Crate sc_executor

A crate that provides means of executing/dispatching calls into the runtime.

There are a few responsibilities of this crate at the moment:

• It provides an implementation of a common entrypoint for calling into the runtime, both wasm and compiled.
• It defines the environment for the wasm execution, namely the host functions that are to be provided into the wasm runtime module.
• It also provides the required infrastructure for executing the current wasm runtime (specified by the current value of :code in the provided externalities), i.e. interfacing with wasm engine used, instance cache.

Modules

• error
  Rust executor possible errors.

Structs

• NativeElseWasmExecutorDeprecated
  A generic CodeExecutor implementation that uses a delegate to determine wasm code equivalence and dispatch to native code when possible, falling back on WasmExecutor when not.
• NativeVersion
  The version of the native runtime.
• RuntimeVersion
  Runtime version. This should not be thought of as classic Semver (major/minor/tiny). This triplet have different semantics and mis-interpretation could cause problems. In particular: bug fixes should result in an increment of spec_version and possibly authoring_version, absolutely not impl_version since they change the semantics of the runtime.
• WasmExecutor
  An abstraction over Wasm code executor. Supports selecting execution backend and manages runtime cache.

Enums

• HeapAllocStrategy
  Defines the heap pages allocation strategy the wasm runtime should use.
• WasmExecutionMethod
  Specification of different methods of executing the runtime Wasm code.
• WasmtimeInstantiationStrategy
  The instantiation strategy to use for the WASM executor.

Constants

• DEFAULT_HEAP_ALLOC_PAGES
  Default heap allocation pages.
• DEFAULT_HEAP_ALLOC_STRATEGY
  Default heap allocation strategy.

Traits

• Codec
  Trait that allows zero-copy read/write of value-references to/from slices in LE format.
• HostFunctions
  Something that provides implementations for host functions.
• NativeExecutionDispatch
  Delegate for dispatching a CodeExecutor call.
• RuntimeVersionOf
  Extracts the runtime version of a given runtime code.

Functions

• read_embedded_version
  Take the runtime blob and scan it for the custom wasm sections containing the version information and construct the RuntimeVersion from them.
• with_externalities_safe
  Set up the externalities and safe calling environment to execute runtime calls.