grassrootseconomics/openethereum
5
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

docs for chainfilter

Browse Source
This commit is contained in:
debris 2015-11-28 22:43:16 +01:00
parent b0c38cb6ec
commit 8c0e063f6b
1 changed files with 44 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
src/chainfilter.rs
View File

@ -1,4 +1,43 @@
//! Multilevel blockchain bloom filter. //! Multilevel blockchain bloom filter.
//!
//! ```
//! extern crate ethcore_util as util;
//! use std::str::FromStr;
//! use util::chainfilter::*;
//! use util::sha3::*;
//! use util::hash::*;
//!
//! fn main() {
//! let (index_size, bloom_levels) = (16, 3);
//! let mut cache = MemoryCache::new();
//!
//! let address = Address::from_str("ef2d6d194084c2de36e0dabfce45d046b37d1106").unwrap();
//!
//! // borrow cache for reading inside the scope
//! let modified_blooms = {
//! let filter = ChainFilter::new(&cache, index_size, bloom_levels);
//! let block_number = 39;
//! let mut bloom = H2048::new();
//! bloom.shift_bloom(&address.sha3());
//! filter.add_bloom(&bloom, block_number)
//! };
//!
//! // number of updated blooms is equal number of levels
//! assert_eq!(modified_blooms.len(), bloom_levels as usize);
//!
//! // lets inserts modified blooms into the cache
//! cache.insert_blooms(modified_blooms);
//!
//! // borrow cache for another reading operations
//! {
//! let filter = ChainFilter::new(&cache, index_size, bloom_levels);
//! let blocks = filter.blocks_with_address(&address, 10, 40);
//! assert_eq!(blocks.len(), 1);
//! assert_eq!(blocks[0], 39);
//! }
//! }
//! ```
//!
use std::collections::{HashMap}; use std::collections::{HashMap};
use hash::*; use hash::*;
use sha3::*; use sha3::*;
@ -255,7 +294,7 @@ impl<'a, D> ChainFilter<'a, D> where D: FilterDataSource
} }
/// Returns numbers of blocks that may contain Topic. /// Returns numbers of blocks that may contain Topic.
pub fn blocks_with_topics(&self, topic: &H256, from_block: usize, to_block: usize) -> Vec<usize> { pub fn blocks_with_topic(&self, topic: &H256, from_block: usize, to_block: usize) -> Vec<usize> {
let mut bloom = H2048::new(); let mut bloom = H2048::new();
bloom.shift_bloom(&topic.sha3()); bloom.shift_bloom(&topic.sha3());
self.blocks_with_bloom(&bloom, from_block, to_block) self.blocks_with_bloom(&bloom, from_block, to_block)
@ -379,27 +418,27 @@ mod tests {
{ {
let filter = ChainFilter::new(&cache, index_size, bloom_levels); let filter = ChainFilter::new(&cache, index_size, bloom_levels);
let blocks = filter.blocks_with_topics(&topic, 0, 100); let blocks = filter.blocks_with_topic(&topic, 0, 100);
assert_eq!(blocks.len(), 1); assert_eq!(blocks.len(), 1);
assert_eq!(blocks[0], 23); assert_eq!(blocks[0], 23);
} }
{ {
let filter = ChainFilter::new(&cache, index_size, bloom_levels); let filter = ChainFilter::new(&cache, index_size, bloom_levels);
let blocks = filter.blocks_with_topics(&topic, 0, 23); let blocks = filter.blocks_with_topic(&topic, 0, 23);
assert_eq!(blocks.len(), 0); assert_eq!(blocks.len(), 0);
} }
{ {
let filter = ChainFilter::new(&cache, index_size, bloom_levels); let filter = ChainFilter::new(&cache, index_size, bloom_levels);
let blocks = filter.blocks_with_topics(&topic, 23, 24); let blocks = filter.blocks_with_topic(&topic, 23, 24);
assert_eq!(blocks.len(), 1); assert_eq!(blocks.len(), 1);
assert_eq!(blocks[0], 23); assert_eq!(blocks[0], 23);
} }
{ {
let filter = ChainFilter::new(&cache, index_size, bloom_levels); let filter = ChainFilter::new(&cache, index_size, bloom_levels);
let blocks = filter.blocks_with_topics(&topic, 24, 100); let blocks = filter.blocks_with_topic(&topic, 24, 100);
assert_eq!(blocks.len(), 0); assert_eq!(blocks.len(), 0);
} }
} }