hsd
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Cryptocurrency bike-shed
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JavaScript
/*!
* bip152.js - compact block object for hsd
* Copyright (c) 2017-2018, Christopher Jeffrey (MIT License).
* https://github.com/handshake-org/hsd
*/
'use strict';
/**
* @module net/bip152
*/
const assert = require('bsert');
const bio = require('bufio');
const consensus = require('../protocol/consensus');
const blake2b = require('bcrypto/lib/blake2b');
const {siphash} = require('bcrypto/lib/siphash');
const AbstractBlock = require('../primitives/abstractblock');
const TX = require('../primitives/tx');
const Headers = require('../primitives/headers');
const Block = require('../primitives/block');
const common = require('./common');
const {encoding} = bio;
/** @typedef {import('../types').Hash} Hash */
/** @typedef {import('../types').BufioWriter} BufioWriter */
/** @typedef {import('../mempool/mempool')} Mempool */
const {
MAX_BLOCK_SIZE,
HEADER_SIZE
} = consensus;
/**
* Compact Block
* Represents a compact block (bip152): `cmpctblock` packet.
* @see https://github.com/bitcoin/bips/blob/master/bip-0152.mediawiki
* @extends AbstractBlock
* @property {Buffer|null} keyNonce - Nonce for siphash key.
* @property {Number[]} ids - Short IDs.
* @property {Object[]} ptx - Prefilled transactions.
* @property {TX[]} available - Available transaction vector.
* @property {Object} idMap - Map of short ids to indexes.
* @property {Number} count - Transactions resolved.
* @property {Buffer|null} sipKey - Siphash key.
*/
class CompactBlock extends AbstractBlock {
/**
* Create a compact block.
* @constructor
* @param {Object?} [options]
*/
constructor(options) {
super();
this.keyNonce = null;
this.ids = [];
this.ptx = [];
this.available = [];
this.idMap = new Map();
this.count = 0;
this.sipKey = null;
this.totalTX = 0;
this.now = 0;
if (options)
this.fromOptions(options);
}
/**
* Inject properties from options object.
* @param {Object} options
*/
fromOptions(options) {
this.parseOptions(options);
assert(Buffer.isBuffer(options.keyNonce));
assert(Array.isArray(options.ids));
assert(Array.isArray(options.ptx));
this.keyNonce = options.keyNonce;
this.ids = options.ids;
this.ptx = options.ptx;
if (options.available)
this.available = options.available;
if (options.idMap)
this.idMap = options.idMap;
if (options.count)
this.count = options.count;
if (options.totalTX != null)
this.totalTX = options.totalTX;
this.sipKey = this.getKey();
return this;
}
/**
* Verify the block.
* @returns {Boolean}
*/
verifyBody() {
return true;
}
/**
* Inject properties from buffer reader.
* @param {bio.BufferReader} br
*/
read(br) {
this.readHead(br);
this.keyNonce = br.readBytes(8);
this.sipKey = this.getKey();
const idCount = br.readVarint();
this.totalTX += idCount;
for (let i = 0; i < idCount; i++) {
const lo = br.readU32();
const hi = br.readU16();
this.ids.push(hi * 0x100000000 + lo);
}
const txCount = br.readVarint();
this.totalTX += txCount;
for (let i = 0; i < txCount; i++) {
const index = br.readVarint();
assert(index <= 0xffff);
assert(index < this.totalTX);
const tx = TX.read(br);
this.ptx.push([index, tx]);
}
return this;
}
/**
* Calculate block serialization size.
* @returns {Number}
*/
getSize() {
let size = 0;
size += this.sizeHead();
size += 8;
size += encoding.sizeVarint(this.ids.length);
size += this.ids.length * 6;
size += encoding.sizeVarint(this.ptx.length);
for (const [index, tx] of this.ptx) {
size += encoding.sizeVarint(index);
size += tx.getSize();
}
return size;
}
/**
* Serialize block to buffer writer.
* @param {BufioWriter} bw
*/
write(bw) {
this.writeHead(bw);
bw.writeBytes(this.keyNonce);
bw.writeVarint(this.ids.length);
for (const id of this.ids) {
const lo = id % 0x100000000;
const hi = (id - lo) / 0x100000000;
assert(hi <= 0xffff);
bw.writeU32(lo);
bw.writeU16(hi);
}
bw.writeVarint(this.ptx.length);
for (const [index, tx] of this.ptx) {
bw.writeVarint(index);
tx.write(bw);
}
return bw;
}
/**
* Convert block to a TXRequest
* containing missing indexes.
* @returns {TXRequest}
*/
toRequest() {
return TXRequest.fromCompact(this);
}
/**
* Attempt to fill missing transactions from mempool.
