Merge pull request #1533 from OttoAllmendinger/add-buffer-writer

Add BufferWriter and BufferReader class
This commit is contained in:
Jonathan Underwood 2020-01-15 17:57:08 +09:00 committed by GitHub
commit f48abd322f
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GPG key ID: 4AEE18F83AFDEB23
8 changed files with 852 additions and 398 deletions

View file

@ -26,43 +26,24 @@ class Block {
}
static fromBuffer(buffer) {
if (buffer.length < 80) throw new Error('Buffer too small (< 80 bytes)');
let offset = 0;
const readSlice = n => {
offset += n;
return buffer.slice(offset - n, offset);
};
const readUInt32 = () => {
const i = buffer.readUInt32LE(offset);
offset += 4;
return i;
};
const readInt32 = () => {
const i = buffer.readInt32LE(offset);
offset += 4;
return i;
};
const bufferReader = new bufferutils_1.BufferReader(buffer);
const block = new Block();
block.version = readInt32();
block.prevHash = readSlice(32);
block.merkleRoot = readSlice(32);
block.timestamp = readUInt32();
block.bits = readUInt32();
block.nonce = readUInt32();
block.version = bufferReader.readInt32();
block.prevHash = bufferReader.readSlice(32);
block.merkleRoot = bufferReader.readSlice(32);
block.timestamp = bufferReader.readUInt32();
block.bits = bufferReader.readUInt32();
block.nonce = bufferReader.readUInt32();
if (buffer.length === 80) return block;
const readVarInt = () => {
const vi = varuint.decode(buffer, offset);
offset += varuint.decode.bytes;
return vi;
};
const readTransaction = () => {
const tx = transaction_1.Transaction.fromBuffer(
buffer.slice(offset),
bufferReader.buffer.slice(bufferReader.offset),
true,
);
offset += tx.byteLength();
bufferReader.offset += tx.byteLength();
return tx;
};
const nTransactions = readVarInt();
const nTransactions = bufferReader.readVarInt();
block.transactions = [];
for (let i = 0; i < nTransactions; ++i) {
const tx = readTransaction();
@ -154,32 +135,20 @@ class Block {
// TODO: buffer, offset compatibility
toBuffer(headersOnly) {
const buffer = Buffer.allocUnsafe(this.byteLength(headersOnly));
let offset = 0;
const writeSlice = slice => {
slice.copy(buffer, offset);
offset += slice.length;
};
const writeInt32 = i => {
buffer.writeInt32LE(i, offset);
offset += 4;
};
const writeUInt32 = i => {
buffer.writeUInt32LE(i, offset);
offset += 4;
};
writeInt32(this.version);
writeSlice(this.prevHash);
writeSlice(this.merkleRoot);
writeUInt32(this.timestamp);
writeUInt32(this.bits);
writeUInt32(this.nonce);
const bufferWriter = new bufferutils_1.BufferWriter(buffer);
bufferWriter.writeInt32(this.version);
bufferWriter.writeSlice(this.prevHash);
bufferWriter.writeSlice(this.merkleRoot);
bufferWriter.writeUInt32(this.timestamp);
bufferWriter.writeUInt32(this.bits);
bufferWriter.writeUInt32(this.nonce);
if (headersOnly || !this.transactions) return buffer;
varuint.encode(this.transactions.length, buffer, offset);
offset += varuint.encode.bytes;
varuint.encode(this.transactions.length, buffer, bufferWriter.offset);
bufferWriter.offset += varuint.encode.bytes;
this.transactions.forEach(tx => {
const txSize = tx.byteLength(); // TODO: extract from toBuffer?
tx.toBuffer(buffer, offset);
offset += txSize;
tx.toBuffer(buffer, bufferWriter.offset);
bufferWriter.offset += txSize;
});
return buffer;
}

View file

@ -1,5 +1,8 @@
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
const types = require('./types');
const typeforce = require('typeforce');
const varuint = require('varuint-bitcoin');
// https://github.com/feross/buffer/blob/master/index.js#L1127
function verifuint(value, max) {
if (typeof value !== 'number')
@ -38,3 +41,97 @@ function reverseBuffer(buffer) {
return buffer;
}
exports.reverseBuffer = reverseBuffer;
/**
* Helper class for serialization of bitcoin data types into a pre-allocated buffer.
*/
class BufferWriter {
constructor(buffer, offset = 0) {
this.buffer = buffer;
this.offset = offset;
typeforce(types.tuple(types.Buffer, types.UInt32), [buffer, offset]);
}
writeUInt8(i) {
this.offset = this.buffer.writeUInt8(i, this.offset);
}
writeInt32(i) {
this.offset = this.buffer.writeInt32LE(i, this.offset);
}
writeUInt32(i) {
this.offset = this.buffer.writeUInt32LE(i, this.offset);
}
writeUInt64(i) {
this.offset = writeUInt64LE(this.buffer, i, this.offset);
}
writeVarInt(i) {
varuint.encode(i, this.buffer, this.offset);
this.offset += varuint.encode.bytes;
}
writeSlice(slice) {
if (this.buffer.length < this.offset + slice.length) {
throw new Error('Cannot write slice out of bounds');
}
this.offset += slice.copy(this.buffer, this.offset);
}
writeVarSlice(slice) {
this.writeVarInt(slice.length);
this.writeSlice(slice);
}
writeVector(vector) {
this.writeVarInt(vector.length);
vector.forEach(buf => this.writeVarSlice(buf));
}
}
exports.BufferWriter = BufferWriter;
/**
* Helper class for reading of bitcoin data types from a buffer.
*/
class BufferReader {
constructor(buffer, offset = 0) {
this.buffer = buffer;
this.offset = offset;
typeforce(types.tuple(types.Buffer, types.UInt32), [buffer, offset]);
}
readUInt8() {
const result = this.buffer.readUInt8(this.offset);
this.offset++;
return result;
}
readInt32() {
const result = this.buffer.readInt32LE(this.offset);
this.offset += 4;
return result;
}
readUInt32() {
const result = this.buffer.readUInt32LE(this.offset);
this.offset += 4;
return result;
}
readUInt64() {
const result = readUInt64LE(this.buffer, this.offset);
this.offset += 8;
return result;
}
readVarInt() {
const vi = varuint.decode(this.buffer, this.offset);
this.offset += varuint.decode.bytes;
return vi;
}
readSlice(n) {
if (this.buffer.length < this.offset + n) {
throw new Error('Cannot read slice out of bounds');
}
const result = this.buffer.slice(this.offset, this.offset + n);
this.offset += n;
return result;
}
readVarSlice() {
return this.readSlice(this.readVarInt());
}
readVector() {
const count = this.readVarInt();
const vector = [];
for (let i = 0; i < count; i++) vector.push(this.readVarSlice());
return vector;
}
}
exports.BufferReader = BufferReader;

