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Merge rust-bitcoin/rust-bitcoin#1180: Clean up bip158 module 

167ee8e72c Improve docs on bip158 module (Tobin C. Harding)
5cfe9169f5 Refactor tests module imports (Tobin C. Harding)
2447d96b44 Use Gcs instead of GCS (Tobin C. Harding)
e9846ad579 Improve docs on filter_header (Tobin C. Harding)
e0fddce9e9 Refactor new_script_filter (Tobin C. Harding)
f6105a16a7 Improve module docs (Tobin C. Harding)
25d1472924 Move new to top of impl block (Tobin C. Harding)
08e55bc4f1 Remove unneeded newlines (Tobin C. Harding)
28853fd3cc Use generics instead of dynamic dispatch (Tobin C. Harding)
d79c6b8358 Remove unnecessary use of Cursor (Tobin C. Harding)

Pull request description:

  In attempt to resolve #1147 clean up the `bip158` module.

  I was unable to resolve the `"confusing method names read and write that look like those from std:i:o::{trait}"`

  I find the `bip158` data types and abstractions kind a funky but was unable to come up with any improvements.

  Open question: Are all the public data types really meant to be public? Perhaps we should have an issue to write an example module that uses the bip158 module?

ACKs for top commit:
  sanket1729:
    ACK 167ee8e72c
  apoelstra:
    ACK 167ee8e72c

Tree-SHA512: 7caa661432f02d90cf32c13b54a635647b871bb1564d1df67957b6422465880fcfca8f74d51d4b0255dc34306a56cd866366febabc9a27ecdc00a2d1e6a21d5a
This commit is contained in:
Andrew Poelstra 2022-08-11 13:04:48 +00:00
parent 9a606fc68a 167ee8e72c
commit d29f81ad25
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1 changed files with 163 additions and 127 deletions
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290
src/util/bip158.rs
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@ -5,14 +5,19 @@
// on 11. June 2019 which is licensed under Apache, that file specifically
// was written entirely by Tamas Blummer, who is re-licensing its contents here as CC0.
//! BIP158 Compact Block Filters for light clients.
//! BIP 158 Compact Block Filters for Light Clients.
//!
//! This module implements a structure for compact filters on block data, for
//! use in the BIP 157 light client protocol. The filter construction proposed
//! is an alternative to Bloom filters, as used in BIP 37, that minimizes filter
//! size by using Golomb-Rice coding for compression.
//!
//! ## Example
//! ### Relevant BIPS
//!
//! * [BIP 157 - Client Side Block Filtering](https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki)
//! * [BIP 158 - Compact Block Filters for Light Clients](https://github.com/bitcoin/bips/blob/master/bip-0158.mediawiki)
//!
//! # Examples
//!
//! ```ignore
//! fn get_script_for_coin(coin: &OutPoint) -> Result<Script, BlockFilterError> {
@ -35,8 +40,8 @@
//!
use crate::prelude::*;
use crate::io;
use crate::io::{self, Cursor};
use core::fmt::{self, Display, Formatter};
use core::cmp::{self, Ordering};
@ -55,12 +60,12 @@ use crate::internal_macros::write_err;
const P: u8 = 19;
const M: u64 = 784931;
/// Errors for blockfilter
/// Errors for blockfilter.
#[derive(Debug)]
pub enum Error {
/// missing UTXO, can not calculate script filter
/// Missing UTXO, cannot calculate script filter.
UtxoMissing(OutPoint),
/// some IO error reading or writing binary serialization of the filter
/// IO error reading or writing binary serialization of the filter.
