Struct FFI_TaskContextProvider 

#[repr(C)]
pub struct FFI_TaskContextProvider {
    pub task_ctx: unsafe extern "C" fn(&Self) -> FFI_Result<FFI_TaskContext>,
    pub clone: unsafe extern "C" fn(plan: &Self) -> Self,
    pub release: unsafe extern "C" fn(arg: &mut Self),
    pub private_data: *mut c_void,
    pub library_marker_id: extern "C" fn() -> usize,
}

Struct for accessing the TaskContext. This method contains a weak reference, so there are no guarantees that the TaskContext remains valid. This is used primarily for protobuf encoding and decoding of data passed across the FFI boundary. See the crate README for additional information.

Fields

task_ctx: unsafe extern "C" fn(&Self) -> FFI_Result<FFI_TaskContext>

Retrieve the current TaskContext provided the provider has not gone out of scope. This function will return an error if the weakly held reference to the underlying TaskContextProvider is no longer available.

clone: unsafe extern "C" fn(plan: &Self) -> Self

Used to create a clone on the task context accessor. This should only need to be called by the receiver of the plan.

release: unsafe extern "C" fn(arg: &mut Self)

Release the memory of the private data when it is no longer being used.

private_data: *mut c_void

Internal data. This is only to be accessed by the provider of the plan. The foreign library should never attempt to access this data.

library_marker_id: extern "C" fn() -> usize

Utility to identify when FFI objects are accessed locally through the foreign interface. See crate::get_library_marker_id and the crate’s README.md for more information.

Trait Implementations

impl Clone for FFI_TaskContextProvider

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FFI_TaskContextProvider

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for FFI_TaskContextProvider

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl From<&Arc<dyn TaskContextProvider>> for FFI_TaskContextProvider

fn from(ctx: &Arc<dyn TaskContextProvider>) -> Self

Converts to this type from the input type.

impl Send for FFI_TaskContextProvider

impl Sync for FFI_TaskContextProvider

impl TryFrom<&FFI_TaskContextProvider> for Arc<TaskContext>

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(ffi_ctx: &FFI_TaskContextProvider) -> Result<Self, Self::Error>

Performs the conversion.