io error handling and slight blockchunker refactoring

ethcore/src/client/client.rs

@@ -777,7 +777,7 @@ impl<V> BlockChainClient for Client<V> where V: Verifier {
 		let best_hash = best_header.hash();
 		let genesis_hash = self.chain.genesis_hash();
 
-		let block_chunk_hashes = BlockChunker::new(self, best_hash, genesis_hash).chunk_all(&path);
+		let block_chunk_hashes = BlockChunker::new(self, best_hash, genesis_hash).chunk_all(&path).unwrap();
 
 		let manifest_data = ManifestData {
 			state_hashes: state_hashes,

ethcore/src/error.rs

@@ -225,7 +225,9 @@ pub enum Error {
 	/// The value of the nonce or mishash is invalid.
 	PowInvalid,
 	/// Error concerning TrieDBs
-	TrieError(TrieError),
+	Trie(TrieError),
+	/// Io error.
+	Io(::std::io::Error),
 }
 
 impl fmt::Display for Error {
@@ -241,7 +243,8 @@ impl fmt::Display for Error {
 				f.write_fmt(format_args!("Unknown engine name ({})", name)),
 			Error::PowHashInvalid => f.write_str("Invalid or out of date PoW hash."),
 			Error::PowInvalid => f.write_str("Invalid nonce or mishash"),
-			Error::TrieError(ref err) => f.write_fmt(format_args!("{}", err)),
+			Error::Trie(ref err) => f.write_fmt(format_args!("{}", err)),
+			Error::Io(ref err) => f.write_fmt(format_args!("{}", err)),
 		}
 	}
 }
@@ -305,7 +308,13 @@ impl From<IoError> for Error {
 
 impl From<TrieError> for Error {
 	fn from(err: TrieError) -> Error {
-		Error::TrieError(err)
+		Error::Trie(err)
+	}
+}
+
+impl From<::std::io::Error> for Error {
+	fn from(err: ::std::io::Error) -> Error {
+		Error::Io(err)
 	}
 }
 

ethcore/src/pv64/mod.rs

@@ -39,9 +39,10 @@ use util::rlp::{DecoderError, Stream, Rlp, RlpStream, UntrustedRlp, View};
 pub struct BlockChunker<'a> {
 	client: &'a BlockChainClient,
 	// block, receipt rlp pairs.
-	rlps: VecDeque<(Bytes, Bytes)>,
+	rlps: VecDeque<Bytes>,
 	genesis_hash: H256,
 	current_hash: H256,
+	hashes: Vec<H256>,
 }
 
 impl<'a> BlockChunker<'a> {
@@ -53,6 +54,7 @@ impl<'a> BlockChunker<'a> {
 			rlps: VecDeque::new(),
 			genesis_hash: genesis_hash,
 			current_hash: best_block_hash,
+			hashes: Vec::new(),
 		}
 	}
 
@@ -68,7 +70,13 @@ impl<'a> BlockChunker<'a> {
 			let block = self.client.block(BlockID::Hash(self.current_hash)).unwrap();
 			let receipts = self.client.block_receipts(&self.current_hash).unwrap();
 
-			let new_loaded_size = loaded_size + (block.len() + receipts.len());
+			let pair = {
+				let mut pair_stream = RlpStream::new_list(2);
+				pair_stream.append(&block).append(&receipts);
+				pair_stream.out()
+			};
+
+			let new_loaded_size = loaded_size + pair.len();
 
 			// cut off the chunk if too large
 			if new_loaded_size > PREFERRED_CHUNK_SIZE {
@@ -78,8 +86,6 @@ impl<'a> BlockChunker<'a> {
 			}
 
 			self.current_hash = BlockView::new(&block).header_view().parent_hash();
-
-			self.rlps.push_front((block, receipts));
 			blocks_loaded += 1;
 		}
 
