enc

This library aids in processing encoded data.

Dependencies & Features

Dependency:

enc = { version = "0.6.0", features = ["full"] }

Transitive Dependencies:

none

Features:

• full: all features
• base-64: base-64 encoding
• hex: hexadecimal encoding
• percent: url percent encoding
• var-int: variable-length encoded integers

Data & Value Encoders

There are separate traits for encoding raw data vs arbitrary values.

The src/data folder holds the traits: Encoder, TextEncoder, Decoder and Validator. These provide an interface for encoders that operate on slices of data such as hex & base-64.

The src/value folder holds the traits: EncodedLen, EncodeToSlice, EncodeToWrite etc. These provide the interface for values that know how to encode and decode themselves such as variable-length integers and can be easily extended by custom types.

Examples

Hexadecimal Encoding

Examples for processing hexadecimal encoded data:

/// Imports
use enc::{Encoder, Decoder, Validator};
use enc::hex::{HexEncoder, HexDecoder, HexValidator};

/// Encoding 
let data: &[u8] = b"\x01\x23\x45\x67\x89\xAB\xCD\xEF";
let encoded: String = HexEncoder::LOWER.encode_as_string(data)?;
assert_eq!(encoded, "0123456789ABCDEF");

/// Decoding
let encoded: &str = "0123456789ABCDEF";
let decoded: Vec<u8> = HexDecoder::default().decode_as_vec(data)?;
assert_eq!(decoded, b"\x01\x23\x45\x67\x89\xAB\xCD\xEF");

/// Validation
let encoded: &str = "0123456789ABCDEF";
let valid: bool = HexValidator::CASELESS.is_valid(data)?;
assert!(valid);

URL Percent Encoding

Examples for processing URL percent encoded data.

/// Imports
use enc::{Encoder, Decoder, Validator};
use enc::percent::{PercentEncoder, PercentDecoder, PercentValidator}

/// Encoding
let encoder: PercentEncoder = "+-!".into(); // these characters won't be encoded
let data: &[u8] = b"Hello, World!";
let encoded: String = encoder.encode_as_string(data)?;
assert_eq(encoded, "Hello%2C%20World!");

/// Decoding
let decoder: PercentDecoder = PercentDecoder::default();
let encoded: &str = "Hello%2C%20World!";
let decoded: String = decoder.decode_as_vec(encoded.as_slice()).to_string_utf8_unchecked();
assert_eq(encoded, "Hello, World!");

/// Validation
let encoded: &str = "%20%AX";
let valid: bool = PercentValidator::default().is_valid(data)?;
assert!(!valid);

Variable Length Encoded Integers

Examples for processing variable-length encoded integers.

/// Imports
use enc::var_int::VarInt64;
use enc::{DecodeFromReadPrefix, EncodeToSlice};

/// Encoding
let value: VarInt64 = VarInt64::from(0xFFFF);
let encoded: Vec<u8> = value.encode_as_vec();
assert_eq!(encoded, b"\xFF\xFF\x03");

/// Decoding
let encoded: Vec<u8> = b"\xFF\xFF\x03".to_vec();
let mut cursor: Cursor<Vec<u8>> = Cursor::new(encoded);
let result: u64 = VarInt64::decode_from_read_prefix(&mut cursor)?.value;
assert_eq!(result, 0xFFFF);