/*!
* chaindb.js - blockchain data management for hsd
* Copyright (c) 2017-2018, Christopher Jeffrey (MIT License).
* https://github.com/handshake-org/hsd
*/
'use strict';
const assert = require('bsert');
const bdb = require('bdb');
const bio = require('bufio');
const blake2b = require('bcrypto/lib/blake2b');
const LRU = require('blru');
const {Tree} = require('urkel');
const {BufferMap, BufferSet} = require('buffer-map');
const ChainMigrator = require('./migrations');
const Amount = require('../ui/amount');
const CoinView = require('../coins/coinview');
const UndoCoins = require('../coins/undocoins');
const consensus = require('../protocol/consensus');
const Block = require('../primitives/block');
const Outpoint = require('../primitives/outpoint');
const Address = require('../primitives/address');
const ChainEntry = require('./chainentry');
const TXMeta = require('../primitives/txmeta');
const CoinEntry = require('../coins/coinentry');
const rules = require('../covenants/rules');
const NameState = require('../covenants/namestate');
const NameUndo = require('../covenants/undo');
const {BitField} = require('../covenants/bitfield');
const {types} = rules;
const layout = require('./layout');
const {
TreeState,
StateCache,
ChainState,
ChainFlags
} = require('./records');
/**
* ChainDB
* @alias module:blockchain.ChainDB
*/
class ChainDB {
/**
* Create a chaindb.
* @constructor
* @param {ChainOptions} options
*/
constructor(options) {
this.options = options;
this.network = this.options.network;
this.logger = this.options.logger.context('chaindb');
this.blocks = options.blocks;
this.db = bdb.create(this.options);
this.name = 'chain';
this.version = 3;
this.tree = new Tree({
hash: blake2b,
bits: 256,
prefix: this.options.treePrefix,
cacheOnly: true,
initCacheSize: -1
});
this.txn = this.tree.txn();
this.treeState = new TreeState();
this.stateCache = new StateCache(this.network);
this.state = new ChainState();
this.field = new BitField();
this.pending = null;
this.pendingTreeState = null;
this.current = null;
this.blocksBatch = null;
this.cacheHash = new LRU(this.options.entryCache, null, BufferMap);
this.cacheHeight = new LRU(this.options.entryCache);
}
/**
* Open and wait for the database to load.
* @returns {Promise}
*/
async open() {
this.logger.info('Opening ChainDB...');
await this.db.open();
await this.tree.open();
const migrator = new ChainMigrator({
...this.options,
chainDB: this,
dbVersion: this.version
});
await migrator.migrate();
const version = await this.db.get(layout.V.encode());
if (!version) {
// Database is fresh.
// Write initial state.
await this.initialize();
this.logger.info('ChainDB successfully initialized.');
} else {
await this.verifyVersion(this.version);
const state = await this.getState();
assert(state);
// Verify options have not changed.
await this.verifyFlags();
// Verify deployment params have not changed.
await this.verifyDeployments();
// Load state caches.
this.stateCache = await this.getStateCache();
// Grab the chainstate if we have one.
this.state = state;
// Grab the current tree state.
if (!this.options.spv) {
const treeState = await this.getTreeState();
assert(treeState);
this.treeState = treeState;
if (treeState.compactionHeight !== 0) {
this.logger.warning(
`Tree is compacted at ${treeState.compactionHeight}`);
}
await this.tree.inject(treeState.treeRoot);
}
// Read bitfield.
this.field = await this.getField();
this.logger.info('ChainDB successfully loaded.');
}
this.txn = this.tree.txn();
this.logger.info(
'Chain State: hash=%x tx=%d coin=%d value=%s burned=%s.',
this.state.tip,
this.state.tx,
this.state.coin,
Amount.coin(this.state.value),
Amount.coin(this.state.burned));
this.logger.info('Tree Root: %x.', this.tree.rootHash());
}
/**
* Initialize fresh database.
* @return {Promise}
*/
async initialize() {
this.start();
try {
await this._initialize();
} catch (e) {
this.drop();
throw e;
}
await this.commit();
}
/**
* Initialize fresh database.
* @returns {Promise}
*/
async _initialize() {
const b = this.batch();
this.writeVersion(b, this.version);
this.writeFlags(b);
this.writeDeployments(b);
await this.writeGenesis();
}
/**
* Write chaindb version.
* @param {Batch} b
* @param {Number} version
*/
writeVersion(b, version) {
const value = Buffer.alloc(this.name.length + 4);
value.write(this.name, 0, 'ascii');
value.writeUInt32LE(version, this.name.length);
b.put(layout.V.encode(), value);
}
/**
* Verify version
* @param {Number}
* @returns {Promise}
*/
async verifyVersion(version) {
const error = 'Database version mismatch for database: "chain".'
+ ' Please run a data migration before opening.';
const data = await this.db.get(layout.V.encode());
if (data.length !== this.name.length + 4)
throw new Error(error);
if (data.toString('ascii', 0, this.name.length) !== this.name)
throw new Error(error);
const num = data.readUInt32LE(this.name.length);
if (num !== version)
throw new Error(error);
}
/**
* Close and wait for the database to close.
* @returns {Promise}
*/
async close() {
await this.tree.close();
this.txn = this.tree.txn();
return this.db.close();
}
/**
* Start a batch.
* @returns {Batch}
*/
start() {
assert(!this.current);
assert(!this.pending);
this.current = this.db.batch();
this.pending = this.state.clone();
this.pendingTreeState = this.treeState.clone();
if (this.blocks)
this.blocksBatch = this.blocks.batch();
this.cacheHash.start();
this.cacheHeight.start();
return this.current;
}
/**
* Put key and value to current batch.
* @param {String} key
* @param {Buffer} value
*/
put(key, value) {
assert(this.current);
this.current.put(key, value);
}
/**
* Delete key from current batch.
* @param {String} key
*/
del(key) {
assert(this.current);
this.current.del(key);
}
/**
* Get current batch.
* @returns {Batch}
*/
batch() {
assert(this.current);
return this.current;
}
/**
* Drop current batch.
* @returns {Batch}
*/
drop() {
const batch = this.current;
const blocksBatch = this.blocksBatch;
assert(this.current);
assert(this.pending);
assert(this.pendingTreeState);
assert(!this.blocks || this.blocksBatch);
this.current = null;
this.pending = null;
this.pendingTreeState = null;
this.blocksBatch = null;
this.cacheHash.drop();
this.cacheHeight.drop();
this.stateCache.drop();
batch.clear();
if (blocksBatch)
blocksBatch.clear();
}
/**
* Commit current batch.