View file

@ -1,6 +1,5 @@
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
const bufferutils = require('./bufferutils');
const bufferutils_1 = require('./bufferutils');
const bcrypto = require('./crypto');
const bscript = require('./script');
@ -47,80 +46,48 @@ class Transaction {
this.outs = [];
}
static fromBuffer(buffer, _NO_STRICT) {
let offset = 0;
function readSlice(n) {
offset += n;
return buffer.slice(offset - n, offset);
}
function readUInt32() {
const i = buffer.readUInt32LE(offset);
offset += 4;
return i;
}
function readInt32() {
const i = buffer.readInt32LE(offset);
offset += 4;
return i;
}
function readUInt64() {
const i = bufferutils.readUInt64LE(buffer, offset);
offset += 8;
return i;
}
function readVarInt() {
const vi = varuint.decode(buffer, offset);
offset += varuint.decode.bytes;
return vi;
}
function readVarSlice() {
return readSlice(readVarInt());
}
function readVector() {
const count = readVarInt();
const vector = [];
for (let i = 0; i < count; i++) vector.push(readVarSlice());
return vector;
}
const bufferReader = new bufferutils_1.BufferReader(buffer);
const tx = new Transaction();
tx.version = readInt32();
const marker = buffer.readUInt8(offset);
const flag = buffer.readUInt8(offset + 1);
tx.version = bufferReader.readInt32();
const marker = bufferReader.readUInt8();
const flag = bufferReader.readUInt8();
let hasWitnesses = false;
if (
marker === Transaction.ADVANCED_TRANSACTION_MARKER &&
flag === Transaction.ADVANCED_TRANSACTION_FLAG
) {
offset += 2;
hasWitnesses = true;
} else {
bufferReader.offset -= 2;
}
const vinLen = readVarInt();
const vinLen = bufferReader.readVarInt();
for (let i = 0; i < vinLen; ++i) {
tx.ins.push({
hash: readSlice(32),
index: readUInt32(),
script: readVarSlice(),
sequence: readUInt32(),
hash: bufferReader.readSlice(32),
index: bufferReader.readUInt32(),
script: bufferReader.readVarSlice(),
sequence: bufferReader.readUInt32(),
witness: EMPTY_WITNESS,
});
}
const voutLen = readVarInt();
const voutLen = bufferReader.readVarInt();
for (let i = 0; i < voutLen; ++i) {
tx.outs.push({
value: readUInt64(),
script: readVarSlice(),
value: bufferReader.readUInt64(),
script: bufferReader.readVarSlice(),
});
}
if (hasWitnesses) {
for (let i = 0; i < vinLen; ++i) {
tx.ins[i].witness = readVector();
tx.ins[i].witness = bufferReader.readVector();
}
// was this pointless?
if (!tx.hasWitnesses())
throw new Error('Transaction has superfluous witness data');
}
tx.locktime = readUInt32();
tx.locktime = bufferReader.readUInt32();
if (_NO_STRICT) return tx;
if (offset !== buffer.length)
if (bufferReader.offset !== buffer.length)
throw new Error('Transaction has unexpected data');
return tx;
}
@ -296,33 +263,16 @@ class Transaction {
arguments,
);
let tbuffer = Buffer.from([]);
let toffset = 0;
function writeSlice(slice) {
toffset += slice.copy(tbuffer, toffset);
}
function writeUInt32(i) {
toffset = tbuffer.writeUInt32LE(i, toffset);
}
function writeUInt64(i) {
toffset = bufferutils.writeUInt64LE(tbuffer, i, toffset);
}
function writeVarInt(i) {
varuint.encode(i, tbuffer, toffset);
toffset += varuint.encode.bytes;
}
function writeVarSlice(slice) {
writeVarInt(slice.length);
writeSlice(slice);
}
let bufferWriter;
let hashOutputs = ZERO;
let hashPrevouts = ZERO;
let hashSequence = ZERO;
if (!(hashType & Transaction.SIGHASH_ANYONECANPAY)) {
tbuffer = Buffer.allocUnsafe(36 * this.ins.length);
toffset = 0;
bufferWriter = new bufferutils_1.BufferWriter(tbuffer, 0);
this.ins.forEach(txIn => {
writeSlice(txIn.hash);
writeUInt32(txIn.index);
bufferWriter.writeSlice(txIn.hash);
bufferWriter.writeUInt32(txIn.index);
});
hashPrevouts = bcrypto.hash256(tbuffer);
}
@ -332,9 +282,9 @@ class Transaction {
(hashType & 0x1f) !== Transaction.SIGHASH_NONE
) {
tbuffer = Buffer.allocUnsafe(4 * this.ins.length);
toffset = 0;
bufferWriter = new bufferutils_1.BufferWriter(tbuffer, 0);
this.ins.forEach(txIn => {
writeUInt32(txIn.sequence);
bufferWriter.writeUInt32(txIn.sequence);
});
hashSequence = bcrypto.hash256(tbuffer);
}
@ -346,10 +296,10 @@ class Transaction {
return sum + 8 + varSliceSize(output.script);
