Crate base32_fs 

base32-fs

This crate implements a variant of BASE32 encoding for hashes that are used as file names: no two encoded hashes can be decoded to the same original hash unless there is a hash collision.

To achieve that the crate

• uses the same characters when encoding and decoding the data as opposed to the original Crockford’s alphabet that permits e.g. both “a” and “A” to be decoded to 10;
• doesn’t zero-extend invalid input lengths when decoding.

Besides that the crate

• uses only lowercase letters instead of uppercase as the most common representation of hashes;
• doesn’t use padding characters;
• doesn’t change the sorting order of the encoded data;
• doesn’t use lookup table when decoding.

Usage

Encode into PathBuf

use std::path::PathBuf;
use base32_fs::{encode, encoded_len, PathBufOutput};

let input = *b"hello";
let mut output = PathBufOutput::with_capacity(encoded_len(input.len()));
encode(&input, &mut output);
assert_eq!(PathBuf::from("d1jprv3f"), output.into_path_buf());

Decode from PathBuf

use std::path::Path;
use base32_fs::{decode, decoded_len, PathBufInput};

let input = PathBufInput::new(Path::new("d1jprv3f"));
let mut output: Vec<u8> = Vec::new();
decode(input, &mut output);
assert_eq!(b"hello", output.as_slice());

Encode into Vec<u8>

use base32_fs::{encode, encoded_len};

let input = *b"hello";
let mut output: Vec<u8> = Vec::with_capacity(encoded_len(input.len()));
encode(&input, &mut output);
let string = std::str::from_utf8(output.as_slice()).expect("Always a valid UTF-8 byte sequence");
assert_eq!("d1jprv3f", string);

Decode from &[u8]

use std::path::Path;
use base32_fs::{decode, decoded_len, PathBufInput};

let input = b"d1jprv3f";
let mut output: Vec<u8> = Vec::with_capacity(decoded_len(input.len()).unwrap());
decode(input.as_slice(), &mut output);
assert_eq!(b"hello", output.as_slice());

Structs

DecodeError

BASE32 decode error.

PathBufInputstd

An implementation of Input for file system paths.

PathBufOutputstd

An implementation of Output for file system paths.

Constants

MAX_INPUT_LEN

Maximum number of bytes that can be encoded as BASE32.

Traits

Input

An input for decode.

Output

An output of encode or decode.

Functions

decode

Decode input byte sequence using BASE32 encoding and write the resulting byte sequence to output.

decoded_len

Returns the length of the original byte sequence for the given BASE32-encoded string length.

encode

Encode input byte sequence using BASE32 encoding and write the resulting byte sequence to output.

encoded_len

Returns the length of the BASE32-encoded string for the given input length.

is_valid

Returns true if the input is a valid BASE32-encoded string.