* @returns {Promise}
*/
async commit() {
assert(this.current);
assert(this.pending);
assert(this.pendingTreeState);
try {
if (this.blocks)
await this.blocksBatch.commitWrites();
await this.current.write();
} catch (e) {
this.current = null;
this.pending = null;
this.pendingTreeState = null;
this.cacheHash.drop();
this.cacheHeight.drop();
this.blocksBatch = null;
throw e;
}
// Overwrite the entire state
// with our new best state
// only if it is committed.
// Note that alternate chain
// tips do not commit anything.
if (this.pending.committed)
this.state = this.pending;
// Overwrite the entire TreeState
// if it's committed. Only happens
// on tree.commits. @see _saveNames
if (this.pendingTreeState.committed)
this.treeState = this.pendingTreeState;
this.current = null;
this.pending = null;
this.pendingTreeState = null;
this.cacheHash.commit();
this.cacheHeight.commit();
this.stateCache.commit();
if (this.blocks)
await this.blocksBatch.commitPrunes();
}
/**
* Test the cache for a present entry hash or height.
* @param {Hash|Number} block - Hash or height.
*/
hasCache(block) {
if (typeof block === 'number')
return this.cacheHeight.has(block);
assert(Buffer.isBuffer(block));
return this.cacheHash.has(block);
}
/**
* Get an entry directly from the LRU cache.
* @param {Hash|Number} block - Hash or height.
*/
getCache(block) {
if (typeof block === 'number')
return this.cacheHeight.get(block);
assert(Buffer.isBuffer(block));
return this.cacheHash.get(block);
}
/**
* Get the height of a block by hash.
* @param {Hash} hash
* @returns {Promise} - Returns Number.
*/
async getHeight(hash) {
if (typeof hash === 'number')
return hash;
assert(Buffer.isBuffer(hash));
if (hash.equals(consensus.ZERO_HASH))
return -1;
const entry = this.cacheHash.get(hash);
if (entry)
return entry.height;
const height = await this.db.get(layout.h.encode(hash));
if (!height)
return -1;
return height.readUInt32LE(0, true);
}
/**
* Get the hash of a block by height. Note that this
* will only return hashes in the main chain.
* @param {Number} height
* @returns {Promise} - Returns {@link Hash}.
*/
async getHash(height) {
if (Buffer.isBuffer(height))
return height;
assert(typeof height === 'number');
if (height < 0)
return null;
const entry = this.cacheHeight.get(height);
if (entry)
return entry.hash;
return this.db.get(layout.H.encode(height));
}
/**
* Retrieve a chain entry by height.
* @param {Number} height
* @returns {Promise} - Returns {@link ChainEntry}.
*/
async getEntryByHeight(height) {
assert(typeof height === 'number');
if (height < 0)
return null;
const cache = this.cacheHeight.get(height);
if (cache)
return cache;
const hash = await this.db.get(layout.H.encode(height));
if (!hash)
return null;
const state = this.state;
const entry = await this.getEntryByHash(hash);
if (!entry)
return null;
// By the time getEntry has completed,
// a reorg may have occurred. This entry
// may not be on the main chain anymore.
if (this.state === state)
this.cacheHeight.set(entry.height, entry);
return entry;
}
/**
* Retrieve a chain entry by hash.
* @param {Hash} hash
* @returns {Promise} - Returns {@link ChainEntry}.
*/
async getEntryByHash(hash) {
assert(Buffer.isBuffer(hash));
if (hash.equals(consensus.ZERO_HASH))
return null;
const cache = this.cacheHash.get(hash);
if (cache)
return cache;
const raw = await this.db.get(layout.e.encode(hash));
if (!raw)
return null;
const entry = ChainEntry.decode(raw);
// There's no efficient way to check whether
// this is in the main chain or not, so
// don't add it to the height cache.
this.cacheHash.set(entry.hash, entry);
return entry;
}
/**
* Retrieve a chain entry.
* @param {Number|Hash} block - Height or hash.
* @returns {Promise} - Returns {@link ChainEntry}.
*/
getEntry(block) {
if (typeof block === 'number')
return this.getEntryByHeight(block);
return this.getEntryByHash(block);
}
/**
* Test whether the chain contains a block.
* @param {Hash} hash
* @returns {Promise} - Returns Boolean.
*/
async hasEntry(hash) {
const height = await this.getHeight(hash);
return height !== -1;
}
/**
* Get ancestor by `height`.
* @param {ChainEntry} entry
* @param {Number} height
* @returns {Promise} - Returns ChainEntry.
*/
async getAncestor(entry, height) {
if (height < 0)
return null;
assert(height >= 0);
assert(height <= entry.height);
if (await this.isMainChain(entry))
return this.getEntryByHeight(height);
while (entry.height !== height) {
const cache = this.getPrevCache(entry);
if (cache)
entry = cache;
else
entry = await this.getPrevious(entry);
assert(entry);
}
return entry;
}
/**
* Get previous entry.
* @param {ChainEntry} entry
* @returns {Promise} - Returns ChainEntry.
*/
getPrevious(entry) {
return this.getEntryByHash(entry.prevBlock);
}
/**
* Get previous cached entry.
* @param {ChainEntry} entry
* @returns {ChainEntry|null}
*/
getPrevCache(entry) {
return this.cacheHash.get(entry.prevBlock) || null;
}
/**
* Get next entry.
* @param {ChainEntry} entry
* @returns {Promise} - Returns ChainEntry.
*/
async getNext(entry) {
const hash = await this.getNextHash(entry.hash);
if (!hash)
return null;
return this.getEntryByHash(hash);
}
/**
* Get next entry.
* @param {ChainEntry} entry
* @returns {Promise} - Returns ChainEntry.
*/
async getNextEntry(entry) {
const next = await this.getEntryByHeight(entry.height + 1);
if (!next)
return null;
// Not on main chain.
if (!next.prevBlock.equals(entry.hash))
return null;
return next;
}
/**
* Lookup a name tree value.
* @param {Hash} root
* @param {Hash} key
* @returns {Buffer}
*/
async lookup(root, key) {
if (this.options.spv)
throw new Error('Cannot lookup in SPV mode.');
const tree = this.tree.snapshot(root);
return tree.get(key);
}
/**
* Create a name tree proof.