}, 0);
tbuffer = Buffer.allocUnsafe(txOutsSize);
toffset = 0;
bufferWriter = new bufferutils_1.BufferWriter(tbuffer, 0);
this.outs.forEach(out => {
writeUInt64(out.value);
writeVarSlice(out.script);
bufferWriter.writeUInt64(out.value);
bufferWriter.writeVarSlice(out.script);
});
hashOutputs = bcrypto.hash256(tbuffer);
} else if (
@ -358,25 +308,25 @@ class Transaction {
) {
const output = this.outs[inIndex];
tbuffer = Buffer.allocUnsafe(8 + varSliceSize(output.script));
toffset = 0;
writeUInt64(output.value);
writeVarSlice(output.script);
bufferWriter = new bufferutils_1.BufferWriter(tbuffer, 0);
bufferWriter.writeUInt64(output.value);
bufferWriter.writeVarSlice(output.script);
hashOutputs = bcrypto.hash256(tbuffer);
}
tbuffer = Buffer.allocUnsafe(156 + varSliceSize(prevOutScript));
toffset = 0;
bufferWriter = new bufferutils_1.BufferWriter(tbuffer, 0);
const input = this.ins[inIndex];
writeUInt32(this.version);
writeSlice(hashPrevouts);
writeSlice(hashSequence);
writeSlice(input.hash);
writeUInt32(input.index);
writeVarSlice(prevOutScript);
writeUInt64(value);
writeUInt32(input.sequence);
writeSlice(hashOutputs);
writeUInt32(this.locktime);
writeUInt32(hashType);
bufferWriter.writeUInt32(this.version);
bufferWriter.writeSlice(hashPrevouts);
bufferWriter.writeSlice(hashSequence);
bufferWriter.writeSlice(input.hash);
bufferWriter.writeUInt32(input.index);
bufferWriter.writeVarSlice(prevOutScript);
bufferWriter.writeUInt64(value);
bufferWriter.writeUInt32(input.sequence);
bufferWriter.writeSlice(hashOutputs);
bufferWriter.writeUInt32(this.locktime);
bufferWriter.writeUInt32(hashType);
return bcrypto.hash256(tbuffer);
}
getHash(forWitness) {
@ -404,64 +354,41 @@ class Transaction {
}
__toBuffer(buffer, initialOffset, _ALLOW_WITNESS = false) {
if (!buffer) buffer = Buffer.allocUnsafe(this.byteLength(_ALLOW_WITNESS));
let offset = initialOffset || 0;
function writeSlice(slice) {
offset += slice.copy(buffer, offset);
}
function writeUInt8(i) {
offset = buffer.writeUInt8(i, offset);
}
function writeUInt32(i) {
offset = buffer.writeUInt32LE(i, offset);
}
function writeInt32(i) {
offset = buffer.writeInt32LE(i, offset);
}
function writeUInt64(i) {
offset = bufferutils.writeUInt64LE(buffer, i, offset);
}
function writeVarInt(i) {
varuint.encode(i, buffer, offset);
offset += varuint.encode.bytes;
}
function writeVarSlice(slice) {
writeVarInt(slice.length);
writeSlice(slice);
}
function writeVector(vector) {
writeVarInt(vector.length);
vector.forEach(writeVarSlice);
}
writeInt32(this.version);
const bufferWriter = new bufferutils_1.BufferWriter(
buffer,
initialOffset || 0,
);
bufferWriter.writeInt32(this.version);
const hasWitnesses = _ALLOW_WITNESS && this.hasWitnesses();
if (hasWitnesses) {
writeUInt8(Transaction.ADVANCED_TRANSACTION_MARKER);
writeUInt8(Transaction.ADVANCED_TRANSACTION_FLAG);
bufferWriter.writeUInt8(Transaction.ADVANCED_TRANSACTION_MARKER);
bufferWriter.writeUInt8(Transaction.ADVANCED_TRANSACTION_FLAG);
}
writeVarInt(this.ins.length);
bufferWriter.writeVarInt(this.ins.length);
this.ins.forEach(txIn => {
writeSlice(txIn.hash);
writeUInt32(txIn.index);
writeVarSlice(txIn.script);
writeUInt32(txIn.sequence);
bufferWriter.writeSlice(txIn.hash);
bufferWriter.writeUInt32(txIn.index);
bufferWriter.writeVarSlice(txIn.script);
bufferWriter.writeUInt32(txIn.sequence);
});
writeVarInt(this.outs.length);
bufferWriter.writeVarInt(this.outs.length);
this.outs.forEach(txOut => {
if (isOutput(txOut)) {
writeUInt64(txOut.value);
bufferWriter.writeUInt64(txOut.value);
} else {
writeSlice(txOut.valueBuffer);
bufferWriter.writeSlice(txOut.valueBuffer);
}
writeVarSlice(txOut.script);
bufferWriter.writeVarSlice(txOut.script);
});
if (hasWitnesses) {
this.ins.forEach(input => {
writeVector(input.witness);
bufferWriter.writeVector(input.witness);
});
}
writeUInt32(this.locktime);
bufferWriter.writeUInt32(this.locktime);
// avoid slicing unless necessary
if (initialOffset !== undefined) return buffer.slice(initialOffset, offset);
if (initialOffset !== undefined)
return buffer.slice(initialOffset, bufferWriter.offset);
return buffer;
}
}

