Remove the --unsafe-pruning CLI-argument (step 1) (#10995)

* sc-client-db: utils::open_database(...) — return OpenDbError so that the caller could tell the `OpenDbError::DoesNotExist` clearly

* sc-client-db: utils::open_database(..) — accept the `create: bool` argument

* sc-client-db: pruning — optional argument in the DatabaseSettings

* sc-state-db: Split `Error<E>` into separate `Error<E>` and `StateDbError`

* StateDb::open: choose the pruning-mode depending on the requested and stored values

* sc-state-db: test for different combinations of stored and requested pruning-modes

* CLI-argument: mark the unsafe-pruning as deprecated

* Fix tests

* tests: do not specify --pruning when running the substrate over the existing storage

* fix types for benches

* cargo fmt

* Check whether the pruning-mode and sync-mode are compatible

* cargo fmt

* parity-db: 0.3.11 -> 0.3.12

* sc-state-db: MetaDb::set_meta — a better doc-test

* cargo fmt

* make MetaDb read-only again!

* Remove the stray newline (and run the CI once again please)

* Last nitpicks

* A more comprehensive error message

substrate/client/cli/src/params/import_params.rs

@@ -40,12 +40,16 @@ pub struct ImportParams {
 	#[clap(flatten)]
 	pub database_params: DatabaseParams,
 
-	/// Force start with unsafe pruning settings.
+	/// THIS IS A DEPRECATED CLI-ARGUMENT.
 	///
-	/// When running as a validator it is highly recommended to disable state
-	/// pruning (i.e. 'archive') which is the default. The node will refuse to
-	/// start as a validator if pruning is enabled unless this option is set.
+	/// It has been preserved in order to not break the compatibility with the existing scripts.
+	/// Enabling this option will lead to a runtime warning.
+	/// In future this option will be removed completely, thus specifying it will lead to a start
+	/// up error.
+	///
+	/// Details: <https://github.com/paritytech/substrate/issues/8103>
 	#[clap(long)]
+	#[deprecated = "According to https://github.com/paritytech/substrate/issues/8103"]
 	pub unsafe_pruning: bool,
 
 	/// Method for executing Wasm runtime code.

substrate/client/cli/src/params/pruning_params.rs

@@ -18,7 +18,7 @@
 
 use crate::error;
 use clap::Args;
-use sc_service::{KeepBlocks, PruningMode, Role};
+use sc_service::{KeepBlocks, PruningMode};
 
 /// Parameters to define the pruning mode
 #[derive(Debug, Clone, PartialEq, Args)]
@@ -39,29 +39,17 @@ pub struct PruningParams {
 
 impl PruningParams {
 	/// Get the pruning value from the parameters
-	pub fn state_pruning(&self, unsafe_pruning: bool, role: &Role) -> error::Result<PruningMode> {
-		// by default we disable pruning if the node is an authority (i.e.
-		// `ArchiveAll`), otherwise we keep state for the last 256 blocks. if the
-		// node is an authority and pruning is enabled explicitly, then we error
-		// unless `unsafe_pruning` is set.
-		Ok(match &self.pruning {
-			Some(ref s) if s == "archive" => PruningMode::ArchiveAll,
-			None if role.is_authority() => PruningMode::ArchiveAll,
-			None => PruningMode::default(),
-			Some(s) => {
-				if role.is_authority() && !unsafe_pruning {
-					return Err(error::Error::Input(
-						"Validators should run with state pruning disabled (i.e. archive). \
-						You can ignore this check with `--unsafe-pruning`."
-							.to_string(),
-					))
-				}
-
-				PruningMode::keep_blocks(s.parse().map_err(|_| {
-					error::Error::Input("Invalid pruning mode specified".to_string())
-				})?)
-			},
-		})
+	pub fn state_pruning(&self) -> error::Result<Option<PruningMode>> {
+		self.pruning
+			.as_ref()
+			.map(|s| match s.as_str() {
+				"archive" => Ok(PruningMode::ArchiveAll),
+				bc => bc
+					.parse()
+					.map_err(|_| error::Error::Input("Invalid pruning mode specified".to_string()))
+					.map(PruningMode::keep_blocks),
+			})
+			.transpose()
 	}
 
 	/// Get the block pruning value from the parameters