* @param {Hash} root
* @param {Hash} key
* @returns {Buffer[]} nodes
*/
async prove(root, key) {
if (this.options.spv)
throw new Error('Cannot prove in SPV mode.');
const tree = this.tree.snapshot(root);
return tree.prove(key);
}
/**
* Get the current name tree root.
* @returns {Hash}
*/
treeRoot() {
return this.tree.rootHash();
}
/**
* Retrieve the tip entry from the tip record.
* @returns {Promise} - Returns {@link ChainEntry}.
*/
getTip() {
return this.getEntryByHash(this.state.tip);
}
/**
* Retrieve the tip entry from the tip record.
* @returns {Promise} - Returns {@link ChainState}.
*/
async getState() {
const data = await this.db.get(layout.R.encode());
if (!data)
return null;
return ChainState.decode(data);
}
/**
* Retrieve tree state from the tree record.
* @returns {Promise<TreeState>}
*/
async getTreeState() {
const data = await this.db.get(layout.s.encode());
if (!data)
return null;
return TreeState.decode(data);
}
/**
* Write genesis block to database.
* @returns {Promise}
*/
async writeGenesis() {
const network = this.network;
const block = Block.decode(network.genesisBlock);
const entry = ChainEntry.fromBlock(block);
const view = new CoinView();
this.logger.info('Writing genesis block to ChainDB.');
for (let i = 0; i < block.txs.length; i++) {
const tx = block.txs[i];
if (i > 0)
assert(await view.spendInputs(this, tx));
view.addTX(tx, 0);
}
for (let i = 0; i < block.txs.length; i++) {
const tx = block.txs[i];
assert(tx.isSane());
assert(tx.verifyInputs(view, network.coinbaseMaturity, network));
}
return this._save(entry, block, view);
}
/**
* Retrieve the database flags.
* @returns {Promise} - Returns {@link ChainFlags}.
*/
async getFlags() {
const data = await this.db.get(layout.O.encode());
if (!data)
return null;
return ChainFlags.decode(data);
}
/**
* Verify current options against db options.
* @returns {Promise}
*/
async verifyFlags() {
const options = this.options;
const flags = await this.getFlags();
if (!flags)
throw new Error('No flags found.');
if (options.network !== flags.network)
throw new Error('Network mismatch for chain.');
if (options.spv && !flags.spv)
throw new Error('Cannot retroactively enable SPV.');
if (!options.spv && flags.spv)
throw new Error('Cannot retroactively disable SPV.');
if (options.prune && !flags.prune)
throw new Error('Cannot retroactively prune.');
if (!options.prune && flags.prune)
throw new Error('Cannot retroactively unprune.');
if (options.indexTX && !flags.indexTX)
throw new Error('Cannot retroactively enable TX indexing.');
if (!options.indexTX && flags.indexTX)
throw new Error('Cannot retroactively disable TX indexing.');
if (options.indexAddress && !flags.indexAddress)
throw new Error('Cannot retroactively enable address indexing.');
if (!options.indexAddress && flags.indexAddress)
throw new Error('Cannot retroactively disable address indexing.');
}
/**
* Get state caches.
* @returns {Promise} - Returns {@link StateCache}.
*/
async getStateCache() {
const stateCache = new StateCache(this.network);
const items = await this.db.range({
gte: layout.v.min(),
lte: layout.v.max(),
values: true
});
for (const item of items) {
const [bit, hash] = layout.v.decode(item.key);
const state = item.value[0];
stateCache.insert(bit, hash, state);
}
return stateCache;
}
/**
* Save deployment table.
* @returns {Promise}
*/
saveDeployments() {
const b = this.db.batch();
this.writeDeployments(b);
return b.write();
}
/**
* Save deployment table.
* @returns {Promise}
*/
writeDeployments(b) {
const bw = bio.write(1 + 17 * this.network.deploys.length);
bw.writeU8(this.network.deploys.length);
for (const deployment of this.network.deploys) {
bw.writeU8(deployment.bit);
bw.writeU32(deployment.startTime);
bw.writeU32(deployment.timeout);
bw.writeI32(deployment.threshold);
bw.writeI32(deployment.window);
}
b.put(layout.D.encode(), bw.render());
}
/**
* Check for outdated deployments.
* @private
* @returns {Promise}
*/
async checkDeployments() {
const raw = await this.db.get(layout.D.encode());
assert(raw, 'No deployment table found.');
const br = bio.read(raw);
const count = br.readU8();
const invalid = [];
for (let i = 0; i < count; i++) {
const bit = br.readU8();
const start = br.readU32();
const timeout = br.readU32();
const threshold = br.readI32();
const window = br.readI32();
const deployment = this.network.byBit(bit);
if (deployment
&& start === deployment.startTime
&& timeout === deployment.timeout
&& threshold === deployment.threshold
&& window === deployment.window) {
continue;
}
invalid.push(bit);
}
return invalid;
}
/**
* Potentially invalidate state cache.
* @returns {Promise}
*/
async verifyDeployments() {
let invalid;
try {
invalid = await this.checkDeployments();
} catch (e) {
if (e.type !== 'EncodingError')
throw e;
invalid = [];
for (let i = 0; i < 32; i++)
invalid.push(i);
}
if (invalid.length === 0)
return true;
const b = this.db.batch();
for (const bit of invalid) {
this.logger.warning('Versionbit deployment params modified.');
this.logger.warning('Invalidating cache for bit %d.', bit);
await this.invalidateCache(bit, b);
}
this.writeDeployments(b);
await b.write();
return false;
}
/**
* Invalidate state cache.
* @private
* @returns {Promise}
*/
async invalidateCache(bit, b) {
const keys = await this.db.keys({
gte: layout.v.min(bit),
lte: layout.v.max(bit)
});
for (const key of keys)
b.del(key);
}
/**
* Retroactively prune the database.
* @returns {Promise}
*/
async prune() {
assert(!this.options.spv, 'Cannot prune chain in SPV mode.');
const options = this.options;
const keepBlocks = this.network.block.keepBlocks;
const pruneAfter = this.network.block.pruneAfterHeight;
const flags = await this.getFlags();
if (flags.prune)
throw new Error('Chain is already pruned.');
const height = await this.getHeight(this.state.tip);
if (height <= pruneAfter + keepBlocks)
return false;
const start = pruneAfter + 1;
const end = height - keepBlocks;
const blocksBatch = this.blocks.batch();
for (let i = start; i <= end; i++) {
const hash = await this.getHash(i);
if (!hash)
throw new Error(`Cannot find hash for ${i}.`);
blocksBatch.pruneBlock(hash);
blocksBatch.pruneUndo(hash);
}
// We do blockstore write first, because if something
// fails during this batch, then db flag wont be set.
