//!
//! ```rust
//! extern crate sbloom;
//! extern crate rustc_hex;
//! use rustc_hex::FromHex;
//! use sbloom::{Bloom, Input};
//!
//! fn main() {
//! let bloom: Bloom = "00000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002020000000000000000000000000000000000000000000008000000001000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000".into();
//! let address = "ef2d6d194084c2de36e0dabfce45d046b37d1106".from_hex().unwrap();
//! let topic = "02c69be41d0b7e40352fc85be1cd65eb03d40ef8427a0ca4596b1ead9a00e9fc".from_hex().unwrap();
//!
//! let mut my_bloom = Bloom::default();
//! assert!(!my_bloom.contains_input(Input::Raw(&address)));
//! assert!(!my_bloom.contains_input(Input::Raw(&topic)));
//!
//! my_bloom.accrue(Input::Raw(&address));
//! assert!(my_bloom.contains_input(Input::Raw(&address)));
//! assert!(!my_bloom.contains_input(Input::Raw(&topic)));
//!
//! my_bloom.accrue(Input::Raw(&topic));
//! assert!(my_bloom.contains_input(Input::Raw(&address)));
//! assert!(my_bloom.contains_input(Input::Raw(&topic)));
//! assert_eq!(my_bloom, bloom);
//! }
//! ```
//!
#![cfg_attr(not(feature="std"), no_std)]
#[cfg(feature="std")]
extern crate core;
extern crate tiny_keccak;
#[macro_use]
extern crate crunchy;
#[macro_use]
extern crate fixed_hash;
#[cfg(feature="serialize")]
extern crate s_types_serialize;
#[cfg(feature="serialize")]
extern crate serde;
#[cfg(feature="serialize")]
use serde::{Serialize, Serializer, Deserialize, Deserializer};
use core::{ops, mem};
use tiny_keccak::keccak256;
#[cfg(feature="std")]
use core::str;
// 3 according to yellowpaper
const BLOOM_BITS: u32 = 3;
const BLOOM_SIZE: usize = 256;
construct_hash!(Bloom, BLOOM_SIZE);
/// Returns log2.
fn log2(x: usize) -> u32 {
if x <= 1 {
return 0;
}
let n = x.leading_zeros();
mem::size_of::<usize>() as u32 * 8 - n
}
pub enum Input<'a> {
Raw(&'a [u8]),
Hash(&'a [u8; 32]),
}
enum Hash<'a> {
Ref(&'a [u8; 32]),
Owned([u8; 32]),
}
impl<'a> From<Input<'a>> for Hash<'a> {
fn from(input: Input<'a>) -> Self {
match input {
Input::Raw(raw) => Hash::Owned(keccak256(raw)),
Input::Hash(hash) => Hash::Ref(hash),
}
}
}
impl<'a> ops::Index<usize> for Hash<'a> {
type Output = u8;
fn index(&self, index: usize) -> &u8 {
match *self {
Hash::Ref(r) => &r[index],
Hash::Owned(ref hash) => &hash[index],
}
}
}
impl<'a> Hash<'a> {
fn len(&self) -> usize {
match *self {
Hash::Ref(r) => r.len(),
Hash::Owned(ref hash) => hash.len(),
}
}
}
impl<'a> PartialEq<BloomRef<'a>> for Bloom {
fn eq(&self, other: &BloomRef<'a>) -> bool {
let s_ref: &[u8] = &self.0;
let o_ref: &[u8] = other.0;
s_ref.eq(o_ref)
}
}
impl<'a> From<Input<'a>> for Bloom {
fn from(input: Input<'a>) -> Bloom {
let mut bloom = Bloom::default();
bloom.accrue(input);
bloom
}
}
impl Bloom {
pub fn is_empty(&self) -> bool {
self.0.iter().all(|x| *x == 0)
}
pub fn contains_input<'a>(&self, input: Input<'a>) -> bool {
let bloom: Bloom = input.into();
self.contains_bloom(&bloom)
}
pub fn contains_bloom<'a, B>(&self, bloom: B) -> bool where BloomRef<'a>: From<B> {
let bloom_ref: BloomRef = bloom.into();
// workaround for https://github.com/rust-lang/rust/issues/43644
self.contains_bloom_ref(bloom_ref)
}
fn contains_bloom_ref(&self, bloom: BloomRef) -> bool {
let self_ref: BloomRef = self.into();
self_ref.contains_bloom(bloom)