View file

@ -1,10 +1,16 @@
import * as assert from 'assert';
import { describe, it } from 'mocha';
import * as bufferutils from '../src/bufferutils';
import { BufferReader, BufferWriter } from '../src/bufferutils';
import * as fixtures from './fixtures/bufferutils.json';
const varuint = require('varuint-bitcoin');
describe('bufferutils', () => {
function concatToBuffer(values: number[][]): Buffer {
return Buffer.concat(values.map(data => Buffer.from(data)));
}
describe('readUInt64LE', () => {
fixtures.valid.forEach(f => {
it('decodes ' + f.hex, () => {
@ -46,4 +52,444 @@ describe('bufferutils', () => {
});
});
});
describe('BufferWriter', () => {
function testBuffer(
bufferWriter: BufferWriter,
expectedBuffer: Buffer,
expectedOffset: number = expectedBuffer.length,
): void {
assert.strictEqual(bufferWriter.offset, expectedOffset);
assert.deepStrictEqual(
bufferWriter.buffer.slice(0, expectedOffset),
expectedBuffer.slice(0, expectedOffset),
);
}
it('writeUint8', () => {
const values = [0, 1, 254, 255];
const expectedBuffer = Buffer.from([0, 1, 0xfe, 0xff]);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((v: number) => {
const expectedOffset = bufferWriter.offset + 1;
bufferWriter.writeUInt8(v);
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
});
it('writeInt32', () => {
const values = [
0,
1,
Math.pow(2, 31) - 2,
Math.pow(2, 31) - 1,
-1,
-Math.pow(2, 31),
];
const expectedBuffer = concatToBuffer([
[0, 0, 0, 0],
[1, 0, 0, 0],
[0xfe, 0xff, 0xff, 0x7f],
[0xff, 0xff, 0xff, 0x7f],
[0xff, 0xff, 0xff, 0xff],
[0x00, 0x00, 0x00, 0x80],
]);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((value: number) => {
const expectedOffset = bufferWriter.offset + 4;
bufferWriter.writeInt32(value);
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
});
it('writeUInt32', () => {
const maxUInt32 = Math.pow(2, 32) - 1;
const values = [0, 1, Math.pow(2, 16), maxUInt32];
const expectedBuffer = concatToBuffer([
[0, 0, 0, 0],
[1, 0, 0, 0],
[0, 0, 1, 0],
[0xff, 0xff, 0xff, 0xff],
]);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((value: number) => {
const expectedOffset = bufferWriter.offset + 4;
bufferWriter.writeUInt32(value);
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
});
it('writeUInt64', () => {
const values = [
0,
1,
Math.pow(2, 32),
Number.MAX_SAFE_INTEGER /* 2^53 - 1 */,
];
const expectedBuffer = concatToBuffer([
[0, 0, 0, 0, 0, 0, 0, 0],
[1, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 0, 0, 0],
[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0x00],
]);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((value: number) => {
const expectedOffset = bufferWriter.offset + 8;
bufferWriter.writeUInt64(value);
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
});
it('writeVarInt', () => {
const values = [
0,
1,
252,
253,
254,
255,
256,
Math.pow(2, 16) - 2,
Math.pow(2, 16) - 1,
Math.pow(2, 16),
Math.pow(2, 32) - 2,
Math.pow(2, 32) - 1,
Math.pow(2, 32),
Number.MAX_SAFE_INTEGER,
];
const expectedBuffer = concatToBuffer([
[0x00],
[0x01],
[0xfc],
[0xfd, 0xfd, 0x00],
[0xfd, 0xfe, 0x00],
[0xfd, 0xff, 0x00],
[0xfd, 0x00, 0x01],
[0xfd, 0xfe, 0xff],
[0xfd, 0xff, 0xff],
[0xfe, 0x00, 0x00, 0x01, 0x00],
[0xfe, 0xfe, 0xff, 0xff, 0xff],
[0xfe, 0xff, 0xff, 0xff, 0xff],
[0xff, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00],
[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0x00],
]);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((value: number) => {
const expectedOffset =
bufferWriter.offset + varuint.encodingLength(value);
bufferWriter.writeVarInt(value);
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
});
it('writeSlice', () => {
const values = [[], [1], [1, 2, 3, 4], [254, 255]];
const expectedBuffer = concatToBuffer(values);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((v: number[]) => {
const expectedOffset = bufferWriter.offset + v.length;
bufferWriter.writeSlice(Buffer.from(v));
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
assert.throws(() => {
bufferWriter.writeSlice(Buffer.from([0, 0]));
}, /^Error: Cannot write slice out of bounds$/);
});
it('writeVarSlice', () => {
const values = [
Buffer.alloc(1, 1),
Buffer.alloc(252, 2),
Buffer.alloc(253, 3),
];
const expectedBuffer = Buffer.concat([
Buffer.from([0x01, 0x01]),
Buffer.from([0xfc]),
Buffer.alloc(252, 0x02),
Buffer.from([0xfd, 0xfd, 0x00]),
Buffer.alloc(253, 0x03),
]);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((value: Buffer) => {
const expectedOffset =
bufferWriter.offset +
varuint.encodingLength(value.length) +
value.length;
bufferWriter.writeVarSlice(value);
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
});
it('writeVector', () => {
const values = [
[Buffer.alloc(1, 4), Buffer.alloc(253, 5)],
Array(253).fill(Buffer.alloc(1, 6)),
];
const expectedBuffer = Buffer.concat([
Buffer.from([0x02]),
Buffer.from([0x01, 0x04]),
Buffer.from([0xfd, 0xfd, 0x00]),
Buffer.alloc(253, 5),
Buffer.from([0xfd, 0xfd, 0x00]),
Buffer.concat(
Array(253)
.fill(0)
.map(() => Buffer.from([0x01, 0x06])),
),
]);
const bufferWriter = new BufferWriter(
Buffer.allocUnsafe(expectedBuffer.length),
);
values.forEach((value: Buffer[]) => {
const expectedOffset =
bufferWriter.offset +
varuint.encodingLength(value.length) +