// If user just reruns the node prune will restart.
await blocksBatch.commit();
try {
options.prune = true;
const flags = ChainFlags.fromOptions(options);
assert(flags.prune);
await this.db.put(layout.O.encode(), flags.encode());
} catch (e) {
options.prune = false;
throw e;
}
return true;
}
/**
* Compact the Urkel Tree.
* Removes all historical state and all data not
* linked directly to the provided root node hash.
* @param {ChainEntry} entry
* @returns {Promise}
*/
async compactTree(entry) {
// Before doing anything to the tree,
// save the target tree root hash to chain database.
// If the tree data gets out of sync or corrupted
// the chain database knows where to resync the tree from.
this.start();
// Note: the tree root commit height is always one block before its
// appearence in a header.
this.put(layout.s.encode(), this.pendingTreeState.commit(
entry.treeRoot,
entry.height - 1
));
await this.commit();
const tmpDir = this.options.treePrefix + '~';
const tmpTree = new Tree({
hash: blake2b,
bits: 256,
prefix: tmpDir
});
// Make sure to remove the tmp directory first.
// There should not be directory, unless it was
// stopped in the middle of compaction.
// Otherwise compacted tree would add on top
// of the previsouly compacted db.
await tmpTree.open();
const tmpStore = tmpTree.store;
await tmpTree.close();
await tmpStore.destroy();
// Rewind tree to historical commitment
await this.tree.inject(entry.treeRoot);
// Delete historical data
await this.tree.compact(tmpDir);
// Reset in-memory tree delta
this.txn = this.tree.txn();
// Mark tree compaction complete
this.start();
this.pendingTreeState.compact(entry.treeRoot, entry.height);
this.put(layout.s.encode(), this.pendingTreeState.commit(
entry.treeRoot,
entry.height - 1
));
await this.commit();
}
/**
* Get the _next_ block hash (does not work by height).
* @param {Hash} hash
* @returns {Promise} - Returns {@link Hash}.
*/
async getNextHash(hash) {
return this.db.get(layout.n.encode(hash));
}
/**
* Check to see if a block is on the main chain.
* @param {Hash} hash
* @returns {Promise} - Returns Boolean.
*/
async isMainHash(hash) {
assert(Buffer.isBuffer(hash));
if (hash.equals(consensus.ZERO_HASH))
return false;
if (hash.equals(this.network.genesis.hash))
return true;
if (hash.equals(this.state.tip))
return true;
const cacheHash = this.cacheHash.get(hash);
if (cacheHash) {
const cacheHeight = this.cacheHeight.get(cacheHash.height);
if (cacheHeight)
return cacheHeight.hash.equals(hash);
}
if (await this.getNextHash(hash))
return true;
return false;
}
/**
* Test whether the entry is in the main chain.
* @param {ChainEntry} entry
* @returns {Promise} - Returns Boolean.
*/
async isMainChain(entry) {
if (entry.isGenesis())
return true;
if (entry.hash.equals(this.state.tip))
return true;
const cache = this.getCache(entry.height);
if (cache)
return entry.hash.equals(cache.hash);
if (await this.getNextHash(entry.hash))
return true;
return false;
}
/**
* Get hash range.
* @param {Number} [start=-1]
* @param {Number} [end=-1]
* @returns {Promise<Hash[]>}
*/
async getHashes(start = -1, end = -1) {
if (start === -1)
start = 0;
if (end === -1)
end >>>= 0;
assert((start >>> 0) === start);
assert((end >>> 0) === end);
return this.db.values({
gte: layout.H.min(start),
lte: layout.H.max(end)
});
}
/**
* Get entries range.
* @param {Number} [start=-1]
* @param {Number} [end=-1]
* @returns {Promise<ChainEntry[]>}
*/
async getEntries(start = -1, end = -1) {
if (start === -1)
start = 0;
if (end === -1)
end >>>= 0;
assert((start >>> 0) === start);
assert((end >>> 0) === end);
const hashes = await this.getHashes(start, end);
return Promise.all(hashes.map((hash) => {
return this.getEntryByHash(hash);
}));
}
/**
* Get all tip hashes.
* @returns {Promise} - Returns {@link Hash}[].
*/
async getTips() {
return this.db.keys({
gte: layout.p.min(),
lte: layout.p.max(),
parse: key => layout.p.decode(key)[0]
});
}
/**
* Get bitfield.
* @returns {Promise<Buffer>}
*/
async getField() {
const raw = await this.db.get(layout.f.encode());
if (!raw)
return new BitField();
return BitField.decode(raw);
}
/**
* Get a coin (unspents only).
* @param {Outpoint} prevout
* @returns {Promise<CoinEntry>} - Returns {@link CoinEntry}.
*/
async readCoin(prevout) {
if (this.options.spv)
return null;
const {hash, index} = prevout;
const raw = await this.db.get(layout.c.encode(hash, index));
if (!raw)
return null;
return CoinEntry.decode(raw);
}
/**
* Get a coin (unspents only).
* @param {Hash} hash
* @param {Number} index
* @returns {Promise} - Returns {@link Coin}.
*/
async getCoin(hash, index) {
const prevout = new Outpoint(hash, index);
const coin = await this.readCoin(prevout);
if (!coin)
return null;
return coin.toCoin(prevout);
}
/**
* Check whether coins are still unspent. Necessary for bip30.
* @see https://bitcointalk.org/index.php?topic=67738.0
* @param {TX} tx
* @returns {Promise} - Returns Boolean.
*/
async hasCoins(tx) {
for (let i = 0; i < tx.outputs.length; i++) {
const key = layout.c.encode(tx.hash(), i);
if (await this.db.has(key))
return true;
}
return false;
}
/**
* Get coin viewpoint.
* @param {TX} tx
* @returns {Promise} - Returns {@link CoinView}.
*/
async getCoinView(tx) {
const view = new CoinView();
for (const {prevout} of tx.inputs) {
const coin = await this.readCoin(prevout);
if (coin)
view.addEntry(prevout, coin);
}
return view;
}
/**
* Get coin viewpoint (historical).