}
pub fn accrue<'a>(&mut self, input: Input<'a>) {
let p = BLOOM_BITS;
let m = self.0.len();
let bloom_bits = m * 8;
let mask = bloom_bits - 1;
let bloom_bytes = (log2(bloom_bits) + 7) / 8;
let hash: Hash = input.into();
// must be a power of 2
assert_eq!(m & (m - 1), 0);
// out of range
assert!(p * bloom_bytes <= hash.len() as u32);
let mut ptr = 0;
assert_eq!(BLOOM_BITS, 3);
unroll! {
for i in 0..3 {
let _ = i;
let mut index = 0 as usize;
for _ in 0..bloom_bytes {
index = (index << 8) | hash[ptr] as usize;
ptr += 1;
}
index &= mask;
self.0[m - 1 - index / 8] |= 1 << (index % 8);
}
}
}
pub fn accrue_bloom<'a, B>(&mut self, bloom: B) where BloomRef<'a>: From<B> {
let bloom_ref: BloomRef = bloom.into();
assert_eq!(self.0.len(), BLOOM_SIZE);
assert_eq!(bloom_ref.0.len(), BLOOM_SIZE);
for i in 0..BLOOM_SIZE {
self.0[i] |= bloom_ref.0[i];
}
}
pub fn data(&self) -> &[u8; BLOOM_SIZE] {
&self.0
}
}
#[derive(Clone, Copy)]
pub struct BloomRef<'a>(&'a [u8; BLOOM_SIZE]);
impl<'a> BloomRef<'a> {
pub fn is_empty(&self) -> bool {
self.0.iter().all(|x| *x == 0)
}
pub fn contains_input<'b>(&self, input: Input<'b>) -> bool {
let bloom: Bloom = input.into();
self.contains_bloom(&bloom)
}
pub fn contains_bloom<'b, B>(&self, bloom: B) -> bool where BloomRef<'b>: From<B> {
let bloom_ref: BloomRef = bloom.into();
assert_eq!(self.0.len(), BLOOM_SIZE);
assert_eq!(bloom_ref.0.len(), BLOOM_SIZE);
for i in 0..BLOOM_SIZE {
let a = self.0[i];
let b = bloom_ref.0[i];
if (a & b) != b {
return false;
}
}
true
}
pub fn data(&self) -> &'a [u8; BLOOM_SIZE] {
self.0
}
}
impl<'a> From<&'a [u8; BLOOM_SIZE]> for BloomRef<'a> {
fn from(data: &'a [u8; BLOOM_SIZE]) -> Self {
BloomRef(data)
}
}
impl<'a> From<&'a Bloom> for BloomRef<'a> {
fn from(bloom: &'a Bloom) -> Self {
BloomRef(&bloom.0)
}
}
#[cfg(feature="serialize")]
impl Serialize for Bloom {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
let mut slice = [0u8; 2 + 2 * BLOOM_SIZE];
s_types_serialize::serialize(&mut slice, &self.0, serializer)
}
}
#[cfg(feature="serialize")]
impl<'de> Deserialize<'de> for Bloom {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'de> {
let mut bytes = [0; BLOOM_SIZE];
s_types_serialize::deserialize_check_len(deserializer, s_types_serialize::ExpectedLen::Exact(&mut bytes))?;
Ok(Bloom(bytes))
}
}
#[cfg(test)]
mod tests {
extern crate rustc_hex;
use self::rustc_hex::FromHex;
use {Bloom, Input};
#[test]
fn it_works() {
let bloom: Bloom = "00000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002020000000000000000000000000000000000000000000008000000001000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000".into();
let address = "ef2d6d194084c2de36e0dabfce45d046b37d1106".from_hex().unwrap();
let topic = "02c69be41d0b7e40352fc85be1cd65eb03d40ef8427a0ca4596b1ead9a00e9fc".from_hex().unwrap();
let mut my_bloom = Bloom::default();
assert!(!my_bloom.contains_input(Input::Raw(&address)));
assert!(!my_bloom.contains_input(Input::Raw(&topic)));
my_bloom.accrue(Input::Raw(&address));
assert!(my_bloom.contains_input(Input::Raw(&address)));
assert!(!my_bloom.contains_input(Input::Raw(&topic)));
my_bloom.accrue(Input::Raw(&topic));
assert!(my_bloom.contains_input(Input::Raw(&address)));
assert!(my_bloom.contains_input(Input::Raw(&topic)));
assert_eq!(my_bloom, bloom);
}
}