fn read_hdlr()

in mp4parse/src/lib.rs [5405:5448]
37 lines of code
6 McCabe index (conditional complexity)

fn read_hdlr<T: Read>(src: &mut BMFFBox<T>, strictness: ParseStrictness) -> Result<HandlerBox> {
    if read_fullbox_version_no_flags(src)? != 0 {
        return Status::HdlrUnsupportedVersion.into();
    }

    let pre_defined = be_u32(src)?;
    if pre_defined != 0 {
        fail_with_status_if(
            strictness == ParseStrictness::Strict,
            Status::HdlrPredefinedNonzero,
        )?;
    }

    let handler_type = FourCC::from(be_u32(src)?);

    for _ in 1..=3 {
        let reserved = be_u32(src)?;
        if reserved != 0 {
            fail_with_status_if(
                strictness == ParseStrictness::Strict,
                Status::HdlrReservedNonzero,
            )?;
        }
    }

    match std::str::from_utf8(src.read_into_try_vec()?.as_slice()) {
        Ok(name) => {
            // `name` must be nul-terminated and any trailing bytes after the first nul ignored.
            // See https://github.com/MPEGGroup/FileFormat/issues/35
            if !name.bytes().any(|b| b == b'\0') {
                fail_with_status_if(
                    strictness != ParseStrictness::Permissive,
                    Status::HdlrNameNoNul,
                )?;
            }
        }
        Err(_) => fail_with_status_if(
            strictness != ParseStrictness::Permissive,
            Status::HdlrNameNotUtf8,
        )?,
    }

    Ok(HandlerBox { handler_type })
}