Io(io::Error),
}
@ -86,15 +91,13 @@ impl std::error::Error for Error {
}
}
impl From<io::Error> for Error {
fn from(io: io::Error) -> Self {
Error::Io(io)
}
}
/// a computed or read block filter
/// A block filter, as described by BIP 158.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct BlockFilter {
/// Golomb encoded filter
@ -102,7 +105,7 @@ pub struct BlockFilter {
}
impl FilterHash {
/// compute the filter header from a filter hash and previous filter header
/// Computes the filter header from a filter hash and previous filter header.
pub fn filter_header(&self, previous_filter_header: &FilterHeader) -> FilterHeader {
let mut header_data = [0u8; 64];
header_data[0..32].copy_from_slice(&self[..]);
@ -112,60 +115,70 @@ impl FilterHash {
}
impl BlockFilter {
/// compute this filter's id in a chain of filters
/// Creates a new filter from pre-computed data.
pub fn new (content: &[u8]) -> BlockFilter {
BlockFilter { content: content.to_vec() }
}
/// Computes a SCRIPT_FILTER that contains spent and output scripts.
pub fn new_script_filter<M>(block: &Block, script_for_coin: M) -> Result<BlockFilter, Error>
where
M: Fn(&OutPoint) -> Result<Script, Error>
{
let mut out = Vec::new();
let mut writer = BlockFilterWriter::new(&mut out, block);
writer.add_output_scripts();
writer.add_input_scripts(script_for_coin)?;
writer.finish()?;
Ok(BlockFilter { content: out })
}
/// Computes this filter's ID in a chain of filters (see [BIP 157]).
///
/// [BIP 157]: <https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki#Filter_Headers>
pub fn filter_header(&self, previous_filter_header: &FilterHeader) -> FilterHeader {
let filter_hash = FilterHash::hash(self.content.as_slice());
filter_hash.filter_header(previous_filter_header)
}
/// create a new filter from pre-computed data
pub fn new (content: &[u8]) -> BlockFilter {
BlockFilter { content: content.to_vec() }
}
/// Compute a SCRIPT_FILTER that contains spent and output scripts
pub fn new_script_filter<M>(block: &Block, script_for_coin: M) -> Result<BlockFilter, Error>
where M: Fn(&OutPoint) -> Result<Script, Error> {
let mut out = Vec::new();
{
let mut writer = BlockFilterWriter::new(&mut out, block);
writer.add_output_scripts();
writer.add_input_scripts(script_for_coin)?;
writer.finish()?;
}
Ok(BlockFilter { content: out })
}
/// match any query pattern
pub fn match_any(&self, block_hash: &BlockHash, query: &mut dyn Iterator<Item=&[u8]>) -> Result<bool, Error> {
/// Returns true if any query matches against this [`BlockFilter`].
pub fn match_any<'a, I>(&self, block_hash: &BlockHash, query: I) -> Result<bool, Error>
where
I: Iterator<Item = &'a [u8]>,
{
let filter_reader = BlockFilterReader::new(block_hash);
filter_reader.match_any(&mut Cursor::new(self.content.as_slice()), query)
filter_reader.match_any(&mut self.content.as_slice(), query)
}
/// match all query pattern
pub fn match_all(&self, block_hash: &BlockHash, query: &mut dyn Iterator<Item=&[u8]>) -> Result<bool, Error> {
/// Returns true if all queries match against this [`BlockFilter`].
pub fn match_all<'a, I>(&self, block_hash: &BlockHash, query: I) -> Result<bool, Error>
where
I: Iterator<Item = &'a [u8]>,
{
let filter_reader = BlockFilterReader::new(block_hash);
filter_reader.match_all(&mut Cursor::new(self.content.as_slice()), query)
filter_reader.match_all(&mut self.content.as_slice(), query)
}
}
/// Compiles and writes a block filter
pub struct BlockFilterWriter<'a> {
/// Compiles and writes a block filter.
pub struct BlockFilterWriter<'a, W> {
block: &'a Block,
writer: GCSFilterWriter<'a>,
writer: GcsFilterWriter<'a, W>,
}
impl<'a> BlockFilterWriter<'a> {
/// Create a block filter writer
pub fn new(writer: &'a mut dyn io::Write, block: &'a Block) -> BlockFilterWriter<'a> {
impl<'a, W: io::Write> BlockFilterWriter<'a, W> {
/// Creates a new [`BlockFilterWriter`] from `block`.