value.reduce(
(sum: number, v) =>
sum + varuint.encodingLength(v.length) + v.length,
0,
);
bufferWriter.writeVector(value);
testBuffer(bufferWriter, expectedBuffer, expectedOffset);
});
testBuffer(bufferWriter, expectedBuffer);
});
});
describe('BufferReader', () => {
function testValue(
bufferReader: BufferReader,
value: Buffer | number,
expectedValue: Buffer | number,
expectedOffset: number = Buffer.isBuffer(expectedValue)
? expectedValue.length
: 0,
): void {
assert.strictEqual(bufferReader.offset, expectedOffset);
if (Buffer.isBuffer(expectedValue)) {
assert.deepStrictEqual(
(value as Buffer).slice(0, expectedOffset),
expectedValue.slice(0, expectedOffset),
);
} else {
assert.strictEqual(value as number, expectedValue);
}
}
it('readUint8', () => {
const values = [0, 1, 0xfe, 0xff];
const buffer = Buffer.from([0, 1, 0xfe, 0xff]);
const bufferReader = new BufferReader(buffer);
values.forEach((v: number) => {
const expectedOffset = bufferReader.offset + 1;
const val = bufferReader.readUInt8();
testValue(bufferReader, val, v, expectedOffset);
});
});
it('readInt32', () => {
const values = [
0,
1,
Math.pow(2, 31) - 2,
Math.pow(2, 31) - 1,
-1,
-Math.pow(2, 31),
];
const buffer = concatToBuffer([
[0, 0, 0, 0],
[1, 0, 0, 0],
[0xfe, 0xff, 0xff, 0x7f],
[0xff, 0xff, 0xff, 0x7f],
[0xff, 0xff, 0xff, 0xff],
[0x00, 0x00, 0x00, 0x80],
]);
const bufferReader = new BufferReader(buffer);
values.forEach((value: number) => {
const expectedOffset = bufferReader.offset + 4;
const val = bufferReader.readInt32();
testValue(bufferReader, val, value, expectedOffset);
});
});
it('readUInt32', () => {
const maxUInt32 = Math.pow(2, 32) - 1;
const values = [0, 1, Math.pow(2, 16), maxUInt32];
const buffer = concatToBuffer([
[0, 0, 0, 0],
[1, 0, 0, 0],
[0, 0, 1, 0],
[0xff, 0xff, 0xff, 0xff],
]);
const bufferReader = new BufferReader(buffer);
values.forEach((value: number) => {
const expectedOffset = bufferReader.offset + 4;
const val = bufferReader.readUInt32();
testValue(bufferReader, val, value, expectedOffset);
});
});
it('readUInt64', () => {
const values = [
0,
1,
Math.pow(2, 32),
Number.MAX_SAFE_INTEGER /* 2^53 - 1 */,
];
const buffer = concatToBuffer([
[0, 0, 0, 0, 0, 0, 0, 0],
[1, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 0, 0, 0],
[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0x00],
]);
const bufferReader = new BufferReader(buffer);
values.forEach((value: number) => {
const expectedOffset = bufferReader.offset + 8;
const val = bufferReader.readUInt64();
testValue(bufferReader, val, value, expectedOffset);
});
});
it('readVarInt', () => {
const values = [
0,
1,
252,
253,
254,
255,
256,
Math.pow(2, 16) - 2,
Math.pow(2, 16) - 1,
Math.pow(2, 16),
Math.pow(2, 32) - 2,
Math.pow(2, 32) - 1,
Math.pow(2, 32),
Number.MAX_SAFE_INTEGER,
];
const buffer = concatToBuffer([
[0x00],
[0x01],
[0xfc],
[0xfd, 0xfd, 0x00],
[0xfd, 0xfe, 0x00],
[0xfd, 0xff, 0x00],
[0xfd, 0x00, 0x01],
[0xfd, 0xfe, 0xff],
[0xfd, 0xff, 0xff],
[0xfe, 0x00, 0x00, 0x01, 0x00],
[0xfe, 0xfe, 0xff, 0xff, 0xff],
[0xfe, 0xff, 0xff, 0xff, 0xff],
[0xff, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00],
[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0x00],
]);
const bufferReader = new BufferReader(buffer);
values.forEach((value: number) => {
const expectedOffset =
bufferReader.offset + varuint.encodingLength(value);
const val = bufferReader.readVarInt();
testValue(bufferReader, val, value, expectedOffset);
});
});
it('readSlice', () => {
const values = [[1], [1, 2, 3, 4], [254, 255]];
const buffer = concatToBuffer(values);
const bufferReader = new BufferReader(buffer);
values.forEach((v: number[]) => {
const expectedOffset = bufferReader.offset + v.length;
const val = bufferReader.readSlice(v.length);
testValue(bufferReader, val, Buffer.from(v), expectedOffset);
});
assert.throws(() => {
bufferReader.readSlice(2);
}, /^Error: Cannot read slice out of bounds$/);
});
it('readVarSlice', () => {
const values = [
Buffer.alloc(1, 1),
Buffer.alloc(252, 2),
Buffer.alloc(253, 3),
];
const buffer = Buffer.concat([
Buffer.from([0x01, 0x01]),
Buffer.from([0xfc]),
Buffer.alloc(252, 0x02),
Buffer.from([0xfd, 0xfd, 0x00]),
Buffer.alloc(253, 0x03),
]);
const bufferReader = new BufferReader(buffer);
values.forEach((value: Buffer) => {
const expectedOffset =
bufferReader.offset +
varuint.encodingLength(value.length) +
value.length;
const val = bufferReader.readVarSlice();
testValue(bufferReader, val, value, expectedOffset);
});
});
it('readVector', () => {
const values = [
[Buffer.alloc(1, 4), Buffer.alloc(253, 5)],
Array(253).fill(Buffer.alloc(1, 6)),
];
const buffer = Buffer.concat([
Buffer.from([0x02]),
Buffer.from([0x01, 0x04]),
Buffer.from([0xfd, 0xfd, 0x00]),
Buffer.alloc(253, 5),
Buffer.from([0xfd, 0xfd, 0x00]),
Buffer.concat(
Array(253)
.fill(0)
.map(() => Buffer.from([0x01, 0x06])),
),
]);
const bufferReader = new BufferReader(buffer);
values.forEach((value: Buffer[]) => {
const expectedOffset =
bufferReader.offset +
varuint.encodingLength(value.length) +
value.reduce(
(sum: number, v) =>
sum + varuint.encodingLength(v.length) + v.length,
0,
);
const val = bufferReader.readVector();
testValue(
bufferReader,
Buffer.concat(val),
Buffer.concat(value),
expectedOffset,
);
});
});
});
});

