nodedb 0.4.0

Local-first, real-time, edge-to-cloud hybrid database for multi-modal workloads
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

// SPDX-License-Identifier: BUSL-1.1

//! Payload→docs decoders for inline sub-plans (multi-way joins consuming an
//! inner-join Response, etc.).

/// Decode a Response payload (msgpack array) back to `(doc_id, msgpack_bytes)` pairs.
///
/// Used for inline sub-plans in multi-way joins: the inner join produces a
/// Response, and the outer join needs its rows as input.
pub(in crate::data::executor) fn decode_response_to_docs(
    response: &crate::bridge::envelope::Response,
) -> Option<Vec<(String, Vec<u8>)>> {
    use nodedb_query::msgpack_scan;

    let payload = response.payload.as_ref();
    if payload.is_empty() {
        return None;
    }

    let (count, mut offset) = msgpack_scan::array_header(payload, 0)?;
    let mut docs = Vec::with_capacity(count);

    for _ in 0..count {
        let entry_start = offset;
        let id = msgpack_scan::extract_field(payload, offset, "id")
            .and_then(|(s, _e)| msgpack_scan::read_str(payload, s).map(|s| s.to_string()))
            .unwrap_or_default();
        let next = msgpack_scan::skip_value(payload, offset)?;
        let entry_bytes = payload[entry_start..next].to_vec();
        docs.push((id, entry_bytes));
        offset = next;
    }

    Some(docs)
}