* @param {Mempool} mempool
* @returns {Boolean}
*/
fillMempool(mempool) {
if (this.count === this.totalTX)
return true;
const set = new Set();
for (const {tx} of mempool.map.values()) {
const hash = tx.witnessHash();
const id = this.sid(hash);
const index = this.idMap.get(id);
if (index == null)
continue;
if (set.has(index)) {
// Siphash collision, just request it.
this.available[index] = null;
this.count -= 1;
continue;
}
this.available[index] = tx;
set.add(index);
this.count += 1;
// We actually may have a siphash collision
// here, but exit early anyway for perf.
if (this.count === this.totalTX)
return true;
}
return false;
}
/**
* Attempt to fill missing transactions from TXResponse.
* @param {TXResponse} res
* @returns {Boolean}
*/
fillMissing(res) {
let offset = 0;
for (let i = 0; i < this.available.length; i++) {
if (this.available[i])
continue;
if (offset >= res.txs.length)
return false;
this.available[i] = res.txs[offset++];
}
return offset === res.txs.length;
}
/**
* Calculate a transaction short ID.
* @param {Hash} hash
* @returns {Number}
*/
sid(hash) {
const [hi, lo] = siphash(hash, this.sipKey);
return (hi & 0xffff) * 0x100000000 + (lo >>> 0);
}
/**
* Test whether an index is available.
* @param {Number} index
* @returns {Boolean}
*/
hasIndex(index) {
return this.available[index] != null;
}
/**
* Initialize the siphash key.
* @private
* @returns {Buffer}
*/
getKey() {
const hash = blake2b.multi(this.toHead(), this.keyNonce);
return hash.slice(0, 16);
}
/**
* Initialize compact block and short id map.
*/
init() {
if (this.totalTX === 0)
throw new Error('Empty vectors.');
if (this.totalTX > MAX_BLOCK_SIZE / 10)
throw new Error('Compact block too big.');
// Custom limit to avoid a hashdos.
// Min valid tx size: (4 + 1 + 40 + 1 + 10 + 4) = 60
// Min block header size: 334
// Max number of transactions: (1000000 - 334) / 60 = 16661
if (this.totalTX > (MAX_BLOCK_SIZE - (HEADER_SIZE + 1)) / 60)
throw new Error('Compact block too big.');
// No sparse arrays here, v8.
for (let i = 0; i < this.totalTX; i++)
this.available.push(null);
let last = -1;
let offset = 0;
for (let i = 0; i < this.ptx.length; i++) {
const [index, tx] = this.ptx[i];
last += index + 1;
assert(last <= 0xffff);
assert(last <= this.ids.length + i);
this.available[last] = tx;
this.count += 1;
}
for (let i = 0; i < this.ids.length; i++) {
const id = this.ids[i];
while (this.available[i + offset])
offset += 1;
// Fails on siphash collision.
if (this.idMap.has(id))
return false;
this.idMap.set(id, i + offset);
}
return true;
}
/**
* Convert completely filled compact
* block to a regular block.
* @returns {Block}
*/
toBlock() {
const block = new Block();
block.version = this.version;
block.prevBlock = this.prevBlock;
block.merkleRoot = this.merkleRoot;
block.witnessRoot = this.witnessRoot;
block.treeRoot = this.treeRoot;
block.reservedRoot = this.reservedRoot;
block.time = this.time;
block.bits = this.bits;
block.nonce = this.nonce;
block.extraNonce = this.extraNonce;
block.mask = this.mask;
block._hash = this._hash;
for (const tx of this.available) {
assert(tx, 'Compact block is not full.');
block.txs.push(tx);
}
return block;
}
/**
* Inject properties from block.
* @param {Block} block
* @param {Buffer?} nonce
* @returns {CompactBlock}
*/
fromBlock(block, nonce) {
this.version = block.version;
this.prevBlock = block.prevBlock;
this.merkleRoot = block.merkleRoot;
this.witnessRoot = block.witnessRoot;
this.treeRoot = block.treeRoot;
this.reservedRoot = block.reservedRoot;
this.time = block.time;
this.bits = block.bits;
this.nonce = block.nonce;
this.extraNonce = block.extraNonce;
this.mask = block.mask;
this.totalTX = block.txs.length;
this._hash = block._hash;
if (!nonce)
nonce = common.nonce();
this.keyNonce = nonce;
this.sipKey = this.getKey();
for (let i = 1; i < block.txs.length; i++) {
const tx = block.txs[i];
const hash = tx.witnessHash();
const id = this.sid(hash);
this.ids.push(id);
}
this.ptx.push([0, block.txs[0]]);
return this;
}
/**
* Instantiate compact block from a block.
* @param {Block} block
* @param {Buffer?} nonce
* @returns {CompactBlock}
*/
static fromBlock(block, nonce) {
return new this().fromBlock(block, nonce);
}
/**
* Convert block to headers.
