math.rs, log2, FixedHash::shift_bloom, FixedHash::contains_bloom

src/hash.rs

@@ -1,12 +1,13 @@
 use std::str::FromStr;
 use std::fmt;
 use std::hash::{Hash, Hasher};
-use std::ops::{Index, IndexMut, BitOr};
+use std::ops::{Index, IndexMut, BitOr, BitAnd};
 use rustc_serialize::hex::*;
 use error::EthcoreError;
 use rand::Rng;
 use rand::os::OsRng;
 use bytes::BytesConvertable;
+use math::log2;
 
 /// types implementing FixedHash must be also BytesConvertable
 pub trait FixedHash: Sized + BytesConvertable {
@@ -15,7 +16,8 @@ pub trait FixedHash: Sized + BytesConvertable {
 	fn randomize(&mut self);
 	fn mut_bytes(&mut self) -> &mut [u8];
 	fn shift_bloom<'a, T>(&'a mut self, b: &T) -> &'a mut Self where T: FixedHash;
-	fn bloom_part<T>(&self) -> T where T: FixedHash;
+	fn bloom_part<T>(&self, m: usize) -> T where T: FixedHash;
+	fn contains_bloom<T>(&self, b: &T) -> bool where T: FixedHash;
 }
 
 macro_rules! impl_hash {
@@ -50,7 +52,7 @@ macro_rules! impl_hash {
 			}
 
 			fn shift_bloom<'a, T>(&'a mut self, b: &T) -> &'a mut Self where T: FixedHash {
-				let bp: Self = b.bloom_part();
+				let bp: Self = b.bloom_part($size);
 				let new_self = &bp | self;
 
 				// impl |= instead
@@ -63,8 +65,45 @@ macro_rules! impl_hash {
 				self
 			}
 
-			fn bloom_part<T>(&self) -> T where T: FixedHash {
-				panic!()
+			fn bloom_part<T>(&self, m: usize) -> T where T: FixedHash {
+				// numbers of bits
+				// TODO: move it to some constant
+				let p = 3;
+
+				let bloom_bits = m * 8;
+				let mask = bloom_bits - 1;
+				let bloom_bytes = (log2(bloom_bits) + 7) / 8;
+				//println!("bb: {}", bloom_bytes);
+
+				// must be a power of 2
+				assert_eq!(m & (m - 1), 0);
+				// out of range
+				assert!(p * bloom_bytes <= $size);
+
+				// return type
+				let mut ret = T::new();
+
+				// 'ptr' to out slice
+				let mut ptr = 0;
+
+				// set p number of bits,
+				// p is equal 3 according to yellowpaper
+				for _ in 0..p {
+					let mut index = 0 as usize;
+					for _ in 0..bloom_bytes {
+						index = (index << 8) | self.0[ptr] as usize;
+						ptr += 1;
+					}
+					index &= mask;
+					ret.mut_bytes()[m - 1 - index / 8] |= 1 << (index % 8);
+				}
+
+				ret
+			}
+
+			fn contains_bloom<T>(&self, b: &T) -> bool where T: FixedHash {
+				let bp: Self = b.bloom_part($size);
+				(&bp & self) == bp
 			}
 		}
 
@@ -138,6 +177,7 @@ macro_rules! impl_hash {
 			}
 		}
 
+		/// BitOr on references
 		impl<'a> BitOr for &'a $from {
 			type Output = $from;
 
@@ -153,6 +193,7 @@ macro_rules! impl_hash {
 			}
 		}
 
+		/// Moving BitOr
 		impl BitOr for $from {
 			type Output = $from;
 
@@ -161,6 +202,31 @@ macro_rules! impl_hash {
 			}
 		}
 
+		/// BitAnd on references
+		impl <'a> BitAnd for &'a $from {
+			type Output = $from;
+
+			fn bitand(self, rhs: Self) -> Self::Output {
+				unsafe {
+					use std::mem;
+					let mut ret: $from = mem::uninitialized();
+					for i in 0..$size {
+						ret.0[i] = self.0[i] & rhs.0[i];
+					}
+					ret
+				}
+			}
+		}
+
+		/// Moving BitAnd
+		impl BitAnd for $from {
+			type Output = $from;
+
+			fn bitand(self, rhs: Self) -> Self::Output {
+				&self & &rhs
+			}
+		}
+
 	}
 }
 
@@ -173,6 +239,11 @@ impl_hash!(H520, 65);
 impl_hash!(H1024, 128);
 impl_hash!(H2048, 256);
 
+#[cfg(test)]
+mod tests {
+	use hash::*;
+	use std::str::FromStr;
+
 	#[test]
 	fn hash() {
 		let h = H64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef]);
@@ -196,3 +267,27 @@ fn hash_bitor() {
 		// move
 		assert_eq!(a | b, c);
 	}
+
+	#[test]
+	fn shift_bloom() {
+		use sha3::Hashable;
+		
+		let bloom = H2048::from_str("00000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002020000000000000000000000000000000000000000000008000000001000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();
+		let address = Address::from_str("ef2d6d194084c2de36e0dabfce45d046b37d1106").unwrap();
+		let topic = H256::from_str("02c69be41d0b7e40352fc85be1cd65eb03d40ef8427a0ca4596b1ead9a00e9fc").unwrap();
+
+		let mut my_bloom = H2048::new();
+		assert!(!my_bloom.contains_bloom(&address.sha3()));
+		assert!(!my_bloom.contains_bloom(&topic.sha3()));
+
+		my_bloom.shift_bloom(&address.sha3());
+		assert!(my_bloom.contains_bloom(&address.sha3()));
+		assert!(!my_bloom.contains_bloom(&topic.sha3()));
+			
+		my_bloom.shift_bloom(&topic.sha3());
+		assert_eq!(my_bloom, bloom);
+		assert!(my_bloom.contains_bloom(&address.sha3()));
+		assert!(my_bloom.contains_bloom(&topic.sha3()));
+	}
+}
+

src/lib.rs

@@ -16,6 +16,7 @@ pub mod db;
 pub mod sha3;
 pub mod hashdb;
 pub mod memorydb;
+pub mod math;
 
 //pub mod network;
 

src/math.rs

@@ -0,0 +1,10 @@
+/// log2
+pub fn log2(x: usize) -> u32 {
+	if x <= 1 {
+		return 0;
+	}
+
+	let n = x.leading_zeros();
+	::std::mem::size_of::<usize>() as u32 * 8 - n
+}
+