Function zero_width_record_array_bounded

src/avro/src/decode.rs:311–342

()

    #[mz_ore::test]
    fn zero_width_record_array_bounded() {
        // Regression for an OOM found by the reader_decode fuzz target: an
        // `array<record{null}>` element is zero-width on the wire (the byte-floor
        // check below can't bound it) yet each element still allocates a
        // `Value::Record`, so a multi-million-element block claimed from a
        // handful of bytes amplified into gigabytes. The cumulative node cap must
        // reject it rather than allocate.
        use std::str::FromStr;

        use super::{AvroDeserializer, GeneralDeserializer};
        use crate::util::zig_i64;
        use crate::{Schema, ValueDecoder};

        let schema = Schema::from_str(
            r#"{"type": "array", "items":
                {"type": "record", "name": "R", "fields": [{"name": "g0", "type": "null"}]}}"#,
        )
        .unwrap();
        // A single block claiming far more zero-width records than the node cap,
        // followed by no element bytes at all.
        let mut body = Vec::new();
        zig_i64(100_000_000, &mut body);
        let dsr = GeneralDeserializer {
            schema: schema.top_node(),
        };
        let mut reader: &[u8] = &body;
        let res = dsr.deserialize(&mut reader, ValueDecoder);
        assert!(
            res.is_err(),
            "an array of zero-width records longer than the node cap must be rejected, not allocated"
        );
    }

    #[mz_ore::test]
    fn small_zero_width_record_array_decodes() {