Crate ssz

Provides encoding (serialization) and decoding (deserialization) in the SimpleSerialize (SSZ) format designed for use in Ethereum 2.0.

Adheres to the Ethereum 2.0 SSZ specification at v0.12.1.

Example

use ssz_derive::{Encode, Decode};
use ssz::{Decode, Encode};

#[derive(PartialEq, Debug, Encode, Decode)]
struct Foo {
    a: u64,
    b: Vec<u16>,
}

fn ssz_encode_decode_example() {
    let foo = Foo {
        a: 42,
        b: vec![1, 3, 3, 7]
    };

    let ssz_bytes: Vec<u8> = foo.as_ssz_bytes();

    let decoded_foo = Foo::from_ssz_bytes(&ssz_bytes).unwrap();

    assert_eq!(foo, decoded_foo);
}

See examples/ for manual implementations of the Encode and Decode traits.

Modules

• legacy
  Provides a “legacy” version of SSZ encoding for Option<T> where T: Encode + Decode.

Macros

• four_byte_option_impl

Structs

• SszDecoder
  Decodes some slices of SSZ into object instances. Should be instantiated using SszDecoderBuilder.
• SszDecoderBuilder
  Builds an SszDecoder.
• SszEncoder
  Allow for encoding an ordered series of distinct or indistinct objects as SSZ bytes.
• UnionSelector
  Provides the one-byte “selector” from the SSZ union specification:

Enums

• DecodeError
  Returned when SSZ decoding fails.

Constants

• BYTES_PER_LENGTH_OFFSET
  The number of bytes used to represent an offset.
• BYTES_PER_UNION_SELECTOR
  The number of bytes used to indicate the variant of a union.
• MAX_LENGTH_VALUE
• MAX_UNION_SELECTOR
  The highest possible union selector value (higher values are reserved for backwards compatible extensions).

Traits

• Decode
  Provides SSZ decoding (de-serialization) via the from_ssz_bytes(&bytes) method.
• Encode
  Provides SSZ encoding (serialization) via the as_ssz_bytes(&self) method.
• TryFromIter
  Partial variant of std::iter::FromIterator.

Functions

• decode_list_of_variable_length_items
  Decodes bytes as if it were a list of variable-length items.
• encode_length
  Encode len as a little-endian byte array of BYTES_PER_LENGTH_OFFSET length.
• read_offset
  Reads a BYTES_PER_LENGTH_OFFSET-byte length from bytes, where bytes.len() >= BYTES_PER_LENGTH_OFFSET.
• split_union_bytes
  Takes bytes, assuming it is the encoding for a SSZ union, and returns the union-selector and the body (trailing bytes).
• ssz_encode
  Convenience function to SSZ encode an object supporting ssz::Encode.