Add new line after writing block to hex file. (#10984)

* add new line after writing block to hex file.

* refactor for testability

* correct import

* better error reporting, code formatting

* multiline imports

* docs

* better docs, move type to common types, merge ImportBlocks and ExportBlocks

* tabs over spaces

* correct test imports

* Apply suggestions from code review

Co-Authored-By: David <dvdplm@gmail.com>

* correct typo

* fixed test import

ethcore/blockchain/src/blockchain.rs

@@ -592,7 +592,7 @@ impl BlockChain {
 			let best_block_rlp = bc.block(&best_block_hash)
 				.expect("Best block is from a known block hash; qed");
 
-			// and write them
+			// and write them to the cache.
 			let mut best_block = bc.best_block.write();
 			*best_block = BestBlock {
 				total_difficulty: best_block_total_difficulty,
@@ -858,12 +858,31 @@ impl BlockChain {
 		}
 	}
 
-	/// clears all caches for testing purposes
+	/// clears all caches, re-loads best block from disk for testing purposes
 	pub fn clear_cache(&self) {
 		self.block_bodies.write().clear();
 		self.block_details.write().clear();
 		self.block_hashes.write().clear();
 		self.block_headers.write().clear();
+		// Fetch best block details from disk
+		let best_block_hash = self.db.key_value().get(db::COL_EXTRA, b"best")
+			.expect("Low-level database error when fetching 'best' block. Some issue with disk?")
+			.as_ref()
+			.map(|r| H256::from_slice(r))
+			.unwrap();
+		let best_block_total_difficulty = self.block_details(&best_block_hash)
+			.expect("Best block is from a known block hash; a known block hash always comes with a known block detail; qed")
+			.total_difficulty;
+		let best_block_rlp = self.block(&best_block_hash)
+			.expect("Best block is from a known block hash; qed");
+
+		// and write them to the cache
+		let mut best_block = self.best_block.write();
+		*best_block = BestBlock {
+			total_difficulty: best_block_total_difficulty,
+			header: best_block_rlp.decode_header(),
+			block: best_block_rlp,
+		};
 	}
 
 	/// Update the best ancient block to the given hash, after checking that

ethcore/src/client/client.rs

@@ -16,14 +16,15 @@
 
 use std::cmp;
 use std::collections::{HashSet, BTreeMap, VecDeque};
-use std::str::FromStr;
+use std::io::{BufRead, BufReader};
+use std::str::{FromStr, from_utf8};
 use std::convert::TryFrom;
 use std::sync::atomic::{AtomicI64, AtomicBool, Ordering as AtomicOrdering};
 use std::sync::{Arc, Weak};
 use std::time::{Instant, Duration};
 
 use blockchain::{BlockReceipts, BlockChain, BlockChainDB, BlockProvider, TreeRoute, ImportRoute, TransactionAddress, ExtrasInsert, BlockNumberKey};
-use bytes::Bytes;
+use bytes::{Bytes, ToPretty};
 use call_contract::{CallContract, RegistryInfo};
 use ethcore_miner::pool::VerifiedTransaction;
 use ethereum_types::{H256, H264, Address, U256};
@@ -35,6 +36,8 @@ use journaldb;
 use kvdb::{DBValue, KeyValueDB, DBTransaction};
 use parking_lot::{Mutex, RwLock};
 use rand::OsRng;
+use rlp::PayloadInfo;
+use rustc_hex::FromHex;
 use types::transaction::{self, LocalizedTransaction, UnverifiedTransaction, SignedTransaction, Action};
 use trie::{TrieSpec, TrieFactory, Trie};
 use types::ancestry_action::AncestryAction;
@@ -43,6 +46,7 @@ use types::filter::Filter;
 use types::log_entry::LocalizedLogEntry;
 use types::receipt::{Receipt, LocalizedReceipt};
 use types::{BlockNumber, header::{Header, ExtendedHeader}};
+use types::data_format::DataFormat;
 use vm::{EnvInfo, LastHashes};
 
 use block::{LockedBlock, Drain, ClosedBlock, OpenBlock, enact_verified, SealedBlock};
@@ -52,7 +56,7 @@ use client::{
 	ReopenBlock, PrepareOpenBlock, ScheduleInfo, ImportSealedBlock,
 	BroadcastProposalBlock, ImportBlock, StateOrBlock, StateInfo, StateClient, Call,
 	AccountData, BlockChain as BlockChainTrait, BlockProducer, SealedBlockImporter,
-	ClientIoMessage, BlockChainReset
+	ClientIoMessage, BlockChainReset, ImportExportBlocks,
 };
 use client::{
 	BlockId, TransactionId, UncleId, TraceId, ClientConfig, BlockChainClient,
@@ -64,7 +68,7 @@ use client::bad_blocks;
 use engines::{MAX_UNCLE_AGE, EthEngine, EpochTransition, ForkChoice, EngineError};
 use engines::epoch::PendingTransition;
 use error::{
-	ImportErrorKind, ExecutionError, CallError, BlockError,
+	ImportErrorKind, ExecutionError, CallError, BlockError, ImportError,
 	QueueError, QueueErrorKind, Error as EthcoreError, EthcoreResult, ErrorKind as EthcoreErrorKind
 };
 use executive::{Executive, Executed, TransactOptions, contract_address};
@@ -154,7 +158,7 @@ struct Importer {
 	pub import_lock: Mutex<()>, // FIXME Maybe wrap the whole `Importer` instead?
 
