Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

feat: ByteArray type #682

Merged
merged 1 commit into from
Dec 17, 2024
Merged

feat: ByteArray type #682

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
222 changes: 222 additions & 0 deletions starknet-core/src/types/byte_array.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,222 @@
use alloc::{string::*, vec::*};

use num_traits::ToPrimitive;

use crate::{
codec::{Decode, Encode, Error as CodecError, FeltWriter},
types::Felt,
};

const BYTES_PER_SLOT: usize = 31;
const FELT_BYTE_SIZE: usize = 32;

/// The `ByteArray` type in Cairo.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ByteArray(Vec<u8>);

impl ByteArray {
/// Returns the number of bytes in the array, also referred to as its 'length'.
pub fn len(&self) -> usize {
self.0.len()
}

/// Returns `true` if the array contains no bytes.
#[must_use]
pub fn is_empty(&self) -> bool {
self.0.is_empty()
}
}

impl From<Vec<u8>> for ByteArray {
fn from(value: Vec<u8>) -> Self {
Self(value)
}
}

impl From<&str> for ByteArray {
fn from(value: &str) -> Self {
Self(value.as_bytes().to_vec())
}
}

impl From<ByteArray> for Vec<u8> {
fn from(value: ByteArray) -> Self {
value.0
}
}

impl TryFrom<ByteArray> for String {
type Error = FromUtf8Error;

fn try_from(value: ByteArray) -> Result<Self, Self::Error> {
Self::from_utf8(value.0)
}
}

impl Encode for ByteArray {
fn encode<W: FeltWriter>(&self, writer: &mut W) -> Result<(), CodecError> {
writer.write((self.len() / BYTES_PER_SLOT).into());
let mut chunks_iter = self.0.chunks_exact(BYTES_PER_SLOT);
for full_slot in chunks_iter.by_ref() {
writer.write(Felt::from_bytes_be_slice(full_slot));
}

let last_chunk = chunks_iter.remainder();
writer.write(Felt::from_bytes_be_slice(last_chunk));
writer.write(last_chunk.len().into());

Ok(())
}
}

impl<'a> Decode<'a> for ByteArray {
fn decode_iter<T>(iter: &mut T) -> Result<Self, CodecError>
where
T: Iterator<Item = &'a Felt>,
{
let length = iter.next().ok_or_else(CodecError::input_exhausted)?;
let length = length
.to_usize()
.ok_or_else(|| CodecError::value_out_of_range(length, "usize"))?;

let mut result = Vec::<u8>::with_capacity(length * BYTES_PER_SLOT + BYTES_PER_SLOT - 1);

for _ in 0..length {
let full_slot = iter.next().ok_or_else(CodecError::input_exhausted)?;
result.extend_from_slice(&full_slot.to_bytes_be()[1..]);
}

let pending_word = iter.next().ok_or_else(CodecError::input_exhausted)?;
let pending_word_len = iter.next().ok_or_else(CodecError::input_exhausted)?;
let pending_word_len = pending_word_len
.to_usize()
.ok_or_else(|| CodecError::value_out_of_range(pending_word_len, "usize"))?;
result
.extend_from_slice(&pending_word.to_bytes_be()[(FELT_BYTE_SIZE - pending_word_len)..]);

Ok(Self(result))
}
}

#[cfg(test)]
mod tests {
use super::*;

#[test]
#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
fn test_string_encode_decode_roundtrip() {
let test_data = [
(
"",
vec![
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000000",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000000",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000000",
),
],
),
(
"abc",
vec![
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000000",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000616263",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000003",
),
],
),
(
"000000000011111111112222222222",
vec![
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000000",
),
Felt::from_hex_unchecked(
"0x0000303030303030303030303131313131313131313132323232323232323232",
),
Felt::from_hex_unchecked(
"0x000000000000000000000000000000000000000000000000000000000000001e",
),
],
),
(
"0000000000111111111122222222223",
vec![
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000001",
),
Felt::from_hex_unchecked(
"0x0030303030303030303030313131313131313131313232323232323232323233",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000000",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000000",
),
],
),
(
"00000000001111111111222222222233",
vec![
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000001",
),
Felt::from_hex_unchecked(
"0x0030303030303030303030313131313131313131313232323232323232323233",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000033",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000001",
),
],
),
(
"00000000001111111111222222222233333333334444444444\
55555555556666666666777777777788888888889999999999",
vec![
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000003",
),
Felt::from_hex_unchecked(
"0x0030303030303030303030313131313131313131313232323232323232323233",
),
Felt::from_hex_unchecked(
"0x0033333333333333333334343434343434343434353535353535353535353636",
),
Felt::from_hex_unchecked(
"0x0036363636363636363737373737373737373738383838383838383838393939",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000039393939393939",
),
Felt::from_hex_unchecked(
"0x0000000000000000000000000000000000000000000000000000000000000007",
),
],
),
];

for (string, expected) in test_data {
let bytes: ByteArray = string.into();

let mut encoded = vec![];
bytes.encode(&mut encoded).unwrap();
assert_eq!(encoded, expected);

let decoded = ByteArray::decode(&expected).unwrap();
assert_eq!(String::try_from(decoded).unwrap(), string);
}
}
}
3 changes: 3 additions & 0 deletions starknet-core/src/types/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,9 @@ pub use msg::MsgToL2;
mod call;
pub use call::Call;

mod byte_array;
pub use byte_array::ByteArray;

// TODO: move generated request code to `starknet-providers`
/// Module containing JSON-RPC request types.
pub mod requests;
Expand Down
Loading