHeight} = treeState;
// sanity check
if (commitHeight < this.height) {
const entry = await this.db.getEntryByHeight(commitHeight + 1);
assert(entry.treeRoot.equals(treeState.treeRoot));
assert(entry.treeRoot.equals(currentRoot));
}
// Replay all blocks since the last tree interval to rebuild
// the `txn` which is the in-memory delta between tree interval commitments.
for (let height = commitHeight + 1; height <= this.height; height++) {
const entry = await this.db.getEntryByHeight(height);
assert(entry);
const block = await this.db.getBlock(entry.hash);
assert(block);
const state = await this.readDeploymentState(entry);
assert(state);
const view = new CoinView();
for (const tx of block.txs)
await this.verifyCovenants(tx, view, height, state.nameFlags);
// If the chain replay crosses a tree interval, it will commit
// and write to disk in saveNames(), resetting the `txn` like usual.
await this.db.saveNames(view, entry, false);
}
this.logger.info('Synchronized Tree Root: %x.', this.db.txn.rootHash());
}
/**
* Perform all necessary contextual verification on a block.
* @private
* @param {Block} block
* @param {ChainEntry} prev
* @param {Number} flags
* @returns {Promise<Array>} - [CoinView, DeploymentState]
*/
async verifyContext(block, prev, flags) {
// Initial non-contextual verification.
const state = await this.verify(block, prev, flags);
// Skip everything if we're in SPV mode.
if (this.options.spv) {
const view = new CoinView();
return [view, state];
}
// Skip everything if we're using checkpoints.
if (this.isHistorical(prev)) {
const view = await this.updateInputs(block, prev, state);
return [view, state];
}
// Verify scripts, spend and add coins.
const view = await this.verifyInputs(block, prev, state);
return [view, state];
}
/**
* Perform all necessary contextual verification
* on a block, without POW check.
* @param {Block} block
* @returns {Promise<Array>} - [CoinView, DeploymentState]
*/
async verifyBlock(block) {
const unlock = await this.locker.lock();
try {
return await this._verifyBlock(block);
} finally {
unlock();
}
}
/**
* Perform all necessary contextual verification
* on a block, without POW check (no lock).
* @private
* @param {Block} block
* @returns {Promise<Array>} - [CoinView, DeploymentState]
*/
async _verifyBlock(block) {
const flags = common.DEFAULT_FLAGS & ~common.flags.VERIFY_POW;
return this.verifyContext(block, this.tip, flags);
}
/**
* Test whether the hash is in the main chain.
* @param {Hash} hash
* @returns {Promise<Boolean>}
*/
isMainHash(hash) {
return this.db.isMainHash(hash);
}
/**
* Test whether the entry is in the main chain.
* @param {ChainEntry} entry
* @returns {Promise<Boolean>}
*/
isMainChain(entry) {
return this.db.isMainChain(entry);
}
/**
* Get ancestor by `height`.
* @param {ChainEntry} entry
* @param {Number} height
* @returns {Promise<ChainEntry?>}
*/
getAncestor(entry, height) {
return this.db.getAncestor(entry, height);
}
/**
* Get previous entry.
* @param {ChainEntry} entry
* @returns {Promise<ChainEntry?>}
*/
getPrevious(entry) {
return this.db.getPrevious(entry);
}
/**
* Get previous cached entry.
* @param {ChainEntry} entry
* @returns {ChainEntry?}
*/
getPrevCache(entry) {
return this.db.getPrevCache(entry);
}
/**
* Get next entry.
* @param {ChainEntry} entry
* @returns {Promise<ChainEntry?>}
*/
getNext(entry) {
return this.db.getNext(entry);
}
/**
* Get next entry.
* @param {ChainEntry} entry
* @returns {Promise<ChainEntry?>}
*/
getNextEntry(entry) {
return this.db.getNextEntry(entry);
}
/**
* Calculate median time past.
* @param {ChainEntry} prev
* @returns {Promise<Number>}
*/
async getMedianTime(prev) {
const timespan = consensus.MEDIAN_TIMESPAN;
const median = [];
let entry = prev;
for (let i = 0; i < timespan && entry; i++) {
median.push(entry.time);
const cache = this.getPrevCache(entry);
if (cache)
entry = cache;
else
entry = await this.getPrevious(entry);
}
median.sort(cmp);
return median[median.length >>> 1];
}
/**
* Test whether the entry is potentially
* an ancestor of a checkpoint.
* @param {ChainEntry} prev
* @returns {Boolean}
*/
isHistorical(prev) {
if (this.options.checkpoints) {
if (prev.height + 1 <= this.network.lastCheckpoint)
return true;
}
return false;
}
/**
* Test whether the height is potentially
* an ancestor of a checkpoint.
* @param {Number} height
* @returns {Boolean}
*/
isHistoricalHeight(height) {
if (this.options.checkpoints) {
if (height <= this.network.lastCheckpoint)
return true;
}
return false;
}
/**
* Contextual verification for a block, including
* version deployments (IsSuperMajority), versionbits,
* coinbase height, finality checks.
* @private
* @param {Block} block
* @param {ChainEntry} prev
* @param {Number} flags
* @returns {Promise<DeploymentState>}
*/
async verify(block, prev, flags) {
assert(typeof flags === 'number');
// Extra sanity check.
if (!block.prevBlock.equals(prev.hash))
throw new VerifyError(block, 'invalid', 'bad-prevblk', 0);
// Verify a checkpoint if there is one.
const hash = block.hash();
if (!this.verifyCheckpoint(prev, hash)) {
throw new VerifyError(block,
'checkpoint',
'checkpoint mismatch',
100);
}
// Skip everything when using checkpoints.
// We can do this safely because every
// block in between each checkpoint was
// validated outside in the header chain.
if (this.isHistorical(prev)) {
// Check merkle root.
if (flags & common.flags.VERIFY_BODY) {
assert(typeof block.createMerkleRoot === 'function');
const root = block.createMerkleRoot();
if (!block.merkleRoot.equals(root)) {
throw new VerifyError(block,
'invalid',
'bad-txnmrklroot',
100,
true);
}
const witnessRoot = block.createWitnessRoot();
if (!block.witnessRoot.equals(witnessRoot)) {
throw new VerifyError(block,
'invalid',
'bad-witnessroot',
100,
true);
}
flags &= ~common.flags.VERIFY_BODY;
}
}
// Non-contextual checks.
if (flags & common.flags.VERIFY_BODY) {
const [valid, reason, score] = block.checkBody();
if (!valid)
throw new VerifyError(block, 'invalid', reason, score, true);
}
// Check name DoS limits.
const set = new BufferSet();
let opens = 0;
let updates = 0;
let renewals = 0;
for (let i = 0; i < block.txs.length; i++) {
const tx = block.txs[i];
opens += rules.countOpens(tx);
if (opens > consensus.MAX_BLOCK_OPENS) {
throw new VerifyError(block,
'invalid',
'bad-blk-opens',
100);
}
updates += rules.countUpdates(tx);
if (updates > consensus.MAX_BLOCK_UPDATES) {
throw new VerifyError(block,
'invalid',
'bad-blk-updates',
100);
}
renewals += rules.countRenewals(tx);
if (renewals > consensus.MAX_BLOCK_RENEWALS) {
throw new VerifyError(block,
'invalid',
'bad-blk-renewals',
100);
}
// Certain covenants can only be used once per name per block
if (rules.hasNames(tx, set)) {
throw new VerifyError(block,
'invalid',
'bad-blk-names',
100);
}
rules.addNames(tx, set);
}
// Ensure the POW is what we expect.
const bits = await this.getTarget(block.time, prev);
if (block.bits !== bits) {
this.logger.debug(
'Bad diffbits: 0x%s != 0x%s',
util.hex32(block.bits),
util.hex32(bits));
throw new VerifyError(block,
'invalid',
'bad-diffbits',
100);
}
// Ensure the timestamp is correct.
const mtp = await this.getMedianTime(prev);
if (block.time <= mtp) {
throw new VerifyError(block,
'invalid',
'time-too-old',
0);
}
// Check timestamp against adj-time+2hours.
// If this fails we may be able to accept
// the block later.
if (block.time > this.network.now() + 2 * 60 * 60) {
throw new VerifyError(block,
'invalid',
'time-too-new',
0,
true);
}
// Skip all blocks in spv mode once
// we've verified the network target.
if (this.options.spv)
return this.state;
// Calculate height of current block.
const height = prev.height + 1;
// Get the new deployment state.
const state = await this.getDeployments(block.time, prev);
// Transactions must be finalized with
// regards to nSequence and nLockTime.
for (let i = 1; i < block.txs.length; i++) {
const tx = block.txs[i];
if (!tx.isFinal(height, mtp)) {
throw new VerifyError(block,
'invalid',
'bad-txns-nonfinal',
10);
}
}
// Make sure the height contained
// in the coinbase is correct.
if (block.getCoinbaseHeight() !== height) {
throw new VerifyError(block,
'invalid',
'bad-cb-height',
100);
}
const cb = block.txs[0];
for (let i = 1; i < cb.inputs.length; i++) {
const {witness} = cb.inputs[i];
if (witness.items.length !== 1) {
throw new VerifyError(block,
'invalid',
'bad-witness-size',
100);
}
if (i >= cb.outputs.length) {
throw new VerifyError(block,
'invalid',
'bad-output',
100);
}
const output = cb.outputs[i];
// Airdrop proof.
if (!output.covenant.isClaim()) {
// Disable airdrop claims if airstop is activated
if (state.hasAirstop) {
throw new VerifyError(block,
'invalid',
'bad-airdrop-disabled',
100);
}
let proof;
try {
proof = AirdropProof.decode(witness.items[0]);
} catch (e) {
throw new VerifyError(block,
'invalid',
'bad-airdrop-format',
100);
}
if (!proof.isSane()) {
throw new VerifyError(block,
'invalid',
'bad-airdrop-sanity',
100);
}
if (prev.height + 1 >= this.network.goosigStop) {
const key = proof.getKey();
if (!key) {
throw new VerifyError(block,
'invalid',
'bad-airdrop-proof',
100);
}
if (key.isGoo()) {
throw new VerifyError(block,
'invalid',
'bad-goosig-disabled',
100);
}
}
// Note: GooSig RSA 1024 is possible to
// crack as well, but in order to make
// it safe we would need to include a
// commitment to the key size (bad).
// We may have to just disallow <2048
// bit for mainnet.
if (state.hasHardening()) {
if (proof.isWeak()) {
throw new VerifyError(block,
'invalid',
'bad-airdrop-sanity',
10);
}
}
continue;
}
// DNSSEC ownership proof.
let proof;
try {
proof = OwnershipProof.decode(witness.items[0]);
} catch (e) {
throw new VerifyError(block,
'invalid',
'bad-dnssec-format',
100);
}
// Verify times.
if (!proof.verifyTimes(prev.time)) {
throw new VerifyError(block,
'invalid',
'bad-dnssec-times',
10);
}
}
return state;
}
/**
* Check all deployments on a chain.
