Function read_header

arrow-avro/src/reader/header.rs:31–51

Read the Avro file header (magic, metadata, sync marker) from `reader`. On success, returns the parsed [`Header`] and the number of bytes read from `reader`.

(mut reader: R)

///
/// On success, returns the parsed [`Header`] and the number of bytes read from `reader`.
pub(crate) fn read_header<R: BufRead>(mut reader: R) -> Result<(Header, u64), AvroError> {
    let mut decoder = HeaderDecoder::default();
    let mut position = 0;
    loop {
        let buf = reader.fill_buf()?;
        if buf.is_empty() {
            break;
        }
        let read = buf.len();
        let decoded = decoder.decode(buf)?;
        reader.consume(decoded);
        position += decoded as u64;
        if decoded != read {
            break;
        }
    }
    decoder
        .flush()
        .map(|header| (header, position))
        .ok_or_else(|| AvroError::EOF("Unexpected EOF while reading Avro header".to_string()))
}

#[derive(Debug)]
enum HeaderDecoderState {