* @returns {Headers}
*/
toHeaders() {
return Headers.fromBlock(this);
}
}
/**
* TX Request
* Represents a BlockTransactionsRequest (bip152): `getblocktxn` packet.
* @see https://github.com/bitcoin/bips/blob/master/bip-0152.mediawiki
* @property {Hash} hash
* @property {Number[]} indexes
*/
class TXRequest extends bio.Struct {
/**
* TX Request
* @constructor
* @param {Object?} [options]
*/
constructor(options) {
super();
this.hash = consensus.ZERO_HASH;
this.indexes = [];
if (options)
this.fromOptions(options);
}
/**
* Inject properties from options.
* @param {Object} options
* @returns {this}
*/
fromOptions(options) {
this.hash = options.hash;
if (options.indexes)
this.indexes = options.indexes;
return this;
}
/**
* Inject properties from compact block.
* @param {CompactBlock} block
* @returns {TXRequest}
*/
fromCompact(block) {
this.hash = block.hash();
for (let i = 0; i < block.available.length; i++) {
if (!block.available[i])
this.indexes.push(i);
}
return this;
}
/**
* Instantiate request from compact block.
* @param {CompactBlock} block
* @returns {TXRequest}
*/
static fromCompact(block) {
return new this().fromCompact(block);
}
/**
* Inject properties from buffer reader.
* @param {bio.BufferReader} br
* @returns {this}
*/
read(br) {
this.hash = br.readHash();
const count = br.readVarint();
for (let i = 0; i < count; i++) {
const index = br.readVarint();
assert(index <= 0xffff);
this.indexes.push(index);
}
let offset = 0;
for (let i = 0; i < count; i++) {
let index = this.indexes[i];
index += offset;
assert(index <= 0xffff);
this.indexes[i] = index;
offset = index + 1;
}
return this;
}
/**
* Calculate request serialization size.
* @returns {Number}
*/
getSize() {
let size = 0;
size += 32;
size += encoding.sizeVarint(this.indexes.length);
for (let i = 0; i < this.indexes.length; i++) {
let index = this.indexes[i];
if (i > 0)
index -= this.indexes[i - 1] + 1;
size += encoding.sizeVarint(index);
}
return size;
}
/**
* Write serialized request to buffer writer.
* @param {BufioWriter} bw
* @returns {BufioWriter}
*/
write(bw) {
bw.writeHash(this.hash);
bw.writeVarint(this.indexes.length);
for (let i = 0; i < this.indexes.length; i++) {
let index = this.indexes[i];
if (i > 0)
index -= this.indexes[i - 1] + 1;
bw.writeVarint(index);
}
return bw;
}
}
/**
* TX Response
* Represents BlockTransactions (bip152): `blocktxn` packet.
* @see https://github.com/bitcoin/bips/blob/master/bip-0152.mediawiki
* @property {Hash} hash
* @property {TX[]} txs
*/
class TXResponse extends bio.Struct {
/**
* Create a tx response.
* @constructor
* @param {Object?} [options]
*/
constructor(options) {
super();
this.hash = consensus.ZERO_HASH;
this.txs = [];
if (options)
this.fromOptions(options);
}
/**
* Inject properties from options.
* @param {Object} options
* @returns {this}
*/
fromOptions(options) {
this.hash = options.hash;
if (options.txs)
this.txs = options.txs;
return this;
}
/**
* Inject properties from buffer reader.
* @param {bio.BufferReader} br
* @returns {this}
*/
read(br) {
this.hash = br.readHash();
const count = br.readVarint();
for (let i = 0; i < count; i++)
this.txs.push(TX.read(br));
return this;
}
/**
* Inject properties from block.
* @param {Block} block
* @param {TXRequest} req
* @returns {TXResponse}
*/
fromBlock(block, req) {
this.hash = req.hash;
for (const index of req.indexes) {
if (index >= block.txs.length)
break;
this.txs.push(block.txs[index]);
}
return this;
}
/**
* Instantiate response from block.
* @param {Block} block
* @param {TXRequest} req
* @returns {TXResponse}
*/
static fromBlock(block, req) {
return new this().fromBlock(block, req);
}
/**
* Calculate request serialization size.
* @returns {Number}
*/
getSize() {
let size = 0;
size += 32;
size += encoding.sizeVarint(this.txs.length);
for (const tx of this.txs)
size += tx.getSize();
return size;
}
/**
* Write serialized response to buffer writer.
* @param {BufioWriter} bw
*/
write(bw) {
bw.writeHash(this.hash);
bw.writeVarint(this.txs.length);
for (const tx of this.txs)
tx.write(bw);
return bw;
}
}
/*
* Expose
*/
exports.CompactBlock = CompactBlock;
exports.TXRequest = TXRequest;
exports.TXResponse = TXResponse;