* @param {Number} time
* @param {ChainEntry} prev
* @returns {Promise<DeploymentState>}
*/
async getDeployments(time, prev) {
const deployments = this.network.deployments;
const state = new DeploymentState(prev.hash);
// Disable RSA-1024.
if (await this.isActive(prev, deployments.hardening))
state.nameFlags |= rules.nameFlags.VERIFY_COVENANTS_HARDENED;
// Disable ICANN, TOP100 and CUSTOM TLDs from getting auctioned.
if (await this.isActive(prev, deployments.icannlockup))
state.nameFlags |= rules.nameFlags.VERIFY_COVENANTS_LOCKUP;
// Disable airdrop claims.
if (await this.isActive(prev, deployments.airstop))
state.hasAirstop = true;
return state;
}
/**
* Set a new deployment state.
* @param {DeploymentState} state
*/
setDeploymentState(state) {
if (this.options.checkpoints && this.height < this.network.lastCheckpoint) {
this.state = state;
return;
}
if (!this.state.hasHardening() && state.hasHardening())
this.logger.warning('RSA hardening has been activated.');
if (this.height === this.network.deflationHeight)
this.logger.warning('Name claim deflation has been activated.');
if (!this.state.hasICANNLockup() && state.hasICANNLockup())
this.logger.warning('ICANN lockup has been activated.');
if (!this.state.hasAirstop && state.hasAirstop)
this.logger.warning('Airdrop claims has been disabled.');
this.state = state;
}
/**
* Spend and update inputs (checkpoints only).
* @private
* @param {Block} block
* @param {ChainEntry} prev
* @param {DeploymentState} state
* @returns {Promise<CoinView>}
*/
async updateInputs(block, prev, state) {
const view = new CoinView();
const height = prev.height + 1;
assert(block.treeRoot.equals(this.db.treeRoot()));
for (let i = 0; i < block.txs.length; i++) {
const tx = block.txs[i];
if (i === 0) {
assert(view.bits.spend(this.db.field, tx));
} else {
assert(await view.spendInputs(this.db, tx),
'BUG: Spent inputs in historical data!');
}
await this.verifyCovenants(tx, view, height, state.nameFlags);
view.addTX(tx, height);
}
return view;
}
/**
* Check block transactions for all things pertaining
* to inputs. This function is important because it is
* what actually fills the coins into the block. This
* function will check the block reward, the sigops,
* the tx values, and execute and verify the scripts (it
* will attempt to do this on the worker pool). If
* `checkpoints` is enabled, it will skip verification
* for historical data.
* @private
* @see TX#verifyInputs
* @see TX#verify
* @param {Block} block
* @param {ChainEntry} prev
* @param {DeploymentState} state
* @returns {Promise<CoinView>}
*/
async verifyInputs(block, prev, state) {
const network = this.network;
const view = new CoinView();
const height = prev.height + 1;
const interval = network.halvingInterval;
let sigops = 0;
let reward = 0;
// Check the name tree root.
if (!block.treeRoot.equals(this.db.treeRoot())) {
throw new VerifyError(block,
'invalid',
'bad-tree-root',
100);
}
// Check all transactions
for (let i = 0; i < block.txs.length; i++) {
const tx = block.txs[i];
// Ensure tx is not double spending an output.
if (i === 0) {
if (!view.bits.spend(this.db.field, tx)) {
throw new VerifyError(block,
'invalid',
'bad-txns-bits-missingorspent',
100);
}
} else {
if (!await view.spendInputs(this.db, tx)) {
throw new VerifyError(block,
'invalid',
'bad-txns-inputs-missingorspent',
100);
}
// Verify sequence locks.
const valid = await this.verifyLocks(prev, tx, view, state.lockFlags);
if (!valid) {
throw new VerifyError(block,
'invalid',
'bad-txns-nonfinal',
100);
}
}
// Count sigops.
sigops += tx.getSigops(view);
if (sigops > consensus.MAX_BLOCK_SIGOPS) {
throw new VerifyError(block,
'invalid',
'bad-blk-sigops',
100);
}
// Contextual sanity checks.
const [fee, reason, score] = tx.checkInputs(view, height, network);
if (fee === -1) {
throw new VerifyError(block,
'invalid',
reason,
score);
}
reward += fee;
if (reward > consensus.MAX_MONEY) {
throw new VerifyError(block,
'invalid',
'bad-cb-amount',
100);
}
// Verify covenants.
await this.verifyCovenants(tx, view, height, state.nameFlags);
// Add new coins.
view.addTX(tx, height);
}
// Make sure the miner isn't trying to conjure more coins.
reward += consensus.getReward(height, interval);
if (block.getClaimed() > reward) {
throw new VerifyError(block,
'invalid',
'bad-cb-amount',
0);
}
// Push onto verification queue.
const jobs = [];
for (let i = 0; i < block.txs.length; i++) {
const tx = block.txs[i];
jobs.push(tx.verifyAsync(view, state.flags, this.workers));
}
// Verify all txs in parallel.
const results = await Promise.all(jobs);
for (const result of results) {
if (!result) {
throw new VerifyError(block,
'invalid',
'mandatory-script-verify-flag-failed',
100);
}
}
return view;
}
/**
* Get main chain height for hash.
* @param {Hash} hash
* @returns {Promise<Number>}
*/
async getMainHeight(hash) {
const entry = await this.db.getEntry(hash);
if (!entry)
return -1;
// Must be the current chain.
if (!await this.db.isMainChain(entry))
return -1;
return entry.height;
}
/**
* Verify a renewal.
* @param {Hash} hash
* @param {Number} height
* @returns {Promise<Boolean>}
*/
async verifyRenewal(hash, height) {
assert(Buffer.isBuffer(hash));
assert((height >>> 0) === height);
// Cannot renew yet.
if (height < this.network.names.renewalMaturity)
return true;
// We require renewals to commit to a block
// within the past 6 months, to prove that
// the user still owns the key. This prevents
// people from presigning thousands of years
// worth of renewals. The block must be at
// least 400 blocks back to prevent the
// possibility of a reorg invalidating the
// covenant.
const entry = await this.db.getEntry(hash);
if (!entry)
return false;
// Must be the current chain.
if (!await this.db.isMainChain(entry))
return false;
// Make sure it's a mature block (unlikely to be reorgd).
if (entry.height > height - this.network.names.renewalMaturity)
return false;
// Block committed to must be
// no older than a 6 months.
if (entry.height < height - this.network.names.renewalPeriod)
return false;
return true;
}
/**
* Verify covenants.
* @param {TX} tx
* @param {CoinView} view
* @param {Number} height
* @param {Number} nameFlags
*/
async verifyCovenants(tx, view, height, nameFlags) {
assert(tx);
assert(view instanceof CoinView);
assert((height >>> 0) === height);
assert(typeof nameFlags === 'number');
const {types} = rules;
const network = this.network;
for (let i = 0; i < tx.outputs.length; i++) {
const output = tx.outputs[i];
const {covenant} = output;
if (!covenant.isName())
continue;
// BID and REDEEM covenants to do not update NameState.
// Therefore, if we are still inside checkpoints we can simply
// assume these covenants are valid without checking anything,
// or even getting and decoding the NameState from the tree.
// We could skip checks for ALL covenant types under checkpoints,
// but since the other types modify the NameState we still
// need to get the data, and the checks themselves are cheap.
if (this.isHistoricalHeight(height)) {
if (covenant.isBid() || covenant.isRedeem())
continue;
}
const nameHash = covenant.getHash(0);
const start = covenant.getU32(1);
const ns = await view.getNameState(this.db, nameHash);
if (ns.isNull()) {
if (!covenant.isClaim() && !covenant.isOpen())
throw new Error('Database inconsistency.');
const name = covenant.get(2);
ns.set(name, height);
}
// Check for name expiration/revocation.
// Note that claimed names never expire
// before the reservation period ends.
// However, they _can_ be revoked.
ns.maybeExpire(height, network);
// Calculate the current state.
const state = ns.state(height, network);
// none -> claim
if (covenant.isClaim()) {
const flags = covenant.getU8(3);
const weak = (flags & 1) !== 0;
// Claims can be re-redeemed any time
// before registration. This is required
// in order for our emergency soft-forks
// to truly behave as _soft_ forks. Once
// re-redeemed, the locktime resets and
// they re-enter the LOCKED state. Note
// that a newer claim invalidates the
// old output by committing to a higher
// height (will fail with nonlocal).
const valid = state === states.OPENING
|| state === states.LOCKED
|| (state === states.CLOSED && !ns.registered);
if (!valid) {
throw new VerifyError(tx,
'invalid',
'bad-claim-state',
100);
}
// Can only claim reserved names.
// Once a reserved name is revoked,
// it is no longer claimable.
if (ns.expired || !rules.isReserved(nameHash, height, network)) {
throw new VerifyError(tx,
'invalid',
'bad-claim-notreserved',
100);
}
// Once the fork is active, we reject
// any weak algorithms (i.e. RSA-1024).