 	/// Used to verify blocks
-	pub verifier: Box<Verifier<Client>>,
+	pub verifier: Box<dyn Verifier<Client>>,
 
 	/// Queue containing pending blocks
 	pub block_queue: BlockQueue,
@@ -197,7 +201,7 @@ pub struct Client {
 	pruning: journaldb::Algorithm,
 
 	/// Client uses this to store blocks, traces, etc.
-	db: RwLock<Arc<BlockChainDB>>,
+	db: RwLock<Arc<dyn BlockChainDB>>,
 
 	state_db: RwLock<StateDB>,
 
@@ -211,7 +215,7 @@ pub struct Client {
 	io_channel: RwLock<IoChannel<ClientIoMessage>>,
 
 	/// List of actors to be notified on certain chain events
-	notify: RwLock<Vec<Weak<ChainNotify>>>,
+	notify: RwLock<Vec<Weak<dyn ChainNotify>>>,
 
 	/// Queued transactions from IO
 	queue_transactions: IoChannelQueue,
@@ -233,12 +237,12 @@ pub struct Client {
 	history: u64,
 
 	/// An action to be done if a mode/spec_name change happens
-	on_user_defaults_change: Mutex<Option<Box<FnMut(Option<Mode>) + 'static + Send>>>,
+	on_user_defaults_change: Mutex<Option<Box<dyn FnMut(Option<Mode>) + 'static + Send>>>,
 
 	registrar_address: Option<Address>,
 
 	/// A closure to call when we want to restart the client
-	exit_handler: Mutex<Option<Box<Fn(String) + 'static + Send>>>,
+	exit_handler: Mutex<Option<Box<dyn Fn(String) + 'static + Send>>>,
 
 	importer: Importer,
 }
@@ -249,8 +253,13 @@ impl Importer {
 		engine: Arc<EthEngine>,
 		message_channel: IoChannel<ClientIoMessage>,
 		miner: Arc<Miner>,
-	) -> Result<Importer, ::error::Error> {
-		let block_queue = BlockQueue::new(config.queue.clone(), engine.clone(), message_channel.clone(), config.verifier_type.verifying_seal());
+	) -> Result<Importer, EthcoreError> {
+		let block_queue = BlockQueue::new(
+			config.queue.clone(),
+			engine.clone(),
+			message_channel.clone(),
+			config.verifier_type.verifying_seal()
+		);
 
 		Ok(Importer {
 			import_lock: Mutex::new(()),
@@ -476,7 +485,16 @@ impl Importer {
 	//
 	// The header passed is from the original block data and is sealed.
 	// TODO: should return an error if ImportRoute is none, issue #9910
-	fn commit_block<B>(&self, block: B, header: &Header, block_data: encoded::Block, pending: Option<PendingTransition>, client: &Client) -> ImportRoute where B: Drain {
+	fn commit_block<B>(
+		&self,
+		block: B,
+		header: &Header,
+		block_data: encoded::Block,
+		pending: Option<PendingTransition>,
+		client: &Client
+	) -> ImportRoute
+		where B: Drain
+	{
 		let hash = &header.hash();
 		let number = header.number();
 		let parent = header.parent_hash();
@@ -2561,6 +2579,116 @@ impl ProvingBlockChainClient for Client {
 