* @param {TX} tx
* @returns {Promise} - Returns {@link CoinView}.
*/
async getSpentView(tx) {
const view = await this.getCoinView(tx);
for (const {prevout} of tx.inputs) {
if (view.hasEntry(prevout))
continue;
const {hash, index} = prevout;
const meta = await this.getMeta(hash);
if (!meta)
continue;
const {tx, height} = meta;
if (index < tx.outputs.length)
view.addIndex(tx, index, height);
}
return view;
}
/**
* Get coins necessary to be resurrected during a reorg.
* @param {Hash} hash
* @returns {Promise} - Returns {@link Coin}[].
*/
async getUndoCoins(hash) {
const data = await this.blocks.readUndo(hash);
if (!data)
return new UndoCoins();
return UndoCoins.decode(data);
}
/**
* Get name state.
* @param {Buffer} nameHash
* @returns {Promise<NameState>}
*/
async getNameState(nameHash) {
const raw = await this.txn.get(nameHash);
if (!raw)
return null;
const ns = NameState.decode(raw);
ns.nameHash = nameHash;
return ns;
}
/**
* Get name state by name.
* @param {Buffer} name
* @returns {Promise<NameState>}
*/
async getNameStateByName(name) {
return this.getNameState(rules.hashName(name));
}
/**
* Get name status.
* @param {Buffer} nameHash
* @param {Number} height - used for expiration checks.
* @returns {Promise<NameState>}
*/
async getNameStatus(nameHash, height) {
assert(Buffer.isBuffer(nameHash));
assert((height >>> 0) === height);
const network = this.network;
const ns = await this.getNameState(nameHash);
if (!ns) {
const state = new NameState();
state.reset(height);
return state;
}
ns.maybeExpire(height, network);
return ns;
}
/**
* Retrieve a block from the database (not filled with coins).
* @param {Hash} hash
* @returns {Promise} - Returns {@link Block}.
*/
async getBlock(hash) {
const data = await this.getRawBlock(hash);
if (!data)
return null;
return Block.decode(data);
}
/**
* Retrieve a block from the database (not filled with coins).
* @param {Hash} hash
* @returns {Promise} - Returns {@link Block}.
*/
async getRawBlock(block) {
if (this.options.spv)
return null;
const hash = await this.getHash(block);
if (!hash)
return null;
return this.blocks.readBlock(hash);
}
/**
* Get a historical block coin viewpoint.
* @param {Block} hash
* @returns {Promise} - Returns {@link CoinView}.
*/
async getBlockView(block) {
const view = new CoinView();
const undo = await this.getUndoCoins(block.hash());
if (undo.isEmpty())
return view;
for (let i = block.txs.length - 1; i > 0; i--) {
const tx = block.txs[i];
for (let j = tx.inputs.length - 1; j >= 0; j--) {
const input = tx.inputs[j];
undo.apply(view, input.prevout);
}
}
// Undo coins should be empty.
assert(undo.isEmpty(), 'Undo coins data inconsistency.');
return view;
}
/**
* Get a transaction with metadata.
* @param {Hash} hash
* @returns {Promise} - Returns {@link TXMeta}.
*/
async getMeta(hash) {
if (!this.options.indexTX)
return null;
const data = await this.db.get(layout.t.encode(hash));
if (!data)
return null;
return TXMeta.decode(data);
}
/**
* Retrieve a transaction.
* @param {Hash} hash
* @returns {Promise} - Returns {@link TX}.
*/
async getTX(hash) {
const meta = await this.getMeta(hash);
if (!meta)
return null;
return meta.tx;
}
/**
* @param {Hash} hash
* @returns {Promise} - Returns Boolean.
*/
async hasTX(hash) {
if (!this.options.indexTX)
return false;
return this.db.has(layout.t.encode(hash));
}
/**
* Get all coins pertinent to an address.
* @param {Address[]} addrs
* @returns {Promise} - Returns {@link Coin}[].
*/
async getCoinsByAddress(addrs) {
if (!this.options.indexAddress)
return [];
if (!Array.isArray(addrs))
addrs = [addrs];
const coins = [];
for (let addr of addrs) {
if (typeof addr === 'string')
addr = Address.fromString(addr);
const hash = Address.getHash(addr);
const keys = await this.db.keys({
gte: layout.C.min(hash),
lte: layout.C.max(hash),
parse: (key) => {
const [, txid, index] = layout.C.decode(key);
return [txid, index];
}
});
for (const [hash, index] of keys) {
const coin = await this.getCoin(hash, index);
assert(coin);
coins.push(coin);
}
}
return coins;
}
/**
* Get all transaction hashes to an address.
* @param {Address[]} addrs
* @returns {Promise} - Returns {@link Hash}[].
*/
async getHashesByAddress(addrs) {
if (!this.options.indexTX || !this.options.indexAddress)
return [];
const hashes = new BufferSet();
for (const addr of addrs) {
const hash = Address.getHash(addr);
await this.db.keys({
gte: layout.T.min(hash),
lte: layout.T.max(hash),
parse: (key) => {
const [, txid] = layout.T.decode(key);
hashes.add(txid);
}
});
}
return hashes.toArray();
}
/**
* Get all transactions pertinent to an address.
* @param {Address[]} addrs
* @returns {Promise} - Returns {@link TX}[].
*/
async getTXByAddress(addrs) {
const mtxs = await this.getMetaByAddress(addrs);
const out = [];
for (const mtx of mtxs)
out.push(mtx.tx);
return out;
}
/**
* Get all transactions pertinent to an address.
* @param {Address[]} addrs
* @returns {Promise} - Returns {@link TXMeta}[].
*/
async getMetaByAddress(addrs) {
if (!this.options.indexTX || !this.options.indexAddress)
return [];
if (!Array.isArray(addrs))
addrs = [addrs];
const hashes = await this.getHashesByAddress(addrs);
const mtxs = [];
for (const hash of hashes) {
const mtx = await this.getMeta(hash);
assert(mtx);
mtxs.push(mtx);
}
return mtxs;
}
/**
* Scan the blockchain for transactions containing specified address hashes.
* @param {Hash} start - Block hash to start at.
* @param {Bloom} filter - Bloom filter containing tx and address hashes.
* @param {Function} iter - Iterator.
