Function read_tx_data

crates/consensus/protocol/src/utils.rs:100–140

Reads transaction data from a reader.

(r: &mut &[u8])

/// Reads transaction data from a reader.
pub fn read_tx_data(r: &mut &[u8]) -> Result<(Vec<u8>, OpTxType), SpanBatchError> {
    let mut tx_data = Vec::new();
    let first_byte =
        *r.first().ok_or(SpanBatchError::Decoding(SpanDecodingError::InvalidTransactionData))?;
    let mut tx_type = 0;
    if first_byte <= 0x7F {
        // EIP-2718: Non-legacy tx, so write tx type
        tx_type = first_byte;
        tx_data.push(tx_type);
        r.advance(1);
    }

    // Read the RLP header with a different reader pointer. This prevents the initial pointer from
    // being advanced in the case that what we read is invalid.
    let rlp_header = Header::decode(&mut (**r).as_ref())
        .map_err(|_| SpanBatchError::Decoding(SpanDecodingError::InvalidTransactionData))?;

    let tx_payload = if rlp_header.list {
        // Grab the raw RLP for the transaction data from `r`. It was unaffected since we copied it.
        let payload_length_with_header = rlp_header.payload_length + rlp_header.length();
        if payload_length_with_header > SpanBatchElement::MAX_SPAN_BATCH_ELEMENTS as usize {
            return Err(SpanBatchError::TooBigSpanBatchSize);
        }
        if payload_length_with_header > r.len() {
            return Err(SpanBatchError::Decoding(SpanDecodingError::InvalidTransactionData));
        }
        let payload = r[0..payload_length_with_header].to_vec();
        r.advance(payload_length_with_header);
        Ok(payload)
    } else {
        Err(SpanBatchError::Decoding(SpanDecodingError::InvalidTransactionData))
    }?;
    tx_data.extend_from_slice(&tx_payload);

    Ok((
        tx_data,
        tx_type
            .try_into()
            .map_err(|_| SpanBatchError::Decoding(SpanDecodingError::InvalidTransactionType))?,
    ))
}

#[cfg(test)]
mod tests {