Struct base64::engine::fast_portable::FastPortable

pub struct FastPortable { /* private fields */ }

A general-purpose base64 engine.

• It uses no vector CPU instructions, so it will work on any system.
• It is reasonably fast (~2GiB/s).
• It is not constant-time, though, so it is vulnerable to timing side-channel attacks. For loading cryptographic keys, etc, it is suggested to use the forthcoming constant-time implementation.

Implementations

impl FastPortable

pub const fn from(alphabet: &Alphabet, config: FastPortableConfig) -> Self

Create a FastPortable engine from an Alphabet.

While not very expensive to initialize, ideally these should be cached if the engine will be used repeatedly.

Trait Implementations

impl Engine for FastPortable

type Config = FastPortableConfig

The config type used by this engine

type DecodeEstimate = FastPortableEstimate

The decode estimate used by this engine

fn encode(&self, input: &[u8], output: &mut [u8]) -> usize

Encode the input bytes into the output buffer based on the mapping in encode_table.

fn decoded_length_estimate(&self, input_len: usize) -> Self::DecodeEstimate

As an optimization to prevent the decoded length from being calculated twice, it is sometimes helpful to have a conservative estimate of the decoded size before doing the decoding, so this calculation is done separately and passed to Engine::decode() as needed.

fn decode(
    &self,
    input: &[u8],
    output: &mut [u8],
    estimate: Self::DecodeEstimate
) -> Result<usize, DecodeError>

Decode input base64 bytes into the output buffer.

fn config(&self) -> &Self::Config

Returns the config for this engine.