pub fn new(writer: &'a mut W, block: &'a Block) -> BlockFilterWriter<'a, W> {
let block_hash_as_int = block.block_hash().into_inner();
let k0 = endian::slice_to_u64_le(&block_hash_as_int[0..8]);
let k1 = endian::slice_to_u64_le(&block_hash_as_int[8..16]);
let writer = GCSFilterWriter::new(writer, k0, k1, M, P);
let writer = GcsFilterWriter::new(writer, k0, k1, M, P);
BlockFilterWriter { block, writer }
}
/// Add output scripts of the block - excluding OP_RETURN scripts
/// Adds output scripts of the block to filter (excluding OP_RETURN scripts).
pub fn add_output_scripts(&mut self) {
for transaction in &self.block.txdata {
for output in &transaction.output {
@ -176,7 +189,7 @@ impl<'a> BlockFilterWriter<'a> {
}
}
/// Add consumed output scripts of a block to filter
/// Adds consumed output scripts of a block to filter.
pub fn add_input_scripts<M>(&mut self, script_for_coin: M) -> Result<(), Error>
where M: Fn(&OutPoint) -> Result<Script, Error> {
for script in self.block.txdata.iter()
@ -191,58 +204,68 @@ impl<'a> BlockFilterWriter<'a> {
Ok(())
}
/// Add arbitrary element to a filter
/// Adds an arbitrary element to filter.
pub fn add_element(&mut self, data: &[u8]) {
self.writer.add_element(data);
}
/// Write block filter
/// Writes the block filter.
pub fn finish(&mut self) -> Result<usize, io::Error> {
self.writer.finish()
}
}
/// Reads and interpret a block filter
/// Reads and interprets a block filter.
pub struct BlockFilterReader {
reader: GCSFilterReader
reader: GcsFilterReader
}
impl BlockFilterReader {
/// Create a block filter reader
/// Creates a new [`BlockFilterReader`] from `block_hash`.
pub fn new(block_hash: &BlockHash) -> BlockFilterReader {
let block_hash_as_int = block_hash.into_inner();
let k0 = endian::slice_to_u64_le(&block_hash_as_int[0..8]);
let k1 = endian::slice_to_u64_le(&block_hash_as_int[8..16]);
BlockFilterReader { reader: GCSFilterReader::new(k0, k1, M, P) }
BlockFilterReader { reader: GcsFilterReader::new(k0, k1, M, P) }
}
/// match any query pattern
pub fn match_any(&self, reader: &mut dyn io::Read, query: &mut dyn Iterator<Item=&[u8]>) -> Result<bool, Error> {
/// Returns true if any query matches against this [`BlockFilterReader`].
pub fn match_any<'a, I, R>(&self, reader: &mut R, query: I) -> Result<bool, Error>
where
I: Iterator<Item = &'a [u8]>,
R: io::Read + ?Sized,
{
self.reader.match_any(reader, query)
}
/// match all query pattern
pub fn match_all(&self, reader: &mut dyn io::Read, query: &mut dyn Iterator<Item=&[u8]>) -> Result<bool, Error> {
/// Returns true if all queries match against this [`BlockFilterReader`].
pub fn match_all<'a, I, R>(&self, reader: &mut R, query: I) -> Result<bool, Error>
where
I: Iterator<Item = &'a [u8]>,
R: io::Read + ?Sized,
{
self.reader.match_all(reader, query)
}
}
/// Golomb-Rice encoded filter reader
pub struct GCSFilterReader {
filter: GCSFilter,
/// Golomb-Rice encoded filter reader.
pub struct GcsFilterReader {
filter: GcsFilter,
m: u64
}
impl GCSFilterReader {
/// Create a new filter reader with specific seed to siphash
pub fn new(k0: u64, k1: u64, m: u64, p: u8) -> GCSFilterReader {
GCSFilterReader { filter: GCSFilter::new(k0, k1, p), m }
impl GcsFilterReader {
/// Creates a new [`GcsFilterReader`] with specific seed to siphash.