// Any future emergency soft-forks should
// also be included below this check.
if ((nameFlags & VERIFY_COVENANTS_HARDENED) && weak) {
throw new VerifyError(tx,
'invalid',
'bad-claim-algorithm',
100);
}
// Check commitment hash.
const block = covenant.getHash(4);
const claimed = await this.getMainHeight(block);
// Implicitly checks for `-1`.
if (claimed !== covenant.getU32(5)) {
throw new VerifyError(tx,
'invalid',
'bad-claim-commit-height',
100);
}
// Implicitly disallows the genesis block.
if (claimed <= ns.claimed) {
throw new VerifyError(tx,
'invalid',
'bad-claim-commit-hash',
100);
}
assert(claimed >= 1);
// Handle inflation-fixing soft-fork.
if (height >= network.deflationHeight) {
const {claimFrequency} = network.names;
// Require claim height to be 1 on
// initial claims. This makes some
// non-contextual verification easier.
if (ns.owner.isNull()) {
if (claimed !== 1) {
throw new VerifyError(tx,
'invalid',
'bad-claim-height',
0);
}
}
// Limit the frequency of re-claims.
if (!ns.owner.isNull() && height < ns.height + claimFrequency) {
throw new VerifyError(tx,
'invalid',
'bad-claim-frequency',
0);
}
// Allow replacement, but require the
// same fee, which is then miner-burned.
if (!ns.owner.isNull()) {
const coin = await this.getCoin(ns.owner.hash, ns.owner.index);
if (!coin || output.value !== coin.value) {
throw new VerifyError(tx,
'invalid',
'bad-claim-value',
0);
}
}
}
ns.setHeight(height);
ns.setRenewal(height);
ns.setClaimed(claimed);
ns.setValue(0);
ns.setOwner(tx.outpoint(i));
ns.setHighest(0);
ns.setWeak(weak);
continue;
}
assert(!tx.isCoinbase());
// none/redeem/open -> open
if (covenant.isOpen()) {
if (state !== states.OPENING) {
throw new VerifyError(tx,
'invalid',
'bad-open-state',
100);
}
// Only one open transaction can ever exist.
if (ns.height !== height) {
throw new VerifyError(tx,
'invalid',
'bad-open-multiple',
100);
}
// Cannot bid on a reserved name.
if (!ns.expired && rules.isReserved(nameHash, height, network)) {
throw new VerifyError(tx,
'invalid',
'bad-open-reserved',
100);
}
// Make sure locked up names are not opened if ICANN LOCKUP has
// activated.
const isLockUpActive = nameFlags & VERIFY_COVENANTS_LOCKUP;
if (isLockUpActive && rules.isLockedUp(nameHash, height, network)) {
throw new VerifyError(tx,
'invalid',
'bad-open-lockedup',
100);
}
// On mainnet, names are released on a
// weekly basis for the first year.
if (!rules.hasRollout(nameHash, height, network)) {
throw new VerifyError(tx,
'invalid',
'bad-open-rollout',
100);
}
continue;
}
// none/redeem/open -> bid
if (covenant.isBid()) {
if (state !== states.BIDDING) {
throw new VerifyError(tx,
'invalid',
'bad-bid-state',
100);
}
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-bid-height',
100);
}
continue;
}
assert(i < tx.inputs.length);
const {prevout} = tx.inputs[i];
switch (covenant.type) {
// bid -> reveal
case types.REVEAL: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-reveal-nonlocal',
100);
}
// Early reveals? No.
if (state !== states.REVEAL) {
throw new VerifyError(tx,
'invalid',
'bad-reveal-state',
100);
}
if (ns.owner.isNull() || output.value > ns.highest) {
ns.setValue(ns.highest);
ns.setOwner(tx.outpoint(i));
ns.setHighest(output.value);
} else if (output.value > ns.value) {
ns.setValue(output.value);
}
break;
}
// reveal -> redeem
case types.REDEEM: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-redeem-nonlocal',
100);
}
// Allow participants to get their
// money out, even in a revoked state.
if (state < states.CLOSED) {
throw new VerifyError(tx,
'invalid',
'bad-redeem-state',
100);
}
// Must be the loser in order
// to redeem the money now.
if (prevout.equals(ns.owner)) {
throw new VerifyError(tx,
'invalid',
'bad-redeem-owner',
100);
}
break;
}
// claim/reveal -> register
case types.REGISTER: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-register-nonlocal',
100);
}
if (state !== states.CLOSED) {
throw new VerifyError(tx,
'invalid',
'bad-register-state',
100);
}
const data = covenant.get(2);
const hash = covenant.getHash(3);
// Verify block hash for renewal.
if (!await this.verifyRenewal(hash, height)) {
throw new VerifyError(tx,
'invalid',
'bad-register-renewal',
100);
}
// Must be the winner in
// order to redeem the name.
if (!prevout.equals(ns.owner)) {
throw new VerifyError(tx,
'invalid',
'bad-register-owner',
100);
}
// Must match the second highest bid.
if (output.value !== ns.value) {
throw new VerifyError(tx,
'invalid',
'bad-register-value',
100);
}
// For claimed names: if the keys used in
// the proof were somehow compromised, the
// name becomes locked until the reservation
// period ends. Note that this is the same
// code path that can be used for emergency
// soft-forks in the case that a large name
// registrar's keys are compromised.
if (ns.isClaimable(height, network)) {
// Soft-fork #1 (RSA hardening).
if ((nameFlags & VERIFY_COVENANTS_HARDENED) && ns.weak) {
throw new VerifyError(tx,
'invalid',
'bad-register-state',
100);
}
// Emergency soft-forks go here.
// Use only to prevent sky from falling.
//
// A vision for an emergency soft-fork:
//
// 1. A list of compromised DNSKEYs are collected
// out of band.
// 2. The chain is scanned on first boot in order
// to find proofs which are vulnerable. The
// relevant names are marked as such.
// - Pruned nodes and nodes without witness
// data will unfortunately need to re-sync.
// 3. Any proof published before the flag day
// is also marked in this way if it contains
// a vulnerable key.
// 4. At soft-fork activation, the "vulnerable"
// check will take place here. This function
// should return true for any name that was
// redeemed with a vulnerable key.
//
// To future generations:
// PUT THE VULNERABLE KEY CHECK HERE!
}
ns.setRegistered(true);
ns.setOwner(tx.outpoint(i));
if (data.length > 0)
ns.setData(data);
ns.setRenewal(height);
break;
}
// update/renew/register/finalize -> update
case types.UPDATE: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-update-nonlocal',
100);
}
if (state !== states.CLOSED) {
throw new VerifyError(tx,
'invalid',
'bad-update-state',
100);
}
const data = covenant.get(2);
ns.setOwner(tx.outpoint(i));
if (data.length > 0)
ns.setData(data);
ns.setTransfer(0);
break;
}
// update/renew/register/finalize -> renew
case types.RENEW: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-renewal-nonlocal',
100);
}
if (state !== states.CLOSED) {
throw new VerifyError(tx,
'invalid',
'bad-renewal-state',
100);
}
const hash = covenant.getHash(2);
if (height < ns.renewal + network.names.treeInterval) {
throw new VerifyError(tx,
'invalid',
'bad-renewal-premature',
100);
}
if (!await this.verifyRenewal(hash, height)) {
throw new VerifyError(tx,
'invalid',
'bad-renewal',
100);
}
ns.setOwner(tx.outpoint(i));
ns.setTransfer(0);
ns.setRenewal(height);
ns.setRenewals(ns.renewals + 1);
break;
}
// update/renew/register/finalize -> transfer
case types.TRANSFER: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-transfer-nonlocal',
100);
}
if (state !== states.CLOSED) {
throw new VerifyError(tx,
'invalid',
'bad-transfer-state',
100);
}
ns.setOwner(tx.outpoint(i));
assert(ns.transfer === 0);
ns.setTransfer(height);
break;
}
// transfer -> finalize
case types.FINALIZE: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-finalize-nonlocal',
100);
}
if (state !== states.CLOSED) {
throw new VerifyError(tx,
'invalid',
'bad-finalize-state',
100);
}
assert(ns.transfer !== 0);
assert(network.names.transferLockup >= network.names.treeInterval);
if (height < ns.transfer + network.names.transferLockup) {
throw new VerifyError(tx,
'invalid',
'bad-finalize-maturity',
100);
}
const flags = covenant.getU8(3);
const weak = (flags & 1) !== 0;
const claimed = covenant.getU32(4);
const renewals = covenant.getU32(5);
const hash = covenant.getHash(6);
if (weak !== ns.weak
|| claimed !== ns.claimed
|| renewals !== ns.renewals) {
throw new VerifyError(tx,
'invalid',
'bad-finalize-statetransfer',
100);
}
if (!await this.verifyRenewal(hash, height)) {
throw new VerifyError(tx,
'invalid',
'bad-finalize-renewal',
100);
}
ns.setOwner(tx.outpoint(i));
ns.setTransfer(0);
ns.setRenewal(height);
ns.setRenewals(ns.renewals + 1);
break;
}
// register/update/renew/transfer/finalize -> revoke
case types.REVOKE: {
if (start !== ns.height) {
throw new VerifyError(tx,
'invalid',
'bad-revoke-nonlocal',
100);
}
if (state !== states.CLOSED) {
throw new VerifyError(tx,
'invalid',
'bad-revoke-state',
100);
}
assert(ns.revoked === 0);
ns.setRevoked(height);
ns.setTransfer(0);
ns.setData(null);
break;
}
default: {
assert.fail('Invalid covenant type.');
break;
}
}
}
return;
}
/**
* Find the block at which a fork ocurred.
* @private
* @param {ChainEntry} fork - The current chain.
* @param {ChainEntry} longer - The competing chain.
* @returns {Promise<ChainEntry>}
*/
async findFork(fork, longer) {
while (!fork.hash.equals(longer.hash)) {
while (longer.height > fork.height) {
longer = await this.getPrevious(longer);
if (!longer)
throw new Error('No previous entry for new tip.');
}
if (fork.hash.equals(longer.hash))
return fork;
fork = await this.getPrevious(fork);
if (!fork)
throw new Error('No previous entry for old tip.');
}
return fork;
}
/**
* Reorganize the blockchain (connect and disconnect inputs).
* Called when a competing chain with a higher chainwork
* is received.
* @private
* @param {ChainEntry} competitor - The competing chain's tip.
* @returns {Promise<ChainEntry>} - Fork block.
*/
async reorganize(competitor) {
const tip = this.tip;
const fork = await this.findFork(tip, competitor);
assert(fork, 'No free space or data corruption.');
// Blocks to disconnect.
const disconnect = [];
let entry = tip;
while (!entry.hash.equals(fork.hash)) {
disconnect.push(entry);
entry = await this.getPrevious(entry);
assert(entry);
}
// Blocks to connect.
const connect = [];
entry = competitor;
while (!entry.hash.equals(fork.hash)) {
connect.push(entry);
entry = await this.getPrevious(entry);
assert(entry);
}
// Disconnect blocks/txs.
for (let i = 0; i < disconnect.length; i++) {
const entry = disconnect[i];
await this.disconnect(entry);
}
// Connect blocks/txs.
// We don't want to connect the new tip here.
// That will be done outside in setBestChain.
for (let i = connect.length - 1; i >= 1; i--) {
const entry = connect[i];
try {
await this.reconnect(entry);
} catch (err) {
if (err.type === 'VerifyError') {
if (!err.malleated) {
while (i--)
this.setInvalid(connect[i].hash);
}
if (this.tip.chainwork.lte(tip.chainwork))
await this.unreorganize(fork, tip);
}
throw err;
}
}
this.logger.warning(
'Chain reorganization: old=%x(%d) new=%x(%d)',
tip.hash,
tip.height,
competitor.hash,
competitor.height
);
await this.emitAsync('reorganize', tip, competitor, fork);
return fork;
}
/**
* Revert a failed reorganization.
* @private
* @param {ChainEntry} fork - The common ancestor.
* @param {ChainEntry} last - The previous valid tip.
