Merge pull request #550 from ethcore/chain_generator

blockchain generator

ethcore/src/blockchain/blockchain.rs

@@ -766,19 +766,24 @@ mod tests {
 	use std::str::FromStr;
 	use rustc_serialize::hex::FromHex;
 	use util::hash::*;
+	use util::sha3::Hashable;
 	use blockchain::{BlockProvider, BlockChain, BlockChainConfig};
 	use tests::helpers::*;
 	use devtools::*;
+	use blockchain::helpers::generators::ChainGenerator;
+	use views::BlockView;
 
 	#[test]
-	fn valid_tests_extra32() {
-		let genesis = "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".from_hex().unwrap();
+	fn basic_blockchain_insert() {
+		let mut canon_chain = ChainGenerator::default();
+		let genesis = canon_chain.next().unwrap();
+		let first = canon_chain.next().unwrap();
+		let genesis_hash = BlockView::new(&genesis).header_view().sha3();
+		let first_hash = BlockView::new(&first).header_view().sha3();
 
 		let temp = RandomTempPath::new();
 		let bc = BlockChain::new(BlockChainConfig::default(), &genesis, temp.as_path());
 
-		let genesis_hash = H256::from_str("3caa2203f3d7c136c0295ed128a7d31cea520b1ca5e27afe17d0853331798942").unwrap();
-
 		assert_eq!(bc.genesis_hash(), genesis_hash.clone());
 		assert_eq!(bc.best_block_number(), 0);
 		assert_eq!(bc.best_block_hash(), genesis_hash.clone());
@@ -786,12 +791,8 @@ mod tests {
 		assert_eq!(bc.block_hash(1), None);
 		assert_eq!(bc.block_details(&genesis_hash).unwrap().children, vec![]);
 
-		let first = "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".from_hex().unwrap();
-
 		bc.insert_block(&first, vec![]);
 
-		let first_hash = H256::from_str("a940e5af7d146b3b917c953a82e1966b906dace3a4e355b5b0a4560190357ea1").unwrap();
-
 		assert_eq!(bc.block_hash(0), Some(genesis_hash.clone()));
 		assert_eq!(bc.best_block_number(), 1);
 		assert_eq!(bc.best_block_hash(), first_hash.clone());
@@ -1041,6 +1042,4 @@ mod tests {
 		assert_eq!(blocks_b2, vec![2]);
 		assert_eq!(blocks_ba, vec![3]);
 	}
-
-
 }

ethcore/src/blockchain/helpers/generators.rs

@@ -0,0 +1,154 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use util::rlp::*;
+use util::hash::{H256, H2048};
+use util::uint::{U256};
+use util::bytes::Bytes;
+use header::{BlockNumber, Header};
+use transaction::SignedTransaction;
+
+/// Chain iterator interface.
+pub trait ChainIterator: Iterator {
+	/// Should be called to create a fork of current iterator.
+	/// Blocks generated by fork will have lower difficulty than current chain.
+	fn fork(&mut self) -> Self;
+	/// Should be called to create new block with given bloom.
+	fn next_with_bloom(&mut self, bloom: H2048) -> Option<Self::Item>;
+}
+
+/// Helper structure, used for encoding blocks.
+#[derive(Default)]
+struct Block {
+	header: Header,
+	transactions: Vec<SignedTransaction>,
+	uncles: Vec<Header>
+}
+
+impl Encodable for Block {
+	fn rlp_append(&self, s: &mut RlpStream) {
+		s.begin_list(3);
+		s.append(&self.header);
+		s.append(&self.transactions);
+		s.append(&self.uncles);
+	}
+}
+
+/// Blockchain generator.
+pub struct ChainGenerator {
+	/// Next block number.
+	number: BlockNumber,
+	/// Next block parent hash.
+	parent_hash: H256,
+	/// Next block difficulty.
+	difficulty: U256,
+	/// Number of forks of current block.
+	number_of_forks: usize,
+}
+
+impl ChainGenerator {
+	fn prepare_block(&self) -> Block {
+		let mut block = Block::default();
+		block.header.parent_hash = self.parent_hash.clone();
+		block.header.number = self.number;
+		block.header.difficulty = self.difficulty;
+		block
+	}
+}
+
+impl Default for ChainGenerator {
+	fn default() -> Self {
+		ChainGenerator {
+			number: 0,
+			parent_hash: H256::default(),
+			difficulty: U256::from(1000),
+			number_of_forks: 0
+		}
+	}
+}
+
+impl Iterator for ChainGenerator {
+	type Item = Bytes;
+
+	fn next(&mut self) -> Option<Self::Item> {
+		let block = self.prepare_block();
+		self.number += 1;
+		self.parent_hash = block.header.hash();
+		self.number_of_forks = 0;
+		Some(encode(&block).to_vec())
+	}
+}
+
+impl ChainIterator for ChainGenerator {
+	fn fork(&mut self) -> Self {
+		self.number_of_forks += 1;
+		ChainGenerator {
+			number: self.number,
+			parent_hash: self.parent_hash.clone(),
+			difficulty: self.difficulty - U256::from(self.number_of_forks),
+			number_of_forks: 0
+		}
+	}
+
+	fn next_with_bloom(&mut self, bloom: H2048) -> Option<Self::Item> {
+		let mut block = self.prepare_block();
+		block.header.log_bloom = bloom;
+		self.number += 1;
+		self.parent_hash = block.header.hash();
+		self.number_of_forks = 0;
+		Some(encode(&block).to_vec())
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use util::hash::H256;
+	use util::sha3::Hashable;
+	use views::BlockView;
+	use super::{ChainIterator, ChainGenerator};
+
+	#[test]
+	fn canon_chain_generator() {
+		let mut canon_chain = ChainGenerator::default();
+
+		let genesis_rlp = canon_chain.next().unwrap();
+		let genesis = BlockView::new(&genesis_rlp);
+
+		assert_eq!(genesis.header_view().parent_hash(), H256::default());
+		assert_eq!(genesis.header_view().number(), 0);
+
+		let b1_rlp = canon_chain.next().unwrap();
+		let b1 = BlockView::new(&b1_rlp);
+
+		assert_eq!(b1.header_view().parent_hash(), genesis.header_view().sha3());
+		assert_eq!(b1.header_view().number(), 1);
+
+		let mut fork_chain = canon_chain.fork();
+
+		let b2_rlp_fork = fork_chain.next().unwrap();
+		let b2_fork = BlockView::new(&b2_rlp_fork);
+
+		assert_eq!(b2_fork.header_view().parent_hash(), b1.header_view().sha3());
+		assert_eq!(b2_fork.header_view().number(), 2);
+
+		let b2_rlp = canon_chain.next().unwrap();
+		let b2 = BlockView::new(&b2_rlp);
+
+		assert_eq!(b2.header_view().parent_hash(), b1.header_view().sha3());
+		assert_eq!(b2.header_view().number(), 2);
+		assert!(b2.header_view().difficulty() > b2_fork.header_view().difficulty());
+	}
+}

ethcore/src/blockchain/helpers/mod.rs

@@ -0,0 +1,17 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+pub mod generators;

ethcore/src/blockchain/mod.rs

@@ -23,6 +23,8 @@ mod bloom_indexer;
 mod cache;
 mod tree_route;
 mod update;
+#[cfg(test)]
+mod helpers;
 
 pub use self::blockchain::{BlockProvider, BlockChain, BlockChainConfig};
 pub use self::cache::CacheSize;