pub fn new(k0: u64, k1: u64, m: u64, p: u8) -> GcsFilterReader {
GcsFilterReader { filter: GcsFilter::new(k0, k1, p), m }
}
/// match any query pattern
pub fn match_any(&self, reader: &mut dyn io::Read, query: &mut dyn Iterator<Item=&[u8]>) -> Result<bool, Error> {
/// Returns true if any query matches against this [`GcsFilterReader`].
pub fn match_any<'a, I, R>(&self, reader: &mut R, query: I) -> Result<bool, Error>
where
I: Iterator<Item = &'a [u8]>,
R: io::Read + ?Sized,
{
let mut decoder = reader;
let n_elements: VarInt = Decodable::consensus_decode(&mut decoder).unwrap_or(VarInt(0));
let reader = &mut decoder;
@ -281,8 +304,12 @@ impl GCSFilterReader {
Ok(false)
}
/// match all query pattern
pub fn match_all(&self, reader: &mut dyn io::Read, query: &mut dyn Iterator<Item=&[u8]>) -> Result<bool, Error> {
/// Returns true if all queries match against this [`GcsFilterReader`].
pub fn match_all<'a, I, R>(&self, reader: &mut R, query: I) -> Result<bool, Error>
where
I: Iterator<Item = &'a [u8]>,
R: io::Read + ?Sized,
{
let mut decoder = reader;
let n_elements: VarInt = Decodable::consensus_decode(&mut decoder).unwrap_or(VarInt(0));
let reader = &mut decoder;
@ -323,38 +350,38 @@ impl GCSFilterReader {
}
}
// fast reduction of hash to [0, nm) range
/// Fast reduction of hash to [0, nm) range.
fn map_to_range(hash: u64, nm: u64) -> u64 {
((hash as u128 * nm as u128) >> 64) as u64
}
/// Colomb-Rice encoded filter writer
pub struct GCSFilterWriter<'a> {
filter: GCSFilter,
writer: &'a mut dyn io::Write,
/// Golomb-Rice encoded filter writer.
pub struct GcsFilterWriter<'a, W> {
filter: GcsFilter,
writer: &'a mut W,
elements: HashSet<Vec<u8>>,
m: u64
}
impl<'a> GCSFilterWriter<'a> {
/// Create a new GCS writer wrapping a generic writer, with specific seed to siphash
pub fn new(writer: &'a mut dyn io::Write, k0: u64, k1: u64, m: u64, p: u8) -> GCSFilterWriter<'a> {
GCSFilterWriter {
filter: GCSFilter::new(k0, k1, p),
impl<'a, W: io::Write> GcsFilterWriter<'a, W> {
/// Creates a new [`GcsFilterWriter`] wrapping a generic writer, with specific seed to siphash.
pub fn new(writer: &'a mut W, k0: u64, k1: u64, m: u64, p: u8) -> GcsFilterWriter<'a, W> {
GcsFilterWriter {
filter: GcsFilter::new(k0, k1, p),
writer,
elements: HashSet::new(),
m
}
}
/// Add some data to the filter
/// Adds data to the filter.
pub fn add_element(&mut self, element: &[u8]) {
if !element.is_empty() {
self.elements.insert(element.to_vec());
}
}
/// write the filter to the wrapped writer
/// Writes the filter to the wrapped writer.
pub fn finish(&mut self) -> Result<usize, io::Error> {
let nm = self.elements.len() as u64 * self.m;
@ -378,21 +405,24 @@ impl<'a> GCSFilterWriter<'a> {
}
}
/// Golomb Coded Set Filter
struct GCSFilter {
/// Golomb Coded Set Filter.
struct GcsFilter {
k0: u64, // sip hash key
k1: u64, // sip hash key
p: u8
}
impl GCSFilter {
/// Create a new filter
fn new(k0: u64, k1: u64, p: u8) -> GCSFilter {
GCSFilter { k0, k1, p }
impl GcsFilter {
/// Creates a new [`GcsFilter`].
fn new(k0: u64, k1: u64, p: u8) -> GcsFilter {
GcsFilter { k0, k1, p }
}
/// Golomb-Rice encode a number n to a bit stream (Parameter 2^k)
fn golomb_rice_encode(&self, writer: &mut BitStreamWriter, n: u64) -> Result<usize, io::Error> {
/// Golomb-Rice encodes a number `n` to a bit stream (parameter 2^k).
