Struct FfiBuffer 

#[repr(C)]
pub struct FfiBuffer {
    pub data: *mut u8,
    pub len: usize,
    pub capacity: usize,
    pub error_code: u32,
}

Buffer for passing data across FFI boundary

This structure follows the “Rust allocates, host frees” pattern:

• Rust creates the buffer and populates it with data
• Host copies the data to its managed heap
• Host calls plugin_free_buffer to release the memory

Memory Safety

The buffer owns its memory. When plugin_free_buffer is called, the memory is deallocated. The host must not use the buffer after freeing it.

Fields

data: *mut u8

Pointer to the data

len: usize

Length of valid data in bytes

capacity: usize

Total capacity of the allocation

error_code: u32

Error code (0 = success)

Implementations

impl FfiBuffer

pub fn empty() -> FfiBuffer

Create an empty buffer

pub fn from_vec(vec: Vec<u8>) -> FfiBuffer

Create a buffer from a Vec

This transfers ownership of the Vec’s memory to the buffer.

pub fn error(code: u32, message: &str) -> FfiBuffer

Create an error buffer

The error message is stored in the buffer data.

pub fn success_json<T>(value: &T) -> FfiBuffer

where T: Serialize,

Create a success buffer with JSON data

pub fn is_error(&self) -> bool

Check if this buffer represents an error

pub fn is_empty(&self) -> bool

Check if this buffer is empty

pub unsafe fn as_slice(&self) -> &[u8]

Get the data as a slice (unsafe - caller must ensure buffer is valid)

Safety

The buffer must contain valid data and not have been freed.

pub unsafe fn free(&mut self)

Free the buffer’s memory

Safety

This must only be called once per buffer. After calling, the buffer is invalid and must not be used.

Trait Implementations

impl Default for FfiBuffer

fn default() -> FfiBuffer

Returns the “default value” for a type.

impl Send for FfiBuffer