Function fz_open_buffer 

pub unsafe extern "C" fn fz_open_buffer(
    ctx: *mut fz_context,
    buf: *mut fz_buffer,
) -> *mut fz_stream

Open a buffer as a stream.

buf: The buffer to open. Ownership of the buffer is NOT passed
in (this function takes its own reference).

Returns pointer to newly created stream. May throw exceptions on
failure to allocate.