* @returns {Promise}
*/
async scan(start, filter, iter) {
if (start == null)
start = this.network.genesis.hash;
if (typeof start === 'number')
this.logger.info('Scanning from height %d.', start);
else
this.logger.info('Scanning from block %x.', start);
let entry = await this.getEntry(start);
if (!entry)
return;
if (!await this.isMainChain(entry))
throw new Error('Cannot rescan an alternate chain.');
let total = 0;
while (entry) {
const block = await this.getBlock(entry.hash);
total += 1;
const txs = [];
if (!block) {
if (!this.options.spv && !this.options.prune)
throw new Error('Block not found.');
await iter(entry, txs);
entry = await this.getNext(entry);
continue;
}
this.logger.info(
'Scanning block %x (%d).',
entry.hash, entry.height);
for (const tx of block.txs) {
if (tx.testAndMaybeUpdate(filter))
txs.push(tx);
}
await iter(entry, txs);
entry = await this.getNext(entry);
}
this.logger.info('Finished scanning %d blocks.', total);
}
/**
* @typedef {Object} ScanBlockResult
* @property {ChainEntry} entry
* @property {TX[]} txs
*/
/**
* Interactive scans block checks.
* @param {Hash|Number} blockID - Block hash or height to start at.
* @param {BloomFilter} [filter] - Starting bloom filter containing tx,
* address and name hashes.
* @returns {Promise<ScanBlockResult>}
*/
async scanBlock(blockID, filter) {
assert(blockID != null);
const entry = await this.getEntry(blockID);
if (!entry)
throw new Error('Could not find entry.');
if (!await this.isMainChain(entry))
throw new Error('Cannot rescan an alternate chain.');
const block = await this.getBlock(entry.hash);
if (!block)
throw new Error('Block not found.');
this.logger.info(
'Scanning block %x (%d)',
entry.hash, entry.height);
let txs = [];
if (!filter) {
txs = block.txs;
} else {
for (const tx of block.txs) {
if (tx.testAndMaybeUpdate(filter))
txs.push(tx);
}
}
return {
entry,
txs
};
}
/**
* Save an entry to the database and optionally
* connect it as the tip. Note that this method
* does _not_ perform any verification which is
* instead performed in {@link Chain#add}.
* @param {ChainEntry} entry
* @param {Block} block
* @param {CoinView?} view - Will not connect if null.
* @returns {Promise}
*/
async save(entry, block, view) {
this.start();
try {
await this._save(entry, block, view);
} catch (e) {
this.drop();
throw e;
}
await this.commit();
}
/**
* Save an entry.
* @private
* @param {ChainEntry} entry
* @param {Block} block
* @param {CoinView?} view
* @returns {Promise}
*/
async _save(entry, block, view) {
const hash = block.hash();
// Hash->height index.
this.put(layout.h.encode(hash), fromU32(entry.height));
// Entry data.
this.put(layout.e.encode(hash), entry.encode());
this.cacheHash.push(entry.hash, entry);
// Tip index.
this.del(layout.p.encode(entry.prevBlock));
this.put(layout.p.encode(hash), null);
// Update state caches.
this.saveUpdates();
if (!view) {
// Save block data.
await this.saveBlock(entry, block);
return;
}
// Hash->next-block index.
if (!entry.isGenesis())
this.put(layout.n.encode(entry.prevBlock), hash);
// Height->hash index.
this.put(layout.H.encode(entry.height), hash);
this.cacheHeight.push(entry.height, entry);
// Connect block and save data.
await this.saveBlock(entry, block, view);
// Commit new chain state.
this.put(layout.R.encode(), this.pending.commit(hash));
}
/**
* Reconnect the block to the chain.
* @param {ChainEntry} entry
* @param {Block} block
* @param {CoinView} view
* @returns {Promise}
*/
async reconnect(entry, block, view) {
this.start();
try {
await this._reconnect(entry, block, view);
} catch (e) {
this.drop();
throw e;
}
await this.commit();
}
/**
* Reconnect block.
* @private
* @param {ChainEntry} entry
* @param {Block} block
* @param {CoinView} view
* @returns {Promise}
*/
async _reconnect(entry, block, view) {
const hash = block.hash();
assert(!entry.isGenesis());
// We can now add a hash->next-block index.
this.put(layout.n.encode(entry.prevBlock), hash);
// We can now add a height->hash index.
this.put(layout.H.encode(entry.height), hash);
this.cacheHeight.push(entry.height, entry);
// Re-insert into cache.
this.cacheHash.push(entry.hash, entry);
// Update state caches.
this.saveUpdates();
// Connect inputs.
await this.connectBlock(entry, block, view);
// Update chain state.
this.put(layout.R.encode(), this.pending.commit(hash));
}
/**
* Disconnect block from the chain.
* @param {ChainEntry} entry
* @param {Block} block
* @returns {Promise}
*/
async disconnect(entry, block) {
this.start();
let view;
try {
view = await this._disconnect(entry, block);
} catch (e) {
this.drop();
throw e;
}
await this.commit();
return view;
}
/**
* Disconnect block.
* @private
* @param {ChainEntry} entry
* @param {Block} block
* @returns {Promise} - Returns {@link CoinView}.
*/
async _disconnect(entry, block) {
// Remove hash->next-block index.
this.del(layout.n.encode(entry.prevBlock));
// Remove height->hash index.
this.del(layout.H.encode(entry.height));
this.cacheHeight.unpush(entry.height);
// Update state caches.
this.saveUpdates();
// Disconnect inputs.
const view = await this.disconnectBlock(entry, block);
// Revert chain state to previous tip.
this.put(layout.R.encode(), this.pending.commit(entry.prevBlock));
return view;
}
/**
* Save state cache updates.