* @returns {Promise}
*/
async unreorganize(fork, last) {
const tip = this.tip;
// Blocks to disconnect.
const disconnect = [];
let entry = tip;
while (!entry.hash.equals(fork.hash)) {
disconnect.push(entry);
entry = await this.getPrevious(entry);
assert(entry);
}
// Blocks to connect.
const connect = [];
entry = last;
while (!entry.hash.equals(fork.hash)) {
connect.push(entry);
entry = await this.getPrevious(entry);
assert(entry);
}
// Disconnect blocks/txs.
for (let i = 0; i < disconnect.length; i++) {
const entry = disconnect[i];
await this.disconnect(entry);
}
// Connect blocks/txs.
for (let i = connect.length - 1; i >= 0; i--) {
const entry = connect[i];
await this.reconnect(entry);
}
this.logger.warning(
'Chain un-reorganization: old=%x(%d) new=%x(%d)',
tip.hash,
tip.height,
last.hash,
last.height
);
// Treat as a reorganize event.
await this.emitAsync('reorganize', tip, last, fork);
}
/**
* Reorganize the blockchain for SPV. This
* will reset the chain to the fork block.
* @private
* @param {ChainEntry} competitor - The competing chain's tip.
* @returns {Promise}
*/
async reorganizeSPV(competitor) {
const tip = this.tip;
const fork = await this.findFork(tip, competitor);
assert(fork, 'No free space or data corruption.');
// Buffer disconnected blocks.
const disconnect = [];
let entry = tip;
while (!entry.hash.equals(fork.hash)) {
disconnect.push(entry);
entry = await this.getPrevious(entry);
assert(entry);
}
// Reset the main chain back
// to the fork block, causing
// us to redownload the blocks
// on the new main chain.
await this._reset(fork.hash, false);
// Emit disconnection events now that
// the chain has successfully reset.
for (const entry of disconnect) {
const headers = entry.toHeaders();
const view = new CoinView();
await this.emitAsync('disconnect', entry, headers, view);
}
this.logger.warning(
'SPV reorganization: old=%x(%d) new=%x(%d)',
tip.hash,
tip.height,
competitor.hash,
competitor.height
);
this.logger.warning(
'Chain replay from height %d necessary.',
fork.height);
return this.emitAsync('reorganize', tip, competitor, fork);
}
/**
* Disconnect an entry from the chain (updates the tip).
* @param {ChainEntry} entry
* @returns {Promise}
*/
async disconnect(entry) {
let block = await this.getBlock(entry.hash);
if (!block) {
if (!this.options.spv)
throw new Error('Block not found.');
block = entry.toHeaders();
}
const prev = await this.getPrevious(entry);
const view = await this.db.disconnect(entry, block);
assert(prev);
this.tip = prev;
this.height = prev.height;
this.emit('tip', prev);
return this.emitAsync('disconnect', entry, block, view);
}
/**
* Reconnect an entry to the chain (updates the tip).
* This will do contextual-verification on the block
* (necessary because we cannot validate the inputs
* in alternate chains when they come in).
* @param {ChainEntry} entry
* @returns {Promise}
*/
async reconnect(entry) {
const flags = common.flags.VERIFY_NONE;
let block = await this.getBlock(entry.hash);
if (!block) {
if (!this.options.spv)
throw new Error('Block not found.');
block = entry.toHeaders();
}
const prev = await this.getPrevious(entry);
assert(prev);
let view, state;
try {
[view, state] = await this.verifyContext(block, prev, flags);
} catch (err) {
if (err.type === 'VerifyError') {
if (!err.malleated)
this.setInvalid(entry.hash);
this.logger.warning(
'Tried to reconnect invalid block: %x (%d).',
entry.hash, entry.height);
}
throw err;
}
await this.db.reconnect(entry, block, view);
this.tip = entry;
this.height = entry.height;
this.setDeploymentState(state);
this.emit('tip', entry);
this.emit('reconnect', entry, block);
if ((entry.height % this.network.names.treeInterval) === 0)
this.emit('tree commit', this.db.tree.rootHash(), entry, block);
return this.emitAsync('connect', entry, block, view);
}
/**
* Set the best chain. This is called on every incoming
* block with greater chainwork than the current tip.
* @private
* @param {ChainEntry} entry
* @param {Block} block
* @param {ChainEntry} prev
* @param {Number} flags
* @returns {Promise}
*/
async setBestChain(entry, block, prev, flags) {
const tip = this.tip;
let fork = null;
// A higher fork has arrived.
// Time to reorganize the chain.
if (!entry.prevBlock.equals(this.tip.hash)) {
try {
// Do as much verification
// as we can before reorganizing.
await this.verify(block, prev, flags);
} catch (err) {
if (err.type === 'VerifyError') {
if (!err.malleated)
this.setInvalid(entry.hash);
this.logger.warning(
'Tried to connect invalid block: %x (%d).',
entry.hash, entry.height);
}
throw err;
}
this.logger.warning('WARNING: Reorganizing chain.');
// In spv-mode, we reset the
// chain and redownload the blocks.
if (this.options.spv)
return this.reorganizeSPV(entry);
fork = await this.reorganize(entry);
}
// Warn of unknown versionbits.
if (entry.hasUnknown(this.network)) {
this.logger.warning(
'Unknown version bits in block %d: %s.',
entry.height, util.hex32(entry.version));
}
// Otherwise, everything is in order.
// Do "contextual" verification on our block
// now that we're certain its previous
// block is in the chain.
let view, state;
try {
[view, state] = await this.verifyContext(block, prev, flags);
} catch (err) {
if (err.type === 'VerifyError') {
if (!err.malleated)
this.setInvalid(entry.hash);
this.logger.warning(
'Tried to connect invalid block: %x (%d).',
entry.hash, entry.height);
if (fork && this.tip.chainwork.lte(tip.chainwork))
await this.unreorganize(fork, tip);
}
throw err;
}
// Save block and connect inputs.
try {
await this.db.save(entry, block, view);
} catch (e) {
const error = new CriticalError(e.message);
this.emit('abort', error);
throw error;
}
// Expose the new state.
this.tip = entry;
this.height = entry.height;
this.setDeploymentState(state);
this.emit('tip', entry);
this.emit('block', block, entry);
if ((entry.height % this.network.names.treeInterval) === 0)
this.emit('tree commit', this.db.tree.rootHash(), entry, block);
return this.emitAsync('connect', entry, block, view);
}
/**
* Save block on an alternate chain.
* @private
* @param {ChainEntry} entry
* @param {Block} block
* @param {ChainEntry} prev
* @param {Number} flags
* @returns {Promise}
*/
async saveAlternate(entry, block, prev, flags) {
// Do not accept forked chain older than the
// last checkpoint.
if (this.options.checkpoints) {
if (prev.height + 1 < this.network.lastCheckpoint)
throw new VerifyError(block,
'checkpoint',
'bad-fork-prior-to-checkpoint',
100);
}
try {
// Do as much verification
// as we can before saving.
await this.verify(block, prev, flags);
} catch (err) {
if (err.type === 'VerifyError') {
if (!err.malleated)
this.setInvalid(entry.hash);
this.logger.warning(
'Invalid block on alternate chain: %x (%d).',
entry.hash, entry.height);
}
throw err;
}
// Warn of unknown versionbits.
if (entry.hasUnknown(this.network)) {
this.logger.warning(
'Unknown version bits in block %d: %s.',
entry.height, util.hex32(entry.version));
}
try {
await this.db.save(entry, block);
} catch (e) {
const error = new CriticalError(e.message);
this.emit('abort', error);
throw error;
}
this.logger.warning('Heads up: Competing chain at height %d:'
+ ' tip-height=%d competitor-height=%d'
+ ' tip-hash=%x competitor-hash=%x'
+ ' tip-chainwork=%s competitor-chainwork=%s'
+ ' chainwork-diff=%s',
entry.height,
this.tip.height,
entry.height,
this.tip.hash,
entry.hash,
this.tip.chainwork.toString(),
entry.chainwork.toString(),
this.tip.chainwork.sub(entry.chainwork).toString());
// Emit as a "competitor" block.
this.emit('competitor', block, entry);
}
/**
* Reset the chain to the desired block. This
* is useful for replaying the blockchain download
* for SPV.
* @param {Hash|Number} block
* @returns {Promise}
*/
async reset(block) {
const unlock = await this.locker.lock();
try {
return await this._reset(block, false);
} finally {
unlock();
}
}
/**
* Reset the chain to the desired block without a lock.
* @private
* @param {Hash|Number} block
* @param {Boolean} silent - don't emit reset.
* @returns {Promise}
*/
async _reset(block, silent = false) {
const tip = await this.db.reset(block);
// Reset state.
this.tip = tip;
this.height = tip.height;
this.synced = false;
const state = await this.getDeploymentState();
this.setDeploymentState(state);
this.emit('tip', tip);
if (!silent)
await this.emitAsync('reset', tip);
// Reset the orphan map completely. There may
// have been some orphans on a forked chain we
// no longer need.
this.purgeOrphans();
this.maybeSync();
}
/**
* Reset the chain to a height or hash. Useful for replaying
* the blockchain download for SPV.
* @param {Hash|Number} block - hash/height
* @returns {Promise}
*/
async replay(block) {
const unlock = await this.locker.lock();
try {
return await this._replay(block, true);
} finally {
unlock();
}
}
/**
* Reset the chain without a lock.
* @private
* @param {Hash|Number} block - hash/height
* @param {Boolean} silent
* @returns {Promise}
*/
async _replay(block, silent) {
const entry = await this.getEntry(block);
if (!entry)
throw new Error('Block not found.');
if (!await this.isMainChain(entry))
throw new Error('Cannot reset on alternate chain.');
if (entry.isGenesis()) {
await this._reset(entry.hash, silent);
return;
}
await this._reset(entry.prevBlock, silent);
}
/**
* Invalidate block.
* @param {Hash} hash
* @returns {Promise}
*/
async invalidate(hash) {
const unlock = await this.locker.lock();
try {
return await this._invalidate(hash);
} finally {
unlock();
}
}
/**
* Invalidate block (no lock).
* @param {Hash} hash
* @returns {Promise}
*/
async _invalidate(hash) {
await this._replay(hash, false);
this.setInvalid(hash);
}
/**
* Retroactively prune the database.
* @returns {Promise<Boolean>}
*/
async prune() {
const unlock = await this.locker.lock();
try {
return await this.db.prune();
} finally {
unlock();
}
}
/**
* Compact the Urkel Tree.
* Removes all historical state and all data not
* linked directly to the provided root node hash.
