Executor: Remove LegacyInstanceReuse strategy (paritytech#1486)

It seems the old strategy have been depracted more than one year. 
So maybe it's time to clean up old strategy for wasm executor.


---
polkadot address: 15ouFh2SHpGbHtDPsJ6cXQfes9Cx1gEFnJJsJVqPGzBSTudr

---------

Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Koute <[email protected]>

substrate/client/cli/src/arg_enums.rs

@@ -38,12 +38,6 @@ pub enum WasmtimeInstantiationStrategy {
 
 	/// Recreate the instance from scratch on every instantiation. Very slow.
 	RecreateInstance,
-
-	/// Legacy instance reuse mechanism. DEPRECATED. Will be removed in the future.
-	///
-	/// Should only be used in case of encountering any issues with the new default
-	/// instantiation strategy.
-	LegacyInstanceReuse,
 }
 
 /// The default [`WasmtimeInstantiationStrategy`].
@@ -92,8 +86,6 @@ pub fn execution_method_from_cli(
 				sc_service::config::WasmtimeInstantiationStrategy::Pooling,
 			WasmtimeInstantiationStrategy::RecreateInstance =>
 				sc_service::config::WasmtimeInstantiationStrategy::RecreateInstance,
-			WasmtimeInstantiationStrategy::LegacyInstanceReuse =>
-				sc_service::config::WasmtimeInstantiationStrategy::LegacyInstanceReuse,
 		},
 	}
 }

substrate/client/executor/benches/bench.rs

@@ -150,13 +150,6 @@ fn bench_call_instance(c: &mut Criterion) {
 	let _ = env_logger::try_init();
 
 	let strategies = [
-		(
-			"legacy_instance_reuse",
-			Method::Compiled {
-				instantiation_strategy: InstantiationStrategy::LegacyInstanceReuse,
-				precompile: false,
-			},
-		),
 		(
 			"recreate_instance_vanilla",
 			Method::Compiled {

substrate/client/executor/common/src/runtime_blob/mod.rs

@@ -46,10 +46,6 @@
 //! is free of any floating point operations, which is a useful step towards making instances
 //! produced from such a module deterministic.
 
-mod data_segments_snapshot;
-mod globals_snapshot;
 mod runtime_blob;
 
-pub use data_segments_snapshot::DataSegmentsSnapshot;
-pub use globals_snapshot::{ExposedMutableGlobalsSet, GlobalsSnapshot, InstanceGlobals};
 pub use runtime_blob::RuntimeBlob;

substrate/client/executor/common/src/runtime_blob/runtime_blob.rs

@@ -20,8 +20,8 @@ use crate::{error::WasmError, wasm_runtime::HeapAllocStrategy};
 use wasm_instrument::{
 	export_mutable_globals,
 	parity_wasm::elements::{
-		deserialize_buffer, serialize, DataSegment, ExportEntry, External, Internal, MemorySection,
-		MemoryType, Module, Section,
+		deserialize_buffer, serialize, ExportEntry, External, Internal, MemorySection, MemoryType,
+		Module, Section,
 	},
 };
 
@@ -52,11 +52,6 @@ impl RuntimeBlob {
 		Ok(Self { raw_module })
 	}
 
-	/// Extract the data segments from the given wasm code.
-	pub(super) fn data_segments(&self) -> Vec<DataSegment> {
-		self.raw_module.data_section().map(|ds| ds.entries()).unwrap_or(&[]).to_vec()
-	}
-
 	/// The number of globals defined in locally in this module.
 	pub fn declared_globals_count(&self) -> u32 {
 		self.raw_module
@@ -190,16 +185,6 @@ impl RuntimeBlob {
 		Ok(())
 	}
 
-	/// Returns an iterator of all globals which were exported by [`expose_mutable_globals`].
-	pub(super) fn exported_internal_global_names(&self) -> impl Iterator<Item = &str> {
-		let exports = self.raw_module.export_section().map(|es| es.entries()).unwrap_or(&[]);
-		exports.iter().filter_map(|export| match export.internal() {
-			Internal::Global(_) if export.field().starts_with("exported_internal_global") =>
-				Some(export.field()),
-			_ => None,
-		})
-	}
-
 	/// Scans the wasm blob for the first section with the name that matches the given. Returns the
 	/// contents of the custom section if found or `None` otherwise.
 	pub fn custom_section_contents(&self, section_name: &str) -> Option<&[u8]> {

substrate/client/executor/common/src/wasm_runtime.rs

@@ -115,16 +115,6 @@ pub trait WasmInstance: Send {
 	///
 	/// This method is only suitable for getting immutable globals.
 	fn get_global_const(&mut self, name: &str) -> Result<Option<Value>, Error>;
-
-	/// **Testing Only**. This function returns the base address of the linear memory.
-	///
-	/// This is meant to be the starting address of the memory mapped area for the linear memory.
-	///
-	/// This function is intended only for a specific test that measures physical memory
-	/// consumption.
-	fn linear_memory_base_ptr(&self) -> Option<*const u8> {
-		None
-	}
 }
 
 /// Defines the heap pages allocation strategy the wasm runtime should use.