* @private
*/
saveUpdates() {
const updates = this.stateCache.updates;
if (updates.length === 0)
return;
this.logger.info('Saving %d state cache updates.', updates.length);
for (const update of updates) {
const {bit, hash} = update;
this.put(layout.v.encode(bit, hash), update.encode());
}
}
/**
* 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 reset(block) {
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 (this.options.prune)
throw new Error('Cannot reset when pruned.');
if (this.treeState.compactionHeight !== 0)
throw new Error('Cannot reset when tree is compacted.');
// We need to remove all alternate
// chains first. This is ugly, but
// it's the only safe way to reset
// the chain.
await this.removeChains();
let tip = await this.getTip();
assert(tip);
this.logger.debug('Resetting main chain to: %x', entry.hash);
for (;;) {
this.start();
// Stop once we hit our target tip.
if (tip.hash.equals(entry.hash)) {
this.put(layout.R.encode(), this.pending.commit(tip.hash));
await this.commit();
break;
}
assert(!tip.isGenesis());
// Revert the tip index.
this.del(layout.p.encode(tip.hash));
this.put(layout.p.encode(tip.prevBlock), null);
// Remove all records (including
// main-chain-only records).
this.del(layout.H.encode(tip.height));
this.del(layout.h.encode(tip.hash));
this.del(layout.e.encode(tip.hash));
this.del(layout.n.encode(tip.prevBlock));
// Disconnect and remove block data.
try {
await this.removeBlock(tip);
} catch (e) {
this.drop();
throw e;
}
// Revert chain state to previous tip.
this.put(layout.R.encode(), this.pending.commit(tip.prevBlock));
await this.commit();
// Update caches _after_ successful commit.
this.cacheHeight.remove(tip.height);
this.cacheHash.remove(tip.hash);
tip = await this.getPrevious(tip);
assert(tip);
}
return tip;
}
/**
* Remove all alternate chains.
* @returns {Promise}
*/
async removeChains() {
const tips = await this.getTips();
// Note that this has to be
// one giant atomic write!
this.start();
try {
for (const tip of tips)
await this._removeChain(tip);
} catch (e) {
this.drop();
throw e;
}
await this.commit();
}
/**
* Remove an alternate chain.
* @private
* @param {Hash} hash - Alternate chain tip.
* @returns {Promise}
*/
async _removeChain(hash) {
let tip = await this.getEntryByHash(hash);
if (!tip)
throw new Error('Alternate chain tip not found.');
this.logger.debug('Removing alternate chain: %x.', tip.hash);
for (;;) {
if (await this.isMainChain(tip))
break;
assert(!tip.isGenesis());
// Remove all non-main-chain records.
this.del(layout.p.encode(tip.hash));
this.del(layout.h.encode(tip.hash));
this.del(layout.e.encode(tip.hash));
if (this.blocks)
this.blocksBatch.pruneBlock(tip.hash);
// Queue up hash to be removed
// on successful write.
this.cacheHash.unpush(tip.hash);
tip = await this.getPrevious(tip);
assert(tip);
}
}
/**
* Save a block (not an entry) to the
* database and potentially connect the inputs.
* @param {ChainEntry} entry
* @param {Block} block
* @param {CoinView?} view
* @returns {Promise} - Returns {@link Block}.
*/
async saveBlock(entry, block, view) {
const hash = block.hash();
if (this.options.spv)
return undefined;
// Write actual block data
this.blocksBatch.writeBlock(hash, block.encode());
if (!view)
return undefined;
return this.connectBlock(entry, block, view);
}
/**
* Remove a block (not an entry) to the database.
* Disconnect inputs.
* @param {ChainEntry} entry
* @returns {Promise} - Returns {@link Block}.
*/
async removeBlock(entry) {
if (this.options.spv)
return new CoinView();
const block = await this.getBlock(entry.hash);
if (!block)
throw new Error('Block not found.');
this.blocksBatch.pruneBlock(block.hash());
return this.disconnectBlock(entry, block);
}
/**
* Commit coin view to database.
* @private
* @param {CoinView} view
*/
saveView(view) {
for (const [hash, coins] of view.map) {
for (const [index, coin] of coins.outputs) {
if (coin.spent) {
this.del(layout.c.encode(hash, index));
continue;
}
const raw = coin.encode();
this.put(layout.c.encode(hash, index), raw);
}
}
// Not optimal. Should be made a file in the future.
if (view.bits.commit(this.field))
this.put(layout.f.encode(), this.field.encode());
}
/**
* Commit names to tree.
* @private
* @param {CoinView} view
* @param {ChainEntry} entry
* @param {Boolean} revert
*/
async saveNames(view, entry, revert) {
this.start();
try {
await this._saveNames(view, entry, revert);
} catch (e) {
this.drop();
throw e;
}
await this.commit();
}
/**
* Commit names to tree, assuming batch is started.
* @private
* @param {CoinView} view
* @param {ChainEntry} entry
* @param {Boolean} revert
*/
async _saveNames(view, entry, revert) {
for (const ns of view.names.values()) {
const {nameHash} = ns;
if (ns.isNull()) {
await this.txn.remove(nameHash);
continue;
}
await this.txn.insert(nameHash, ns.encode());
}
if ((entry.height % this.network.names.treeInterval) === 0) {
// Explanation:
//
// During a reorg, we must revert the snapshot
// back to the beginning of the interval. We
// can still incrementally revert the database
// transaction with state deltas, but unless
// we get the tree hash back to what it was
// at the start, we will end up rejecting blocks
// during reconnection.
//
// This is an invalid state that cannot be
// recovered from. Luckily, the block we're
// disconnecting commits to the _previous_ tree
// root, not the current one.
if (revert)
await this.tree.inject(entry.treeRoot);
else
await this.txn.commit();
// Commit new tree state.
// Chain will need to recover current txn
// from treeState.commitHeight + 1 (including).
this.put(layout.s.encode(), this.pendingTreeState.commit(
this.tree.rootHash(),
entry.height
));
}
}
/**
* Connect names to tree.
* @private
* @param {CoinView} view
* @param {ChainEntry} entry
*/
async connectNames(view, entry) {
const undo = view.toNameUndo();
if (undo.names.length === 0)
this.del(layout.w.encode(entry.height));
else
this.put(layout.w.encode(entry.height), undo.encode());
return this._saveNames(view, entry, false);
}
/**
* Disconnect names from tree.
* @private
* @param {CoinView} view
* @param {ChainEntry} entry
*/
async disconnectNames(view, entry) {
const raw = await this.db.get(layout.w.encode(entry.height));
if (raw) {
const undo = NameUndo.decode(raw);
for (const [nameHash, delta] of undo.names) {
const ns = await view.getNameState(this, nameHash);
ns.applyState(delta);
}
this.del(layout.w.encode(entry.height));
}
return this._saveNames(view, entry, true);
}
/**
* Connect block inputs.
* @param {ChainEntry} entry
* @param {Block} block
* @param {CoinView} view
* @returns {Promise} - Returns {@link Block}.