View file

@ -1,4 +1,4 @@
import { reverseBuffer } from './bufferutils';
import { BufferReader, BufferWriter, reverseBuffer } from './bufferutils';
import * as bcrypto from './crypto';
import { Transaction } from './transaction';
import * as types from './types';
@ -18,47 +18,28 @@ export class Block {
static fromBuffer(buffer: Buffer): Block {
if (buffer.length < 80) throw new Error('Buffer too small (< 80 bytes)');
let offset: number = 0;
const readSlice = (n: number): Buffer => {
offset += n;
return buffer.slice(offset - n, offset);
};
const readUInt32 = (): number => {
const i = buffer.readUInt32LE(offset);
offset += 4;
return i;
};
const readInt32 = (): number => {
const i = buffer.readInt32LE(offset);
offset += 4;
return i;
};
const bufferReader = new BufferReader(buffer);
const block = new Block();
block.version = readInt32();
block.prevHash = readSlice(32);
block.merkleRoot = readSlice(32);
block.timestamp = readUInt32();
block.bits = readUInt32();
block.nonce = readUInt32();
block.version = bufferReader.readInt32();
block.prevHash = bufferReader.readSlice(32);
block.merkleRoot = bufferReader.readSlice(32);
block.timestamp = bufferReader.readUInt32();
block.bits = bufferReader.readUInt32();
block.nonce = bufferReader.readUInt32();
if (buffer.length === 80) return block;
const readVarInt = (): number => {
const vi = varuint.decode(buffer, offset);
offset += varuint.decode.bytes;
return vi;
};
const readTransaction = (): any => {
const tx = Transaction.fromBuffer(buffer.slice(offset), true);
offset += tx.byteLength();
const tx = Transaction.fromBuffer(
bufferReader.buffer.slice(bufferReader.offset),
true,
);
bufferReader.offset += tx.byteLength();
return tx;
};
const nTransactions = readVarInt();
const nTransactions = bufferReader.readVarInt();
block.transactions = [];
for (let i = 0; i < nTransactions; ++i) {
@ -183,37 +164,24 @@ export class Block {
toBuffer(headersOnly?: boolean): Buffer {
const buffer: Buffer = Buffer.allocUnsafe(this.byteLength(headersOnly));
let offset: number = 0;
const writeSlice = (slice: Buffer): void => {
slice.copy(buffer, offset);
offset += slice.length;
};
const bufferWriter = new BufferWriter(buffer);
const writeInt32 = (i: number): void => {
buffer.writeInt32LE(i, offset);
offset += 4;
};
const writeUInt32 = (i: number): void => {
buffer.writeUInt32LE(i, offset);
offset += 4;
};
writeInt32(this.version);
writeSlice(this.prevHash!);
writeSlice(this.merkleRoot!);
writeUInt32(this.timestamp);
writeUInt32(this.bits);
writeUInt32(this.nonce);
bufferWriter.writeInt32(this.version);
bufferWriter.writeSlice(this.prevHash!);
bufferWriter.writeSlice(this.merkleRoot!);
bufferWriter.writeUInt32(this.timestamp);
bufferWriter.writeUInt32(this.bits);
bufferWriter.writeUInt32(this.nonce);
if (headersOnly || !this.transactions) return buffer;
varuint.encode(this.transactions.length, buffer, offset);
offset += varuint.encode.bytes;
varuint.encode(this.transactions.length, buffer, bufferWriter.offset);
bufferWriter.offset += varuint.encode.bytes;
this.transactions.forEach(tx => {
const txSize = tx.byteLength(); // TODO: extract from toBuffer?
tx.toBuffer(buffer, offset);
offset += txSize;
tx.toBuffer(buffer, bufferWriter.offset);
bufferWriter.offset += txSize;
});
return buffer;

View file

@ -1,3 +1,8 @@
import * as types from './types';
const typeforce = require('typeforce');
const varuint = require('varuint-bitcoin');
// https://github.com/feross/buffer/blob/master/index.js#L1127
function verifuint(value: number, max: number): void {
if (typeof value !== 'number')
@ -42,3 +47,109 @@ export function reverseBuffer(buffer: Buffer): Buffer {
}
return buffer;
}
/**
* Helper class for serialization of bitcoin data types into a pre-allocated buffer.
*/
export class BufferWriter {
constructor(public buffer: Buffer, public offset: number = 0) {
typeforce(types.tuple(types.Buffer, types.UInt32), [buffer, offset]);
}
writeUInt8(i: number): void {
this.offset = this.buffer.writeUInt8(i, this.offset);
}
writeInt32(i: number): void {
this.offset = this.buffer.writeInt32LE(i, this.offset);
}
writeUInt32(i: number): void {
this.offset = this.buffer.writeUInt32LE(i, this.offset);
}
writeUInt64(i: number): void {
this.offset = writeUInt64LE(this.buffer, i, this.offset);
}
writeVarInt(i: number): void {
varuint.encode(i, this.buffer, this.offset);
this.offset += varuint.encode.bytes;
}
writeSlice(slice: Buffer): void {
if (this.buffer.length < this.offset + slice.length) {
throw new Error('Cannot write slice out of bounds');
}
this.offset += slice.copy(this.buffer, this.offset);
}
writeVarSlice(slice: Buffer): void {
this.writeVarInt(slice.length);
this.writeSlice(slice);
}
writeVector(vector: Buffer[]): void {
this.writeVarInt(vector.length);
vector.forEach((buf: Buffer) => this.writeVarSlice(buf));
}
}
/**
* Helper class for reading of bitcoin data types from a buffer.
*/
export class BufferReader {
constructor(public buffer: Buffer, public offset: number = 0) {
typeforce(types.tuple(types.Buffer, types.UInt32), [buffer, offset]);
}
readUInt8(): number {
const result = this.buffer.readUInt8(this.offset);
this.offset++;
return result;
}
readInt32(): number {
const result = this.buffer.readInt32LE(this.offset);
this.offset += 4;
return result;
}
readUInt32(): number {
const result = this.buffer.readUInt32LE(this.offset);
this.offset += 4;
return result;
}
readUInt64(): number {
const result = readUInt64LE(this.buffer, this.offset);
this.offset += 8;
return result;
}
readVarInt(): number {
const vi = varuint.decode(this.buffer, this.offset);
this.offset += varuint.decode.bytes;
return vi;
}
readSlice(n: number): Buffer {
if (this.buffer.length < this.offset + n) {
throw new Error('Cannot read slice out of bounds');
}
const result = this.buffer.slice(this.offset, this.offset + n);
this.offset += n;
return result;
}
readVarSlice(): Buffer {
return this.readSlice(this.readVarInt());
}
readVector(): Buffer[] {
const count = this.readVarInt();
const vector: Buffer[] = [];
for (let i = 0; i < count; i++) vector.push(this.readVarSlice());
return vector;
}
}