fn golomb_rice_encode<'a, W>(&self, writer: &mut BitStreamWriter<'a, W>, n: u64) -> Result<usize, io::Error>
where
W: io::Write,
{
let mut wrote = 0;
let mut q = n >> self.p;
while q > 0 {
@ -405,8 +435,11 @@ impl GCSFilter {
Ok(wrote)
}
/// Golomb-Rice decode a number from a bit stream (Parameter 2^k)
fn golomb_rice_decode(&self, reader: &mut BitStreamReader) -> Result<u64, io::Error> {
/// Golomb-Rice decodes a number from a bit stream (parameter 2^k).
fn golomb_rice_decode<R>(&self, reader: &mut BitStreamReader<R>) -> Result<u64, io::Error>
where
R: io::Read
{
let mut q = 0u64;
while reader.read(1)? == 1 {
q += 1;
@ -415,22 +448,22 @@ impl GCSFilter {
Ok((q << self.p) + r)
}
/// Hash an arbitrary slice with siphash using parameters of this filter
/// Hashes an arbitrary slice with siphash using parameters of this filter.
fn hash(&self, element: &[u8]) -> u64 {
siphash24::Hash::hash_to_u64_with_keys(self.k0, self.k1, element)
}
}
/// Bitwise stream reader
pub struct BitStreamReader<'a> {
/// Bitwise stream reader.
pub struct BitStreamReader<'a, R> {
buffer: [u8; 1],
offset: u8,
reader: &'a mut dyn io::Read,
reader: &'a mut R,
}
impl<'a> BitStreamReader<'a> {
/// Create a new BitStreamReader that reads bitwise from a given reader
pub fn new(reader: &'a mut dyn io::Read) -> BitStreamReader {
impl<'a, R: io::Read> BitStreamReader<'a, R> {
/// Creates a new [`BitStreamReader`] that reads bitwise from a given `reader`.
pub fn new(reader: &'a mut R) -> BitStreamReader<'a, R> {
BitStreamReader {
buffer: [0u8],
reader,
@ -438,7 +471,17 @@ impl<'a> BitStreamReader<'a> {
}
}
/// Read nbit bits
/// Reads nbit bits, returning the bits in a `u64` starting with the rightmost bit.
///
/// # Examples
/// ```
/// # use bitcoin::util::bip158::BitStreamReader;
/// # let data = vec![0xff];
/// # let mut input = data.as_slice();
/// let mut reader = BitStreamReader::new(&mut input); // input contains all 1's
/// let res = reader.read(1).expect("read failed");
/// assert_eq!(res, 1_u64);
/// ```
pub fn read(&mut self, mut nbits: u8) -> Result<u64, io::Error> {
if nbits > 64 {
return Err(io::Error::new(io::ErrorKind::Other, "can not read more than 64 bits at once"));
@ -459,16 +502,16 @@ impl<'a> BitStreamReader<'a> {
}
}
/// Bitwise stream writer
pub struct BitStreamWriter<'a> {
/// Bitwise stream writer.
pub struct BitStreamWriter<'a, W> {
buffer: [u8; 1],
offset: u8,
writer: &'a mut dyn io::Write,
writer: &'a mut W,
}
impl<'a> BitStreamWriter<'a> {
/// Create a new BitStreamWriter that writes bitwise to a given writer
pub fn new(writer: &'a mut dyn io::Write) -> BitStreamWriter {
impl<'a, W: io::Write> BitStreamWriter<'a, W> {
/// Creates a new [`BitStreamWriter`] that writes bitwise to a given `writer`.
pub fn new(writer: &'a mut W) -> BitStreamWriter<'a, W> {
BitStreamWriter {
buffer: [0u8],
writer,
@ -476,7 +519,7 @@ impl<'a> BitStreamWriter<'a> {
}
}
/// Write nbits bits from data
/// Writes nbits bits from data.