@@ -91,11 +97,11 @@ impl<'a> BlockChunker<'a> {
 	}
 
 	// write out the data in the buffers to a chunk on disk
-	fn write_chunk(&mut self, path: &Path) -> H256 {
+	fn write_chunk(&mut self, path: &Path) -> Result<(), Error> {
 		// Todo [rob]: compress raw data, put parent hash and block number into chunk.
 		let mut rlp_stream = RlpStream::new_list(self.rlps.len());
-		for (block, receipts) in self.rlps.drain(..) {
-			rlp_stream.begin_list(2).append(&block).append(&receipts);
+		for pair in self.rlps.drain(..) {
+			rlp_stream.append(&pair);
 		}
 
 		let raw_data = rlp_stream.out();
@@ -106,10 +112,11 @@ impl<'a> BlockChunker<'a> {
 		let mut file_path = path.to_owned();
 		file_path.push(hash.hex());
 
-		let mut file = File::create(file_path).unwrap();
-		file.write_all(&raw_data).unwrap();
+		let mut file = try!(File::create(file_path));
+		try!(file.write_all(&raw_data));
 
-		hash
+		self.hashes.push(hash);
+		Ok(())
 	}
 
 	/// Create and write out all block chunks to disk, returning a vector of all
@@ -117,18 +124,16 @@ impl<'a> BlockChunker<'a> {
 	///
 	/// The path parameter is the directory to store the block chunks in.
 	/// This function assumes the directory exists already.
-	pub fn chunk_all(mut self, path: &Path) -> Vec<H256> {
-		let mut chunk_hashes = Vec::new();
-
+	pub fn chunk_all(mut self, path: &Path) -> Result<Vec<H256>, Error> {
 		while self.fill_buffers() {
-			chunk_hashes.push(self.write_chunk(path));
+			try!(self.write_chunk(path));
 		}
 
 		if self.rlps.len() != 0 {
-			chunk_hashes.push(self.write_chunk(path));
+			try!(self.write_chunk(path));
 		}
 
-		chunk_hashes
+		Ok(self.hashes)
 	}
 }
 
@@ -145,7 +150,7 @@ impl<'a> StateChunker<'a> {
 	//
 	// If the buffer is greater than the desired chunk size,
 	// this will write out the data to disk.
-	fn push(&mut self, key: Bytes, value: Bytes) {
+	fn push(&mut self, key: Bytes, value: Bytes) -> Result<(), Error> {
 		let pair = {
 			let mut stream = RlpStream::new_list(2);
 			stream.append(&key).append(&value);
@@ -153,16 +158,18 @@ impl<'a> StateChunker<'a> {
 		};
 
 		if self.cur_size + pair.len() >= PREFERRED_CHUNK_SIZE {
-			self.write_chunk();
+			try!(self.write_chunk());
 		}
 
 		self.cur_size += pair.len();
 		self.rlps.push(pair);
+
+		Ok(())
 	}
 
 	// Write out the buffer to disk, pushing the created chunk's hash to
 	// the list.
-	fn write_chunk(&mut self) {
+	fn write_chunk(&mut self) -> Result<(), Error> {
 		trace!(target: "pv64_snapshot", "writing state chunk. uncompressed size: {}", self.cur_size);
 
 		let bytes = {
@@ -178,11 +185,13 @@ impl<'a> StateChunker<'a> {
 		let mut path = self.snapshot_path.to_owned();
 		path.push(hash.hex());
 
-		let mut file = File::create(path).unwrap();
-		file.write_all(&bytes).unwrap();
+		let mut file = try!(File::create(path));
+		try!(file.write_all(&bytes));
 
 		self.hashes.push(hash);
 		self.cur_size = 0;
+
+		Ok(())
 	}
 
 	/// Walk the given state database starting from the given root,
@@ -210,11 +219,11 @@ impl<'a> StateChunker<'a> {
 			let account_db = AccountDB::from_hash(db, account_key_hash);
 
 			let fat_rlp = try!(account.to_fat_rlp(&account_db));
-			chunker.push(account_key, fat_rlp);
+			try!(chunker.push(account_key, fat_rlp));
 		}
 
 		if chunker.cur_size != 0 {
-			chunker.write_chunk();
+			try!(chunker.write_chunk());
 		}
 
 		Ok(chunker.hashes)