View file

@ -1,5 +1,4 @@
import * as bufferutils from './bufferutils';
import { reverseBuffer } from './bufferutils';
import { BufferReader, BufferWriter, reverseBuffer } from './bufferutils';
import * as bcrypto from './crypto';
import * as bscript from './script';
import { OPS as opcodes } from './script';
@ -68,85 +67,46 @@ export class Transaction {
static readonly ADVANCED_TRANSACTION_FLAG = 0x01;
static fromBuffer(buffer: Buffer, _NO_STRICT?: boolean): Transaction {
let offset: number = 0;
function readSlice(n: number): Buffer {
offset += n;
return buffer.slice(offset - n, offset);
}
function readUInt32(): number {
const i = buffer.readUInt32LE(offset);
offset += 4;
return i;
}
function readInt32(): number {
const i = buffer.readInt32LE(offset);
offset += 4;
return i;
}
function readUInt64(): number {
const i = bufferutils.readUInt64LE(buffer, offset);
offset += 8;
return i;
}
function readVarInt(): number {
const vi = varuint.decode(buffer, offset);
offset += varuint.decode.bytes;
return vi;
}
function readVarSlice(): Buffer {
return readSlice(readVarInt());
}
function readVector(): Buffer[] {
const count = readVarInt();
const vector: Buffer[] = [];
for (let i = 0; i < count; i++) vector.push(readVarSlice());
return vector;
}
const bufferReader = new BufferReader(buffer);
const tx = new Transaction();
tx.version = readInt32();
tx.version = bufferReader.readInt32();
const marker = buffer.readUInt8(offset);
const flag = buffer.readUInt8(offset + 1);
const marker = bufferReader.readUInt8();
const flag = bufferReader.readUInt8();
let hasWitnesses = false;
if (
marker === Transaction.ADVANCED_TRANSACTION_MARKER &&
flag === Transaction.ADVANCED_TRANSACTION_FLAG
) {
offset += 2;
hasWitnesses = true;
} else {
bufferReader.offset -= 2;
}
const vinLen = readVarInt();
const vinLen = bufferReader.readVarInt();
for (let i = 0; i < vinLen; ++i) {
tx.ins.push({
hash: readSlice(32),
index: readUInt32(),
script: readVarSlice(),
sequence: readUInt32(),
hash: bufferReader.readSlice(32),
index: bufferReader.readUInt32(),
script: bufferReader.readVarSlice(),
sequence: bufferReader.readUInt32(),
witness: EMPTY_WITNESS,
});
}
const voutLen = readVarInt();
const voutLen = bufferReader.readVarInt();
for (let i = 0; i < voutLen; ++i) {
tx.outs.push({
value: readUInt64(),
script: readVarSlice(),
value: bufferReader.readUInt64(),
script: bufferReader.readVarSlice(),
});
}
if (hasWitnesses) {
for (let i = 0; i < vinLen; ++i) {
tx.ins[i].witness = readVector();
tx.ins[i].witness = bufferReader.readVector();
}
// was this pointless?
@ -154,10 +114,10 @@ export class Transaction {
throw new Error('Transaction has superfluous witness data');
}
tx.locktime = readUInt32();
tx.locktime = bufferReader.readUInt32();
if (_NO_STRICT) return tx;
if (offset !== buffer.length)
if (bufferReader.offset !== buffer.length)
throw new Error('Transaction has unexpected data');
return tx;
@ -388,29 +348,7 @@ export class Transaction {
);
let tbuffer: Buffer = Buffer.from([]);
let toffset: number = 0;
function writeSlice(slice: Buffer): void {
toffset += slice.copy(tbuffer, toffset);
}
function writeUInt32(i: number): void {
toffset = tbuffer.writeUInt32LE(i, toffset);
}
function writeUInt64(i: number): void {
toffset = bufferutils.writeUInt64LE(tbuffer, i, toffset);
}
function writeVarInt(i: number): void {
varuint.encode(i, tbuffer, toffset);
toffset += varuint.encode.bytes;
}
function writeVarSlice(slice: Buffer): void {
writeVarInt(slice.length);
writeSlice(slice);
}
let bufferWriter: BufferWriter;
let hashOutputs = ZERO;
let hashPrevouts = ZERO;
@ -418,11 +356,11 @@ export class Transaction {
if (!(hashType & Transaction.SIGHASH_ANYONECANPAY)) {
tbuffer = Buffer.allocUnsafe(36 * this.ins.length);
toffset = 0;
bufferWriter = new BufferWriter(tbuffer, 0);
this.ins.forEach(txIn => {
writeSlice(txIn.hash);
writeUInt32(txIn.index);
bufferWriter.writeSlice(txIn.hash);
bufferWriter.writeUInt32(txIn.index);
});
hashPrevouts = bcrypto.hash256(tbuffer);
@ -434,10 +372,10 @@ export class Transaction {
(hashType & 0x1f) !== Transaction.SIGHASH_NONE
) {
tbuffer = Buffer.allocUnsafe(4 * this.ins.length);
toffset = 0;
bufferWriter = new BufferWriter(tbuffer, 0);
this.ins.forEach(txIn => {
writeUInt32(txIn.sequence);
bufferWriter.writeUInt32(txIn.sequence);
});
hashSequence = bcrypto.hash256(tbuffer);
@ -452,11 +390,11 @@ export class Transaction {
}, 0);
tbuffer = Buffer.allocUnsafe(txOutsSize);
toffset = 0;
bufferWriter = new BufferWriter(tbuffer, 0);
this.outs.forEach(out => {
writeUInt64(out.value);
writeVarSlice(out.script);
bufferWriter.writeUInt64(out.value);
bufferWriter.writeVarSlice(out.script);
});
hashOutputs = bcrypto.hash256(tbuffer);
@ -467,28 +405,28 @@ export class Transaction {
const output = this.outs[inIndex];
