Struct PassFatPointerAndRead

pub struct PassFatPointerAndRead<T>(/* private fields */);

Pass a value into the host by a fat pointer.

This casts the value into a &[u8] and passes a pointer to that byte blob and its length to the host. Then the host reads that blob and converts it into an owned type and passes it (either as an owned type or as a reference) to the host function.

Raw FFI type: u64 (a fat pointer; upper 32 bits is the size, lower 32 bits is the pointer)

Trait Implementations

impl<'a> FromFFIValue<'a> for PassFatPointerAndRead<&'a [u8]>

type Owned = Vec<u8>

The owned inner type.

fn from_ffi_value( context: &mut dyn FunctionContext, arg: Self::FFIType, ) -> Result<Self::Owned>

Creates Self::Owned from the given arg received through the FFI boundary from the runtime.

fn take_from_owned(owned: &'a mut Self::Owned) -> Self::Inner

Creates Self::Inner from an owned value.

fn write_back_into_runtime( _value: Self::Owned, _context: &mut dyn FunctionContext, _arg: Self::FFIType, ) -> Result<()>

Write back a modified value back into the runtime’s memory.

impl<'a> FromFFIValue<'a> for PassFatPointerAndRead<&'a str>

type Owned = String

The owned inner type.

fn from_ffi_value( context: &mut dyn FunctionContext, arg: Self::FFIType, ) -> Result<Self::Owned>

Creates Self::Owned from the given arg received through the FFI boundary from the runtime.

fn take_from_owned(owned: &'a mut Self::Owned) -> Self::Inner

Creates Self::Inner from an owned value.

fn write_back_into_runtime( _value: Self::Owned, _context: &mut dyn FunctionContext, _arg: Self::FFIType, ) -> Result<()>

Write back a modified value back into the runtime’s memory.

impl<'a> FromFFIValue<'a> for PassFatPointerAndRead<Vec<u8>>

type Owned = Vec<u8>

The owned inner type.

fn from_ffi_value( context: &mut dyn FunctionContext, arg: Self::FFIType, ) -> Result<Self::Owned>

Creates Self::Owned from the given arg received through the FFI boundary from the runtime.

fn take_from_owned(owned: &'a mut Self::Owned) -> Self::Inner

Creates Self::Inner from an owned value.

fn write_back_into_runtime( _value: Self::Owned, _context: &mut dyn FunctionContext, _arg: Self::FFIType, ) -> Result<()>

Write back a modified value back into the runtime’s memory.

impl<T> RIType for PassFatPointerAndRead<T>

type FFIType = u64

The raw FFI type that is used to pass Self through the host <-> runtime boundary.

type Inner = T

The inner type without any serialization strategy wrapper.