Struct sc_executor_common::runtime_blob::RuntimeBlob

pub struct RuntimeBlob { /* private fields */ }

A bunch of information collected from a WebAssembly module.

Implementations

impl RuntimeBlob

pub fn uncompress_if_needed(wasm_code: &[u8]) -> Result<Self, WasmError>

Create RuntimeBlob from the given wasm code. Will attempt to decompress the code before deserializing it.

See sp_maybe_compressed_blob for details about decompression.

pub fn new(wasm_code: &[u8]) -> Result<Self, WasmError>

Create RuntimeBlob from the given wasm code.

Returns Err if the wasm code cannot be deserialized.

pub fn declared_globals_count(&self) -> u32

The number of globals defined in locally in this module.

pub fn imported_globals_count(&self) -> u32

The number of imports of globals.

pub fn expose_mutable_globals(&mut self)

Perform an instrumentation that makes sure that the mutable globals are exported.

pub fn inject_stack_depth_metering(
    self,
    stack_depth_limit: u32
) -> Result<Self, WasmError>

Run a pass that instrument this module so as to introduce a deterministic stack height limit.

It will introduce a global mutable counter. The instrumentation will increase the counter according to the “cost” of the callee. If the cost exceeds the stack_depth_limit constant, the instrumentation will trap. The counter will be decreased as soon as the the callee returns.

The stack cost of a function is computed based on how much locals there are and the maximum depth of the wasm operand stack.

pub fn entry_point_exists(&self, entry_point: &str) -> bool

Perform an instrumentation that makes sure that a specific function entry_point is exported

pub fn convert_memory_import_into_export(&mut self) -> Result<(), WasmError>

Converts a WASM memory import into a memory section and exports it.

Does nothing if there’s no memory import.

May return an error in case the WASM module is invalid.

pub fn add_extra_heap_pages_to_memory_section(
    &mut self,
    extra_heap_pages: u32
) -> Result<(), WasmError>

Increases the number of memory pages requested by the WASM blob by the given amount of extra_heap_pages.

Will return an error in case there is no memory section present, or if the memory section is empty.

Only modifies the initial size of the memory; the maximum is unmodified unless it’s smaller than the initial size, in which case it will be increased so that it’s at least as big as the initial size.

pub fn custom_section_contents(&self, section_name: &str) -> Option<&[u8]>

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 serialize(self) -> Vec<u8>

Consumes this runtime blob and serializes it.

pub fn into_inner(self) -> Module

Destructure this structure into the underlying parity-wasm Module.

Trait Implementations

impl Clone for RuntimeBlob

fn clone(&self) -> RuntimeBlob

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.