pub fn write(&mut self, data: u64, mut nbits: u8) -> Result<usize, io::Error> {
if nbits > 64 {
return Err(io::Error::new(io::ErrorKind::Other, "can not write more than 64 bits at once"));
@ -494,7 +537,7 @@ impl<'a> BitStreamWriter<'a> {
Ok(wrote)
}
/// flush bits not yet written
/// flush bits not yet written.
pub fn flush(&mut self) -> Result<usize, io::Error> {
if self.offset > 0 {
self.writer.write_all(&self.buffer)?;
@ -509,18 +552,15 @@ impl<'a> BitStreamWriter<'a> {
#[cfg(test)]
mod test {
use crate::io::Cursor;
use crate::hash_types::BlockHash;
use crate::hashes::hex::FromHex;
use super::*;
extern crate serde_json;
use self::serde_json::Value;
use std::collections::HashMap;
use serde_json::Value;
use crate::consensus::encode::deserialize;
use std::collections::HashMap;
use crate::hash_types::BlockHash;
use crate::hashes::hex::FromHex;
#[test]
fn test_blockfilters() {
@ -596,7 +636,7 @@ mod test {
let mut out = Vec::new();
{
let mut writer = GCSFilterWriter::new(&mut out, 0, 0, M, P);
let mut writer = GcsFilterWriter::new(&mut out, 0, 0, M, P);
for p in &patterns {
writer.add_element(p.as_slice());
}
@ -607,34 +647,30 @@ mod test {
{
let query = vec![Vec::from_hex("abcdef").unwrap(), Vec::from_hex("eeeeee").unwrap()];
let reader = GCSFilterReader::new(0, 0, M, P);
let mut input = Cursor::new(bytes.clone());
assert!(reader.match_any(&mut input, &mut query.iter().map(|v| v.as_slice())).unwrap());
let reader = GcsFilterReader::new(0, 0, M, P);
assert!(reader.match_any(&mut bytes.as_slice(), &mut query.iter().map(|v| v.as_slice())).unwrap());
}
{
let query = vec![Vec::from_hex("abcdef").unwrap(), Vec::from_hex("123456").unwrap()];
let reader = GCSFilterReader::new(0, 0, M, P);
let mut input = Cursor::new(bytes.clone());
assert!(!reader.match_any(&mut input, &mut query.iter().map(|v| v.as_slice())).unwrap());
let reader = GcsFilterReader::new(0, 0, M, P);
assert!(!reader.match_any(&mut bytes.as_slice(), &mut query.iter().map(|v| v.as_slice())).unwrap());
}
{
let reader = GCSFilterReader::new(0, 0, M, P);
let reader = GcsFilterReader::new(0, 0, M, P);
let mut query = Vec::new();
for p in &patterns {
query.push(p.clone());
}
let mut input = Cursor::new(bytes.clone());
assert!(reader.match_all(&mut input, &mut query.iter().map(|v| v.as_slice())).unwrap());
assert!(reader.match_all(&mut bytes.as_slice(), &mut query.iter().map(|v| v.as_slice())).unwrap());
}
{
let reader = GCSFilterReader::new(0, 0, M, P);
let reader = GcsFilterReader::new(0, 0, M, P);
let mut query = Vec::new();
for p in &patterns {
query.push(p.clone());
}
query.push(Vec::from_hex("abcdef").unwrap());
let mut input = Cursor::new(bytes);
assert!(!reader.match_all(&mut input, &mut query.iter().map(|v| v.as_slice())).unwrap());
assert!(!reader.match_all(&mut bytes.as_slice(), &mut query.iter().map(|v| v.as_slice())).unwrap());
}
}
@ -655,7 +691,7 @@ mod test {
let bytes = out;
assert_eq!("01011010110000110000000001110000", format!("{:08b}{:08b}{:08b}{:08b}", bytes[0], bytes[1], bytes[2], bytes[3]));
{
let mut input = Cursor::new(bytes);
let mut input = bytes.as_slice();
let mut reader = BitStreamReader::new(&mut input);
assert_eq!(reader.read(1).unwrap(), 0);
assert_eq!(reader.read(2).unwrap(), 2);