tbuffer = Buffer.allocUnsafe(8 + varSliceSize(output.script));
toffset = 0;
writeUInt64(output.value);
writeVarSlice(output.script);
bufferWriter = new BufferWriter(tbuffer, 0);
bufferWriter.writeUInt64(output.value);
bufferWriter.writeVarSlice(output.script);
hashOutputs = bcrypto.hash256(tbuffer);
}
tbuffer = Buffer.allocUnsafe(156 + varSliceSize(prevOutScript));
toffset = 0;
bufferWriter = new BufferWriter(tbuffer, 0);
const input = this.ins[inIndex];
writeUInt32(this.version);
writeSlice(hashPrevouts);
writeSlice(hashSequence);
writeSlice(input.hash);
writeUInt32(input.index);
writeVarSlice(prevOutScript);
writeUInt64(value);
writeUInt32(input.sequence);
writeSlice(hashOutputs);
writeUInt32(this.locktime);
writeUInt32(hashType);
bufferWriter.writeUInt32(this.version);
bufferWriter.writeSlice(hashPrevouts);
bufferWriter.writeSlice(hashSequence);
bufferWriter.writeSlice(input.hash);
bufferWriter.writeUInt32(input.index);
bufferWriter.writeVarSlice(prevOutScript);
bufferWriter.writeUInt64(value);
bufferWriter.writeUInt32(input.sequence);
bufferWriter.writeSlice(hashOutputs);
bufferWriter.writeUInt32(this.locktime);
bufferWriter.writeUInt32(hashType);
return bcrypto.hash256(tbuffer);
}
@ -531,82 +469,48 @@ export class Transaction {
if (!buffer)
buffer = Buffer.allocUnsafe(this.byteLength(_ALLOW_WITNESS)) as Buffer;
let offset = initialOffset || 0;
const bufferWriter = new BufferWriter(buffer, initialOffset || 0);
function writeSlice(slice: Buffer): void {
offset += slice.copy(buffer!, offset);
}
function writeUInt8(i: number): void {
offset = buffer!.writeUInt8(i, offset);
}
function writeUInt32(i: number): void {
offset = buffer!.writeUInt32LE(i, offset);
}
function writeInt32(i: number): void {
offset = buffer!.writeInt32LE(i, offset);
}
function writeUInt64(i: number): void {
offset = bufferutils.writeUInt64LE(buffer!, i, offset);
}
function writeVarInt(i: number): void {
varuint.encode(i, buffer, offset);
offset += varuint.encode.bytes;
}
function writeVarSlice(slice: Buffer): void {
writeVarInt(slice.length);
writeSlice(slice);
}
function writeVector(vector: Buffer[]): void {
writeVarInt(vector.length);
vector.forEach(writeVarSlice);
}
writeInt32(this.version);
bufferWriter.writeInt32(this.version);
const hasWitnesses = _ALLOW_WITNESS && this.hasWitnesses();
if (hasWitnesses) {
writeUInt8(Transaction.ADVANCED_TRANSACTION_MARKER);
writeUInt8(Transaction.ADVANCED_TRANSACTION_FLAG);
bufferWriter.writeUInt8(Transaction.ADVANCED_TRANSACTION_MARKER);
bufferWriter.writeUInt8(Transaction.ADVANCED_TRANSACTION_FLAG);
}
writeVarInt(this.ins.length);
bufferWriter.writeVarInt(this.ins.length);
this.ins.forEach(txIn => {
writeSlice(txIn.hash);
writeUInt32(txIn.index);
writeVarSlice(txIn.script);
writeUInt32(txIn.sequence);
bufferWriter.writeSlice(txIn.hash);
bufferWriter.writeUInt32(txIn.index);
bufferWriter.writeVarSlice(txIn.script);
bufferWriter.writeUInt32(txIn.sequence);
});
writeVarInt(this.outs.length);
bufferWriter.writeVarInt(this.outs.length);
this.outs.forEach(txOut => {
if (isOutput(txOut)) {
writeUInt64(txOut.value);
bufferWriter.writeUInt64(txOut.value);
} else {
writeSlice((txOut as any).valueBuffer);
bufferWriter.writeSlice((txOut as any).valueBuffer);
}
writeVarSlice(txOut.script);
bufferWriter.writeVarSlice(txOut.script);
});
if (hasWitnesses) {
this.ins.forEach(input => {
writeVector(input.witness);
bufferWriter.writeVector(input.witness);
});
}
writeUInt32(this.locktime);
bufferWriter.writeUInt32(this.locktime);
// avoid slicing unless necessary
if (initialOffset !== undefined) return buffer.slice(initialOffset, offset);
if (initialOffset !== undefined)
return buffer.slice(initialOffset, bufferWriter.offset);
return buffer;
}
}

View file

@ -1,3 +1,35 @@
export declare function readUInt64LE(buffer: Buffer, offset: number): number;
export declare function writeUInt64LE(buffer: Buffer, value: number, offset: number): number;
export declare function reverseBuffer(buffer: Buffer): Buffer;
/**
* Helper class for serialization of bitcoin data types into a pre-allocated buffer.
*/
export declare class BufferWriter {
buffer: Buffer;
offset: number;
constructor(buffer: Buffer, offset?: number);
writeUInt8(i: number): void;
writeInt32(i: number): void;
writeUInt32(i: number): void;
writeUInt64(i: number): void;
writeVarInt(i: number): void;
writeSlice(slice: Buffer): void;
writeVarSlice(slice: Buffer): void;
writeVector(vector: Buffer[]): void;
}
/**
* Helper class for reading of bitcoin data types from a buffer.
*/
export declare class BufferReader {
buffer: Buffer;
offset: number;
constructor(buffer: Buffer, offset?: number);
readUInt8(): number;
readInt32(): number;
readUInt32(): number;
readUInt64(): number;
readVarInt(): number;
readSlice(n: number): Buffer;
readVarSlice(): Buffer;
readVector(): Buffer[];
}