Adds cli interface to allow reseting chain to a particular block (#9782)

* added BlockChainReset trait, client impl, and cli interface

* show block hashes to be deleted and new best block, update best block in db, better cli interface

* delete BlockNumber from COL_EXTRA

* add TODO comment

* add BlockReciepts to imports

* refactor block_headers_from_best_block, better cli documentation

* exit gracefully if reset arg isn't supplied

* fix cli usage macro

* removed stray int literals

* use Vec::with_capacity

Co-Authored-By: seunlanlege <seunlanlege@gmail.com>

* cast n to usize

* correct imports

* make db reset arg required

parity/blockchain.rs

@@ -26,7 +26,8 @@ use ethereum_types::{U256, H256, Address};
 use bytes::ToPretty;
 use rlp::PayloadInfo;
 use ethcore::account_provider::AccountProvider;
-use ethcore::client::{Mode, DatabaseCompactionProfile, VMType, Nonce, Balance, BlockChainClient, BlockId, BlockInfo, ImportBlock};
+use ethcore::client::{Mode, DatabaseCompactionProfile, VMType, Nonce, Balance, BlockChainClient, BlockId, BlockInfo,
+	ImportBlock, BlockChainReset};
 use ethcore::error::{ImportErrorKind, ErrorKind as EthcoreErrorKind, Error as EthcoreError};
 use ethcore::miner::Miner;
 use ethcore::verification::queue::VerifierSettings;
@@ -40,6 +41,7 @@ use dir::Directories;
 use user_defaults::UserDefaults;
 use ethcore_private_tx;
 use db;
+use ansi_term::Colour;
 
 #[derive(Debug, PartialEq)]
 pub enum DataFormat {
@@ -71,6 +73,21 @@ pub enum BlockchainCmd {
 	Import(ImportBlockchain),
 	Export(ExportBlockchain),
 	ExportState(ExportState),
+	Reset(ResetBlockchain)
+}
+
+#[derive(Debug, PartialEq)]
+pub struct ResetBlockchain {
+	pub dirs: Directories,
+	pub spec: SpecType,
+	pub pruning: Pruning,
+	pub pruning_history: u64,
+	pub pruning_memory: usize,
+	pub tracing: Switch,
+	pub fat_db: Switch,
+	pub compaction: DatabaseCompactionProfile,
+	pub cache_config: CacheConfig,
+	pub num: u32,
 }
 
 #[derive(Debug, PartialEq)]
@@ -153,6 +170,7 @@ pub fn execute(cmd: BlockchainCmd) -> Result<(), String> {
 		}
 		BlockchainCmd::Export(export_cmd) => execute_export(export_cmd),
 		BlockchainCmd::ExportState(export_cmd) => execute_export_state(export_cmd),
+		BlockchainCmd::Reset(reset_cmd) => execute_reset(reset_cmd),
 	}
 }
 
@@ -709,6 +727,28 @@ fn execute_export_state(cmd: ExportState) -> Result<(), String> {
 	Ok(())
 }
 
+fn execute_reset(cmd: ResetBlockchain) -> Result<(), String> {
+	let service = start_client(
+		cmd.dirs,
+		cmd.spec,
+		cmd.pruning,
+		cmd.pruning_history,
+		cmd.pruning_memory,
+		cmd.tracing,
+		cmd.fat_db,
+		cmd.compaction,
+		cmd.cache_config,
+		false,
+		0,
+	)?;
+
+	let client = service.client();
+	client.reset(cmd.num)?;
+	info!("{}", Colour::Green.bold().paint("Successfully reset db!"));
+
+	Ok(())
+}
+
 pub fn kill_db(cmd: KillBlockchain) -> Result<(), String> {
 	let spec = cmd.spec.spec(&cmd.dirs.cache)?;
 	let genesis_hash = spec.genesis_header().hash();

parity/cli/mod.rs

@@ -217,6 +217,15 @@ usage! {
 			CMD cmd_db_kill {
 				"Clean the database of the given --chain (default: mainnet)",
 			}
+
+			CMD cmd_db_reset {
+				"Removes NUM latests blocks from the db",
+
+				ARG arg_db_reset_num: (u32) = 10u32,
+				"<NUM>",
+				"Number of blocks to revert",
+			}
+
 		}
 
 		CMD cmd_export_hardcoded_sync
@@ -1612,6 +1621,7 @@ mod tests {
 			cmd_tools_hash: false,
 			cmd_db: false,
 			cmd_db_kill: false,
+			cmd_db_reset: false,
 			cmd_export_hardcoded_sync: false,
 
 			// Arguments
@@ -1631,6 +1641,7 @@ mod tests {
 			arg_dapp_path: None,
 			arg_account_import_path: None,
 			arg_wallet_import_path: None,
+			arg_db_reset_num: 10,
 
 			// -- Operating Options
 			arg_mode: "last".into(),

parity/configuration.rs

@@ -48,7 +48,7 @@ use ethcore_private_tx::{ProviderConfig, EncryptorConfig};
 use secretstore::{NodeSecretKey, Configuration as SecretStoreConfiguration, ContractAddress as SecretStoreContractAddress};
 use updater::{UpdatePolicy, UpdateFilter, ReleaseTrack};
 use run::RunCmd;
-use blockchain::{BlockchainCmd, ImportBlockchain, ExportBlockchain, KillBlockchain, ExportState, DataFormat};
+use blockchain::{BlockchainCmd, ImportBlockchain, ExportBlockchain, KillBlockchain, ExportState, DataFormat, ResetBlockchain};
 use export_hardcoded_sync::ExportHsyncCmd;
 use presale::ImportWallet;
 use account::{AccountCmd, NewAccount, ListAccounts, ImportAccounts, ImportFromGethAccounts};
@@ -176,6 +176,19 @@ impl Configuration {
 			}
 		} else if self.args.cmd_tools && self.args.cmd_tools_hash {
 			Cmd::Hash(self.args.arg_tools_hash_file)
+		} else if self.args.cmd_db && self.args.cmd_db_reset {
+			Cmd::Blockchain(BlockchainCmd::Reset(ResetBlockchain {
+				dirs,
+				spec,
+				pruning,
+				pruning_history,
+				pruning_memory: self.args.arg_pruning_memory,
+				tracing,
+				fat_db,
+				compaction,
+				cache_config,
+				num: self.args.arg_db_reset_num,
+			}))
 		} else if self.args.cmd_db && self.args.cmd_db_kill {
 			Cmd::Blockchain(BlockchainCmd::Kill(KillBlockchain {
 				spec: spec,