*/
async connectBlock(entry, block, view) {
if (this.options.spv)
return undefined;
const hash = block.hash();
this.pending.connect(block);
// Update chain state value.
for (let i = 0; i < block.txs.length; i++) {
const tx = block.txs[i];
if (i > 0) {
for (const {prevout} of tx.inputs) {
const output = view.getOutput(prevout);
assert(output);
// REGISTER->REVOKE covenants have no effect.
if (output.covenant.type >= types.REGISTER
&& output.covenant.type <= types.REVOKE) {
continue;
}
this.pending.spend(output);
}
}
for (let i = 0; i < tx.outputs.length; i++) {
const output = tx.outputs[i];
if (output.isUnspendable())
continue;
// Registers are burned.
if (output.covenant.isRegister())
this.pending.burn(output);
// REGISTER->REVOKE covenants have no effect.
if (output.covenant.type >= types.REGISTER
&& output.covenant.type <= types.REVOKE) {
continue;
}
// Only add value from the first claim.
if (output.covenant.isClaim()) {
if (output.covenant.getU32(5) !== 1)
continue;
}
this.pending.add(output);
}
// Index the transaction if enabled.
this.indexTX(tx, view, entry, i);
}
// Commit new coin state.
this.saveView(view);
// Write undo coins (if there are any).
if (!view.undo.isEmpty())
this.blocksBatch.writeUndo(hash, view.undo.commit());
// Prune height-288 if pruning is enabled.
await this.pruneBlock(entry);
// Connect name state.
return this.connectNames(view, entry);
}
/**
* Disconnect block inputs.
* @param {ChainEntry} entry
* @param {Block} block
* @returns {Promise} - Returns {@link CoinView}.
*/
async disconnectBlock(entry, block) {
const view = new CoinView();
if (this.options.spv)
return view;
const hash = block.hash();
const undo = await this.getUndoCoins(hash);
this.pending.disconnect(block);
// Disconnect all transactions.
for (let i = block.txs.length - 1; i >= 0; i--) {
const tx = block.txs[i];
if (i === 0) {
view.bits.undo(tx);
} else {
for (let j = tx.inputs.length - 1; j >= 0; j--) {
const {prevout} = tx.inputs[j];
undo.apply(view, prevout);
const output = view.getOutput(prevout);
assert(output);
// REGISTER->REVOKE covenants have no effect.
if (output.covenant.type >= types.REGISTER
&& output.covenant.type <= types.REVOKE) {
continue;
}
this.pending.add(output);
}
}
// Remove any created coins.
view.removeTX(tx, entry.height);
for (let j = tx.outputs.length - 1; j >= 0; j--) {
const output = tx.outputs[j];
if (output.isUnspendable())
continue;
// Registers are burned.
if (output.covenant.isRegister())
this.pending.unburn(output);
// REGISTER->REVOKE covenants have no effect.
if (output.covenant.type >= types.REGISTER
&& output.covenant.type <= types.REVOKE) {
continue;
}
// Only remove value from the first claim.
if (output.covenant.isClaim()) {
if (output.covenant.getU32(5) !== 1)
continue;
}
this.pending.spend(output);
}
// Remove from transaction index.
this.unindexTX(tx, view);
}
// Undo coins should be empty.
assert(undo.isEmpty(), 'Undo coins data inconsistency.');
// Commit new coin state.
this.saveView(view);
this.blocksBatch.pruneUndo(hash);
// Connect name state.
await this.disconnectNames(view, entry);
return view;
}
/**
* Prune a block from the chain and
* add current block to the prune queue.
* @private
* @param {ChainEntry} entry
* @returns {Promise}
*/
async pruneBlock(entry) {
if (this.options.spv)
return;
if (!this.options.prune)
return;
const height = entry.height - this.network.block.keepBlocks;
if (height <= this.network.block.pruneAfterHeight)
return;
const hash = await this.getHash(height);
if (!hash)
return;
this.blocksBatch.pruneUndo(hash);
this.blocksBatch.pruneBlock(hash);
}
/**
* Save database options.
* @returns {Promise}
*/
saveFlags() {
const b = this.db.batch();
this.writeFlags(b);
return b.write();
}
/**
* Write database options.
* @param {Batch} b
*/
writeFlags(b) {
const flags = ChainFlags.fromOptions(this.options);
b.put(layout.O.encode(), flags.encode());
}
/**
* Index a transaction by txid and address.
* @private
* @param {TX} tx
* @param {CoinView} view
* @param {ChainEntry} entry
* @param {Number} index
*/
indexTX(tx, view, entry, index) {
const hash = tx.hash();
if (this.options.indexTX) {
const meta = TXMeta.fromTX(tx, entry, index);
this.put(layout.t.encode(hash), meta.encode());
if (this.options.indexAddress) {
for (const addr of tx.getHashes(view))
this.put(layout.T.encode(addr, hash), null);
}
}
if (!this.options.indexAddress)
return;
if (!tx.isCoinbase()) {
for (const {prevout} of tx.inputs) {
const {hash, index} = prevout;
const coin = view.getOutput(prevout);
assert(coin);
const addr = coin.getHash();
if (!addr)
continue;
this.del(layout.C.encode(addr, hash, index));
}
}
for (let i = 0; i < tx.outputs.length; i++) {
const output = tx.outputs[i];
const addr = output.getHash();
if (!addr)
continue;
this.put(layout.C.encode(addr, hash, i), null);
}
}
/**
* Remove transaction from index.
* @private
* @param {TX} tx
* @param {CoinView} view
*/
unindexTX(tx, view) {
const hash = tx.hash();
if (this.options.indexTX) {
this.del(layout.t.encode(hash));
if (this.options.indexAddress) {
for (const addr of tx.getHashes(view))
this.del(layout.T.encode(addr, hash));
}
}
if (!this.options.indexAddress)
return;
if (!tx.isCoinbase()) {
for (const {prevout} of tx.inputs) {
const {hash, index} = prevout;
const coin = view.getOutput(prevout);
assert(coin);
const addr = coin.getHash();
if (!addr)
continue;
this.put(layout.C.encode(addr, hash, index), null);
}
}
for (let i = 0; i < tx.outputs.length; i++) {
const output = tx.outputs[i];
const addr = output.getHash();
if (!addr)
continue;
this.del(layout.C.encode(addr, hash, i));
}
}
}
/*
* Helpers
*/
function fromU32(num) {
const data = Buffer.allocUnsafe(4);
data.writeUInt32LE(num, 0, true);
return data;
}
/*
* Expose
*/
module.exports = ChainDB;