* @returns {Promise}
*/
async compactTree() {
if (this.options.spv)
return;
if (this.height < this.network.block.keepBlocks)
throw new Error('Chain is too short to compact tree.');
const unlock = await this.locker.lock();
this.logger.info('Compacting Urkel Tree...');
// To support chain reorgs of limited depth we compact the tree
// to some commitment point in recent history, then rebuild it from there
// back up to the current chain tip. In order to support pruning nodes,
// all blocks above this depth must be available on disk.
// This actually further reduces the ability for a pruning node to recover
// from a deep reorg. On mainnet, `keepBlocks` is 288. A normal pruning
// node can recover from a reorg up to that depth. Compacting the tree
// potentially reduces that depth to 288 - 36 = 252. A reorg deeper than
// that will result in a `MissingNodeError` thrown by Urkel inside
// chain.saveNames() as it tries to restore a deleted state.
// Oldest block available to a pruning node.
const oldestBlock = this.height - this.network.block.keepBlocks;
const {treeInterval} = this.network.names;
// Distance from that block to the start of the oldest tree interval.
const toNextInterval = (treeInterval - (oldestBlock % treeInterval))
% treeInterval;
// Get the oldest Urkel Tree root state a pruning node can recover from.
const oldestTreeIntervalStart = oldestBlock + toNextInterval + 1;
const entry = await this.db.getEntryByHeight(oldestTreeIntervalStart);
try {
// TODO: For RPC calls, If compaction fails while compacting
// and we never hit syncTree, we need to shut down the node
// so on restart chain can recover.
// Error can also happen in syncTree, but that means the DB
// is done for. (because restart would just retry syncTree.)
// It's fine on open, open throwing would just stop the node.
// Rewind Urkel Tree and delete all historical state.
this.emit('tree compact start', entry.treeRoot, entry);
await this.db.compactTree(entry);
await this.syncTree();
this.emit('tree compact end', entry.treeRoot, entry);
} catch(e) {
const error = new CriticalError(e.message);
this.emit('abort', error);
throw error;
} finally {
unlock();
}
}
/**
* Reconstruct the Urkel Tree.
* @returns {Promise}
*/
async reconstructTree() {
if (this.options.spv)
return;
if (this.options.prune)
throw new Error('Cannot reconstruct tree in pruned mode.');
const unlock = await this.locker.lock();
const treeState = await this.db.getTreeState();
if (treeState.compactionHeight === 0)
throw new Error('Nothing to reconstruct.');
// Compact all the way to the first block and
// let the syncTree do its job.
const entry = await this.db.getEntryByHeight(1);
try {
this.emit('tree reconstruct start');
await this.db.compactTree(entry);
await this.syncTree();
this.emit('tree reconstruct end');
} finally {
unlock();
}
}
/**
* Scan the blockchain for transactions containing specified address hashes.
* @param {Hash|Number} start - Block hash or height to start at.
* @param {BloomFilter} filter - Bloomfilter containing tx and address hashes.
* @param {Function} iter - Iterator.
* @returns {Promise<void>}
*/
async scan(start, filter, iter) {
const unlock = await this.locker.lock();
try {
return await this.db.scan(start, filter, iter);
} finally {
unlock();
}
}
/** @typedef {import('./common').ScanAction} ScanAction */
/**
* @callback ScanInteractiveIterCB
* @param {ChainEntry} entry
* @param {TX[]} txs
* @returns {Promise<ScanAction>}
*/
/**
* Interactive scan the blockchain for transactions containing specified
* address hashes. Allows repeat and abort.
* @param {Hash|Number} start - Block hash or height to start at.
* @param {BloomFilter} filter - Starting bloom filter containing tx,
* address and name hashes.
* @param {ScanInteractiveIterCB} iter - Iterator.
* @param {Boolean} [fullLock=false]
* @returns {Promise<void>}
*/
async scanInteractive(start, filter, iter, fullLock = false) {
if (fullLock) {
const unlock = await this.locker.lock();
try {
// We lock the whole chain, no longer lock per block scan.
return await this._scanInteractive(start, filter, iter, false);
} catch (e) {
this.logger.debug('Scan(interactive) errored. Error: %s', e.message);
throw e;
} finally {
unlock();
}
}
return this._scanInteractive(start, filter, iter, true);
}
/**
* Interactive scan the blockchain for transactions containing specified
* address hashes. Allows repeat and abort.
* @param {Hash|Number} start - Block hash or height to start at.
* @param {BloomFilter} filter - Starting bloom filter containing tx,
* address and name hashes.
* @param {ScanInteractiveIterCB} iter - Iterator.
* @param {Boolean} [lockPerScan=true] - if we should lock per block scan.
* @returns {Promise<void>}
*/
async _scanInteractive(start, filter, iter, lockPerScan = true) {
if (start == null)
start = this.network.genesis.hash;
if (typeof start === 'number')
this.logger.info('Scanning(interactive) from height %d.', start);
else
this.logger.info('Scanning(interactive) from block %x.', start);
let hash = start;
while (hash != null) {
let unlock;
if (lockPerScan)
unlock = await this.locker.lock();
try {
const {entry, txs} = await this.db.scanBlock(hash, filter);
const action = await iter(entry, txs);
if (!action || typeof action !== 'object')
throw new Error('Did not get proper action');
switch (action.type) {
case scanActions.REPEAT: {
break;
}
case scanActions.REPEAT_SET: {
// try again with updated filter.
filter = action.filter;
break;
}
case scanActions.REPEAT_ADD: {
if (!filter)
throw new Error('No filter set.');
for (const chunk of action.chunks)
filter.add(chunk);
break;
}
case scanActions.NEXT: {
const next = await this.getNext(entry);
hash = next && next.hash;
break;
}
case scanActions.ABORT: {
this.logger.info('Scan(interactive) aborted at %x (%d).',
entry.hash, entry.height);
throw new Error('scan request aborted.');
}
default:
this.logger.debug('Scan(interactive) aborting. Unknown action: %d',
action.type);
throw new Error('Unknown action.');
}
} catch (e) {
this.logger.debug('Scan(interactive) errored. Error: %s', e.message);
throw e;
} finally {
if (lockPerScan)
unlock();
}
}
}
/**
* Add a block to the chain, perform all necessary verification.
* @param {Block} block
* @param {Number?} flags
* @param {Number?} id
* @returns {Promise<ChainEntry?>}
*/
async add(block, flags, id) {
const hash = block.hash();
const unlock = await this.locker.lock(hash);
try {
return await this._add(block, flags, id);
} finally {
unlock();
}
}
/**
* Add a block to the chain without a lock.
* @private
* @param {Block} block
* @param {Number?} flags
* @param {Number?} id
* @returns {Promise<ChainEntry?>}
*/
async _add(block, flags, id) {
const hash = block.hash();
if (flags == null)
flags = common.DEFAULT_FLAGS;
if (id == null)
id = -1;
// Special case for genesis block.
if (hash.equals(this.network.genesis.hash)) {
this.logger.debug('Saw genesis block: %x.', block.hash());
throw new VerifyError(block, 'duplicate', 'duplicate', 0);
}
// Do we already have this block in the queue?
if (this.hasPending(hash)) {
this.logger.debug('Already have pending block: %x.', block.hash());
throw new VerifyError(block, 'duplicate', 'duplicate', 0);
}
// If the block is already known to be
// an orphan, ignore it.
if (this.hasOrphan(hash)) {
this.logger.debug('Already have orphan block: %x.', block.hash());
throw new VerifyError(block, 'duplicate', 'duplicate', 0);
}
// Do not revalidate known invalid blocks.
if (this.hasInvalid(block)) {
this.logger.debug('Invalid ancestors for block: %x.', block.hash());
throw new VerifyError(block, 'duplicate', 'duplicate', 100);
}
// Check the POW before doing anything.
if (flags & common.flags.VERIFY_POW) {
if (!block.verifyPOW())
throw new VerifyError(block, 'invalid', 'high-hash', 50);
}
// Do we already have this block?
if (await this.hasEntry(hash)) {
this.logger.debug('Already have block: %x.', block.hash());
throw new VerifyError(block, 'duplicate', 'duplicate', 0);
}
// Find the previous block entry.
const prev = await this.getEntry(block.prevBlock);
// If previous block wasn't ever seen,
// add it current to orphans and return.
if (!prev) {
this.storeOrphan(block, flags, id);
return null;
}
// Connect the block.
const entry = await this.connect(prev, block, flags);
// Handle any orphans.
if (this.hasNextOrphan(hash))
await this.handleOrphans(entry);
return entry;
}
/**
* Connect block to chain.
* @private
* @param {ChainEntry} prev
* @param {Block} block
* @param {Number} flags
* @returns {Promise<ChainEntry?>}
*/
async connect(prev, block, flags) {
const start = util.bench();
// Sanity check.
assert(block.prevBlock.equals(prev.hash));
// 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 connected. Hopefully the
// deserialized blocks get cleaned up by the
// GC quickly.
if (block.isMemory()) {
try {
block = block.toBlock();
} catch (e) {
this.logger.error(e);
throw new VerifyError(block,
'malformed',
'error parsing message',
10,
true);
}
}
// Transactions are not allowed in any block before
// a certain amount of chainwork has been accumulated.
// This is a non-malleated, permanently invalid block
// and whoever sent it should be banned.
if (prev.height + 1 < this.network.txStart) {
let invalid = false;
// No transactions allowed besides coinbase
if (block.txs.length > 1)
invalid = true;
if (!this.options.spv) {
// No claims or airdrops allowed in coinbase yet.
const cb = block.txs[0];
if (cb.outputs.length > 1)
invalid = true;
// Sanity check
if (!cb.outputs[0].covenant.isNone())
invalid = true;
}
if (invalid) {
this.setInvalid(block.hash());
throw new VerifyError(block,
'invalid',
'no-tx-allowed-yet',
100,
false);
}
}
// Create a new chain entry.
const entry = ChainEntry.fromBlock(block, prev);
// The block is on a alternate 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.lte(this.tip.chainwork)) {
// Save block to an alternate chain.
await this.saveAlternate(entry, block, prev, flags);
} else {
// Attempt to add block to the chain index.
await this.setBestChain(entry, block, prev, flags);
}
// Keep track of stats.
this.logStatus(start, block, entry);
// Check sync state.
this.maybeSync();
return entry;
}
/**
* Handle orphans.
* @private
* @param {ChainEntry} entry
* @returns {Promise}
*/
async handleOrphans(entry) {
let orphan = this.resolveOrphan(entry.hash);
while (orphan) {
const {block, flags, id} = orphan;
try {
entry = await this.connect(entry, block, flags);
} catch (err) {
if (err.type === 'VerifyError') {
this.logger.warning(
'Could not resolve orphan block %x: %s.',
block.hash(), err.message);
this.emit('bad orphan', err, id);
break;
}
throw err;
}
this.logger.debug(
'Orphan block was resolved: %x (%d).',
block.hash(), entry.height);
this.emit('resolved', block, entry);
orphan = this.resolveOrphan(entry.hash);
}
}
/**
* Test whether the chain has reached its slow height.