 impl SnapshotClient for Client {}
 
+impl ImportExportBlocks for Client {
+	fn export_blocks<'a>(
+		&self,
+		mut out: Box<dyn std::io::Write + 'a>,
+		from: BlockId,
+		to: BlockId,
+		format: Option<DataFormat>
+	) -> Result<(), String> {
+		let from = self.block_number(from).ok_or("Starting block could not be found")?;
+		let to = self.block_number(to).ok_or("End block could not be found")?;
+		let format = format.unwrap_or_default();
+
+		for i in from..=to {
+			if i % 10000 == 0 {
+				info!("#{}", i);
+			}
+			let b = self.block(BlockId::Number(i)).ok_or("Error exporting incomplete chain")?.into_inner();
+			match format {
+				DataFormat::Binary => {
+					out.write(&b).map_err(|e| format!("Couldn't write to stream. Cause: {}", e))?;
+				}
+				DataFormat::Hex => {
+					out.write_fmt(format_args!("{}\n", b.pretty())).map_err(|e| format!("Couldn't write to stream. Cause: {}", e))?;
+				}
+			}
+		}
+		Ok(())
+	}
+
+	fn import_blocks<'a>(
+		&self,
+		mut source: Box<dyn std::io::Read + 'a>,
+		format: Option<DataFormat>
+	) -> Result<(), String> {
+		const READAHEAD_BYTES: usize = 8;
+
+		let mut first_bytes: Vec<u8> = vec![0; READAHEAD_BYTES];
+		let mut first_read = 0;
+
+		let format = match format {
+			Some(format) => format,
+			None => {
+				first_read = source.read(&mut first_bytes).map_err(|_| "Error reading from the file/stream.")?;
+				match first_bytes[0] {
+					0xf9 => DataFormat::Binary,
+					_ => DataFormat::Hex,
+				}
+			}
+		};
+
+		let do_import = |bytes: Vec<u8>| {
+			let block = Unverified::from_rlp(bytes).map_err(|_| "Invalid block rlp")?;
+			let number = block.header.number();
+			while self.queue_info().is_full() { std::thread::sleep(Duration::from_secs(1)); }
+			match self.import_block(block) {
+				Err(EthcoreError(EthcoreErrorKind::Import(ImportErrorKind::AlreadyInChain), _)) => {
+					trace!("Skipping block #{}: already in chain.", number);
+				},
+				Err(e) => {
+					return Err(format!("Cannot import block #{}: {:?}", number, e));
+				},
+				Ok(_) => {},
+			}
+			Ok(())
+		};
+
+		match format {
+			DataFormat::Binary => {
+				loop {
+					let (mut bytes, n) = if first_read > 0 {
+						(first_bytes.clone(), first_read)
+					} else {
+						let mut bytes = vec![0; READAHEAD_BYTES];
+						let n = source.read(&mut bytes)
+							.map_err(|err| format!("Error reading from the file/stream: {:?}", err))?;
+						(bytes, n)
+					};
+					if n == 0 { break; }
+					first_read = 0;
+					let s = PayloadInfo::from(&bytes)
+						.map_err(|e| format!("Invalid RLP in the file/stream: {:?}", e))?.total();
+					bytes.resize(s, 0);
+					source.read_exact(&mut bytes[n..])
+						.map_err(|err| format!("Error reading from the file/stream: {:?}", err))?;
+					do_import(bytes)?;
+				}
+			}
+			DataFormat::Hex => {
+				for line in BufReader::new(source).lines() {
+					let s = line
+						.map_err(|err| format!("Error reading from the file/stream: {:?}", err))?;
+					let s = if first_read > 0 {
+						from_utf8(&first_bytes)
+							.map_err(|err| format!("Invalid UTF-8: {:?}", err))?
+							.to_owned() + &(s[..])
+					} else {
+						s
+					};
+					first_read = 0;
+					let bytes = s.from_hex()
+						.map_err(|err| format!("Invalid hex in file/stream: {:?}", err))?;
+					do_import(bytes)?;
+				}
+			}
+		};
+		self.flush_queue();
+		Ok(())
+	}
+}
+
 /// Returns `LocalizedReceipt` given `LocalizedTransaction`
 /// and a vector of receipts from given block up to transaction index.
 fn transaction_receipt(

ethcore/src/client/mod.rs

@@ -38,7 +38,7 @@ pub use self::chain_notify::{ChainNotify, NewBlocks, ChainRoute, ChainRouteType,
 pub use self::traits::{
     Nonce, Balance, ChainInfo, BlockInfo, ReopenBlock, PrepareOpenBlock, TransactionInfo, ScheduleInfo, ImportSealedBlock, BroadcastProposalBlock, ImportBlock,
     StateOrBlock, StateClient, Call, EngineInfo, AccountData, BlockChain, BlockProducer, SealedBlockImporter, BadBlocks,
-	BlockChainReset
+	BlockChainReset, ImportExportBlocks
 };
 pub use state::StateInfo;
 pub use self::traits::{BlockChainClient, EngineClient, ProvingBlockChainClient, IoClient};

ethcore/src/client/traits.rs

@@ -31,6 +31,7 @@ use types::basic_account::BasicAccount;
 use types::block_status::BlockStatus;
 use types::blockchain_info::BlockChainInfo;
 use types::call_analytics::CallAnalytics;
+use types::data_format::DataFormat;
 use types::encoded;
 use types::filter::Filter;
 use types::header::Header;
@@ -477,3 +478,29 @@ pub trait BlockChainReset {
 	/// reset to best_block - n
 	fn reset(&self, num: u32) -> Result<(), String>;
 }
+
+/// Provides a method for importing/exporting blocks
+pub trait ImportExportBlocks {
+	/// Export blocks to destination, with the given from, to and format argument.
+	/// destination could be a file or stdout.
+	/// If the format is hex, each block is written on a new line.
+	/// For binary exports, all block data is written to the same line.
+	fn export_blocks<'a>(
+		&self,
+		destination: Box<dyn std::io::Write + 'a>,
+		from: BlockId,
+		to: BlockId,
+		format: Option<DataFormat>
+	) -> Result<(), String>;
+
+	/// Import blocks from destination, with the given format argument
+	/// Source could be a file or stdout.
+	/// For hex format imports, it attempts to read the blocks on a line by line basis.
+	/// For binary format imports, reads the 8 byte RLP header in order to decode the block
+	/// length to be read.
+	fn import_blocks<'a>(
+		&self,
+		source: Box<dyn std::io::Read + 'a>,
+		format: Option<DataFormat>
+	) -> Result<(), String>;
+}