multiversx_sc_codec/single/
nested_en.rs

1use crate::{codec_err::EncodeError, DefaultErrorHandler, EncodeErrorHandler, NestedEncodeOutput};
2use alloc::vec::Vec;
3
4/// Trait that allows zero-copy write of value-references to slices in LE format.
5///
6/// Implementations should override `using_top_encoded` for value types and `dep_encode` and `size_hint` for allocating types.
7/// Wrapper types should override all methods.
8pub trait NestedEncode: Sized {
9    /// NestedEncode to output, using the format of an object nested inside another structure.
10    /// Does not provide compact version.
11    fn dep_encode<O: NestedEncodeOutput>(&self, dest: &mut O) -> Result<(), EncodeError> {
12        self.dep_encode_or_handle_err(dest, DefaultErrorHandler)
13    }
14
15    /// Version of `dep_encode` that can handle errors as soon as they occur.
16    /// For instance in can exit immediately and make sure that if it returns, it is a success.
17    /// By not deferring error handling, this can lead to somewhat smaller bytecode.
18    fn dep_encode_or_handle_err<O, H>(&self, dest: &mut O, h: H) -> Result<(), H::HandledErr>
19    where
20        O: NestedEncodeOutput,
21        H: EncodeErrorHandler,
22    {
23        match self.dep_encode(dest) {
24            Ok(()) => Ok(()),
25            Err(e) => Err(h.handle_error(e)),
26        }
27    }
28
29    /// Allows the framework to do monomorphisation of special cases where the data is of type `u8`.
30    ///
31    /// Especially useful for serializing byte arrays.
32    ///
33    /// Working with this also involves transmuting low-level data. Only use if you really know what you are doing!
34    #[doc(hidden)]
35    #[allow(unused_variables)]
36    fn if_u8<Output, If, Else, R>(output: Output, if_branch: If, else_branch: Else) -> R
37    where
38        If: FnOnce(Output) -> R,
39        Else: FnOnce(Output) -> R,
40    {
41        else_branch(output)
42    }
43}
44
45/// Convenience function for getting an object nested-encoded to a Vec<u8> directly.
46pub fn dep_encode_to_vec<T: NestedEncode>(obj: &T) -> Result<Vec<u8>, EncodeError> {
47    let mut bytes = Vec::<u8>::new();
48    obj.dep_encode(&mut bytes)?;
49    Ok(bytes)
50}
multiversx_sc_codec/single/nested_en.rs

multiversx_sc_codec/single/
nested_en.rs