* @private
* @returns {Boolean}
*/
isSlow() {
if (this.options.spv)
return false;
if (this.synced)
return true;
if (this.height === 1 || this.height % 20 === 0)
return true;
if (this.height >= this.network.block.slowHeight)
return true;
return false;
}
/**
* Calculate the time difference from
* start time and log block.
* @private
* @param {Array} start
* @param {Block} block
* @param {ChainEntry} entry
*/
logStatus(start, block, entry) {
if (!this.isSlow())
return;
// Report memory for debugging.
this.logger.memory();
const elapsed = util.bench(start);
this.logger.info(
'Block %x (%d) added to chain (size=%d txs=%d time=%d).',
entry.hash,
entry.height,
block.getSize(),
block.txs.length,
elapsed);
}
/**
* Verify a block hash and height against the checkpoints.
* @private
* @param {ChainEntry} prev
* @param {Hash} hash
* @returns {Boolean}
*/
verifyCheckpoint(prev, hash) {
if (!this.options.checkpoints)
return true;
const height = prev.height + 1;
const checkpoint = this.network.checkpointMap[height];
if (!checkpoint)
return true;
if (hash.equals(checkpoint)) {
this.logger.debug('Hit checkpoint block %x (%d).', hash, height);
this.emit('checkpoint', hash, height);
return true;
}
// Someone is either mining on top of
// an old block for no reason, or the
// consensus protocol is broken and
// there was a 20k+ block reorg.
this.logger.warning(
'Checkpoint mismatch at height %d: expected=%x received=%x',
height,
checkpoint,
hash
);
this.purgeOrphans();
return false;
}
/**
* Store an orphan.
* @private
* @param {Block} block
* @param {Number?} flags
* @param {Number?} id
*/
storeOrphan(block, flags, id) {
const height = block.getCoinbaseHeight();
const orphan = this.orphanPrev.get(block.prevBlock);
// The orphan chain forked.
if (orphan) {
assert(!orphan.block.hash().equals(block.hash()));
assert(orphan.block.prevBlock.equals(block.prevBlock));
this.logger.warning(
'Removing forked orphan block: %x (%d).',
orphan.block.hash(), height);
this.removeOrphan(orphan);
}
this.limitOrphans();
this.addOrphan(new Orphan(block, flags, id));
this.logger.debug(
'Storing orphan block: %x (%d).',
block.hash(), height);
this.emit('orphan', block);
}
/**
* Add an orphan.
* @private
* @param {Orphan} orphan
* @returns {Orphan}
*/
addOrphan(orphan) {
const block = orphan.block;
const hash = block.hash();
assert(!this.orphanMap.has(hash));
assert(!this.orphanPrev.has(block.prevBlock));
assert(this.orphanMap.size >= 0);
this.orphanMap.set(hash, orphan);
this.orphanPrev.set(block.prevBlock, orphan);
return orphan;
}
/**
* Remove an orphan.
* @private
* @param {Orphan} orphan
* @returns {Orphan}
*/
removeOrphan(orphan) {
const block = orphan.block;
const hash = block.hash();
assert(this.orphanMap.has(hash));
assert(this.orphanPrev.has(block.prevBlock));
assert(this.orphanMap.size > 0);
this.orphanMap.delete(hash);
this.orphanPrev.delete(block.prevBlock);
return orphan;
}
/**
* Test whether a hash would resolve the next orphan.
* @private
* @param {Hash} hash - Previous block hash.
* @returns {Boolean}
*/
hasNextOrphan(hash) {
return this.orphanPrev.has(hash);
}
/**
* Resolve an orphan.
* @private
* @param {Hash} hash - Previous block hash.
* @returns {Orphan}
*/
resolveOrphan(hash) {
const orphan = this.orphanPrev.get(hash);
if (!orphan)
return null;
return this.removeOrphan(orphan);
}
/**
* Purge any waiting orphans.
*/
purgeOrphans() {
const count = this.orphanMap.size;
if (count === 0)
return;
this.orphanMap.clear();
this.orphanPrev.clear();
this.logger.debug('Purged %d orphans.', count);
}
/**
* Prune orphans, only keep the orphan with the highest
* coinbase height (likely to be the peer's tip).
*/
limitOrphans() {
const now = util.now();
let oldest = null;
for (const orphan of this.orphanMap.values()) {
if (now < orphan.time + 60 * 60) {
if (!oldest || orphan.time < oldest.time)
oldest = orphan;
continue;
}
this.removeOrphan(orphan);
}
if (this.orphanMap.size < this.options.maxOrphans)
return;
if (!oldest)
return;
this.removeOrphan(oldest);
}
/**
* Test whether an invalid block hash has been seen.
* @private
* @param {Block} block
* @returns {Boolean}
*/
hasInvalid(block) {
const hash = block.hash();
if (this.invalid.has(hash))
return true;
if (this.invalid.has(block.prevBlock)) {
this.setInvalid(hash);
return true;
}
return false;
}
/**
* Mark a block as invalid.
* @private
* @param {Hash} hash
*/
setInvalid(hash) {
this.invalid.set(hash, true);
}
/**
* Forget an invalid block hash.
* @private
* @param {Hash} hash
*/
removeInvalid(hash) {
this.invalid.remove(hash);
}
/**
* Test the chain to see if it contains
* a block, or has recently seen a block.
* @param {Hash} hash
* @returns {Promise} - Returns Boolean.
*/
async has(hash) {
if (this.hasOrphan(hash))
return true;
if (this.locker.has(hash))
return true;
if (this.invalid.has(hash))
return true;
return this.hasEntry(hash);
}
/**
* Find the corresponding block entry by hash or height.
* @param {Hash|Number} hash
* @returns {Promise<ChainEntry?>}
*/
getEntry(hash) {
return this.db.getEntry(hash);
}
/**
* Retrieve a chain entry by height.
* @param {Number} height
* @returns {Promise<ChainEntry?>}
*/
getEntryByHeight(height) {
return this.db.getEntryByHeight(height);
}
/**
* Retrieve a chain entry by hash.
* @param {Hash} hash
* @returns {Promise<ChainEntry?>}
*/
getEntryByHash(hash) {
return this.db.getEntryByHash(hash);
}
/**
* Get the hash of a block by height. Note that this
* will only return hashes in the main chain.
* @param {Number} height
* @returns {Promise<Hash>}
*/
getHash(height) {
return this.db.getHash(height);
}
/**
* Get the height of a block by hash.
* @param {Hash} hash
* @returns {Promise<Number>}
*/
getHeight(hash) {
return this.db.getHeight(hash);
}
/**
* Test the chain to see if it contains a block.
* @param {Hash} hash
* @returns {Promise<Boolean>}
*/
hasEntry(hash) {
return this.db.hasEntry(hash);
}
/**
* Get the _next_ block hash (does not work by height).
* @param {Hash} hash
* @returns {Promise<Hash>}
*/
getNextHash(hash) {
return this.db.getNextHash(hash);
}
/**
* Check whether coins are still unspent.
* @param {TX} tx
* @returns {Promise<Boolean>}
*/
hasCoins(tx) {
return this.db.hasCoins(tx);
}
/**
* Get all tip hashes.
* @returns {Promise<Hash[]>}
*/
getTips() {
return this.db.getTips();
}
/**
* Get range of hashes.
* @param {Number} [start=-1]
* @param {Number} [end=-1]
* @returns {Promise<Hash[]>}
*/
getHashes(start = -1, end = -1) {
return this.db.getHashes(start, end);
}
/**
* Get range of entries.
* @param {Number} [start=-1]
* @param {Number} [end=-1]
* @returns {Promise<ChainEntry[]>}
*/
getEntries(start = -1, end = -1) {
return this.db.getEntries(start, end);
}
/**
* Get a coin (unspents only).
* @param {Outpoint} prevout
* @returns {Promise<CoinEntry?>}
*/
readCoin(prevout) {
return this.db.readCoin(prevout);
}
/**
* Get a coin (unspents only).
* @param {Hash} hash
* @param {Number} index
* @returns {Promise<Coin?>}
*/
getCoin(hash, index) {
return this.db.getCoin(hash, index);
}
/**
* Retrieve a block from the database (not filled with coins).
* @param {Hash} hash
* @returns {Promise<Block?>}
*/
getBlock(hash) {
return this.db.getBlock(hash);
}
/**
* Retrieve a block from the database (not filled with coins).
* @param {Hash|Number} hashHeight
* @returns {Promise<Buffer|null>}
*/
getRawBlock(hashHeight) {
return this.db.getRawBlock(hashHeight);
}
/**
* Get a historical block coin viewpoint.
* @param {Block} block
* @returns {Promise<CoinView>}
*/
getBlockView(block) {
return this.db.getBlockView(block);
}
/**
* Get a transaction with metadata.
* @param {Hash} hash
* @returns {Promise<TXMeta>}
*/
getMeta(hash) {
return this.db.getMeta(hash);
}
/**
* Retrieve a transaction.
* @param {Hash} hash
* @returns {Promise<TX>}
*/
getTX(hash) {
return this.db.getTX(hash);
}
/**
* @param {Hash} hash
* @returns {Promise<Boolean>}
*/
hasTX(hash) {
return this.db.hasTX(hash);
}
/**
* Get all coins pertinent to an address.
* @param {Address[]} addrs
* @returns {Promise<Coin[]>}
*/
getCoinsByAddress(addrs) {
return this.db.getCoinsByAddress(addrs);
}
/**
* Get all transaction hashes to an address.
* @param {Address[]} addrs
* @returns {Promise<Hash[]>}
*/
getHashesByAddress(addrs) {
return this.db.getHashesByAddress(addrs);
}
/**
* Get all transactions pertinent to an address.
* @param {Address[]} addrs
* @returns {Promise<TX[]>}
*/
getTXByAddress(addrs) {
return this.db.getTXByAddress(addrs);
}
/**
* Get all transactions pertinent to an address.
* @param {Address[]} addrs
* @returns {Promise<TXMeta[]>}
*/
getMetaByAddress(addrs) {
return this.db.getMetaByAddress(addrs);
}
/**
* Get an orphan block.
* @param {Hash} hash
* @returns {Block?}
*/
getOrphan(hash) {
return this.orphanMap.get(hash) || null;
}
/**
* Test the chain to see if it contains an orphan.
* @param {Hash} hash
* @returns {Boolean}
*/
hasOrphan(hash) {
return this.orphanMap.has(hash);
}
/**
* Test the chain to see if it contains a pending block in its queue.
* @param {Hash} hash
* @returns {Boolean} - Returns Boolean.
