fraiseql-wire 2.3.2

//! Byte manipulation utilities for protocol parsing

use bytes::{Buf, Bytes};
use std::io;

/// Extension trait for Bytes operations
pub trait BytesExt {
    /// Read a null-terminated string
    ///
    /// # Errors
    ///
    /// Returns `io::Error` with `InvalidData` if no null terminator is found or
    /// the bytes before the terminator are not valid UTF-8.
    fn read_cstr(&mut self) -> io::Result<String>;

    /// Read a 32-bit big-endian integer
    ///
    /// # Errors
    ///
    /// Returns `io::Error` with `UnexpectedEof` if fewer than 4 bytes remain.
    fn read_i32_be(&mut self) -> io::Result<i32>;

    /// Read a 16-bit big-endian integer
    ///
    /// # Errors
    ///
    /// Returns `io::Error` with `UnexpectedEof` if fewer than 2 bytes remain.
    fn read_i16_be(&mut self) -> io::Result<i16>;
}

impl BytesExt for Bytes {
    fn read_cstr(&mut self) -> io::Result<String> {
        let null_pos = self
            .iter()
            .position(|&b| b == 0)
            .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "no null terminator"))?;

        let s = String::from_utf8(self.slice(..null_pos).to_vec())
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;

        self.advance(null_pos + 1);
        Ok(s)
    }

    fn read_i32_be(&mut self) -> io::Result<i32> {
        if self.remaining() < 4 {
            return Err(io::Error::new(
                io::ErrorKind::UnexpectedEof,
                "not enough bytes",
            ));
        }
        Ok(self.get_i32())
    }

    fn read_i16_be(&mut self) -> io::Result<i16> {
        if self.remaining() < 2 {
            return Err(io::Error::new(
                io::ErrorKind::UnexpectedEof,
                "not enough bytes",
            ));
        }
        Ok(self.get_i16())
    }
}

#[cfg(test)]
mod tests;