Module uniffi::ffi

Types that can cross the FFI boundary.

Modules

• callbackinterface
  Callback interfaces are traits specified in UDL which can be implemented by foreign languages.
• ffidefault
  FfiDefault trait
• foreignbytes
• foreigncallbacks
  This module contains code to handle foreign callbacks - C-ABI functions that are defined by a foreign language, then registered with UniFFI. These callbacks are used to implement callback interfaces, async scheduling etc. Foreign callbacks are registered at startup, when the foreign code loads the exported library. For each callback type, we also define a “cell” type for storing the callback.
• foreignfuture
  This module defines a Rust Future that wraps an async foreign function call.
• handle
• rustbuffer
• rustcalls
  Low-level support for calling rust functions
• rustfuture

Structs

• ForeignBytes
  Support for reading a slice of foreign-language-allocated bytes over the FFI.
• ForeignFuture
  Perform a call to a foreign async method C struct that represents the foreign future.
• ForeignFutureResult
  C struct that represents the result of a foreign future
• Handle
  Object handle
• RustBuffer
  Support for passing an allocated-by-Rust buffer of bytes over the FFI.
• RustCallStatus
  Represents the success/error of a rust call
• UnexpectedUniFFICallbackError
  Used when internal/unexpected error happened when calling a foreign callback, for example when a unknown exception is raised

Enums

• RustCallStatusCode
  Result of a FFI call to a Rust function
• RustFuturePoll
  Result code for rust_future_poll. This is passed to the continuation function.

Traits

• FfiDefault

Functions

• foreign_async_call
• foreign_future_complete
• rust_call
  Handle a scaffolding calls
• rust_future_cancel^⚠
  Cancel a Rust future
• rust_future_complete^⚠
  Complete a Rust future
• rust_future_free^⚠
  Free a Rust future, dropping the strong reference and releasing all references held by the future.
• rust_future_new
  Create a new Handle for a Rust future
• rust_future_poll^⚠
  Poll a Rust future
• uniffi_rustbuffer_alloc
  This helper allocates a new byte buffer owned by the Rust code, and returns it to the foreign-language code as a RustBuffer struct. Callers must eventually free the resulting buffer, either by explicitly calling uniffi_rustbuffer_free defined below, or by passing ownership of the buffer back into Rust code.
• uniffi_rustbuffer_free
  Free a byte buffer that had previously been passed to the foreign language code.
• uniffi_rustbuffer_from_bytes
  This helper copies bytes owned by the foreign-language code into a new byte buffer owned by the Rust code, and returns it as a RustBuffer struct. Callers must eventually free the resulting buffer, either by explicitly calling the destructor defined below, or by passing ownership of the buffer back into Rust code.
• uniffi_rustbuffer_reserve
  Reserve additional capacity in a byte buffer that had previously been passed to the foreign language code.

Type Definitions

• ForeignFutureCallback
  Callback that’s passed to a foreign async functions.
• ForeignFutureCallbackData
  Handle for a callback data associated with a foreign future.
• ForeignFutureHandle
  Handle for a foreign future
• RustFutureContinuationCallback
  Foreign callback that’s passed to rust_future_poll