*/
hasPending(hash) {
return this.locker.pending(hash);
}
/**
* Get coin viewpoint.
* @param {TX} tx
* @returns {Promise<CoinView>}
*/
getCoinView(tx) {
return this.db.getCoinView(tx);
}
/**
* Get coin viewpoint (spent).
* @param {TX} tx
* @returns {Promise<CoinView>}
*/
async getSpentView(tx) {
const unlock = await this.locker.lock();
try {
return await this.db.getSpentView(tx);
} finally {
unlock();
}
}
/**
* Test the chain to see if it is synced.
* @returns {Boolean}
*/
isFull() {
return this.synced;
}
/**
* Potentially emit a `full` event.
* @private
*/
maybeSync() {
if (this.synced)
return;
if (this.options.checkpoints) {
if (this.height < this.network.lastCheckpoint)
return;
}
if (!this.hasChainwork())
return;
if (this.tip.time < this.network.now() - this.network.block.maxTipAge)
return;
this.synced = true;
this.emit('full');
}
/**
* Test the chain to see if it has the
* minimum required chainwork for the
* network.
* @returns {Boolean}
*/
hasChainwork() {
return this.tip.chainwork.gte(this.network.pow.chainwork);
}
/**
* Get the fill percentage.
* @returns {Number} percent - Ranges from 0.0 to 1.0.
*/
getProgress() {
const start = this.network.genesis.time;
const current = this.tip.time - start;
const end = this.network.now() - start - 40 * 60;
return Math.min(1, current / end);
}
/**
* Calculate chain locator (an array of hashes).
* @param {Hash?} start - Height or hash to treat as the tip.
* The current tip will be used if not present. Note that this can be a
* non-existent hash, which is useful for headers-first locators.
* @returns {Promise<Hash[]>}
*/
async getLocator(start) {
const unlock = await this.locker.lock();
try {
return await this._getLocator(start);
} finally {
unlock();
}
}
/**
* Calculate chain locator without a lock.
* @private
* @param {Hash?} start
* @returns {Promise<Hash[]>}
*/
async _getLocator(start) {
if (start == null)
start = this.tip.hash;
assert(Buffer.isBuffer(start));
let entry = await this.getEntry(start);
const hashes = [];
if (!entry) {
entry = this.tip;
hashes.push(start);
}
let main = await this.isMainChain(entry);
let hash = entry.hash;
let height = entry.height;
let step = 1;
hashes.push(hash);
while (height > 0) {
height -= step;
if (height < 0)
height = 0;
if (hashes.length > 10)
step *= 2;
if (main) {
// If we're on the main chain, we can
// do a fast lookup of the hash.
hash = await this.getHash(height);
assert(hash);
} else {
const ancestor = await this.getAncestor(entry, height);
assert(ancestor);
main = await this.isMainChain(ancestor);
hash = ancestor.hash;
}
hashes.push(hash);
}
return hashes;
}
/**
* Calculate the orphan root of the hash (if it is an orphan).
* @param {Hash} hash
* @returns {Hash}
*/
getOrphanRoot(hash) {
let root = null;
assert(hash);
for (;;) {
const orphan = this.orphanMap.get(hash);
if (!orphan)
break;
root = hash;
hash = orphan.block.prevBlock;
}
return root;
}
/**
* Calculate the time difference (in seconds)
* between two blocks by examining chainworks.
* @param {ChainEntry} to
* @param {ChainEntry} from
* @returns {Number}
*/
getProofTime(to, from) {
const pow = this.network.pow;
let sign, work;
if (to.chainwork.gt(from.chainwork)) {
work = to.chainwork.sub(from.chainwork);
sign = 1;
} else {
work = from.chainwork.sub(to.chainwork);
sign = -1;
}
work = work.imuln(pow.targetSpacing);
work = work.div(this.tip.getProof());
if (work.bitLength() > 53)
return sign * Number.MAX_SAFE_INTEGER;
return sign * work.toNumber();
}
/**
* Calculate the next target based on the chain tip.
* @returns {Promise} - returns Number
* (target is in compact/mantissa form).
*/
async getCurrentTarget() {
return this.getTarget(this.network.now(), this.tip);
}
/**
* Get median block by timestamp.
* @param {ChainEntry} prev
* @returns {Promise<ChainEntry>}
*/
async getSuitableBlock(prev) {
assert(prev);
let z = prev;
let y = await this.getPrevious(z);
let x = await this.getPrevious(y);
assert(x);
if (x.time > z.time)
[x, z] = [z, x];
if (x.time > y.time)
[x, y] = [y, x];
if (y.time > z.time)
[y, z] = [z, y];
return y;
}
/**
* Calculate the next target.
* @param {Number} time - Next block timestamp.
* @param {ChainEntry} prev - Previous entry.
* @returns {Promise<Number>} - returns Number
* (target is in compact/mantissa form).
*/
async getTarget(time, prev) {
const pow = this.network.pow;
// Genesis
if (!prev) {
assert(time === this.network.genesis.time);
return pow.bits;
}
// Do not retarget
if (pow.noRetargeting)
return pow.bits;
// Special behavior for testnet:
if (pow.targetReset) {
if (time > prev.time + pow.targetSpacing * 2)
return pow.bits;
}
assert(pow.blocksPerDay === 144);
assert(pow.targetWindow === 144);
if (prev.height < pow.blocksPerDay + 2) {
assert(prev.bits === pow.bits);
return pow.bits;
}
const last = await this.getSuitableBlock(prev);
const height = prev.height - pow.blocksPerDay;
assert(height >= 0);
const ancestor = await this.getAncestor(prev, height);
const first = await this.getSuitableBlock(ancestor);
return this.retarget(first, last);
}
/**
* Calculate the next target.
* @param {ChainEntry} first - Suitable block from 1 day prior.
* @param {ChainEntry} last - Last suitable block.
* @returns {Number} target - Target in compact/mantissa form.
*/
retarget(first, last) {
assert(last.height > first.height);
const pow = this.network.pow;
const maxChainwork = ChainEntry.MAX_CHAINWORK;
const minActual = pow.blocksPerDay / 4;
const maxActual = pow.blocksPerDay * 4;
assert(minActual === 36); // 72 on BCH
assert(maxActual === 576); // 288 on BCH
assert(minActual * pow.targetSpacing === pow.minActual);
assert(maxActual * pow.targetSpacing === pow.maxActual);
const work = last.chainwork.sub(first.chainwork);
work.imuln(pow.targetSpacing);
let actualTimespan = last.time - first.time;
if (actualTimespan < minActual * pow.targetSpacing)
actualTimespan = minActual * pow.targetSpacing;
if (actualTimespan > maxActual * pow.targetSpacing)
actualTimespan = maxActual * pow.targetSpacing;
work.idivn(actualTimespan);
if (work.isZero())
return pow.bits;
const target = maxChainwork.div(work).isubn(1);
if (target.gt(pow.limit))
return pow.bits;
const cmpct = consensus.toCompact(target);
this.logger.debug('Retargetting to: %s (0x%s).',
consensus.fromCompact(cmpct).toString('hex', 64),
util.hex32(cmpct));
return cmpct;
}
/**
* Find a locator. Analagous to bitcoind's `FindForkInGlobalIndex()`.
* @param {Hash[]} locator - Hashes.
* @returns {Promise<Hash>} (the hash of the latest known block).
*/
async findLocator(locator) {
for (const hash of locator) {
if (await this.isMainHash(hash))
return hash;
}
return this.network.genesis.hash;
}
/**
* Check whether a versionbits deployment is active (BIP9: versionbits).
* @example
* await chain.isActive(tip, deployments.segwit);
* @see https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki
* @param {ChainEntry} prev - Previous chain entry.
* @param {Object} deployment - Deployment.
* @returns {Promise<Boolean>}
*/
async isActive(prev, deployment) {
const state = await this.getState(prev, deployment);
return state === thresholdStates.ACTIVE;
}
/**
* Get chain entry state for a deployment (BIP9: versionbits).
* @example
* await chain.getState(tip, deployments.segwit);
* @see https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki
* @param {ChainEntry} prev - Previous chain entry.
* @param {Object} deployment - Deployment.
* @returns {Promise<Number>}
*/
async getState(prev, deployment) {
const bit = deployment.bit;
let window = this.network.minerWindow;
let threshold = this.network.activationThreshold;
if (deployment.threshold !== -1)
threshold = deployment.threshold;
if (deployment.window !== -1)
window = deployment.window;
if (((prev.height + 1) % window) !== 0) {
const height = prev.height - ((prev.height + 1) % window);
prev = await this.getAncestor(prev, height);
if (!prev)
return thresholdStates.DEFINED;
assert(prev.height === height);
assert(((prev.height + 1) % window) === 0);
}
let entry = prev;
let state = thresholdStates.DEFINED;
const compute = [];
while (entry) {
const cached = this.db.stateCache.get(bit, entry);
if (cached !== -1) {
state = cached;
break;
}
const time = await this.getMedianTime(entry);
if (time < deployment.startTime) {
state = thresholdStates.DEFINED;
this.db.stateCache.set(bit, entry, state);
break;
}
compute.push(entry);
const height = entry.height - window;
entry = await this.getAncestor(entry, height);
}
while (compute.length) {
const entry = compute.pop();
switch (state) {
case thresholdStates.DEFINED: {
const time = await this.getMedianTime(entry);
if (time >= deployment.timeout) {
state = thresholdStates.FAILED;
break;
}
if (time >= deployment.startTime) {
state = thresholdStates.STARTED;
break;
}
break;
}
case thresholdStates.STARTED: {
const time = await this.getMedianTime(entry);
if (time >= deployment.timeout) {
state = thresholdStates.FAILED;
break;
}
let block = entry;
let count = 0;
for (let i = 0; i < window; i++) {
if (block.hasBit(bit))
count += 1;
if (count >= threshold) {
state = thresholdStates.LOCKED_IN;
break;
}
block = await this.getPrevious(block);
assert(block);
}
break;
}
case thresholdStates.LOCKED_IN: {
state = thresholdStates.ACTIVE;
break;
}
case thresholdStates.FAILED:
case thresholdStates.ACTIVE: {
break;
}
default: {
assert(false, 'Bad state.');
break;
}
}
this.db.stateCache.set(bit, entry, state);
}
return state;
}
/**
* Get signalling statistics for BIP9/versionbits soft fork
* @param {ChainEntry} prev - Previous chain entry.
* @param {Object} deployment - Deployment.
* @returns {Promise<Object>}
*/
async getBIP9Stats(prev, deployment) {
const state = await this.getState(prev, deployment);
if (state !== thresholdStates.STARTED)
throw new Error(`Deployment "${deployment.name}" not in STARTED state.`);
const bit = deployment.bit;
let window = this.network.minerWindow;
let threshold = this.network.activationThreshold;
// Deployments like `segsignal` (BIP91) have custom window & threshold
if (deployment.window !== -1)
window = deployment.window;
if (deployment.threshold !== -1)
threshold = deployment.threshold;
let count = 0;
let block = prev;
while((block.height + 1) % window !== 0) {
if (block.hasBit(bit))
count++;
block = await this.getPrevious(block);
if(!block)
break;
}
return {
period: window,
threshold: threshold,
elapsed: (prev.height + 1) % window,
count: count,
possible: (window - threshold) >= ((prev.height + 1) % window) - count
};
}
/**
* Compute the version for a new block (BIP9: versionbits).
* @see https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki
* @param {ChainEntry} prev - Previous chain entry (usually the tip).
* @returns {Promise<Number>}
*/
async computeBlockVersion(prev) {
let version = 0;
for (const deployment of this.network.deploys) {
const state = await this.getState(prev, deployment);
if (state === thresholdStates.LOCKED_IN
|| state === thresholdStates.STARTED) {
version |= 1 << deployment.bit;
}
}
version >>>= 0;
return version;
}
/**
* Get the current deployment state of the chain. Called on load.
* @private
* @returns {Promise<DeploymentState>}
*/
async getDeploymentState() {
return this.readDeploymentState(this.tip);
}
/**
* Get deployment state.
* @private
* @param {ChainEntry} tip
* @returns {Promise<DeploymentState>}
*/
async readDeploymentState(tip) {
const prev = await this.getPrevious(tip);
if (!prev) {
assert(tip.isGenesis());
return new DeploymentState(this.network.genesis.hash);
}
if (this.options.spv)
return new DeploymentState(this.network.genesis.hash);
return this.getDeployments(tip.time, prev);
}
/**
* Get the next deployment state of the chain.
* @returns {Promise<DeploymentState>}
*/
async getNextState() {
if (this.options.spv)
return this.state;
return this.getDeployments(this.network.now(), this.tip);
}
/**
* Check transaction finality, taking into account MEDIAN_TIME_PAST
* if it is present in the lock flags.
* @param {ChainEntry} prev - Previous chain entry.
* @param {TX} tx
* @param {LockFlags} flags
* @returns {Promise} - Returns Boolean.
*/
async verifyFinal(prev, tx, flags) {
const height = prev.height + 1;
// We can skip MTP if the locktime is height.
if (!(tx.locktime & consensus.LOCKTIME_FLAG))
return tx.isFinal(height, -1);
const time = await this.getMedianTime(prev);
return tx.isFinal(height, time);
}
/**
* Get the necessary minimum time and height sequence locks for a transaction.
* @param {ChainEntry} prev
* @param {TX} tx
* @param {CoinView} view
* @param {LockFlags} flags
* @returns {Promise}
*/
async getLocks(prev, tx, view, flags) {
const GRANULARITY = consensus.SEQUENCE_GRANULARITY;
const DISABLE_FLAG = consensus.SEQUENCE_DISABLE_FLAG;
const TYPE_FLAG = consensus.SEQUENCE_TYPE_FLAG;
const MASK = consensus.SEQUENCE_MASK;
if (tx.isCoinbase())
return [-1, -1];
let minHeight = -1;
let minTime = -1;
for (const {prevout, sequence} of tx.inputs) {
if (sequence & DISABLE_FLAG)
continue;
let height = view.getHeight(prevout);
if (height === -1)
height = this.height + 1;
if (!(sequence & TYPE_FLAG)) {
height += (sequence & MASK) - 1;
minHeight = Math.max(minHeight, height);
continue;
}
height = Math.max(height - 1, 0);
const entry = await this.getAncestor(prev, height);
assert(entry, 'Database is corrupt.');
let time = await this.getMedianTime(entry);
time += ((sequence & MASK) << GRANULARITY) - 1;
minTime = Math.max(minTime, time);
}
return [minHeight, minTime];
}
/**
* Verify sequence locks.
* @param {ChainEntry} prev
* @param {TX} tx
* @param {CoinView} view
* @param {LockFlags} flags
* @returns {Promise} - Returns Boolean.
*/
async verifyLocks(prev, tx, view, flags) {
const [height, time] = await this.getLocks(prev, tx, view, flags);
if (height !== -1) {
if (height >= prev.height + 1)
return false;
}
if (time !== -1) {
const mtp = await this.getMedianTime(prev);
if (time >= mtp)
return false;
}
return true;
}
/**
* Get safe tree root.
* @returns {Promise<Hash>}
*/
async getSafeRoot() {
// The tree is committed on an interval.
// Mainnet is 36 blocks, meaning at height 36,
// the name set of the past 36 blocks are
// inserted into the tree. The commitment for
// that insertion actually appears in a block
// header one block later (height 37). We
// want the the root _before_ the current one
// so we can calculate that with:
// chain_height - (chain_height % interval)
const interval = this.network.names.treeInterval;
let mod = this.height % interval;
// If there's enough proof-of-work
// on top of the most recent root,
// it should be safe to use it.
if (mod >= 12)
mod = 0;
const height = this.height - mod;
const entry = await this.getEntryByHeight(height);
assert(entry);
return entry.treeRoot;
}
}
/**
* ChainOptions
* @alias module:blockchain.ChainOptions
*/
class ChainOptions {
/**
* Create chain options.
* @constructor
* @param {Object} options
*/
constructor(options) {
this.network = Network.primary;
this.logger = Logger.global;
this.blocks = null;
this.workers = null;
this.prefix = null;
this.location = null;
this.treeLocation = null;
this.memory = true;
this.maxFiles = 64;
this.cacheSize = 32 << 20;
this.compression = true;
this.spv = false;
this.prune = false;
this.indexTX = false;
this.indexAddress = false;
this.entryCache = 5000;
this.maxOrphans = 20;
this.checkpoints = true;
this.chainMigrate = -1;
this.compactTreeOnInit = false;
this.compactTreeInitInterval = 10000;
if (options)
this.fromOptions(options);
}
/**
* Inject properties from object.
* @private
* @param {Object} options
* @returns {ChainOptions}
*/
fromOptions(options) {
if (!options.spv) {
assert(typeof options.blocks === 'object', 'Chain requires BlockStore.');
this.blocks = options.blocks;
}
if (options.network != null)
this.network = Network.get(options.network);
if (options.logger != null) {
assert(typeof options.logger === 'object');
this.logger = options.logger;
}
if (options.workers != null) {
assert(typeof options.workers === 'object');
this.workers = options.workers;
}
if (options.spv != null) {
assert(typeof options.spv === 'boolean');
this.spv = options.spv;
}
if (options.prefix != null) {
assert(typeof options.prefix === 'string');
this.prefix = options.prefix;
this.location = this.spv
? path.join(this.prefix, 'spvchain')
: path.join(this.prefix, 'chain');
this.treePrefix = path.join(this.prefix, 'tree');
}
if (options.location != null) {
assert(typeof options.location === 'string');
this.location = options.location;
}
if (options.treePrefix != null) {
assert(typeof options.treePrefix === 'string');
this.treePrefix = options.treePrefix;
}
if (options.memory != null) {
assert(typeof options.memory === 'boolean');
this.memory = options.memory;
}
if (options.maxFiles != null) {
assert((options.maxFiles >>> 0) === options.maxFiles);
this.maxFiles = options.maxFiles;
}
if (options.cacheSize != null) {
assert(Number.isSafeInteger(options.cacheSize));
assert(options.cacheSize >= 0);
this.cacheSize = options.cacheSize;
}
if (options.compression != null) {
assert(typeof options.compression === 'boolean');
this.compression = options.compression;
}
if (options.prune != null) {
assert(typeof options.prune === 'boolean');
assert(!options.prune || !options.spv, 'Can not prune in spv mode.');
this.prune = options.prune;
}
if (options.indexTX != null) {
assert(typeof options.indexTX === 'boolean');
this.indexTX = options.indexTX;
}
if (options.indexAddress != null) {
assert(typeof options.indexAddress === 'boolean');
this.indexAddress = options.indexAddress;
}
if (options.entryCache != null) {
assert((options.entryCache >>> 0) === options.entryCache);
this.entryCache = options.entryCache;
}
if (options.maxOrphans != null) {
assert((options.maxOrphans >>> 0) === options.maxOrphans);
this.maxOrphans = options.maxOrphans;
}
if (options.checkpoints != null) {
assert(typeof options.checkpoints === 'boolean');
this.checkpoints = options.checkpoints;
}
if (options.chainMigrate != null) {
assert(typeof options.chainMigrate === 'number');
this.chainMigrate = options.chainMigrate;
}
if (options.compactTreeOnInit != null) {
assert(typeof options.compactTreeOnInit === 'boolean');
this.compactTreeOnInit = options.compactTreeOnInit;
}
if (options.compactTreeInitInterval != null) {
const {keepBlocks} = this.network.block;
assert(typeof options.compactTreeInitInterval === 'number');
assert(options.compactTreeInitInterval >= keepBlocks,
`compaction interval must not be smaller than ${keepBlocks}.`);
this.compactTreeInitInterval = options.compactTreeInitInterval;
}
if (this.spv || this.memory)
this.treePrefix = null;
return this;
}
/**
* Instantiate chain options from object.
* @param {Object} options
* @returns {ChainOptions}
*/
static fromOptions(options) {
return new ChainOptions().fromOptions(options);
}
}
/**
* Deployment State
* @alias module:blockchain.DeploymentState
* @property {VerifyFlags} flags
* @property {LockFlags} lockFlags
*/
class DeploymentState {
/**
* Create a deployment state.
* @param {Hash} tip
* @constructor
*/
constructor(tip) {
this.tip = tip;
this.flags = Script.flags.MANDATORY_VERIFY_FLAGS;
this.lockFlags = common.MANDATORY_LOCKTIME_FLAGS;
this.nameFlags = rules.MANDATORY_VERIFY_COVENANT_FLAGS;
this.hasAirstop = false;
}
hasHardening() {
return (this.nameFlags & VERIFY_COVENANTS_HARDENED) !== 0;
}
hasICANNLockup() {
return (this.nameFlags & VERIFY_COVENANTS_LOCKUP) !== 0;
}
}
/**
* Orphan
* @ignore
*/
class Orphan {
/**
* Create an orphan.
* @constructor
*/
constructor(block, flags, id) {
this.block = block;
this.flags = flags;
this.id = id;
this.time = util.now();
}
}
/*
* Helpers
*/
function cmp(a, b) {
return a - b;
}
/*
* Expose
*/
Chain.ChainOptions = ChainOptions;
module.exports = Chain;